Sarcopenia the largely neglected "penia"

There are now at least four classes of medications that have received FDA approach for the treatment of osteoporosis and, according to various guidelines, for certain instances of " high risk"  cases of osteopenia.Family practitioners,internists and gynecologists have all joined the crusade to detect by using a questionnaire based risk tool and by bone  density scans  those patients thought to be at high risk" for fragility fractures and thousands of prescriptions for the bisphosphonate  category of anti osteoporosis drugs have been written.

In regard to the other age related loss of tissue integrity ,sarcopenia, there are no medications proven to help and no popular screening test.Only resistance exercise along with an adequate protein intake have been shown to mitigate the loss and in some relatively short periods of time in clinical trials have actually increased muscle mass and strength.

In regard to quantification of the loss of muscle size and strength a number of clinical papers have been published.Here are the stylized facts: From abut age 40 to age 70 there is about a 1-1.5% annual loss of strength as least as measured by the leg extension tests. Then  things get worse around  age 70 where losses of 2.5% or more per year have been documented. Men have been shown to show a greater proportional loss than women and in one study Afro Americans showing a greater loss than Caucasians.

There is a  proportionally greater loss in type 11, ( fast twitch)  muscle fibers  than the slow twitch type 1 fibers. Some of the muscle loss is due to a loss of anterior horn cells with aging. with more type 11 muscle cell loss.Some of the type 11 are replaced by type 1 cells.There is also evidence of qualitative  changes in muscles in the elderly among which there is the deposition of fat within fibers and possibly changes in the angular or spatial arrangement of fibers. Walking , cycling and other aerobic type exercises are largely powered by the slow twitch fibers and a  reasonable anti sarcopenia regimen would include aerobic and resistance exercises,the latter to try a preserve some type 11 fivers. .

The age related decline in maximal oxygen uptake can also be blamed in part on loss of muscle function. About half of the loss of max 02 is due to stroke volume of  the heart and about half to decrease in  a-v o2 uptake which is driven by loss of muscle mass with the associated decrease in the capillary density and mitochondrial mass.

Sarcopenia and osteopenia are related in several ways.The prevention of sarcopenia by resistance exercises also can increase bone density.The sarcopenic person is more likely to fall and sustain a fracture.No randomized trials  are likely to be done to compare a program with resistance exercise and weight bearing excise versus any one the anti-osteoporosis medications.

Which goal of the ABIM Foundation is not part of traditional medical ethics?

The ABIM Foundation's mission is  putting the Charter ( insert full name) into practice. The Charter's main themes are patient welfare,patient autonomy and social justice. In their own words the ABIM Foundation to advocate for " a just and cost effective distribution of finite resources." Are just and cost effective independent characteristics i.e  do these modifiers represent different things? Could a distribution be cost effective and unjust? Certainly- at least  by some definitions of what is justice. Rawls has stated that a distribution that is unequal can only be just if it benefits the most disadvantaged. A cost effectiveness decision does not necessarily advantage the least advantaged members of society.

Could a distribution be just and not cost effective. A significant part of our society is designed with a eye toward achieving justice without  cost considerations. It would be much more cost effective to eliminate most all of the rights of the accused in our criminal justice system and simply take all person accused of a crime out and shoot them. The Bill of Rights did not go through a vigorous cost effectiveness analysis before its acceptance. So the ABIDF's advocacy would seem to be for  things that are both just and cost effective yet in Rawls's ethical scheme cost effectiveness is not just because it ignores the separateness of individuals and may sacrifice some individuals welfare for some greater aggregate utility.Or maybe the authors of the ABIM pronouncements just thought the words sounded good together.


Of course, the social justice element of the Charter is what is not part of traditional medical ethics.

The above  quote explains what the social justice element of their mission is about i.e their version of social justice- just and cost effective distribution of medical resources.

D B Wolfson says in regard to their " choosing wisely" program  is about "exactly the care than is needed".

The physicians in the social justice advocacy world of the ABIM Foundation will play key roles in this just and cost effective distribution of finite resources.Actually there will be two levels of activity. Fist there will be the physician planners and analysts who will "determine" what is cost effective and what is not and what is just  and secondly there are the worker bee physicians (or more broadly the health care providers) who will carry out the details of the just and/or cost effective distribution through directives euphemistically called guidelines. In this way the physicians will fulfill their roles as stewards of the finite medical resources. To determine what is just and cost effective is far beyond the pay grade and technical and professional expertise of the practicing physician and must therefore be left to those with special training and expertise.

Implicit in this construct is the collective ownership of the medical resources. Implicit is this construct is the incredibly overgrown hubris of those who claim they are not only able to determine what is best for the individual by for society as well while  providing "exactly" the care that is needed.

The history of the twentieth century should have made it clear how central planning on a social level works out. Even a cursory survey of what transpired in Russia,in communist China,in India in the era of the collectivization of the farms  and the current Korean peninsula should disabuse anyone of the notion that central planning is the way to go..Galbraith recommended Soviet styled five year plans,in India. Yet central planning of medical care is exactly what Drs. Brennan and Berwick recommended in their  "New Rules".

But this time it will be different.Planning for the millions of people in regard to their health care. this time it will be rational and determined to be of  "high value" and the good of all will be achieved though a rational plan providing what some group of platonic guardians have determined exactly what everyone needs, you know the right medicine for the right patient and the right time



 

Geoffey Roses Population Medicine and big Pharma- is this another baptists and bootleggers story?

Goeffrey Rose in his 1985 book "Sick Individuals and Sick Populations" likely never intended to provide the intellectual grist for the mill of the major pharmaceutical industry but I argue he did.

His thesis was that a large number of people at small risk for a given disease may give rise to more cases than the small number of those at high risk. Rose's population strategy was that there would be a large benefit to the population by treating the low risk people .Large benefit to the community may offer little to the each participating person and in some instances harm and bringing more benefit to an individual may have small impact on the population's health. This was labelled the Prevention Paradox. Interesting, this conception assumes that it makes logical sense to speak of the health of an aggregate which I argue is a category error. Is there a health of the community distinct from the health of its individual members?

Rose's imperative was to decrease the total disease burden of a population.What is important in this formulation is that the aggregate is more important that any of the individuals who make up the aggregate.Individual bees mater little , it is the health of the hive that must be promoted.

Next the idea of risk factor comes into play. This notion was brought into prominence and became an accepted item in the jargon of medicine by the  authors of the Framingham study which was  tasked to find the cause of coronary heart disease and concluded there is not one single cause but rather there are a number of factors, designated as risk factors,the possession of which by a person can be considered to increase  his risk of developing coronary heart disease. The field was ripe for the "treatment" of risk factors and "preventative" medicine blossomed ( replacing the archaic " preventive ")

The slippery notion of the nature of risk was given little attention in medical journals ( with the notable exception of this article by  Dr Goodman )- see here- as the risk factor revolution of medicine burst forth, first with coronary heart disease and then for as many diseases whose risk factors the epidemiologists   ( and young general medicine department faculty members with recently minted MPH degrees) could generate with increasingly broad based and coarse grained data dredging .To name a few, osteoporosis,hypertension, diabetes,cancers, all have accumulated their own array of risk factors as have  alcoholic abuse, depression and internet addiction.With greatly increased access to computer statistics programs and processing and p value hacking it seemed that almost everything is a risk factor for something.  and making big deals over small differences ( relative risks less than 2) increased the risk that reading the daily news would makes the average reader think he was at a risk for something.

With Rose's population thesis and the epidemiologists' increasing supply of risk factors the opportunities for the drug companies burst forth.The idea that just about any disease can be described as a public health issue opening the door for "public health solutions" which typically involves governmental involvement if not governable coercion, at least in the form  nudges consisting of grants and public education campaigns.

People were increasing treated for pre-diseases; pre-coronary heart disease, pre- hypertension,pre-diabetes, and even pre-bipolar treatment for moody,irritable ,grumpy kids .Cardiologist Tom Giles sarcastically talked about everyone  possessing the risk factors for  being "pre-dead".

Pre-patients ,after being informed of some risk factor for something,were advised to see their physician health care provider to "determine" their personal risk.This is of course an impossibility because all the provider can do is to parrot what the pre-patient has already read, namely that he is a member of a group   which has allegedly an increased risk, there being no technique learned in medical school  health care provider school that enables the provider to magically provide a personal risk, that concept making no logical sense.

Is FUBAR the basic default position for the world -part 1

"Default" in financial terms means that someone is unable to fulfill an financial obligation and defaults on the loan, i.e. is unable to repay.This is not the default I am talking about.

In the computer world a default is a pre setting and pre build in  arrangement which will become operational unless it is overwritten with some other option. Your computer may come with Internet Explorer as the default browser so when you turn it on there is Explorer. But if you might prefer say Firefox you could program your machine to go to Firefox as the default browser when you turn on the computer.

Car dealers may have default packing of extras for their various car models . But you can opt for another set of bell and whistles and engines.

FUBAR is said to have originated as a military acronym meaning Fouled up ( more commonly fu**ked up) beyond  all or any repair or reasonable redemption. ( Paraphrased from Wikipedia)
 The military seems to have been the source of so many such situation that it is not surprising the term arouse from that source.

 A series of animated shorts was produced by Warner Brothers in 1944 featuring three brothers, Sergeants  Fubar,Snafu and Tarfu, the latter two standing for situation normal all fouled up and things are really fouled up. The vignettes were prefaced by a promotion to buy war bonds and and the great voice actor Mel Brooks played the brothers.

The writers seemed to recognize a gradation of fouledupness, with SNAFUs perhaps not so bad that they could still be patched up a bit or mitigated , but could progress to the unfixable last phase, the FUBAR.


The more I read about so many things, politics,governmental programs and much to my sorrow the current state of medical practice,the more I think the depressing thought that FUBAR is the default position for about everything Not everything- some things still work pretty well, but so many don't.

And yet the incredible progress  of the world since the 1700s give clear evidence that all is is not fubar, There are there patterns of activity that predispose to fubar situations  and some that do much less so. The thing that stands out is that central planning is the most fertile ground ever for fubaring .
 Societies with strong property rights,rule of law, contract law and  individual freedom while far from perfect and certainty not foolproof seem less like to end up as irreparably broken. although 90 years of progressivism just might do it.

Effect of aging on pulmonary function, structure and exercise capacity

Most of the blame for the progressive age related decrease in exercise capacity is correctly directed at the  cardiovascular system. Traditionally focus has been on the maximal oxygen uptake ( O2 Max) decrease with exercise with both components of that value , the cardiac output and the a-v 02 difference both contributing.The stylized physiological narrative is that O2Max decreases about 5-10% per decade on average although there are some outliers whose per decade loss is much less. It has been suggested that about half of that loss is due to decrease in the heart's stroke volume and about half of the blame goes the a decreased A-V o2 difference-i.e. the ability of muscles to take up O2 efficiently.The benefit of exercise in heart failure is likely due mainly to the effects of exercise on the muscles and their mitochondria and capillary density and less on making the heart beat better.


O'Donnell   and co-authors in their paper "Physiological Impairment in Mild COPD" tell us that mild COPD  and the effects of aging are qualitatively similar While arterial blood gas values change little  and acid base balance is maintained there are well described age related functional and structural changes.

Airway resistance increases as large and small airway narrow and there are also some age related enlargement of the air spaces.Residual  volume increases while inspiratory capacity decreases while total lung volume changes little.Airway resistance increases as air flow increases and compliance fall a phenomenon called frequency dependent compliance, once a source of interest to pulmonary physiologists but not so much with pulmonary doctors.

When older endurance athletes are compared with young subjects several workers  have demonstrated that the older subject have a higher ventilation for a given work load.The minute ventilation (VE and VE/VCo2) are increased said to be due to greater dead space ventilation  which is considered  one form of  ventilation perfusion inequality. The mechanism for this V/Q imbalance is not clear.

So getting older, lung wise is a bit like mild COPD  similar to getting older heart wise is similar to a little of diastolic dysfunction.-more on that later.




O'Donnell, DE et al. " Physiological Impairment in Mild COPD), Respirology , 2015 doi 10 1111/resp.12619 Published on line 2 Sept 2015

Does The American College of Physicians see everything through the lens of the progressive mind set?

Arnold Kling' useful framework of describing how libertarians,conservatives and progressives see the world is thoughtful and has more than a little predictive value.The progressive's lens is shaped  to see things in terms of the oppressed and the oppressor while the libertarian tends to see things in terms of freedom and coercion and the conservative sees the world often in terms of the civilization and barbarism.He calls this notion the Three Axis Model and is available on Amazon  in an inexpensive Kindle format.

Applying this to the issue of concierge  or retainer model of medical practice ( also known as Direct Paitent Care Plan or DPCP) the recent response of the ACP ( see here) fits well with the progressive view which I claim is their default analysis for many issues.

(Mr Bob Dohrty , who is the senior VP of government affairs and public policy of the ACP, inexplicably has denied my claim that their policies are progressive. See here.)

In regard to concierge practice or DPCP, ACP said in part " it must be recognized that DPCPS potentially exacerbate racial,ethnic and socioeconomic disparities in  health care and impose too high cost on some lower income patients".


The progressive view sees things in terms of the oppressor-oppressed model and often uses a defining metric of  inequality along some  or other parameter. IMHO It seems that ACP thinks  most everything about medical care is all about social justice.

New and better ways to distinguish "athlete's heart" from abnormal heart enlargement

It has been long recognized that athletes may have larger hearts and changes on the EKG that are difficult to distinguish from abnormal findings such as those seen in an abnormally enlarged thickened  left ventricle with hypertrophic muscles as is seen in long standing hypertension and in hypertrophic cardiomyopathy(HCM).

In fact . athletes have enlarged heart muscle as well and cardiologists have attempted to provided some wall thickness values above  which it indicated abnormality. . A distinction  based on various  EKG criteria have never been that reliable.

In addition, all athletic activity does not seem to bring out the same type of physiological adaptive changes. A distinction is typically made between endurance athletes and strength athletes, recognizing that some athletes do both endurance and strength training.

Generally endurance athletes increase cardiac output under conditions of  reduced peripheral resistance while strength trained athletes increase cardiac output against increased peripheral resistance. It would  be expected that these difference would be reflected in the heart's adaption

The stylized facts are that  the endurance athletes have increased wall thickness  as do the strength folks but endurance athletes have larger chambers . e.g left atrial size and left ventricular diastolic diameters. The usual definition of the upper limit of normal for the left atrium is often said to be 35ml while one  study of endurance athletes has shown value of 37.7 ml.The left  ventricular wall is sometimes greater than 13 mm ( in one study of elite endurance athletes 13% were greater than 13 but none above 15 mm.  About 1/3 of elite endurance athletes have LV cavity end diastolic greater than 60 ml. whereas  upper  normal is typically consisted 55 ml .Typically endurance  athletes are said to have eccentric hypertrophy while endurance athletes have concentric but that concept has  been challenged.

At least one study reported that endurance athletes had indicators of  better diastolic function that do strength trained athletes. (Vinereanu,D, Clin Sci 2002).However, overall the data are conflicting as to whether endurance exercise improves diastolic filling apart from  heart rate changes and
 as to whether any diastolic function improvement persists in senior athletes to significantly mitigate the seemingly universal age related increases   myocardial stiffness. ( Perhaps another example of the Woody Allen physiological maxim ,paraphrased when you get old everything  that should be soft gets hard and everything that should be hard gets soft.)

In any event the athletes hearts seems to work quite well particularity when compared with the enlarged hearts that can result from hypertension both in terms of pumping  the blood during systole but also  in rapidly refilling the ventricular chamber in diastole preparatory for the next ejection

Athletes hearts  pump more effectively  blood during systole This is   usually expressed as as EF, value ( ejection fraction) which is  generally greater in endurance athletes than in  normals but the range overlaps. .But also the athlete's  ventricles  fill faster in the relation phase of the left ventricle , i.e. diastole so their enhanced cardiac output results from more filling  and more ejection giving them higher stroke volumes.

Using various indicators of diastolic function ( such as the early phase of filling versus the later phase of filling (an e/a ratio being one such measure) it has been  clearly demonstrated that left ventricular filing is normal or supra normal in the endurance  athletes with increased wall thickness while the opposite occur to varying degrees in hypertensive heart disease and other causes of LVH such as aortic stenosis and hypertrophic cardiomyopathy .

Newer echo techniques have provided even more evidence of a distinction   between the enhanced  cardiac function of the endurance trained athletes and those with hypertensive heart disease and to aid in the differential diagnosis of hypertrophic cardiomyopathy.

In the last ten years a technique referred to as deformation imaging ( which can be subdivided into 1)TDI and 2)speckle-tracing 2D strain imaging)  has provide a new way to elucidate cardiac physiology. The techniques can distinguish between active and passive myocardial segment motion.

In echo speak "strain" mean deformation, unlike the  everyone day English language meaning  and these techniques measure strain and strain rate.Strain is considered the fractional change in length of a myocardial segment and can be expressed as a percentage.Ultra sound images contain natural acoustic markers, called speckles, which can be tracked as muscle segments move during contraction and relaxation and actively contracting muscles segment can be distinguished from areas moving poorly. 

Speckle tracing studies have shown that the ventricular hypertrophy as in  hypertension is associated with decrease strain ,that is less deformation, which is functionally disadvantageous while the hypertrophy of endurance athletes does not differ appreciably from normal controls and is not associated with  functional impairment.In other words this is  an advantageous remodeling.

A similar distinction between pathological left ventricular hypertrophy and  physiologic athletic hypertrophy  has been made using MRIs of the heart. ( Peterson SE, 2005 , J Cardiovas Mag Reason 2005:7,(3) 551. Speckle tracing is much less expensive .

For the most part newer testing techniques have done away with concerns about exercise causing the heart to enlarge in a deleterious physiological way with the interesting possible exceptions of  harmful changes or remodeling of the right ventricle and of the left atrium with a putative increased risk of atrial fibrillation. Several authors have argued and provided some evidence that prolonged endurance type exercise can bring about a condition similar to an inherited disease called arrhythmogenic  right ventricular hypertrophy (ARRV), a topic I wrote about before see here.

addendum: added 10/1/15 5:46 PM.  Here is more on the differences between strength athletes and endurance athletes. Rowers were compared with Long distance runners and the authors fond  that the runners had larger left ventricular volumes,lower and in the normal range for ventricular mass and a tendency to less thickened left ventricular walls.  (Wasfy,M Endurance exercise-induced cardiac remodeling: Not all Sports are created equal,Journal of the American society of echocardiography, 2015,Sept 9


addendum 2/9/16. Minor wording changes made in last paragraph.
  addendum 6/6/21 Several typos corrected.

George Soros's Open Society Institute and American Board of Internal Medicine Foundation programs,strange bedfellows or birds of a feather?

Medical Professionalism for the new Millennium; A Physician's Charter was published in 2002 both  in the Annals of Internal Medicine and in the Lancet reflecting an international authorship. In 2003, George Soros's Open Society Institute founded a think tank, advocacy organization called Institute on Medicine as a Profession. (IMAP) with a 7.5 million dollar grant.

Later two grants ($350,000 in 2003 and $ 60,000 in 2008) was  given to IMAP by the ABIMF.ABIMF is chiefly funded by the ABIM and has a common leadership roster.In turn ABIM makes its money by testing internists and managing their Maintenance of Certification (MOC) program,a program that has generated a firestorm of protests from practicing internists and a serious effort to establish a rival means of maintenance of certification.

What is the ACP-ABIM(F) version of medical professionalism. Among other features, this "charter" calls for physicians to be "stewards of society's medical resources" and to work for social justice. It speaks of an obligation not only to the patient but to society as least in the sense of conservation of these allegedly common resources and to work for a just distribution of these resources.

The Charter was not cut from whole cloth, neither was it a tailored answer to the alleged problems that were claimed to be causing physicians angst  in the new millennium.Rather it was another manifestation or application of the new Bioethics about which Pope Benedict XVI had this to say in his 2010 address to the Pontifical Academy for Life:

"Under traditional medical ethics the guiding principle is 'do no harm". But contemporary bioethics abandons this in an effort to find the utilitarian goal of the greatest good for the greatest number Under these principles preserving the life of the human patient is not considered paramount."

Wait. what  does the charter have to say about greatest good for the greatest number? Explicitly it said nothing but advocating social justice.

Social Justice is a loose , vague and indeterminate term, which although it has a useful rhetorical value   might puzzle physicians as to how they might actually work for the nebulous social justice in their everyday practices. The ABIMF in its publications and on its website made it explicit -follow the guidelines. In that way they claim  resources would be wisely distributed and fairly  thus furthering social justice. Here we get the greatest good for the greatest number in the collective. The collective may just be the HMO or ACO or possibly all members of society.So while the Charter seems on the surface to be medical ethical Principlism , a la Beaumont and Childress, underneath there is a strong utilitarian initiative .

ABIMF's mission appears to be to further this brand of medical professionalism and to
champion the "Choosing Wisely" initiative.

 The Soros funded IMAP describes its mission in the following way:
Their vision of medical professionalism  embodies 4 values;

1) altruism that is a unwavering commitment to the patient.
2)Physician Self regulation
3)Maintenance of technical competence-a commitment to life long learning
4)Civic engagement "Physicians should enlarge their scope of concerns from the welfare of the individual patient to a concern for the welfare of all patients" ( my underlining)

This parallels the outline of the Charter which continues to speak of duty to the patient but an additional obligation was grafted on to that traditional prime directive namely to conserve resources and work for an efficient and fair distribution of resources.Numbers 1,2, and 3 add nothing to traditional medical ethics but number 4 is another matter.

So IMAP more or less recapitulates the Charter blending the traditional mom and apple pie medical ethics with a new obligation to work somehow for all patients.It should be no mystery why ABIMF might share some of its resources with another advocacy group with similar if not identical goals. My question is why does Soros wish to promote the new professionalism i.e. the Charter ?

So here it is- the physician's goal should not just be the welfare of her patient but rather the welfare of everyone.And the best way she could accomplish that goal is to follow guidelines which will provide the best bang for the buck (efficient "parsimonious care") .And one way to save money is  to limit care to the elderly which is being sold as improving the quality of life in folks in their twilight days and months.

One of the leaders in the effort to limit care to the elderly , Dr.Joanne Lynn,perhaps said more that she intended when she said:"Not only the right thing to do, it makes good business sense".

Good business sense, is that what Choosing Wisely is all about?And whose business are we talking about.


 Addendum: 4/1/16 Minor changes in wording made.

Still more data linking endurance exercise and atrial fibrillation

A number of  studies have shown a relationship between long time endurance exercise and increased  risk of atrial arrhythmias. and there is a growing consensus that this is a causal relationship. As a long time marathoner I don't welcome the news but I cannot no longer ignore it and have to worry about it. 

One of Bradford Hill's classic  criteria for assessing if a relationship between variables is causal is the dose response principle also referred to as biological gradient. This simply means that a larger dose or exposure should lead to a greater incidence of the effects.Myrstar and co authors  have published a study demonstrating a dose response relationship between years of endurance type activity and risk of atrial fibrillation and atrial flutter. In this article Myrstad and co-authors reported an odds ratio of development of atrial fibrillation of 1.16 per ten years of endurance exercise. (confidence interval 1.06--1.29).

 In another study from Norway the same lead author reported in regard to  a cohort study  of 2626 long time cross-country skiers and 2326 people from the general population. He found a prevalence of 12.3%  of self reported atrial fibrillation (AF) in the skiers versus 5% in the non-skiers. Of those, 64% continued to engage in regular endurance exercise after the onset of AF.Interestingly some 1/3 of AF patients did not use oral anticoagulants even though they had a CHA2DS-VASc scored of greater than or equal to 2,a score that current conventional medical wisdom believes anti coagulation is needed to decrease stroke risk.

 To get some approximation of context consider the ATRIA study (Go,A, et al, JAMA 2001:285:2370) which reported a prevalence of 0.1% in those younger than 60 years,3.8 % age 60 and older, and 9 % age 90 and older More extensive data can be found here in the discussion of a pooled analysis of five randomized clinical trials in which the relative risk of a fib increased 1.4 by decade ( C.I. 1.1 to 1.8). Some older runners would like to take those factoids to suggest that getting old is even more risky than running.

 An enlarged left atrium  has thought to be the  likely link between atrial fibrillation and hypertension.Some long term endurance athletes have been demonstrated to have larger left atria and while it can be considered a "physiological" adaption to increased exercise and periods of increased cardiac output the increased surface per se  may predispose to atrial rhythm mischief.Is the enlarged athletes' left atrium less pathological than that of the long term hypertensive patient?


Most of this is a "dog bites man" or duhh story but I continue to be impressed with how easily one can effortlessly find medical articles even in Journals that are not that widely read. The second article mentioned above was first published  in the official journal of the German Cardiac Society, one that I do not typically read. The ease with which you can follow current journal articles on a number of topics of your choosing on the free app QxMD is amazing particularly for someone who grew up wrestling the unwieldy Index Medicus tomes and wandering the medical library book stacks to find the volume of interest missing.You can easily learn more in an hour with that app and your tablet than you could in all day at the medical library.


addendum:10/1/15 some editorial flourishes made.

addendum: 12/2/2016 Another article presented some  data on dose response relationship.Anderson and co workers from Sweden compered the risk of atrial fib and brady rhythm problems in a large cohort of cross-country skiers. Those who took part in five or more events were compared with those who only completed on one  90km race and found a hazard ratio of 1.3 (1.08--1.58) for those who raced more. Though a increased risk of atrial fibrillation gets most of the attention , this study  showed a greater risk of bradyarrhythmias with a HR.of 1.85 , though not statistically  significant with a CI of 0.97--3.54.The quantification of the "dose" is crude as well but data are suggestive.
(Anderson, K et al., Risk of arrhythmias in 52 775 long-distance cross country Skiers: a cohort study.
European Heart Journal 2013 34: 3264 )

Born to run (slowly) and to loaf-The Leiberman hypothesis?

Harvard Professor David E. Leiberman  has taken Theodosius Dobzhansky's maxim to heart; "Nothing in biology makes sense except in the light of evolution."

Leiberman,also known as the barefoot professor for his interest and advocacy of barefoot running ,expounded his thesis along with co author Dennis Bramble in a 2004 article in Nature entitled " Endurance running and the evolution of the genus homo."

Quoting from the above article ;" The fossil evidence of these features [features that facilitate endurance running] suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years and may have been instrumental in the evolution of he human body form."


Leiberman's theory suggests that Homo evolved the ability to run long distances and hunt and forage in the heat before the human brain grew and humans got smart enough to  rule the roost .

The creature than evolved  could be described as a fur less,short toed,sweaty bipedal endurance athlete who was typically at the edge of negative calorie balance and who tended to loaf and rest whenever he could to conserve energy as food was scarce and difficult to obtain.These were the hunter gatherers whose survival depended on their ability to track and hunt animals over long distances in the climates of the African savannas as well as to dig around and find what they could to eat. That stylized story is that is how our ancestors lived as recently as some 600 generations ago, according to some estimates.

As the pressing need to work very hard physically became less and less necessary for more and more people the evolved human's drive to rest and conserve energy persisted and when not countered by lots of exercise obesity and the modern maladies such as  arterial diseases and type 2 diabetes went from rare to increasingly common.

It is an appealing story,one that resonates with those among us who like to do endurance type exercise. This includes Leiberman .  Much of it seems to make sense and is rich in physiologic insights, but is it all  just an "as if story"?

Hans Vaihinger is known as the philosopher of "as if". His view was that one should not ask if a theory or belief was true in some deep probably unknowable objective sense but rather is it useful to act as if the theory were true. ( I think Milton Freidman spoke of economic models or theory in that way, that is are they useful.) From reading descriptions of Vaihinger's work, I think it seems to him maybe most stories are "as if stories". George Box is quoted as saying that all models are wrong but some are useful.

Leiberman writes and speaks well in an entertaining way and regales us with mechanisms  such why tighter ( rather than more lax) Achilles tendon enables running and why longer toes are a detriment to running  and how sweating works much better as a heat dissipation mechanism than panting.

Bob Wachter's defense of ABIM's shenanigans and Mel Brooks

Dr. Bob Wachter,former chair of the ABIM, has spoken out in defense of ABIM and , of course, of himself.

Several medical bloggers have offered their critique of his comments including Michel Accad,  ,Walter Bond. and Dr RW..In my opinion all make  some good points with which I agree.

But I think Med Brooks' comments  may be the most appropriate.

Can Dr. Cassel and her collaborators at the National Quality Forum repeal Goodhart's Law?

In the December 4, 2014 issue of the NEJM, Dr. Chistine K.Cassel et al expound on performance measures.She freely admits there have been some problems but also apparently some successes.It is just a matter of learning from the mistakes and  leveraging the successes. We just have to work harder and be smarter. "Getting More Performance from Performance Measurements" Cassel, CK et al , NEJM 371,23 2014). When people talk about "leveraging" you can be sure the tripe level is dangerous high.

She offers her explanation of  why the notorious "four hour pneumonia rule" did not work out well. That particular clinical situation was "not the right place to intervene". .."There was too much clinical variability for the measure to help physicians on exactly the right course of action." True enough but that was not the reason.

The underlying insight is found in Goodhart's Law which states that when a measure becomes a target it loses its value as a measure.A more basic insight is that people respond to incentives. When folks are graded, or rewarded or punished based on some measure they will find ways to achieve that target and if better care results fine but there is not reason to think apriori  that it will. Teachers will teach to the tests and students will study for the test regardless of how well or how badly the test reflects the students' mastery of the subject.


Goodhart wrote about his "law " in 1975 and in 1976 Donald Campbell wrote in regard to education and testing :

"achievement tests may well be valuable indicators of general school achievement under conditions of normal teaching aimed at general competence. But when test scores become the goal of the teaching process, they both lose their value as indicators of educational status and distort the educational process in undesirable ways.

It is tempting to substitute medical care for  the teaching process and we get "But when quality measures become the goal of the medical care process , they both loose their value as indicators of medical care and distort the process in undesirable ways."

I submit that devising better measures will not change the situation.

Dr. Cassel et al would disagree with my view and she closes her commentary with  the usual boiler plate words about "stakeholders"  and better quality down the road. "All stakeholder groups are now invested in getting more  performance out of measurements ,which should ultimately drive the care improvements that patients need and deserve."

 The economist,Arnold Kling, give his take on performance measures or P4P  here.

I have commented on this general subject before and here  the issue of a conflict between P4P and traditional medical ethics is talked about.

The folks at the National Quality Forum can no more negate Goodhart's law than they can make it now longer the case that people respond to incentives.The stakeholders of which Cassel speaks , of course, included the NQF itself as it is in the business of writing quality standards .

There are some amazing octogenarians out there

Some  know-it-all-officious-busybodies   medical progressive elite presume to know when various medical procedures should be limited on the basis of age. Some even presume to know how long someone will live as in recommendations regarding limiting of medical procedures for those deemed to have less than ten years life expectancy or using 75 as a cut off date for certain type of screening tests.My pathology professor in medical school was fond of saying when you tell someone how long he has to live they may piss on your grave.Spock's "live long and prosper" butts up against Dr.Zeke's proposed forgoing of preventive measures for those 75 and older, well at least for him, or so he claims now.

Two recent journal articles shed some physiological light on  some  folks in their 80s,folks about whom some of the progressive elite would desire to limit medical care.

Trine Karlsen et al described a remarkable 80 year old Norwegian.The authors believe that the subject of their study may have a world record for maximal oxygen uptake (VO2max). for his age 50,ml/kilo/min.Accordingly to the authors this value is compatible of a normal, active, non endurance trained 35 year old Norwegian man.(How to be 80 year old and have a V02max of a 35 year old, Case Reports in Medicine, Vol 2015, article id 909561). The "how " seems to be to have great genes and to be very physically active.


 To put V02 max  in some perspective; It is a measure of the highest rate at which oxygen can be utilized by the body during intense exercise.It is a function of how much blood the heart can deliver to the muscle ( cardiac output) and how  much oxygen the muscles can take up measured by the a-v oxygen difference.


It is generally believed to peak somewhere between age 25 and 35 and decreases afterwards. Various estimates of the rate of decline have been made. A stylized version is that the decrement is of the order of 5-10 % per decade until about age 70 and then V02 max declines more rapidly.For those who continue to do endurance exercise training the decrease is in the 5% per decade range.Some data indicate that endurance athletes' VO2 max actually decreases more per decade in absolute terms ( ml/minute/kilogram) but since they begin the decline with a higher absolute value their percentage decline is about half of that of the non trained healthy person. In that regard as in most things there are some conflicting data and considerable individual variation. Karlsen's subject has his 02 max measured at age45 so that the calculated decrease in his 02 max  from age 45 to age 80 was a remarkable 2.3 ml/min/kilo per decade while previous reports suggested the average decrease is 5.4 ml/min/kilo per decade. At age 25 he was measured at 75 ml,min/kilo.

World class endurance athletes typically have values in the 70s and 80's. The value of 90 is often quoted as the highest record, this in a 24 year old cross country skier while other publications quote the recording of 95 . The value of 17.5 ml/kilo/min ( 5 mets)  has has been labelled the aerobic frailty level, the value below which a person is by one  imprecise definition, frail, and would find the activities of every day life consuming such a high percentage of their O2 max that fatigue would greatly limit function.A value of 7 ml oxygen /kilo is said to be the lowest level compatible with life.Endurance exercise training programs typically increase 02 max by 10-15% ( with the occasional outlier of more than 30%) but those folks in the 70 plus range can thank their parents ( at least one of them) for their exercise capacity.The sled dogs who race have 02 max values in the range of 240!


Scott Trappe and co authors in an earlier article in the Journal of Applied Physiology ( see here) published detailed physiological data including results of muscle biopsies and muscle enzyme studies on 15 active healthy octogenarians (one actually was 91).Nine were long time endurance athletes and 6 were age matched healthy untrained men without serious medical conditions and who were fit enough to do the exercise testing. Not only had the athletic group been competitive cross country skiers in their youth, they had continued with vigorous programs and all had trained  on average 8 hours a week for the last fifty years. ( Fifty years is not a typo).The endurance athletes had 02 max values between 34 and 42 while the healthy non endurance folks had on average a 21.

And then there is Ed Whitlock.See here for details of his setting the marathon time record for a 82 year old human . He finished at 3:41:58 which is nine minutes 49 second per mile.Whitlock is also noted for being the only man to run a sub three hour marathon at age 70 or older.Estimating his V02 max using table 2.3 from Tim Noakes's Lore of Running ( which is derived from data of Davies and Thompson) gives a value of about 48 ml/kilo/min, which is close to Karlsen's subject's measured value..

 
addendum: 8/28/2015
Ed Whitlock is not the only 80something who ran a sub four hour marathon. Ed Benham ran a 3:48 marathon at age 82 and Harold Wilson did 3:58 in Boston at age 80. In the half marathon category Anne Garrett ran 2:13 at age 80 .

 Addendum: 1/19/16 Thee were four men 80 and over ( who made the six hour cutoff, in the 2016 Houston Marathon, the fastest of which ran a 4 hour 23 minute race. According to the guesstimate form the above quoted table from Noakes,he would have a 02 max of  39-40 , not too far from Karlsen's subject and way out of the curve for 80 years olds. 

do you need a physician to order your blood tests?

There are a number of folks who want to eliminate at least one aspect of  gate-keeper role of the physician  or at least allow people  to order blood tests without getting a physician's order.

To name a few: Dr Eric Topol,Elizabeth Homes,and apparently the governor of Arizona.

Elizabeth Holmes is founder and CEO of a company named Theranos,which has developed a technology to enable a very large number of blood tests to be done from a few drops of blood,less than the tube drawn on a standard veni- puncture.

In April 2015 , the governor of Arizona signed a statute "allowing" clinical labs to perform blood tests without a physician's health care provider's order.

Laboratory Corporation of American has recently announced that they will perform lab tests on folks without requiring a doctor's order. See here for article.

According to the Bloomberg article linked above some twenty states already allow blood tests to be done without a physician's order.However according to this chart more states than that allow what is call "direct access testing". (This table is from a website called Longevity Testing.Com and I cannot attest to its accuracy as there are no links to supporting data.)

LabCorp and Quest and other large commercial labs have seen decrease in fees from CMS cuts and also from fewer referrals from independent physician's office as more doctors move to large groups or are being bought out by hospitals,who have their own labs. So they obviously welcome more direct assess customers.

In some instances a person's copay for a visit to a doctor to get a hall pass for a blood test may be more than the fee for service going the direct access route plus you do not have to wait in the doc;s office to see him and then wait for his office to send you your results.Of course,this assumes that the quality and resource conservation guidelines that he is "encouraged"   to follow will "allow" you to have the test.As you know the American College of Physicians and the American Board of Internal Medicine have declared that physicians are the "stewards" of the allegedly collectively owned national medical resources

Direct access testing fits in nicely with Dr. Topol's latest book The Patient will see you now in which he argues that smart phone based technology will go a long way to the democratization of medicine and the continuing stamping out of the lingering paternalism that was a regular feature of medicine for centuries.

Bad news for pediatricians-good news for ABMS and the hegemony of the progressive medical elite

See this blog posting regarding the unfortunate situation regarding board certification for pediatricians and how, at least so far, the  monopoly of ABMS is preserved.

If possible the MOC situation regarding peds is even worse that that regarding internists and their board, the ABIM.

One major insurer has refused to recognize certification from anything other than a ABMS recognized board.

Quoting Dr. Med Edison in her blog:

 " After months of speculation about insurer acceptance of anything other than ABMS certification, Blue Cross Blue Shield of Michigan is on record refusing certification through the National Board of Physicians and Surgeons. To my knowledge, they are the first to do so.
This is actually a big deal for pediatricians in Michigan. For our internist friends, the ABIM has slowed down implementation of MOC. But the American Board of Pediatrics refuses to listen to pediatricians, and instead instructs insurers to “check” our certificates yearly."

From the narrative related by Dr. Edison the folks at ABIM seem like avuncular colleagues compared to the even more hard nosed folks at the pediatrics board.

It may be too early to say  but it looks like we might see another situation in which the dogs bark and the caravan moves on. If other insurance companies refuse to accept NBPAS certification the viability  of that organization is in doubt.

Who elected the ACP as the"conscience" of medicine?

In a embarrassing display of  self congratulatory praise , in this  commentary Bob Doherty ,senior vice president of the American College of Physicians office of government affairs and public policy, makes the assertion that internists and particularly  the ACP are the "conscience of medicine".

How does he support that claim? First, he cites the advocacy that ACP has provided for universal health care and for other causes..He also quotes from a commentary from Lancet which declared that internists and ACP were the conscience of medicine.Further, he makes the claim that the ACP has always put the patient first even if some aspect of their advocacy might not be in the best interests of internists,while other professional organizations lobby in Washington  for their parochial interests. In his view apparently ACP (or at least its leadership) knows what it is best for the public good and selflessly strives to achieve those goals.

Conscience can be defined as the complex of ethical and moral principles that controls or inhibits the actions or thoughts of an individual or an inner sense impelling one toward right action.

Does Mr. Doherty believe that the ACP has acted in some way or ways that distinguish it from other medical professional groups  in regard to this alleged role as medicine's conscience?

What about pediatricians and their professional organization,the American Academy of Pediatricians, (AAP). If advocacy in regard to certain positions for various social issues is one criterion for being medicine's conscience,one could argue that the AAP has "out-advocated" ACP or at least earned a tie.Maybe ACP and AAP could be the co-conscience of medicine.

For example AAP has taken stands on measures to decrease firearms deaths,supported the Affordable Care Act,increased funding for the Children's health Insurance Program (CHIP) to name a few of their efforts.Since its founding  AAP has  advocated for the "health of all children", so ACP has no monopoly in putting "the patient first" and to claim that it is only internists that put patients first is without foundation and seems more like self serving rhetoric .

The American Psychiatric Association says its mission is in part to promote the highest quality care for individuals. That sounds like they put patients first too. The APA is more modest , however, in that their claim is that APA is the "voice and conscience of modern psychiatry".So maybe ACP should soften its claim and say they are the "conscience of medicine except for psychiatric issues".

In light of the most recent Newsweek revelation regarding executive pay and booking keeping practices and other alleged improprieties  at ABIM in regard to its maintenance of certification program (MOC), perhaps ACP could flex its conscience muscles and actually make a comment about ABIM's behavior.

It might also be in order to make a statement regarding ACP's educational products sold to internists that are promoted  as helpful for ABIM recertification.There are  numbers of internists out there who, rightly or wrongly,suspect there has been a very cozy and cahoots relationship between ABIM and ACP and their foundations with a revolving door type situation regarding the leadership ranks of those not for profit organizations . Surely, the voice of the conscience of  medicine should have something to say about that.

 Does advocacy for certain solutions to perceived social ills or problems constitute evidence for someone or something acting out of conscience?  It might but would it not be more correct to characterize ACP's advocacy for certain solutions as simply expressing views consistent with mainstream progressive thought which is in  some if not most  instances  contrary to mainstream conservative or libertarian thinking.While it may be possible that a majority of internists (I am not aware of a head count) consider themselves progressive, there are doubtlessly many libertarian and conservative internists who find ACP's views on a number of topics not an expression of their conscience.

Can a regular exercise program improve cardiac function in asymptomatic diastolic dysfunction with and without heart failure?

 Well ,at least one recent research paper answered that question in the affirmative.

 Dr. Nole and colleagues  (see below for reference) did a detailed study on the effects of endurance and resistance exercise on a small group of patients, some of who only had diastolic dysfunction (DD) and others who in addition had heart failure (HF) with preserved ejection fraction.

 For purposes of the study normal diastolic function was defined as having: the following echocardiographic findings 1) E/A greater than one,2)E/e prime less than  10 and 3) preserved E/A greater than one during the valsalva maneuver.The E/A ratio is the ratio of early diastolic filling of the ventricle to the late filling (aka atrial kick).The E/e prime ratio is the ratio of velocity of early diastolic filling to the movement of the mitral value annulus as determined by tissue Doppler  and is thought to be a reasonable estimate of the pulmonary capillary pressure,but not under all conditions including Left bundle branch block.

 See here for the full text article.

Basically the exercise program which was mainly endurance training with some resistance exercise which was added later in the program lead to improvement in symptoms in those who were symptomatic and in indices of diastolic function as determined by cardiac echos.

Other studies have also demonstrated that exercise training can improve diastolic function.I have commented before about the effects of long time endurance exercise and the possible mitigation of age related diastolic dysfunction.

 The other site of improvement in exercise capacity resulting from an exercise program is improvement in the A-V 02 difference and several studies have indicated that it is that aspect of physiology that improves in HF patients who benefit from endurance exercise.This is the first paper I have seen that suggests that the heart  benefits as well.


.WNolte K., Schwarz S., Gelbrich G., Mensching S., Siegmund F., Wachter R., Hasenfuss G., Düngen H.-D., Herrmann-Lingen C., Halle M., Pieske B., and Edelmann F. (2014) Effects of long-term endurance and resistance training on diastolic function, exercise capacity, and quality of life in asymptomatic diastolic dysfunction vs. heart failure with preserved ejection fraction, ESC Heart Failure, 1, pages 59–74, doi: 10.1002/ehf2.12007




 

Summertime running in the south, quicker glygogen depletion and possible value of ice slurries

You don't have to be an exercise physiologists to know you cannot run as fast or as long in the summer.

One of the reasons long training runs don't work out as well is  glycogen depletion occurring sooner in hot weather. .This seems to be a fairly well demonstrated physiological fact.See here. Of course, volume depletion is a more dominant limiting factor.

 First, a brief taste of stylized "glycogenology". The classical 70 kilogram person of physiology textbook lore carries around about 100 grams of glycogen in the liver and about 500 grams in muscles.Liver glycogen can be broken down and released into the blood as glucose while muscle glycogen can only be directly used locally to fuel muscle action,getting ATP to the myosin heads.

After a 24 hour fast some 50-60% of liver glycogen is depleted to supply glucose for resting metabolic activities. Indirectly, muscle glycogen can function as a blood sugar source by producing lactate which can be transported to the liver and converted back to glucose (Cori Cycle).Glycogen depletion is a major factor in endurance exercise adventures and this can be mitigated a bit by glycogen loading,ingesting carbohydrates during the event,repleting liver glycogen before the event and by lots of training which hopefully shifts the fuel mix somewhat to fat utilization delaying the time of glycogen depletion.When that occurs you slow down appreciably as muscles fuled mainly by free fatty acids cannot contract as rapidly. 

 So, maybe if you can keep cooler you can delay glycogen depletion.

One thing  you can do to keep cooler seems to be to drink ice slurries.

I quote from an article in the Scandinavian Journal of Medicine and Science in Sports By authors Tan and Lee from the National University of Singapore.See here for abstract.

"The ingestion of ice slurry during exercise is a practical and an effective strategy that greatest the greatest heat sink because of the additional energy required to effect a phase change from solid ice to liquid water.A smaller volume of ice slurrry ( as compared with that of cold drinks is required to achieve similar reductions in body core temperature and improvements in endurance performance."

An earlier paper by J Dugas compared running times in the heat ingesting slurries with cold water and found his subjects could run further before exhaustion with the slurry. See here.

A similar study from Australia   by Siegel and co authors also showed a increase in running duration ( about 20%) in the heat when cold water ingestion was compared with ingestion of ice slurry.See here.

The ice slurry function as a Heat Sink, a concept well known to folks who fiddle around inside computers.The small ice particles have a high surface area to volume ratio which facilitates heat transfer.

If you like snow cones you might give it a try on a hot summer days. I find the  slurries refreshing and fun to eat whether my endurance is enhanced on not. 

The U.S. medical care boondoggle depends on hookwinking the physicians

The terms hoodwink and boondoggle are so appropriate. My comments here were inspired in large measure by Dr Michel Accad's Jan 2009 insightful  blog entry from which I quote:

'... beyond ignoring the obvious tension between the individual and the group,hoodwinking physicians into practicing "population medicine" is of course the essential  means to confuse practitioners into thoughtlessly carrying out sweeping intervention whose primary benefit is the profit of third parties."

 to this I add :  and the profit-not necessarily in monetary terms-of the academics whose writings give a scholarly veneer to this monumental hoodwinking enterprise.

See here for Dr. Accad's entire essay,

In this regard several terms and concepts are important:  population medicine, physicians as stewards of finite resources,cost  effectiveness research and  high value care. The key idea is to establish the notion that medical resources is a collectively owned resource and all are entitled to it by virtue of their existence. From this follows that the  utility of the aggregate matters and not that of the individual and that  some one has to manage this collectively owned resource and the elite medical progressives are the self nominated candidates for that job.

The medical  progressive's claim  to being egalitarian advocates of social justice is contradicted by their advocacy for a utilitarian approach to the allocation of these finite resources. Utilitarianism is not a subset of egalitarianism.A leading egalitarian, John Rawls accurately characterizes utilitarianism as being inattentive to the separateness of individuals and treating people merely as means for the achievement of some aggregate or social end. The medical progressives claim to promote social justice in the abstract but operationally sponsor utilitarian calculus in which some individuals may suffer to further  some alleged statistical benefit to the collective. The progressives play the social justice card frequently in their polemics profiting from this polymorphic notion's lack of generally agreed upon specificity - the term social justice is loose , vague and indeterminate.

The medical progressives causally dismiss the notion of rationing by their unilateral re-definition  which excludes the limiting of "low value" care from their universe  of rationing. Rationing according to this formulation means only limiting high value care and they presume they will be the arbiters of what value is high and what value is low. 


Another linguistic trap is to speak of a given medical expenditure as a "cost to the system" rather than an exchange.  So when someone goes to the ER with chest pain or severe headache that is considered to be a cost to the system or even more ridiculously a drain of resources rather than providing a service for a fee and the transfer of funds as part of various exchanges that are part of the ER medical encounters.

 When someone goes to a car repair shop to replace a radiator or visits a barber for a haircut why do we not speak of draining the car care industry's resources or depleting the finite hair care resources?It is because to a large degree we are paying for the medical care with someone else's money It is the third party payers and their academic facilitators that have accomplished a monumental hoodwinking of the public and most of the medical profession by distorting the language of medical care and shifted the emphasis from a long standing  oath based imperative to care for the patient to one of limiting care the effect of which is to benefit the third party payers

 The language of medicine has been transformed into the language of medical collectivism and the third party payers owe a large debt to the efforts of the collectivists in medical academia and to some of those individuals in influential leadership positions of certain professional medical associations.

In support of the claim that many physicians have been hoodwinked is the amazing amount of support  from professionals medical organizations for the passage of the so-called "doc-fix" or MACRA which mainly replaced one centrally planned system of price controls with another such system , one that placed even more control of medical care in the hands of federal planners and administrators and some "thought leaders" who have arisen from the leadership of various national medical organizations with important input from the lobbyists from the "Bigs" (big pharma,big hospital, big insurance,etc)


In closing I quote Dr. Accad again with this masterful summary:

" But beyond ignoring the obvious tension between the individual and the group, hoodwinking physicians into practicing “population medicine” is of course the essential means to confuse practitioners into thoughtlessly carrying out sweeping interventions whose primary benefit is the profit of third parties.  Only clever sophistry can claim to reconcile the needs of patients with the profit margin of insurance companies, the bottom line of hospital administrators, the end-of-the-month income of practitioners, the annual reports of employers, the promises of legislators, the zeal of government regulators, the self-importance of academics, the confused intentions of voters, and the pocketbooks of taxpayers.  The term “society” simply conceals the myriad of interest groups that partake in the boondoggle we call the health care system."

endurance exercise and the right ventricle-some thoughts

The issue of the effect(s) of endurance exercise on the right ventricle bothers me from time to time and I have blogged about it before.(see here)

A number of studies have shown that endurance exercise, marathons,triathlons, etc,  may result in transient changes in right ventricular function  (increased volume , decreased ejection fraction), while such changes in the left ventricle are typically not the case although some transient changes have been documented..But an important question is- do repeated episodes of prolonged exercise lead to some deleterious changes in the right  ventricle  which could include a predisposition to ventricular tachycardia or worse.Is there an exercise induced clinical picture of ARVD in someone who does not have the recognized genetic profile for ARVD?(see below).After thinking about it again and reading more about it,I think maybe but it does not seem to happen very often.

J. Ector and co workers studied right ventricular  (RV) function  in a group of  22 endurance athletes who had experienced episodes  of ventricular arrhythmias and concluded "Endurance athletes with arrhythmias have a high prevalence of right ventricular structural and/or arrhythmic involvement." ,the implication being the repeated endurance events predisposed to the rhythm problems (Eur Heart J. 2007, Feb 28 (3),345-53)

LaGerche studied 39 endurance athletes, see here, immediately after an endurance event,and one week later with echocardiography and Magnetic resonance Imaging. with gadolinium. Transient RV function changes noted immediately after  the event resolved by one week but 5/39 demonstrated  late deposition of gadolinium (delayed gadolenium enhancement or DGE) in the interventricular septum.The authors seemed to assume that the MR findings were fibrotic lesions and were causally related  to multiple bouts of endurance exercise but the actual cause of the late deposition of gadolinium has not been determined but it is true that  in some contexts ( maybe most) the histologic basis of the delayed gadolenium uptake is fibrosis.

Arrhymogenic right ventricular dysplasia (ARVD)-also called Arrhymogenic right ventricular cardiomyopathy) is an inherited condition primarily involving the right ventricle with replacement of cardiac muscle with fibrous tissue and fat, leading to decreased  right ventricular function and predisposition to arrhythmias including ventricular tachycardia and ventricular fibrillation.. Typically it is inherited as an autosomal dominant and involves several mutations in the genes that code for the desomsomal adhesive proteins which function to help bind muscle cells together.

ARVC is much more common in Italy and naturally there is more awareness in Italy and more more published research. The most common cause of sudden cardiac  death in the young in Italy is ARVC accounting for 22% of deaths versus 7 % from hypertrophic cardiomyopathy (HCM) in contrast to  HCM being the most common congenital problem found in sudden deaths in young athletes in the United states.See here for details of the long standing cardiac screening program in Italy.

While it seem reasonable to conjecture that a person with one of the ARVD gene patterns might hasten the clinical manifestations of ARVD by endurance exercise , is it possible/likely that a person could bring about an  ARVD-like clinical picture by repeated endurance training and endurance events in the absence of the Italian or other recognized  genetic patterns ?

Earlier work in 2009  by Breuckmann et al ( see here ) also demonstrated some marathoners with delayed gadolenium enhancement (DGE) but in a different distribution that seen in LaGerche's subjects. Of 102 marathon runners age 50-72 who had run at least five marathons in the preceding 3 years,12 showed a DGE .Of those, 5 had a "coronary artery disease" pattern along the distribution of the left anterior descending coronary artery while 7 showed a "predominantly midmyocardial patchy pattern".Could these midmyocardial patches of presumed fibrosis be the earliest lesions of a endurance athlete's cardiomyopathy, which to my knowledge, except for arguably ARVC , has not been reported. Have autopsies been done on Tarahumara runners?