Exercise may prevent age related motor unit loss

Regular exercise may prevent-or at least  significantly slow down- motor unit loss  in the muscle groups exercised.  GA Powers et al demonstrated that there was significantly less loss of motor units in the tibialis anterior  muscles of long time runner as compared with older sedentary otherwise healthy subjects.   

The estimated number of motor units in the group of masters runner (average 65 years)was the same as those in young active runners (age average 25)

 

Interestingly the arm muscle of the runners did not show less motor unit loss, although one would think the arm movement during running would be helpful in that regard.

Muscle loss can be due motor unit loss ( remember the motor unit includes the anterior horn cell) or muscle atrophy or both. You have to think that once anterior horn cells die no amount of exercise will rejuvenate the muscle.

1) Power, GA et al  Motor unit number estimates in masters runners: use it or losse it?

Med Sci Sports Exerc 2010 Sept 42 (9) 1644-50

Population Medicine, The Baptists and Bootleggers and risk factor epidemiology.

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

His thesis is  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,except  for perhaps the queen, 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 part of the the jargon of medicine by the  authors of the Framingham study who set out 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 "preventive" medicine would find  many new things to prevent.

The slippery notion of the nature of risk was given little attention in medical journals.- 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. 

Note: This is a lightly edited version of a blog entry from five  year ago. It hits on several of the themes I have obsessed and ranted about for some time and thought it would be a good posting for my 1200 th blog entry since February 2005. 

In regard to the topic of population medicine I highly recommend the book 'Moving Mountains" by Dr. Michel Accad. In the book Accad discusses the emergence of population medicine as the results  of developments in economics,science and the ethics of healthcare much to the detriment of the physician patient relationship.

In regard to The Baptist and Bootleggers.I am referring to the concept popularized by Bruce Yandle . See "Bootleggers and Baptists. How Economic and moral Persuasion interact to shape regulatory Policy." Baptists and bootleggers both supported laws forbidding alcohol sales on Sundays , but for different reasons.