Friday, February 06, 2009

Normal Weight Obesity joins normal blood pressure hypertension and others

It has been well recognized for a while that an elevated body mass index (BMI) does not necessary mean that a person has too much fat. Men and women with well developed muscles may have an elevated BMI and still have a low percentage of body fat. Look at any NBA game and you can see poster guys for that.

The BMI as an indicator of body fat also can also fail at the lower end. As humans age , often weight may not change but body composition does, with muscle mass decreasing and body fat increasing so that you may not gain weight but have a high percentage of body fat. Sarcopenia, or muscle loss, is a major element of old age fragility and so far the only way shown to mitigate that is resistance exercise.Aerobic exercise does not seem to help mitigate the apparently inexorable loss of the fast twitch muscle fibers whose loss is most marked in the age related decline in strength.

Nomal weight obesity (NWO) is a recently minted term that is meant to refer to the condition in which the BMI is in the generally accepted normal range but by some (perhaps less than widely accepted) standard of percentage of body fat, the person is deemed to have "too much". Hence they suffer (well, we haven't really shown yet that they suffer) from NWO. My term would be too much fat (TMF) because we have used BMI to operationally define obesity (as bad an indicator as it may be) and some may think we have at least the appearance of a contradiction in terms. People with this entity may be the some of the same people we used to call flabby.

Researchers from Mayo Clinic have published an article that correlates this NWO with risk for the metabolic syndrome. (You may remember this entity as something perhaps no longer believed in by endocrinologists but still by cardiologists. See here for comments regarding that schism). So, it appears that NWO or TMF would be a risk factor for a risk factor (metabolic syndrome) which is a risk factor for heart disease and diabetes, just to name two.

Tip of hat to Dr. Michel Accad's blog Alertandoriented for alerting me to this "novel" risk factor. Here is a press release for the May0 Clinic article.

The Mayo clinic researchers recommend that a shift from focusing on BMI and perhaps monitoring percentage of body fat or least waist measurements since the "real" definition of obesity is too much fat.

Data
from CDC show that 35% of American are obese (as defined by BMI >= 30. Using NHANES data from 2003-2004 we see that 66% of Americans are either overweight or obese.That leaves 34% with a normal BMI but Mayo docs tell us about half of those are really obese after all leaving something around 17-20% of us who do not have too much fat. We now know that there are fat people that don't even look fat., a secret epidemic of fat people who don't look fat. (OK, some of them probably have a bulging tummy).A nation of reverse Lake Wobegon, where most everyone is worse than average.

There are new risk factors cropping up all the time. Risk and pre-risk and proto-risk abound. The cardiologist Dr. Thomas Giles, remarked that we are all pre-dead. Prompt and massive public health funding is the only answer,maybe as part of the stimulus package.

1 comment:

Anonymous said...

Thoughts about Obesity

Obesity has been defined as when excess body fat accumulates in one to where their physical overgrowth makes the person unhealthy to varying degrees. Obesity is different than being overweight, as others determine obesity to be of a more serious concern.
As measured by one’s body mass index (BMI), one’s BMI of 25 to 30 kg/m is considered overweight. If their BMI is 30 to 35 kg/m, they are class I obese, 35 to 40 BMI would be class II obese, and any BMI above 40 is class III obesity.
Presently, with obesity affecting children progressively more, the issue of obesity has become a serious public health concern.
Approximately half of all children under the age of 12 are either obese are overweight. About twenty percent of children ages 2 to 5 years old are either obese are overweight. The consequences of these stats on our children are very concerning, considering the health issues they may or likely experience as they get older.
Worldwide, nearly one and a half billion people are either obese or overweight. In the United States, about one third of adults are either obese or overweight.
Women of low socioeconomic status are likely to be twice as obese compared with those who are not at this status. It is now predicted that, for the first time in about 150 years, our life expectancy is suppose to decline because primarily of this obesity problem.
Morbid obesity is defined as one who has a body mass index of 30 kg/m or greater, and this surgery, along with the three other types of surgery for morbid obesity, should be considered a last resort after all other methods to reduce the patient’s weight have chronically failed. Morbid obesity greatly affects the health of the patient in a very negative way. It has about 10 co-morbidities that can develop if the situation is not corrected. Some if not most of these co-morbidities are life-threatening.
One solution beneficial in many cases of morbid obesity if one’s obesity is not eventually controlled or corrected is what is known as gastric bypass surgery. This is a type of bariatric surgery that essentially reduces the volume of the human stomach in order to correct and treat morbid obesity by surgical re-construction of the stomach and small intestine.
Patients for such surgeries are those with a BMI of greater than 40, or a BMI greater than 35 if the patient has co-morbidities aside from obesity. This surgery should be considered for the severely obese when other treatment options have failed. The standard of care illustrating as to whether this surgery is reasonable and necessary should be clarified.
There are three surgical variations of gastric bypass surgery, and one is chosen by the surgeon based on their experience and success from the variation they will utilize. Generally, these surgeries are procedures related to gastric restrictive operations or mal-absorptive operations.
Over 200,000 gastric bypass surgeries are performed each year, and this surgery being performed continues to progress as a suitable option for the morbidly obese. There is evidence that this surgery is particularly beneficial for those obese patients that have non-insulin dependent Diabetes Mellitus as well.
It is believed that the results of this surgery to correct morbid obesity greatly limits or prevents such co-morbidities associated with those who are obese. Yet about two percent of those who undergo this surgery die as a result from about a half a dozen complications that could occur. However, the surgery reduces the overall mortality of the patient by 40 percent or so, yet this percentage is debatable due to conflicting clinical studies at times.
Age of the patient should be taken into consideration, as to whether or not the risks of this surgery outweigh any potential benefits for the patient who may have existing co-morbidities that have already caused physiological damage to the patient. Also what should be determined by the surgeon is the amount of safety, effectiveness, and rationale for a particular patient regarding those patients who are elderly, for example.
Many feel bariatric surgery such as this should be considered as a last resort when exercise and diet have failed for a great length of time.
If a person or a doctor is considering this type of surgery, there is a website dedicated to bariatric surgery, which is: www.asmbs.org,

Dan Abshear