The Obesity Paradox-Redux

Much like the French Paradox of the late 1990′s, the current obesity paradox remains an enduring mystery; a Bermuda Triangle of medicine. For several years now, many a well done study has demonstrated a reduction in the incidence of cardiovascular and other morbidity and mortality in those over the ideal body mass index (BMI) of 18-25. The groups having the best outcomes are often in the overweight, and in some cases in the slightly obese category, according to BMI measures. To some extent that was attributable to the overall poor job that BMI does as a measure of obesity, something covered many times here in the blog (search the archives for BMI to catch up!). However, this new wrinkle to obesity paradox might even have Stephen Hawking scratching his head. It is remarkable because a better correlate to obesity, waist circumference was also used as a measure. In men, a waist circumference of 40 inches or more indicates a high risk group. For women, it is 37 inches or more that is considered high risk. Even more intriguing was the improved survival of the heavier group with heart failure; a condition for which previous studies have shown obesity to be a risk factor for developing. Heart failure has many causes, but the end result is a condition in which the heart muscle is weakened and unable to pump efficiently enough to meet the demands of the body. A condition, by which all conventional wisdom would agree should be exacerbated by increased weight.That’s not what the data showed.A study done at The University of California found that adults with heart failure who were overweight or obese had lower risk of death. Their survival was superior to both underweight (a known higher risk group) and those with a “normal” BMI (between 18-25). Not only was the risk of death lower, but the higher weight groups were less likely to require a heart transplant or suffer other related morbidities. The study examined approximately 2,700 heart failure patients. The participants were followed for two years. The study found men with a high waist circumference and a high BMI were more likely to survive and were less likely to need a heart transplant. Overweight and obese women also fared better than normal-weight women. The cardioprotective effect was significant: men with a normal BMI and smaller waist circumference had a 34 percent higher risk for adverse outcomes and normal-weight women had a 38 percent higher risk for adverse outcomes.An interesting hypothesis suggested by the study authors involves increased serum lipoproteins (molecules in the body which transport fats), which they suggest may have anti-inflammatory properties. Fascinating food for thought-for those attending the American Culinary Federation national Convention in Orlando, Florida next week, Dr. Mike will be lecturing on this and related topics.

Horwich, T. et al.American Journal of Cardiology, July 1 2012