August 13, 2008 - Blasting stereotypes that obese people are more prone to heart disease, a new study shows there is a higher prevalence of heart problems among normal-weight individuals and a higher prevalence of metabolically healthy obese individuals than previously thought.
The study was released under the title “The Obese Without Cardiometabolic Risk Factor Clustering and the Normal Weight With Cardiometabolic Risk Factor Clustering” in this Aug. 11 issue of the journal Archives of Internal Medicine. The researchers wanted to know the prevalence obese individuals who are resistant to the development of the adiposity-associated cardiometabolic abnormalities and normal-weight individuals who display cardiometabolic risk factors, since this correlation has not been well examined.
Researchers used the combined body mass index and cardiometabolic groups to assess 5,440 participants of the National Health and Nutrition Examination Surveys 1999-2004. Cardiometabolic abnormalities included elevated blood pressure; elevated levels of triglycerides, fasting plasma glucose, and C-reactive protein; elevated homeostasis model assessment of insulin resistance value; and low high-density lipoprotein cholesterol level.
The study showed 23.5 percent (about 16.3 million adults) of normal-weight adults were metabolically abnormal, whereas 51.3 percent (about 35.9 million adults) of overweight adults and 31.7 percent (approximately 19.5 million adults) of obese adults were metabolically healthy.
The authors of the study said variation in metabolic and cardiovascular disease (CVD) risk factors observed among individuals of similar body mass index (BMI), and recent studies indicating individuals’ CVD risk may depend jointly on their body size and metabolic profile has led to increasing recognition that the disease risks associated with obesity may not be uniform. This has resulted in the investigation of body size phenotypes. One recognized body size phenotype is the metabolically healthy but obese individual, sometimes referred to as “uncomplicated” obesity. Although obese (BMI ≥30), this subset of individuals appears to be relatively resistant to the development of the adiposity-associated cardiometabolic abnormalities that increase CVD risk, researchers found. A second body size phenotype includes individuals with normal weight (BMI
Among those with two or more metabolic abnormalities, the study found the two most common cardiometabolic risk factor combinations within all body size groupings were high triglyceride level/low HDL-C level and high blood pressure/high glucose level.
The study’s lead authors are Rachel P. Wildman, Ph.D., Albert Einstein College of Medicine in New York, and MaryFran R. Sowers, Ph.D., University of Michigan.
For more information: http://archinte.ama-assn.org/