The relationship of body fat to metabolic disease: Influence of sex and ethnicity

Clinical investigations designed to determine risk profiles for the development of cardiovascular disease (CVD) and type 2 diabetes mellitus (DM) are usually performed in homogenous populations and often focus on body mass index (BMI), waist circumference (WC), and fasting triglyceride (TG) levels. However, there are major ethnic differences in the relationship of these risk factors to outcomes. For example, the BMI risk threshold may be higher in blacks than in whites and higher in women than in men. Furthermore, a WC that predicts an obese BMI in white women only predicts a BMI in the overweight category in black women. In addition, overweight black men have a greater risk of developing type 2 DM than do overweight black women. Although TG levels are excellent predictors of insulin resistance in whites, they are not effective markers of insulin resistance in blacks. Among the criteria sets currently available to predict the development of CVD and type 2 DM, the most well known is the metabolic syndrome. The metabolic syndrome has 5 criteria: central obesity, hypertriglyceridemia, low high-density lipoprotein (HDL) levels, fasting hyperglycemia, and hypertension. To make the diagnosis of the metabolic syndrome, 3 of the 5 factors must be present. For central obesity and low HDL, the metabolic syndrome guidelines are sex specific. Diagnostic guidelines should also take ethnic differences into account, particularly in the diagnosis of central obesity and hypertriglyceridemia.