Racial differences in adipocyte size and relationship to the metabolic syndrome in obese women

To determine whether racial differences exist in the relationship of the abnormalities defining the metabolic syndrome (MS) to regional adiposity and fat cell size (FCS) in obese postmenopausal women.

We determined the relationship of metabolic variables associated with the MS to regional body composition and abdominal (ABD) and gluteal (GLT) FCS in 25 white (CAU) and 25 African-American (AF-AMER) older women matched for age (58 +/- 5 years; mean +/- SD) and BMI (35 +/- 4 kg/m2).

MS was present in 36% of the AF-AMER and 57% of the CAU women. There were no differences in total body, trunk, gluteofemoral fat mass or regional FCS, but AF-AMER women had 22% lower visceral fat, 24% higher insulin, and 31% lower triglyceride levels than CAU women (p < 0.05). Multiple regression analysis with body fat, visceral ABD fat area, and FCS as independent variables showed that GLT FCS was independently correlated with 2-hour insulin (r = 0.56), triglyceride (r = 0.62), and high-density lipoprotein cholesterol (r = -0.72) levels in AF-AMER women but not in CAU women, where only systolic blood pressure correlated with subcutaneous ABD fat area (r = 0.57) (p < 0.05).

The associations between GLT FCS and metabolic dysfunction in obese AF-AMER but not CAU women suggest that central obesity is a less valid predictor of the MS in obese postmenopausal AF-AMER women than in CAU women and that GLT FCS may be a more sensitive indicator of risk for the MS in AF-AMER women.