RACIAL DIFFERENCE IN RESTING AND MAXIMAL OXYGEN CONSUMPTION AMONG POSTMENOPAUSAL WOMEN

Abstract

332 Young black women have a lower resting metabolic rate (RMR) and are less physically active than young white women which may contribute to the higher prevalence of obesity in black compared to white women. To examine whether there are racial differences in RMR & maximal oxygen consumption(VO2max) in older women, we measured body composition (dual energy x-ray absorptiometry, LUNAR), RMR (indirect calorimetry, Deltatrac), & VO2max on a treadmill in black (n=18) & white (n=48) postmenopausal women (59±1 yrs). Body weight, body mass index (BMI), and fat free mass(FFM) were higher in black than white women, while fat mass was similar between races (Table). After correcting for individual differences in FFM, RMR was 6% lower and VO2max was 10% lower in black than white women (P<0.05). In a multiple regression model which included FFM, race and age, race was a significant predictor of both RMR and VO2max. Thus, for a given FFM and age, black women have a lower RMR and VO2max which may contribute to the epidemic of obesity in black women.Table