Abdominal Adiposity Change in White and Black Midlife Women: The Study of Women's Health Across the Nation

Objective: The principal objective of this investigation was to compare the naturalistic intra-abdominal adipose tissue (IAAT) change among black and white women during midlife. Methods: A cohort of 222 (56%) white and 171 (44%) black midlife women were investigated in the Fat Patterning Study at the Chicago site of the Study of Women's Health Across the Nation. The subjects' total body fat was assessed by dual-energy X-ray absorptiometry and IAAT by a planimetric computed tomography (at the level of L4-L5) annually over up to 4 years. Results: The total body fat at initial evaluation was higher in black women (45.1% +/- 68.2%) when compared with white women (41.3% 68.7%, P < 0.001) and did not significantly change over the longitudinal follow-up. No significant racial differences were found in the mean annualized gain of IAAT (4.4% +/- 60.5%) in models adjusted for total body fat, initial IAAT, age, race, time and race interaction, physical activity, depressive symptoms, menopausal status, and menopausal hormone therapy. Conclusions: During a naturalistic observation, black and white midlife women had similar abdominal fat gain adjusted for differences in baseline adiposity. These data inform future research aimed to prevent IAAT gain during the critical midlife period of rising cardiovascular risk.