Cardiovascular fat in women at midlife: effects of race, overall adiposity, and central adiposity. The SWAN Cardiovascular Fat Study

Objectives: Cardiovascular fat (CF) is associated with greater coronary heart disease (CHD) risk. Postmenopausal women have greater CF volumes than premenopausal women, and the association between specific CF depot volumes and CHD risk is more pronounced after menopause. Race, central adiposity, and visceral adiposity are important factors that could impact CF volumes. Whether racial differences in CF volumes and in their associations with central (visceral fat [VAT]) and general adiposity (body mass index [BMI]) exist in midlife women have not been addressed before. Methods: In all, 524 participants from the Study of Women's Health Across the Nation (mean age: 50.9 +/- 2.9 years; 62% White and 38% Black) who had data on CF volumes (epicardial fat [EAT], paracardial fat [PAT], total heart fat, and aortic perivascular fat), VAT, and BMI were studied. Results: In models adjusted for age, study site, menopausal status, comorbid conditions, alcohol consumption, and physical activity, Black women had 19.8% less EAT, 24.5% less PAT, 20.4% less total heart fat, and 13.2% less perivascular fat than White women (all P<0.001). These racial differences remained significant after additional adjustment for BMI or VAT. Race significantly modified associations between adiposity measures and CF volumes. Every 1-SD higher BMI was associated with 66.7% greater PAT volume in White compared with 42.4% greater PAT volume in Black women (P = 0.004), whereas every 1-SD higher VAT was associated with 32.3% greater EAT volume in Black compared with 25.3% greater EAT volume in White women (P = 0.039). Conclusions: Racial differences were found in CF volumes and in their associations with adiposity measures among midlife women. Future research should determine how race-specific changes in CF volumes impact CHD risk in women.