Abstract P327: Associations Between Ectopic Cardiovascular Fat Depots and Aortic Calcification Vary by Race and Menopausal Status in Women at Midlife: The Study of Women’s Health Across the Nation (SWAN) Ectopic Cardiovascular Fat Ancillary Study

Abstract

Objective: Mounting evidence demonstrates a role of ectopic cardiovascular fat (ECF), which surrounds the heart and vasculature, in the pathogenesis of cardiovascular disease (CVD). It is unknown whether ECF depots are related to atherosclerotic burden in women transitioning through menopause, a time of increasing CVD risk. We evaluated the cross-sectional associations between volumes of epicardial (EAT), pericardial (PAT), total heart (TAT; TAT=EAT+PAT) and perivascular (peri-aortic) (PVAT) adipose tissues and aortic calcification (AC) in a sample of white and black midlife women. Effect modifications by race and menopausal status were also examined. Design: Data were obtained from the SWAN ectopic cardiovascular fat ancillary study. AC and ECF depots were quantified by electron beam computed tomography. Outcomes were presence of AC among all women, and extent of AC among women with an Agatston score >0. Logistic and linear regression were used as appropriate. Final models were adjusted for age, race, study site, menopausal status, body mass index (BMI), systolic blood pressure, lipids and insulin resistance. Results: The study included 257 women (32.7% Black; 58.7% pre-/early peri-menopausal and 41.3% late peri-/postmenopausal) aged 46-58 years with data on any of the 4 ECF depots (EAT, PAT and TAT: n=227, PVAT: n=191). AC was found in 184 (71.6%) participants. Pre-/early peri menopausal women had less EAT (median (Q1, Q3): 35.0 (28.4, 51.7) cm 3 vs. 43.5 (32.9, 58.3) cm 3 , P = 0.02) and TAT (median (Q1, Q3): 42.5 (33.2, 64.5) cm 3 vs. 50.3 (38.9, 74.3) cm 3 , P = 0.05) than late peri-/postmenopausal women, respectively. In final models, only EAT (OR (95%CI): 3.29 (1.14, 9.54)) was associated with higher odds of presence of AC. Interactions with race or menopausal status were not significant. Relationships between ECF depots (EAT,PAT and TAT) and extent of AC varied by race (all P <0.05); in that higher volumes of EAT, PAT and TAT were associated with greater AC in black compared with white women in final models. Irrespective of race or menopausal status, higher volumes of PVAT (β (SE): 1.60 (0.63), P= 0.01, per 1 log-unit increase in PVAT) were associated with greater extent of AC in the fully adjusted model. In black women only, the associations of PAT and TAT with extent of AC varied by menopausal status (all P <0.05) independent of age, BMI and other CVD risk factors: late peri-/postmenopausal women had significantly more AC than pre-/early peri-menopausal women for each 1-log unit increase in PAT (β (SE): 1.57 (0.66), P=0.02) and TAT (β (SE): 2.29 (1.04), P=0.03). Conclusion: ECF depots are associated with aortic calcification in women at midlife and the associations vary by race and menopausal status. Perhaps ECF plays a role in the higher risk of CVD reported in women after menopause.