Abstract P256: Associations Between Periaortic Vascular Adipose Tissue, Cardiometabolic Risk Factors and Aortic Calcification in a Multiethnic Cohort of Men From the ERA JUMP Study

Abstract

Background: Aortic calcification (AC) is a direct measure of subclinical cardiovascular disease (CVD) linked with CVD events and mortality. Periaortic vascular adipose tissue (PVAT) may exert local pro-atherogenic effects on the arteries, through secretion of pro-inflammatory adipocytokines, in addition to systemic effects. Racial differences exist between various adipose depots including visceral and epicardial fats, however little is known for PVAT. Our objectives were to evaluate 1) the associations between PVAT volume and cardiometabolic risk factors and 2) the relationship between PVAT volume and AC among middle-aged White, Japanese American, and Korean men. Methods: We measured thoracic PVAT volume (cm 3 ) in 54 (17 US White, 19 Japanese American and 18 Korean) men with high AC (AC Agatston Score ≥400) and in 59 (20 US White, 19 Japanese American and 20 Korean) age- and BMI- frequency matched controls with low AC (0-100) from the ERA-JUMP study. PVAT volume was quantified in aortic scans by electron-beam computed tomography using Slice-O-Matic reading software and a Hounsfield Units range of -190 to -30 for adipose tissue. Overall and race-specific univariate correlations were calculated to assess associations of PVAT with cardiometabolic risk factors and logistic regression was used to assess PVAT associations with AC≥400. Results: Overall mean (SD) age and BMI were 45.6 (3.0) years and 27.1 (2.8) kg/m 2 , respectively. Median PVAT was 44.4 (IQR: 35.7-56.0) and differed by race; 50.3 (IQR: 39.5-60.0) in Whites, 47.9 (IQR: 37.5-55.8) in Japanese Americans and 37.4 (IQR: 32.5-49.2) in Koreans, p=0.002. Waist circumference, BMI, visceral and subcutaneous fat, total cholesterol, HDL-C, triglycerides, and insulin were significantly associated with PVAT volume in the overall group. In race-specific analyses, all measures of adiposity were significantly associated with PVAT. Furthermore, PVAT volume was significantly associated with HDL-C (inversely) in Whites, with triglycerides in Whites and Japanese Americans and with BP in Japanese Americans. Median PVAT volume was higher in cases than controls [47.9 cm 3 (IQR: 34.5-61.1) vs 44.0 cm 3 (IQR: 36.7-51.0)] though not significantly different. PVAT was not significantly associated with high AC. Conclusions: In this multiethnic group of men aged 40-49 years, PVAT was higher in US Whites and Japanese Americans and lower in Koreans. PVAT was associated with overall and central adiposity and with markers of cardiometabolic risk across racial/ethnic groups. However, additional research needs to be done to substantiate these findings.