Racial differences in aortic perivascular adipose tissue volume and its association with arterial stiffness in middle-aged men

Abstract

Background and aims: Ectopic fat depots, such as aortic perivascular adipose tissue (aPVAT), are emerging as key factors in cardiovascular health. Individuals of African ancestry have lower ectopic fat levels, including visceral adipose tissue (VAT), than European ancestry. However, racial differences in aPVAT volume and its association with arterial stiffness remain unclear.

Methods: This cross-sectional study examined 325 men aged 40-49 (252 White, 73 African American). aPVAT and VAT were quantified using electron-beam computed tomography, and carotid-femoral pulse wave velocity (cfPWV), the gold standard measure of arterial stiffness, was assessed using a noninvasive testing device. Participant characteristics, aPVAT, and cfPWV were compared by race. Multivariable linear regression models evaluated the association between race and aPVAT and between aPVAT and cfPWV, adjusting for cardiovascular risk and lifestyle factors, body mass index (BMI), and VAT. Interaction terms were included to test race-specific effects.

Results: African Americans had significantly lower aPVAT volume than White Americans (42.7 cm³ vs. 49.1 cm³, p = 0.01). This difference became non-significant after adjusting for VAT. aPVAT was positively associated with cfPWV, independent of VAT, BMI, and other confounders (β = 1.52 cm/s, p = 0.04), with no race-specific interactions (p = 0.41). cfPWV did not differ significantly between racial groups (p = 0.64).

Conclusions: African Americans had lower aPVAT volume than White Americans, primarily explained by differences in VAT. The positive relationship between aPVAT and cfPWV underscores the potential role of aPVAT in arterial stiffness across racial groups. Longitudinal studies are needed to explore causality and mechanisms underlying these associations.

Keywords: Aortic perivascular adipose tissue (aPVAT); Arterial stiffness; Carotid-femoral pulse wave velocity; Ectopic fat; Racial differences; Visceral adipose tissue.