Social stress, visceral obesity, and coronary artery atherosclerosis in female primates

Abstract

Our previous work in cynomolgus monkeys demonstrated significant relationships between (i) social reorganization stress and visceral fat deposition, and (ii) central fat deposition and coronary artery atherosclerosis (CAA). Nevertheless, direct relationships between CAA and visceral fat have not been demonstrated in people or animals, nor have relationships among stress, visceral obesity, and CAA been observed within a single study. Here, we examine the hypothesis that visceral obesity provides a link between social stress and CAA. Subjects were 41 socially housed females that consumed an atherogenic diet for 32 months. Social behavior and ovarian function were continuously recorded; dexamethasone suppression tests, telemetered overnight heart rate, BMI, visceral (VAT) and subcutaneous abdominal (SAT) adipose tissue were measured before necropsy. Females with high VAT:SAT were relatively subordinate, socially isolated, received more aggression and less grooming, desensitized to circulating glucocorticoids, had impaired ovarian function, higher heart rates late in the day, and more CAA than low VAT:SAT females. High-BMI females had higher heart rates than low-BMI females. Poor ovarian function in high VAT:SAT females is a novel observation suggesting the need for studies of fat distribution and ovarian function in women. The results of this study are the first to demonstrate a relationship between CAA and visceral obesity, and suggest that social stress may exacerbate CAA in part by increasing the ratio of visceral:subcutaneous fat mass in selected individuals susceptible to diet-induced CAA. Further studies are needed to understand the complex and multifactorial temporal relationship among relative visceral obesity, physiological stress responses, and CAA.