Abstract
INTRODUCTION: Chronic emotional stress is a well-recognized risk factor for psychiatric and cardiometabolic disorders. The mediating role of low-grade inflammation in older, ethnically diverse populations has never been studied. METHODS: The multiethnic ≥50-year-old study population is a subset of the Health and Aging Brain Study: Health Disparities (HABS-HD) study. Adjusted logistic and linear regression were used to assess associations. Statistical mediation analysis with non-parametric bootstrapping of confidence intervals was used to determine the intermediate role of Interleukin-6 (IL-6). RESULTS: The study included 2173 participants (50-92 years). Black participants disclosed higher chronic stress levels than White and Hispanic participants. Having a chronic stress total score ≥ six points is associated with 53 % higher odds of disclosing concomitant cardiovascular disease (CVD) (adj.OR = 1.53 [1.10-2.53]), 31 % of Type-2 diabetes (T(2)DM) (adj.OR = 1.31[1.06-1.62]), 23 % of hypertension (adj.OR = 1.23 [1.02-1.49]), and 30 % obesity (adj.OR = 1.3[1.09-1.55]). These associations were statistically mediated by IL-6 (12 % (p-value (FDR) = 0.012) of the association with CVD, 17 % T(2)DM (p-value (FDR)<0.001), 18 % hypertension (p-value (FDR)<0.001), and 29 % obesity (p-value (FDR) = 0.005)). CONCLUSIONS: The study highlights a further aspect of the pathophysiological mechanisms involved in the brain-body communication. While IL-6 partially explains statistical associations between chronic emotional stress and major cardiometabolic disorders, no causal effects can be inferred from this study owing to the cross-sectional design. Larger longitudinal studies are needed to better clarify the temporal relationship between the events and to build upon our findings.