THE ROLE OF SYSTEMIC INFLAMMATION IN HEALTH NOW, LATER, AND CHANGE OVER TIME: EVIDENCE FROM MIDUS

Abstract

Abstract Systemic inflammation is theorized to be a biological pathway through which chronic stressors (e.g., discrimination, social marginalization) contribute to adverse health outcomes and disparities among older adults. Cross sectional research documents associations between inflammation and a broad array of health outcomes. Less is known about whether and how inflammation may influence health longitudinally. This study investigated whether a composite measure of inflammatory burden predicted physical health: a) concurrently, b) approximately 7 years later, and c) changes during that time. Data derive the National Survey of Midlife in the United States (MIDUS) participants who provided inflammatory biomarker data (2004-2009 Biomarker study) and health data in MIDUS 2 (2004-2006) and MIDUS 3 (2013-2014) (N=931, Mage 57, 45% male, 91% White). Inflammatory burden reflected the number of inflammatory biomarkers in the highest risk quartile, out of five: C-reactive protein, interleukin-6, fibrinogen, E-selectin, and intracellular adhesion molecule. Three general indicators of physical health were examined: number of commonplace chronic physical health conditions, out of 7; functional limitations; and self-rated physical health. Multivariate regression analyses indicated that inflammatory burden predicted all three concurrent physical health outcomes and the same health outcomes seven years later (p-values <.02). Inflammatory burden was unrelated to changes in these outcomes over time. This study adds to the literature on stress-related biological mechanisms of health and identifies a potential clinical indicator of enduring health problems. It also suggests that while inflammatory burden may demonstrate consistent relationships with physical health over time, other mechanisms may account for health changes and deterioration.