Longitudinal analysis of cytokines, chemokines, and inflammatory markers in a middle-aged cohort

Systemic chronic low-grade inflammation increases with aging and contributes to the risk or progression of a myriad of chronic diseases. Greater midlife inflammation has detrimental effects on future health outcomes. However, few studies have quantified inflammatory markers from midlife longitudinal measurements. Here, we measured cytokines, chemokines, and clinical biomarkers of inflammation at three different time points in a cohort of middle-aged (mean age 48) African American and White men and women. We analyzed longitudinal data for these inflammatory markers examining possible interactions across time, age, race, and sex. We report sex differences in the levels of CXCL10/IP-10, CXCL11/ITAC, and uric acid. Ferritin levels differed by sex and race; the highest levels were in White men and lowest in White women. MCP-1 and WBC count were higher in White participants than African American participants, and uric acid levels were lower for older White participants, but higher for older African American participants. In this longitudinal study, we found that IL-22 levels decreased over time while ferritin levels increased over time. For high sensitivity C-reactive protein (hsCRP), values changed differently over time across sex where men's values increased and women's values decreased over time. In addition, IL-10, CXCL11/ITAC, and hsCRP levels decreased over time in White participants, but not for African American participants. These data indicate that cytokine, chemokine, and clinical inflammatory biomarkers vary across time, age, sex, and race in a middle-aged cohort. Understanding inflammation at midlife may provide keys to reducing negative health outcomes later in life.