Race, socioeconomic status, and low-grade inflammatory biomarkers across the lifecourse: A pooled analysis of seven studies

Cardiovascular diseases are patterned by race and socioeconomic status, and chronic low-grade inflammation is proposed as a key underlying mechanism. Theories for how racial and socioeconomic disadvantages foster inflammation emphasize a lifecourse approach: social disadvantages enable chronic or repeated exposure to stressors, unhealthy behaviors, and environmental risks that accumulate across the lifecourse to increase low-grade inflammation. However, single samples rarely include multiple racial and socioeconomic groups that each span a wide age range, precluding examination of this proposition. To address this issue, the current study combined seven studies that measured C-reactive protein and interleukin-6, producing a pooled sample of 1650 individuals aged 11–60 years. We examined (a) whether race and socioeconomic disparities in inflammatory biomarkers vary across the lifecourse, (b) whether adiposity operates as a pathway leading to these disparities, and (c) whether any indirect pathways through adiposity also vary across the lifecourse. Relative to White individuals, Black individuals exhibited higher, whereas Asian individuals exhibited lower, levels of inflammatory biomarkers, and adiposity accounted for these racial differences. Similarly, lower socioeconomic status was associated with higher inflammatory biomarkers via elevated adiposity. Importantly, both racial and socioeconomic disparities, as well as their pathways via adiposity, widened across the lifecourse. This pattern suggests that the impact of social disadvantages compound with age, leading to progressively larger disparities in low-grade inflammation. More broadly, these findings highlight the importance of considering age when examining health disparities and formulating conceptual models that specify how and why disparities may vary across the lifecourse.