Early life adversity and C-reactive protein in diverse populations of older adults: a cross-sectional analysis from the International Mobility in Aging Study (IMIAS)

BACKGROUND Recent studies suggest potential associations between childhood adversity and chronic inflammation at older ages. Our aim is to compare associations between childhood health, social and economic adversity and high sensitivity C-reactive protein (hsCRP) in populations of older adults living in different countries. METHODS We used the 2012 baseline data (n = 1340) from the International Mobility in Aging Study (IMIAS) of community-dwelling people aged 65-74 years in Natal (Brazil), Manizales (Colombia) and Canada (Kingston, Ontario; Saint-Hyacinthe, Quebec). Multiple linear and Poisson regressions with robust covariance were fitted to examine the associations between early life health, social, and economic adversity and hsCRP, controlling for age, sex, financial strain, marital status, physical activity, smoking and chronic conditions both in the Canadian and in the Latin American samples. RESULTS Participants from Canadian cities have less adverse childhood conditions and better childhood self-reported health. Inflammation was lower in the Canadian cities than in Manizales and Natal. Significant associations were found between hsCRP and childhood social adversity in the Canadian but not in the Latin American samples. Among Canadian older adults, the fully-adjusted mean hsCRP was 2.2 (95% CI 1.7; 2.8) among those with none or one childhood social adversity compared with 2.8 (95% CI 2.1; 3.8) for those with two or more childhood social adversities (p = 0.053). Similarly, the prevalence of hsCRP > 3 mg/dL was 40% higher among those with higher childhood social adversity but after adjustment by health behaviors and chronic conditions the association was attenuated. No associations were observed between hsCRP and childhood poor health or childhood economic adversity. CONCLUSIONS Inflammation was higher in older participants living in the Latin American cities compared with their Canadian counterparts. Childhood social adversity, not childhood economic adversity or poor health during childhood, was an independent predictor of chronic inflammation in old age in the Canadian sample. Selective survival could possibly explain the lack of association between social adversity and hsCRP in the Latin American samples.