In utero and early life exposure to the Great Chinese Famine and risk of rheumatoid arthritis in adulthood.

VanEvery, Hannah; Yang, Wen-Hao; Olsen, Nancy; Zhang, Xinyuan; Shu, Rong; Lu, Bing; Wu, Shouling; Cui, Liufu; Gao, Xiang

OBJECTIVE To investigate whether early life exposure to the Great Chinese Famine of 1959-1961 was associated with risk of RA in adulthood. METHODS Included were 101,510 participants of the Kailuan Study that joined at baseline (2006). RA cases were confirmed by medical record review. We used logistic regression to calculate the odds ratio (OR) and 95% confidence interval (95% CI) for RA, according to famine exposure status (exposed in utero, or between years 0 and 3, years 3 and 6, or at 6 years or older), in comparison to participants born after 1961 (not exposed to famine). RESULTS During 12 years of follow-up (2006-2018), we identified 187 RA cases. Individuals exposed to famine in utero or during years 0-3, had a higher prevalence of RA, relative to other groups (0.24%-0.35% vs 0.08-0.20%). After adjustment for potential confounders, the OR of RA was 2.95 (95% CI: 1.55, 5.59) for in utero exposed individuals, 4.53 (95% CI: 2.72, 7.54) for those exposed in age 0-3 y, 2.55 (95% CI: 1.43, 4.57) for those exposed in age 3-6 y, and 2.72 (95% CI: 1.70, 4.36) for those exposed after age 6 y versus individuals born after 1961. A similar association was observed for men and women (P-interaction= 0.89). CONCLUSION Individuals exposed to famine in utero or early childhood (0-3 years), were more likely to suffer from RA in adulthood, highlighting the importance of early life as a vulnerable developmental period.