Association of famine exposure during early life with the risk of type 2 diabetes in adulthood: a meta-analysis

The association between famine exposure (defined as lengthy and continuous deprivation of food) during early life and type 2 diabetes (T2DM) in adulthood remains controversial. A meta-analysis was performed to better clarify the relation of famine exposure to later T2DM risk. A systematic literature search was performed in PubMed, Web of Science, Embase and China National Knowledge Infrastructure for relevant available articles. The articles were limited to those in English or Chinese from January 1990 to June 2016. Observational studies evaluating the association between famine exposure and T2DM were included. The pooled relative risk (RR) with 95% confidence interval (CI) was used to estimate the effect of famine exposure on T2DM. The I (2) was used to assess heterogeneity, and the random effects model (REM) was adopted as the pooling method. We included 11 published articles with 12391 T2DM cases for this meta-analysis. A significant association of early life famine exposure with increased risk of T2DM was observed (RR = 1.38, 95% CI 1.17-1.63; I (2) = 63.4%; P (heterogeneity) = 0.002). Compared with the unexposed, the RRs of T2DM were 1.36 (95% CI 1.12-1.65) for fetal-infant exposed and 1.40 (95% CI 0.98-1.99) for childhood exposed. After excluding one article that had a strong effect on heterogeneity, the pooled RR was 1.46 (95% CI 1.27-1.69). The meta-analysis indicates that famine exposure during early life especially fetal-infant exposure may increase the risk of T2DM in adulthood. Measures should be taken to prevent malnutrition during important stages of growth and development to reduce the prevalence of T2DM.