Preterm birth and risk of type 1 and type 2 diabetes: systematic review and meta‐analysis

Summary Preterm birth is suggested to play an important role in the development of diabetes. However, results have been inconsistent. We conducted a systematic review and meta‐analysis to clarify the relationship between preterm birth and type 1 and type 2 diabetes. P ub M ed, E mbase and ISI W eb of S cience were searched. A total of 18 studies (including 2,176,480 participants and 22,073 cases) for type 1 diabetes and five studies (including 31,478 participants and 1,898 cases) for type 2 diabetes were included in the current meta‐analyses. We calculated pooled odds ratio ( OR ) and 95% confidence interval ( CI ) using fixed‐effects model to evaluate the relations between preterm birth and type 1 and type 2 diabetes. The results suggested that preterm birth was significantly associated with increased risk of type 1 diabetes ( OR  = 1.18, 95% CI  = 1.11–1.25), with no evidence of between‐study heterogeneity ( I 2  = 13.2%, P  = 0.296). Preterm birth was also significantly associated with increased risk of type 2 diabetes ( OR  = 1.51, 95% CI  = 1.32–1.72), with no evidence of ( I 2  = 0.0%, P  = 0.557). Subgroup analyses suggested that there was significant association in both case‐control studies ( OR  = 1.16, 95% CI  = 1.06–1.26) and cohort studies (relative risk = 1.20, 95% CI  = 1.11–1.29) for type 1 diabetes, and similar results were found for type 2 diabetes. The results suggested that preterm birth was a significant and independent risk factor for both type 1 and type 2 diabetes.