The association between birth weight and the risk of type 2 diabetes mellitus: a systematic review and meta-analysis.

Previous studies have shown a relationship between type 2 diabetes mellitus and birth weight. We performed this meta-analysis to resolve the problem of inconsistent results. We conducted a literature search of PubMed, Embase and the Cochrane Library using "Diabetes Mellitus, Type 2," "Birth Weight," and some related free words. Twenty-one studies were included in accordance with inclusion and exclusion criteria, involving a total of 313,165 participants and 22,341 type 2 diabetes mellitus cases. A modified version of the Newcastle-Ottawa Scale was used to evaluate the methodological quality of studies included. We used Review Manager 5.3 for data merging and statistical analysis. Results were expressed as odds ratio (OR) and 95% confidence interval (95% CI). The risk of diabetes with low birth weight (<2,500 g) was higher than that with birth weight ≥2,500 g, (OR = 1.51, 95% CI: 1.43, 1.58). Compared with normal birth weight (2,500-4,000 g), low birth weight, but not high birth weight, increased the risk of diabetes (OR = 1.41, 95% CI: 1.26, 1.58). There is a negative association between birth weight and the future risk of type 2 diabetes mellitus.