Birth Weight and Weight Gain during First Year of Life Related to the Increased Risk of Type 1 Diabetes

"Twelve studies involving 2,398,150 persons of whom 7,491 had Type 1 diabetes provided odds ratios and 95% confidence intervals of Type 1 diabetes associated with birth weight. Four studies provided data on weight and/or weight gain during the first year of life. High birth weight (<4,000 g) was associated with increased risk of Type 1 diabetes (odds ratio=1.17, 95% confidence interval (CI): 1.09, 1.26). According to sensitivity analysis, this result was not influenced by particular study characteristics. The pooled confounder-adjusted estimate was 1.43 (95% CI: 1.11, 1.85). No heterogeneity was found (I(2)=0%) and no publication bias. Low birth weight (<2,500 g) was associated with a nonsignificantly decreased risk of Type 1 diabetes (odds ratio=0.82, 95% CI: 0.54, 1.23). Each 1,000-g increase in birth weight was associated with a 7% increase in Type 1 diabetes risk. In all studies, patients with Type 1 diabetes showed increased weight gain during the first year of! life, compared with controls," wrote T. Harder and colleagues, Charite University.

The researchers concluded, "This meta-analysis indicates that high birth weight and increased early weight gain are risk factors for Type 1 diabetes."

Harder and colleagues published their study in American Journal of Epidemiology (Birth weight, early weight gain, and subsequent risk of type 1 diabetes: systematic review and meta-analysis. American Journal of Epidemiology, 2009;169(12):1428-36).