Association between maternal blood cadmium and lead concentrations and gestational diabetes mellitus in the Japan Environment and Children’s Study

Purpose: To examine the association between elevated blood cadmium (Cd) and lead (Pb) concentrations and increased risk of gestational diabetes mellitus (GDM). Methods: This cross-sectional study included pregnant women (n = 16,955) enrolled in the Japan Environment and Children’s Study. Concentrations of Cd and Pb in blood samples collected at 22–28 weeks’ gestation were measured by inductively coupled plasma mass spectrometry. GDM was diagnosed according to the 2011 Japan Society of Obstetrics and Gynecology and Japan Association of Obstetricians and Gynecologists criteria. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression analysis. Results: Blood Cd and Pb concentrations were slightly higher among women with GDM than among those without GDM; however, these differences were not statistically significant. Elevated blood Cd and Pb concentrations were not associated with increased GDM risk in the nulliparous group (Cd OR 0.76; 95% CI 0.28–2.08 for high vs low category; Pb OR 2.51; 95% CI 0.72–8.72) or the parous group (Cd OR 0.64; 95% CI 0.29–1.44; Pb OR 0.31; 95% CI 0.04–2.29). Conclusions: This study demonstrates that Cd and Pb exposure, in the range of blood levels observed, has no significant relationship with the development of GDM. Further prospective studies would be valuable to confirm these findings.