Joint effects of folate and vitamin B imbalance with maternal characteristics on gestational diabetes mellitus.

BACKGROUND

This study examined whether folate and vitamin B imbalance is associated with gestational diabetes mellitus (GDM) and explored interactions between B vitamin imbalance and maternal risk factors for GDM.

METHODS

A cross-sectional study was performed in 406 Chinese pregnant women. Serum folate, vitamin B , and blood glucose concentrations were measured at 24 to 28 weeks gestation during GDM screening. A diagnosis of GDM was made based on International Association of Diabetes and Pregnancy Study Groups criteria (fasting plasma glucose [FPG] ≥5.1 mM, 1-hour plasma glucose ≥10.0 mM, or 2-hour plasma glucose ≥8.5 mM). Binary logistic regression was used to obtain odds ratios (ORs) after controlling for different confounders.

RESULTS

Higher folate levels were associated with higher glucose concentrations and a higher risk of GDM (OR 1.98; 95% confidence interval [CI] 1.00-3.90), whereas higher vitamin B levels were associated with lower FPG and a lower risk of GDM (OR 0.30; 95% CI 0.15-0.60). A higher folate: vitamin B ratio was associated with higher glucose and a higher risk of GDM (OR 3.08; 95% CI 1.63-5.83). The presence of both a higher folate: vitamin B ratio and advanced age further increased the OR to 2.13 (95% CI 1.09-4.15) with a significant additive interaction. Furthermore, a higher folate: vitamin B ratio and a higher prepregnancy body mass index (pp-BMI) were synergistically associated with an increased risk of GDM (OR 3.03; 95% CI 1.40-6.57).

CONCLUSIONS

An imbalance between folate and vitamin B , represented by a higher folate: vitamin B ratio, was highly associated with GDM risk, and this association could be further modified by maternal age and pp-BMI.