Joint effects of folate and vitamin B12 imbalance with maternal characteristics on gestational diabetes mellitus.

BACKGROUND

This study examined whether folate and vitamin B12 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 B12 , 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 B12 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 B12 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 B12 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 B12 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 B12 , represented by a higher folate: vitamin B12 ratio, was highly associated with GDM risk, and this association could be further modified by maternal age and pp-BMI.