Serum Folate and Vitamin B Modify the Associations of Genetic Variants with Gestational Diabetes Mellitus: A Cross-Sectional Study in Chinese Pregnant Women.

PURPOSE

This study aimed to explore the association between N-6 adenine-specific DNA methyltransferase 1 () single nucleotide polymorphisms (SNPs) and gestational diabetes mellitus (GDM) and the modification of the relationship by folate and vitamin B.

METHODS

A cross-sectional study involving 1303 pregnant women (262 GDM and 1041 non-GDM) was performed in Tianjin, China. Nine SNPs in were genotyped, and serum folate, vitamin B, and homocysteine (Hcy) levels were measured. The logistic regression models determined the odds ratios (ORs) for SNPs in and the gene-nutrition interactions on GDM.

RESULTS

rs7282280, rs1048546, and rs1997605 were related to GDM under the dominant model after adjusting for multiple covariates. Individuals carrying the rs7282280 TC/TT genotypes had a lower risk of developing GDM, regardless of serum folate and vitamin B levels. However, rs1048546 TG/GG genotypes were associated with lower GDM risk when serum folate ≥ 6.0 ng/mL. Pregnancies with the risk genotypes in and higher serum folate or lower vitamin B are more prone to GDM. The study also showed a statistically significant additive interaction between rs1997605 GG genotypes and lower vitamin B (RERI: 2.54; 95% CI: 0.17, 4.92).

CONCLUSION

SNPs in were found to be associated with GDM, and serum folate and vitamin B levels can modify their associations.