Transcription factor 7-like 2 gene polymorphisms and gestational diabetes mellitus

Transcription factor 7-like 2 (TCF7L2) gene polymorphisms were shown to be associated with insulin resistance. We examined two single nucleotide exchanges in this gene in women with gestational diabetes mellitus (GDM) and in women with normal glucose tolerance.

A total of 1800 unselected women were prospectively screened for GDM by oral glucose tolerance test (OGTT) between 24 and 28 weeks of gestation. Two hundred and fifty Caucasian women of this collective, 125 patients with pathological OGTT and 125 patients with normal glucose tolerance were randomly selected. DNA samples were isolated and TCF7L2 gene polymorphisms (TCF7L2rs12255372 and TCF7L2rs7903146) were analyzed.

Women with GDM were significantly older (30.1 ± 3.4 years vs. 28.2 ± 4.8 years, p = 0.01), had a significantly higher body mass index (26.4 kg/m(2); interquartile range: 23.33-31.19 vs. 24.6 kg/m(2); interquartile range: 21.05-27.28, p = 0.02) and were significantly more often homozygous for the T allele of TCF7L2rs12255372 (17.2% vs. 2.6%, p = 0.002) than patients with normal glucose tolerance. Binary logistic regression analysis showed that the homozygous variant of TCF7L2rs12255372 (T/T) is an independent risk factor for GDM (OR 7.7, 95% CI: 1.71-34.60), but not the homozygous variant of TCF7L2rs7903146 (T/T).

TCF7L2rs12255372 variant (T/T) is associated with increased risk of GDM in Caucasian women.