Background: Variation in TCF7L2 gene is associated with type 2 diabetes and with gestational diabetes mellitus in several populations, but there are no data in Mexican women with gestational diabetes mellitus. In this study, we examined metabolic and hormonal measurements as well as TCF7L2 genetic variants.
Methods: We selected 108 pregnant women with normal glucose tolerance and 90 with gestational diabetes mellitus according to 2010 American Diabetes Association criteria matched for gestational week. We collected data on blood pressure, body mass index (BMI) and concentrations of blood glucose, HbA1c , lipids profile, insulin and glucagon-like peptide-1 (GLP-1). The genotyping of rs7903146 and rs12255372 polymorphisms were made with polymerase chain reaction-restriction fragment length polymorphism.
Results: Actual and pre-gestational BMI, fasting glucose and HbA1c were higher (p < 0.001), and high-density lipoprotein cholesterol was lower (p < 0.02) in gestational diabetes mellitus women than euglycemic women. No significant differences were found for lipids, insulin and homeostasis model assessment-insulin resistance. Gestational diabetes mellitus women had high GLP-1 levels (32 vs 24, p < 0.004) and decreased β-cell function (266 vs 438, p < 0.001). The frequency of rs12255372 risk allele in gestational diabetes women was significantly higher than that in euglycemic women (χ² = 8.96; p < 0.003) and confers a risk for gestational diabetes mellitus (OR = 9.1, 95% CI 2.8-29, p < 0.0002; and OR = 4.3, 95% CI 1.6-11.4, p < 0.003 based on dominant and co-dominant model, respectively). The generalized linear model showed that low beta function, high pre-gestational BMI and rs12255372 risk allele are independently associated with gestational diabetes.
Conclusions: The elevated GLP-1 levels in gestational diabetes women suggested some abnormality in insulin secretion. The low β-cell function, high pre-gestational BMI and rs12255372 risk allele are risk factors independently associated with the development of gestational diabetes.
Keywords: GDM hormonal characteristics; TCF7L2 gene polymorphisms; gestational diabetes.
Copyright © 2014 John Wiley & Sons, Ltd.