Transcription Factor 7-Like 2 (TCF7L2) Polymorphism and Hyperglycemia in an Adult Italian Population-Based Cohort

OBJECTIVE: To assess whether TCF7L2 polymorphism has a role in the deterioration of glycemic control. RESEARCH DESIGN AND METHODS: Metabolic variables were evaluated at baseline and after 6-year follow-up in 1,480 Caucasian subjects from a population-based cohort. RESULTS: At baseline, T-allele carriers showed significantly lower BMI and homeostasis model assessment for β-cell function (HOMA-B) values and higher fasting glycemia and diabetes prevalence. At follow-up, fasting glucose and HOMA-B index were increased and reduced, respectively, in carriers of the T-allele. Incident impaired fasting glucose (IFG) and incident diabetes were 5.7, 10.7, 16.9% and 1.6, 1.7, 3.0% in the CC, CT, and TT genotypes, respectively. In a multiple logistic regression model, the association between incident IFG and the T-allele was significant (odds ratio [OR] 2.08 [95% CI 1.35–3.20] and 3.56 [2.11–5.98] in CT and TT genotypes, respectively). CONCLUSIONS: The T-allele of TCF7L2 rs7903146 polymorphism was independently associated with increasing fasting glucose values toward hyperglycemia in the follow-up.