TCF7L2 and type 2 diabetes mellitus: In never drinking subgroup, after adjustment for gender, age, BMI and smoking status by logistic regression analysis, the TCF7L2 rs290481 TC/CC and TC genotypes increased T2DM risk compared with the TCF7L2 rs290481 TT genotype [TC vs. TT: adjusted OR = 1.33, 95% CI 1.02–1.74, P = 0.034 and TC/CC vs. TT: adjusted OR = 1.32, 95% CI = 1.03–1.70, P = 0.030 (Table 4)].