Association of KCNQ1 polymorphisms with gliclazide efficacy in Chinese type 2 diabetic patients

To investigate the effects of KCNQ1 polymorphisms on the efficacy of gliclazide in type 2 diabetic patients.

A total of 443 newly diagnosed type 2 diabetic patients were included in this study. After enrollment, patients went on an 8-week gliclazide monotherapy. Fasting plasma glucose (FPG) was measured before and after the treatment. Life-style information was collected by weekly follow-up. Genotyping of the two single-nucleotide polymorphisms was performed using the single base primer extension method. T-test, one-way analysis of variance, and Pearson χ-test were used to evaluate the effects of rs2237892 and rs2237897 on the FPG reduction and treatment success rate.

After 8 weeks of gliclazide therapy, the FPG decreased significantly from 10.9±2.8 to 7.4±2.2 mmol/l (P<0.001). Compared with the CC genotype, patients with CT or TT genotypes of rs2237897 achieved greater reduction in FPG (3.9±2.6 vs. 3.2±2.4 mmol/l, P=0.003; 33.9±19.0 vs. 27.7±17.4%, P<0.001) and a higher rate of treatment success (74.1 vs. 65.2%, P=0.042 for criterion 1; 61.1 vs. 44.5%, P<0.001 for criterion 2, respectively), whereas no significant difference was found in the FPG reduction and treatment success rate among different genotypes of rs2237892.

Our results indicated that a common variant of KCNQ1, rs2237897, was associated with the efficacy of gliclazide after 8-week monotherapy in Chinese newly diagnosed type 2 diabetic patients. The FPG reduction and treatment success rate were significantly higher in carriers of CT and TT genotypes.