A variation in NOS1AP gene is associated with repaglinide efficacy on insulin resistance in type 2 diabetes of Chinese

Aim: To investigate a potential association between SNP rs10494366 in the neural nitric oxide synthase adaptor protein (NOS1AP) and efficacy of repaglinide (an insulin secretagogue) in newly diagnosed Shanghai Chinese type 2 diabetes patients. Methods: A total of 104 newly diagnosed type 2 diabetes patients (69 men, 35 women) were recruited and treated with repaglinide for 24 weeks. Anthropometric measurements, clinical laboratory tests were obtained at baseline and after 24-week treatment. Genotyping was performed by sequencing. Results: The baseline value of BMI, HOMA-IR, HOMA-B, and fasting insulin level were significantly different between GG, GT, and TT genotypes (P=0.024, 0.030, 0.005, and 0.007, respectively). Carriers of TT genotype were in significant insulin resistance at baseline. After 24-week repaglinide monotherapy, the Delta value of fasting insulin (P=0.019) and HOMA-IR (P=0.011) were significantly different. TT carriers had the least insulin resistance after treatment. The mixed model analysis showed that the variation had an interaction effect with repaglinide treatment only on HOMA-IR (P=0.013). Conclusion: A common variant in rs10494366 is associated with repaglinide monotherapy efficacy on insulin resistance in newly diagnosed Shanghai Chinese type 2 diabetes patients.