Association analysis of the variant in the regulatory subunit of phosphoinositide 3-kinase (p85α) with Type 2 diabetes mellitus and hypertension in the Chinese Han population

Aims To determine whether variants in the gene for the regulatory subunit of phosphoinositide 3-kinase (p85 alpha) are associated with Type 2 diabetes mellitus (Type 2 DM) and hypertension in a Chinese population. Methods We performed a case-control study genotyping the Met3261le and IVS4+82A>G polymorphisms in 494 patients with Type 2 DM and hypertension and 557 normal controls from the north of China. Individual genotypes were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The IVS4+82A>G polymorphism was further confirmed by direct sequencing in 20 randomly selected cases. Results The IVS4+82A>G polymorphism that is common in Caucasians was not detected in our population. Frequencies of genotypes and alleles of Met3261le polymorphism were not significantly different between cases and controls in whole samples by univariate analysis. Logistic regression analysis demonstrated that Ile3261le genotype was associated with a 2.085-fold (95% CI, 1.043-4.168, P = 0.0377) relative risk of diabetes and hypertension. After stratification by obesity, the frequency of Ile3261le genotype in cases was higher than that in controls (18/304 vs. 13/510, P = 0.015) among non-obese individuals (BMI < 28 kg/m(2)). We did not find that this missense mutation was associated with blood pressure, glucose and blood lipids in the control group. Conclusion Our data indicate that the Met326Ile variation in the gene encoding the p85 alpha protein might contribute to the increased risk of Type 2 DM and hypertension in Chinese.