Potassium inwardly-rectifying channel subfamily J member 11 (KCNJ11) gene polymorphism in Egyptian type 2 diabetic patients: a single-center study.

Background: The KCNJ11 gene belongs to the potassium channel gene family. It has a major role in the secretion of insulin. Genetic variations in KCNJ11 are possibly responsible for the progression of type 2 diabetes mellitus (T2DM). In this study, we investigated the possible correlation between KCNJ11 (rs5210) gene polymorphism and T2DM.

Subjects and method: This study included 92 individuals divided into two groups. Group 1 included 46 type 2 diabetic patients. Group 2 (control group) included 46 healthy participants. A complete history was taken and a full physical examination was performed. Anthropometric data were measured. Laboratory investigations included fasting blood glucose (FBG), two hours post-prandial blood glucose (2HPPBG), glycated hemoglobin (HbA1c), and fasting lipid profile. KCNJ11 (rs5210) single nucleotide polymorphism was detected by polymerase chain reaction restriction-fragment length polymorphism (PCR-RFLP).

Results: Both AG and GG genotypes were associated with increased risk for T2DM (OR 5.2, 95% CI 1.32-20.5, P = 0.01 for AG; and OR 18.2, 95% CI 2.99-31.7, P = 0.002 for GG). Also, the frequency of the G allele was significantly higher in type 2 diabetic patients compared to healthy controls (50% versus 23.9%, respectively). The G allele of rs5210 in KCNJ11 contributed to an increased risk of T2DM (OR 3.18, 95% CI 1.31-7.75, P = 0.01). There was a statistically significant association between increased 2HPPBG and HbA1c levels and the carrier of AG and GG genotypes (P = 0.01 and 0.007, respectively). There was a statistically significant association between total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), and high-density lipoprotein-cholesterol (HDL-c) levels and the carrier of AG and GG genotypes (P < 0.001, 0.02, and 0.007, respectively). Regression analysis detected that body mass index (BMI), 2HPPBG, TC, triglycerides (TG), and the G allele of rs5210 in KCNJ11 gene showed a significant association with T2DM (P = 0.004, 0.042, 0.003, 0.006, and 0.01, respectively) while no association was observed with FBG, HbA1c, LDL-c or HDL-c (P = 0.099, 0.123, 0.522, and 0.765, respectively).

Conclusion: KCNJ11 rs5210 genetic polymorphism may raise the risk for the occurrence of T2DM among Egyptians.