Association of KCNJ11 gene (rs5219) polymorphism with HOMA-IR & HOMA B values in type 2 diabetes mellitus in India: A case-control study

Abstract

Objectives Type 2 diabetes mellitus (T2DM) is a complex illness that results from either insulin resistance or insufficient insulin, which raises blood sugar levels. Numerous genes interact to influence the secretion of insulin. A gene of great interest is KCNJ11 of subfamily-J, member 11, which functions as an inwardly rectifying ATP-sensitive potassium (KATP) channel in pancreatic beta cells and is involved in glucose-stimulated insulin release. Material & Methods The present case-control study attempts to delineate the genetic impact of KCNJ11 (rs5219) gene polymorphism on the risk of T2DM in the Indian population. It involves 55 patients with type 2 diabetes (fasting plasma glucose of >126 mg/dl, 2-h glucose of >200 mg/dl, or HbA1c level of >6.4%) and 55 healthy controls (fasting plasma glucose of <100 mg/dl, 2-h glucose of <140 mg/dl, or HbA1c level of <6.4%). polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) was used to study KCNJ11 polymorphism through a standard protocol. Enzyme Linked Immunosorbent Assay (ELISA) was used to estimate serum Insulin levels. HOMA-IR & HOMA-β values were calculated. Statistical analysis was done using t-test, Chi-Square test, and One-way analysis of variance (ANOVA) test. Results Serum insulin levels and HOMA-IR values were significantly decreased in cases than in the control group. Logistic regression analysis showed that the frequency of KK genotype in T2DM individuals (21.8%) was higher than the control group (9%) (p = 0.01). Frequency of K allele (38%) in patients was higher than the control group (18%) (p = 0.001). The K allele risk in diabetic patients was 9.9 times higher as compared to controls (p = 0.001, OR 9.9, 95%Cl 0.036–0.36). Homeostatic model assessment β (HOMA-β) values of KK genotype (59.9±27.8315) were lower than that of EK (76.8±33.23) and EE (127.9±44.59) genotypes (p < 0.001). Conclusion The presence of KCNJ11 (rs 5219) gene polymorphism shows a noteworthy correlation with the likelihood of developing T2DM among the North Indian population. K allele is more likely to be present in individuals with T2DM than the control group. Moreover, HOMA-β values of those with the KK genotype were found to be lower than the individuals having EK and EE genotypes.