The Role of Circulating MicroRNA in the Regulation of Beta Cell Function and Insulin Resistance among Indians with Type 2 Diabetes

BACKGROUND: Circulating microRNA (miRNA/miR) levels are emerging out as markers of tissue level changes; however, their role in type 2 diabetes (T2D) needs to be explored. The study aimed to compare the circulating levels of the miRNA (miR9, miR30d, miR1, miR133a, miR29a, miR143) between T2D and gender matched controls and also to evaluate the strength of association between circulating miRNAs and beta cell function/insulin resistance among Indians with T2D. SUBJECTS AND METHODS: Thirty T2D (25–60 years) and their gender matched controls (n = 30) were recruited. Plasma glucose and insulin, HbA1c, lipid profile, and miRNA levels were estimated. Insulin resistance and beta cell function (HOMA IR and %B) were derived. Body composition was assessed by Dual-energy-x-ray absorptiometry (DXA). Comparison between the study groups was performed using independent “t” test and strength of association by Pearson's correlation. RESULTS: There was a significant difference in HOMA IR (P = 0.03) and %B (P = 0.001) between the two study groups. The muscle mass, percent body fat, and muscle to fat ratio were comparable between the two study groups. miRNA 30d was significantly higher in the T2D compared to control group even after controlling for age (P = 0.005). There was a significant positive association between miR30d with HOMA-IR (r = 0.26, P = 0.04). CONCLUSION: The current study demonstrated that miR30d (insulin gene transcription in pancreatic beta cell and regulator of insulin sensitivity in skeletal muscle) was overexpressed among T2D. Further role of other miRNA and their interaction in regulation of beta cell function and insulin resistance needs to be studied.