Association of serum osteocalcin with beta cell function, insulin resistance, and glycemic parameters in south Indian type 2 diabetic subjects

摘要

Background Osteocalcin (OC), also known as bone Gla (gamma-carboxyglutamic acid) protein, is a marker of bone formation. OC has effect on glucose and fat metabolism. Role of OC in type 2 diabetes mellitus (T2DM) is not well studied in Indian population. Our study aimed to see the relationship between OC and parameters of glucose metabolism in type 2 diabetes mellitus. Methods This cross-sectional study included 120 subjects with T2DM. In each subject, fasting insulin, serum osteocalcin (measured by ELISA), fasting plasma glucose (FPG), post prandial plasma glucose (PPG), and glycated Hb (HbA1c) were measured. HOMA 2.0 model was used to measure insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta). Then, serum osteocalcin levels were correlated with HOMA-IR, HOMA-beta, FPG, PPG, and HbA1c. Results Serum OC levels reduced with increase in insulin resistance (HOMA-IR) (r = -0.274, p = 0.004); however, there was no association with the beta cell function. OC had negative association with FPG (r = -0.14, p = 0.12) and PPG (r = -0.123, p = 0.18); however, it was statistically insignificant. Glycated hemoglobin (HbA1c) was significantly reduced in diabetic patients with higher OC levels (r = -0.208, p = 0.025). Conclusion Serum OC has significant association with insulin resistance and HbA1c in subjects with T2DM, which might suggest possible role of serum OC in glucose metabolism in T2DM.