Association of Osteocalcin with Metabolic Syndrome and its Correlation with Insulin Resistance

Abstract

Introduction: Metabolic Syndrome (MetS) is an important public health burden associated with five-fold risk of developing Type 2 Diabetes Mellitus (T2DM) and two fold risk of Cardio Vascular Disease (CVD). Recent studies described that osteoblasts produce osteocalcin which increases insulin secretion and adiponectin production resulting in insulin sensitivity. Aim: To determine the association of serum osteocalcin with MetS and to assess the correlation of insulin resistance Homeostatic Model Assessment for Insulin Resistance (HOMAIR) with osteocalcin. Materials and Methods: This case-control study was carried out in the Department of Biochemistry at MKCG Medical College, Brahmapur, Odisha, India. By observing the mean and standard deviation from previous studies, with 95% Confidence Interval (CI) and 80% power of study, the sample size was calculated to be 45. Forty eight cases between 20-45 years of age meeting the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria of MetS and 50 age and sex matched healthy individuals were taken as controls. Individuals with any systemic illness or on any kind of medications were excluded from the study. Fasting blood sugar, lipid profile were measured by standard procedures. Serum osteocalcin and serum insulin was estimated by Enzyme-linked Immunosorbent Assay (ELISA) LISA SCAN READER and ROCHE e COBAS 411 electrochemiluminiscence, respectively. Statistical analysis was done in Statistical Package for the Social Sciences (SPSS) 22.0 version software. Results: Serum osteocalcin was found to be lower in cases as compared to controls (7.74±4.62 ng/mL and 23.24±9.74 ng/mL) respectively. Osteocalcin was also found to be significantly negatively correlated with HOMA-IR, Waist Circumference (WC), triglyceride and fasting blood sugar in cases with (r=-0.322, p=0.025), (r=-0.519, p<0.001), (r=-0.401, p=0.005), (r=-0.539, p<0.001), respectively and also in controls with (r=-0.494, p<0.001), (r=-0.176, p=0.245), (r=-0.398, p<0.05), (r=-0.141, p<0.05), respectively. Conclusion: Serum osteocalcin being negatively correlated with insulin resistance may have therapeutic role in prevention of MetS which may be substantiated with further study.

Keywords

• bone specific insulin resistance
• cadiovascular risk factors
• dyslipidemias
• glucose homeostasis