Serum osteocalcin levels in metabolic syndrome

Osteocalcin has recently been proposed to play an important role in modulating glucose, lipid and energy metabolism. This study was undertaken to determine serum osteocalcin levels in metabolic syndrome and to study its association with measures of insulin resistance and cardiovascular risk factors.

The study included 45 cases diagnosed as having metabolic syndrome defined by NCEP ATPIII criteria and 45 normal healthy subjects as controls. A fasting serum sample was collected from each subject and assayed for Fasting Blood Sugar, Lipid Profile, Insulin and Osteocalcin. Body Mass index (BMI), Waist hip ratio (WHR) and Homeostatic model assessment (HOMA) were calculated.

The mean serum Osteocalcin (ng/mL) levels were 4.56±1.75 and 10.302±1.96 in cases and controls respectively (p<0.001). In cases, Hyperglycemia and Hypertriglyceridemia were the most prevalent risk factors. The cases had a statistically significant negative correlation between osteocalcin and BMIand Triglyceride and a statistically significant positive correlation between osteocalcin and High Density Lipoprotein (HDL)(r = +0.964, p< 0.001). Metabolic syndrome subjects had lower serum osteocalcin levels. Greater the number of risk factors present, the lower was the osteocalcin level. The strongest positive association was found between osteocalcin and HDL. Osteocalcin was negatively associated with HOMA, FBS, BMI and triglyceride.

These findings suggest that osteocalcin may have an essential role in modulating glucose and energy metabolism and in the pathophysiology of metabolic syndrome. Further studies may determine the utility of osteocalcin for cardiovascular risk prediction and strategies to increase osteocalcin levels, thus efficiently optimizing glucose, lipid and energy utilization.