Relationships between serum osteocalcin, leptin and the effect of weight loss by pharmacological treatment in healthy, nonsmoking Korean obese adults

Recent studies have reported a relationship between osteocalcin (OC) levels and factors associated with energy metabolism and insulin resistance. As any detailed understanding of OC mechanisms still remains elusive, this study aimed at revealing a correlation between serum OC levels and obesity in healthy, nonsmoking, Korean obese adults who had undergone weight loss through pharmacological treatment. 119 healthy, nonsmoking, Korean obese adults were investigated at 3months following weight loss through pharmacological treatment. Serum OC, leptin, HOMA score, ghrelin, visceral fat mass, total body fat, and BMI were measured. Increase in serum OC was significantly associated with decreases in: BMI (and weight change %) (r=−0.209, p=0.023), visceral fat mass (r=−0.189, p=0.049), HOMA (r=−0.203 p=0.027), and leptin (r=−0.253 p=0.006), but not with changes in adiponectin (r=+0.029, p=NS), and Ghrelin (r=+0.019, p=NS). Decrease in leptin (β=−0.280, p=0.002) was significantly associated with an increase in serum OC, after pharmacological weight loss treatment was adjusted for age, sex, drug type, and BMI (or visceral fat mass). Serum OC was significantly increased at 3months after pharmacological weight loss. We further found that leptin levels were associated with changes in serum OC. These findings suggest a relationship between bone and adipose tissue. ► Serum OC was significantly increased at 3months after pharmacological weight loss ► We further found that leptin levels were associated with changes in serum OC. ► These findings suggest a relationship between bone and adipose tissue.