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

Background: 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.

Methods: 119 healthy, nonsmoking, Korean obese adults were investigated at 3 months following weight loss through pharmacological treatment. Serum OC, leptin, HOMA score, ghrelin, visceral fat mass, total body fat, and BMI were measured.

Results: 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).

Conclusions: Serum OC was significantly increased at 3 months 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.