Leptin and Postmenopausal Osteoporosis

Objective: To investigate plasma leptin concentrations in postmenopausal women to improve the understanding of the role of leptin in determining bone mass. Design: A prospective observational cross-sectional study. Setting: Departments of Obstetrics Gynecology, Rheumatology and Chemical Pathology at Kasr El-Aini Hospital, Cairo University. Participants: Thirty postmenopausal women with osteoporosis (ages range 45-73 years and body mass index (BMI) range 23.31-39.37Kg/m^2), and 30 age- and BMImatched healthy postmenopausal women. Methods: Bone mineral densities were measured by dual energy X-ray absorptiometry (DEXA). Plasma leptin concentrations were measured using enzyme-linked immunosorbent assay (ELIZA). Main outcome measures: The correlation of plasma leptin concentrations and bone mineral density (BMD). Results: Plasma leptin concentrations were significantly higher in the osteoporotic group than the control group (67.44±48.60 Vs. 38.10±19.58, p=0.004). No correlation was observed between plasma leptin and BMD values in the osteoporotic group (r=0.2462, p=0.198; r=0.3452, p=0.067 and r=0.1898, p=0.324 for T score spine, Rt. hip and Lt. hip, respectively) and the control group (r=0.0050, p=0.980;r=0.2564, p=0.188 and r=-0.0967, p=0.624 for T score spine, Rt. hip and Lt. hip, respectively), but there was a significant positive correlation between plasma leptin and BMI in the osteoporotic group (r=0.4911, p=0.001) and the control group (r=0.8205, p 0.001). Conclusion: Circulating plasma leptin does not have a significant direct influence on bone mass in postmenopausal women.