Relationship between serum leptin concentrations and bone mineral density as well as biochemical markers of bone turnover in women with postmenopausal osteoporosis

Abstract

Objective To determine whether leptin is involved in bone remodeling in patients with postmenopausal osteoporosis. Design Cross-sectional study. Setting Department of Obstetrics and Gynecology, Faculty of Medicine, Cairo University. Patient(s) Ninety postmenopausal osteoporotic women (37 obese and 53 nonobese) and 30 healthy premenopausal women from the same clinic served as controls. Lumbar spine bone mineral density (LS-BMD) of osteoporotic patients was more than 2.5 SD below the normal mean of healthy premenopausal women. Main outcome measure(s) Serum levels of leptin, osteocalcin (OC), bone alkaline phosphatase (B-ALP), urinary deoxypyridinoline (DPyr), and N-telopeptide of type 1 collagen (NTX) as well as LS-BMD using dual energy X-ray absorptiometry (DEXA). Result(s) The serum leptin level in obese postmenopausal osteoporotic patients was significantly increased compared with nonobese osteoporotic patients. There were no significant differences of bone formation markers (B-ALP, OC), bone resorption markers (DPyr, NTX), or LS-BMD between the obese and nonobese groups. There were no significant correlations between serum leptin and any biomarkers of bone turnover and BMD. Conclusion(s) In postmenopausal osteoporotic patients with increased bone turnover, serum leptin concentration is not correlated with BMD or with the biomarkers of bone formation or bone resorption.