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

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.