Research paperInterrelationships between obesity and bone markers in post-menopausal women with either obesity or osteoporosis

PurposeObesity and bone metabolism are interrelated. The aim of this study is to investigate the relationship between obesity and bone markers, leptin and insulin resistance in post-menopausal osteoporosis.Material and methodsFour study groups were included in the study. Group 1 (n = 19): osteoporosis (T-score < -2.5 at the lumbar spine and/or femoral neck) + obese; group 2 (n = 29): non-osteoporosis + obese; group 3 (n = 25): osteoporosis + non-obese and as control group (n = 14): non-osteoporosis + non-obese. The serum levels of osteoprotegerin (OPG; osteoclastogenic marker), RECEPTOR activator of nuclear factor ligand (RANKL; osteoclastic marker), tartarate resistant acid phosphatase (TRAP; osteoclastic marker), bone alkaline phosphatase (b-ALP; osteoblastic marker) and leptin were measured by ELISA. Glucose and insulin levels were analyzed by colorimetric and electrochemiluminescence methods.ResultsOPG and b-ALP levels were significantly lower in group 1 compared to group 2 (P < 0.05 and P < 0.01). Comparison of group 1 with group 3 revealed significantly higher leptin levels in the former (P < 0.001). OPG, TRAP, RANKL, bone ALP were significantly lower (P < 0.001, P < 0.001, P < 0.01, P < 0.01) and leptin levels higher (P < 0.05) in group 1 compared to control group. Comparison of group 3 with control group revealed significantly lower values of OPG, RANKL, bone ALP, TRAP for the patient group (P < 0.001, P < 0.01, P < 0.01, P < 0.001). OPG, RANKL, bone ALP, TRAP levels were significantly lower (for each P < 0.01) and leptin levels were significantly higher (P < 0.05) in group 2 compared to control group.ConclusionOsteoprotegerin, TRAP, RANKL, bone ALP and leptin levels can be used as significant markers in the development of osteoporosis and/or obesity in post-menopausal women.