Osteocalcin, a promising marker of osteoporosis: evaluation in post-menopausal females with osteoporosis

Background: Osteocalcin, has high affinity for calcium. In osteoporotic women, deficiency of calcium may lead to lowering of the formation of hydroxyapatite crystals. Thus, in the state of hypo mineralization, free osteocalcin available in the circulation. Therefore, present study was designed to evaluate significance of serum osteocalcin in diagnosis of osteoporosis, and relationship between Serum Osteocalcin and BMD (Bone mineral Density) in post-menopausal females with osteoporosis and without osteoporosis. Methods: One hundred and forty seven post-menopausal women between age 45 to 80 years attending the hospital OPD were studied. To be eligible for the study they had to have been postmenopausal for at least one year. The diagnosis of osteoporosis was made based on T-Scores (BMD) at the lumber spine (L1 to L4 and femaral neck) by DEXA (GE lunar Densitometer). Serum osteocalcin level was estimated by LIAISON osteocalcin assay. Patients with chronic conditions affecting skeletal health and patients on drugs affecting the skeleton were excluded from the study. Results: Serum osteocalcin level in post-menopausal female without osteoporosis was 9.87±1.04ng/ml, while post-menopausal female with osteoporosis had 22.62±2.25ng/ml suggesting significant increase in bone marker level in osteoporotic females (p<0.05.) Correlation study between BMD and osteocalcin showed strong Negative Correlation (r=-0.77, p<0.05). Conclusions: Serum osteocalcin can be considered as a specific marker of osteoblast function as its levels have been shown to correlate with bone formation rates. Thus, serum osteocalcin can be used for diagnosis and monitoring of response to therapy and this may be the better predictor than BMD.