Osteocalcin

Overview:

Evaluate bone disease. Increased levels of osteocalcin are found in bone diseases characterized by increased bone turnover. Osteocalcin has been found to be elevated in Paget disease of the bone, cancer accompanied by bone metastases, primary hyperparathyroidism and renal osteodystrophy. Osteocalcin levels may serve as useful index in evaluating the therapeutic management of the patient.

Osteocalcin, or bone Gla protein (BGP), is the major noncollagenous protein of bone matrix. It has a molecular weight of approximately 5.8 kilodaltons and consists of 49 amino acids, including three residues of γ-carboxyglutamic acid. Osteocalcin is synthesized in bone by osteoblasts. After production, it is partly incorporated into the bone matrix and partly delivered to the circulatory system. The precise physiological function of osteocalcin is still unclear. A large number of studies have shown that the circulating level of osteocalcin reflects the rate of bone formation.

Determination of serum osteocalcin has proven to be valuable as an aid in identifying women at risk of developing osteoporosis, for monitoring bone metabolism during perimenopause and postmenopause, and during antiresorptive therapy.
Bjarnason NH, Bjarnason K, Haarbo J, Rosenquist C, Christiansen C. Tibolone: prevention of bone loss in late postmenopausal women. J Clin Endocrinol Metab. 1996 Jul; 81(7):2419-2422. PubMed 8675554

Christian C, Tanko LB, Warming L, et al. Dose dependent effects on bone resorption and formation of intermittently administered intravenous ibandronate. Osteoporos Int. 2003; 14(7):609-613. PubMed 12830369

Junqueira PA, da Fonseca AM, Bagnoli VR, et al. Comparison of bone remodeling indicators in climacteric women. Int J Fertil Womens Med. 2002; 47(4):174-181. PubMed 12199414

Marcus R, Holloway L, Wells B, et al. The relationship of biochemical markers of bone turnover to bone density changes on postmenopausal women: Results from the postmenopausal estrogen/progestin interventions (PEPI) trial. J Bone Miner Res. 1999; 14(9):1583-1595. PubMed 10469288

McClung M, Clemmesen B, Daifotis A. Alendronate prevents postmenopausal bone loss in women without osteoporosis. A double-blind, randomized, controlled trial. Alendronate Osteoporosis Prevention Study Group. Ann Intern Med. 1998 Feb 15; 128(4):253-261. PubMed 9471927

Meunier PJ, Confaveux E, Tupinon I. Prevention of early postmenopausal bone loss with cyclical etidronate therapy (A double-blind, placebo-controlled study and 1-year follow-up). J Clin Endocrinol Metab. 1997; 82(9):2784-2791; erratum: J Clin Endocrinol Metab. 1997; 82(11):3740. PubMed 9284696

Ohishi T, Takahashi M, Kushida K, et al. Changes of biochemical markers during fracture healing. Arch Orthop Trama Surg. 1998; 118(3):126-130. PubMed 9932185

Ravn P, Clemmesen B, Christiansen C. Biochemical markers can predict the response in bone mass during alendronate treatment in early postmenopausal women. Alendronate Osteoporosis Prevention Study Group. Bone. 1999; 24(3):237-244. PubMed 10071916

Ravn P, Clemmesen B, Riis BJ, et al. The effects on bone mass and bone markers of different doses of ibandronate: A new bisphosphate for prevention and treatment of postmenopausal osteoporosis: A 1-year, randomized, double-blind, placebo-controlled, dose-finding study. Bone. 1996; 19(5):527-533. PubMed 8922653

Ravn P, Christensen JO, Baumann M. Changes in biochemical markers and bone mass after withdrawal of ibandronate treatment: Prediction of bone mass changes during treatment. Bone. 1998; 22(5):559-564. PubMed 9600792

Ravn P, Rix M, Andreassen H. High bone turnover is associated with low bone mass and spinal fracture in postmenopausal women. Calcif Tissue Int. 1997; 6(30):255-260. PubMed 9069162

Rosenquist C, Qvist P, Bjarnason NH, et al. Measurement of a more stable region of osteocalcin in serum by ELISA with two monoclonal antibodies. Clin Chem. 1995; 41(10):1439-1445. PubMed 7586514

Takahashi M, Kushida K, Nagano A, et al. Comparison of the analytical and clinical performance characteristics of an N-MID versus an intact osteocalcin immunoradiometric assay. Clin Chim Acta. 2000; 294(1-2):67-76. PubMed 10727674

Tanko LB, Mouritzen U, Lehmann HJ, et al. Oral ibandronate: Changes in markers of bone turnover during adequately dosed continuous and weekly therapy and during different suboptimally dosed treatment regimens. Bone. 2003; 32(6):687-693. PubMed 12810176