Osteocalcin, Serum

Osteocalcin, Serum

Number
	010249
CPT
	83937
Synonyms
	BGP ; Bone GLA Protein
Specimen
	Serum, frozen
Volume
	2 mL
Minimum Volume
	0.3 mL (Note: This volume does not allow for repeat testing.)
Container
	Red-top tube or gel-barrier tube
Collection
	Transfer the serum into a LabCorp PP transpak frozen purple tube with screw cap (LabCorp N^o 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions
	Freeze
Causes for Rejection
	Plasma specimen
Reference Interval
	Refer to report.
Use
	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.
Methodology
	Enzyme-linked immunosorbent assay (ELISA)
Additional Information
	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 gamma-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.
References
	Bjarnason NH, Bjarnason J, Haarbo J, et al, “Tibolone: Prevention of Bone Loss in Late Postmenopausal Women,” J Clin Endocrinol Metab, 1996, 81(7):2419-22. 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):609-13. Junqueira PA, daFonseca AM, Bagnoli VR, et al, “Comparison of Bone Remodeling Indicators in Climateric Women,” Int J Fertil Womens Med, 2002, 47(4):174-81. 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):1583-95. McClung M, Clemmesen B, Daifotis, et al, “Alendronate Prevents Postmenopausal Bone Loss in Women Without Osteoporosis. A Double-Blind, Randomized, Controlled Trial. Alendronate Osteoporosis Prevention Study Group,” Ann Intern Med, 128(4):253-61. Meunier PJ, Confaveux E, and 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):2784-91; erratum: J Clin Endocrinol Metab, 1997, 82(11):3740. Ohishi T, Takahashi M, Kushida K, et al, “Changes of Biochemical Markers During Fracture Healing,” Arch Orthop Trama Surg, 1998, 118(3):126-30. Ravn P, Clemmesen B, and 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):237-44. 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 Treat of Postmenopausal Osteoporosis: A 1-Year, Randomized, Double-Blind, Placebo-Controlled, Dose-Finding Study,” Bone, 1996, 19(5):527-33. Ravn P, Christensen JO, and 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):559-64. Ravn P, Rix M, and Andreassen H, “High Bone Turnover Is Associated With Low Bone Mass and Spinal Fracture in Postmenopausal Women,” Calcif Tissue Int, 1997, 6(30):255-60. 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):1439-45. 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. 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):687-93.