Sign in →

Test ID: OSCAL Osteocalcin, Serum

Reporting Name

Osteocalcin, S

Useful For

Monitoring and assessing effectiveness of antiresorptive therapy in patients treated for osteopenia, osteoporosis, Paget's disease, or other disorders in which osteocalcin levels are elevated

 

As an adjunct in the diagnosis of medical conditions associated with increased bone turnover, including Paget's disease, cancer accompanied by bone metastases, primary hyperparathyroidism, and renal osteodystrophy

 

This test is not useful for the diagnosis of osteoporosis. 

Clinical Information

Osteocalcin, the most important noncollagen protein in bone matrix, accounts for approximately 1% of the total protein in human bone. It is a 49-amino acid protein with a molecular weight of approximately 5800 daltons. Osteocalcin contains up to 3 gamma-carboxyglutamic acid residues as a result of posttranslational, vitamin K-dependent enzymatic carboxylation. Its production is dependent upon vitamin K and is stimulated by 1,25 dihydroxy vitamin D.

 

Osteocalcin is produced by osteoblasts and is widely accepted as a marker of bone osteoblastic activity. Osteocalcin, incorporated into the bone matrix, is released into the circulation from the matrix during bone resorption and, hence, is considered a marker of bone turnover rather than a specific marker of bone formation. Osteocalcin levels are increased in metabolic bone diseases with increased bone or osteoid formation including osteoporosis, osteomalacia, rickets, hyperparathyroidism, renal osteodystrophy, thyrotoxicosis, and in individuals with fractures, acromegaly and bone metastasis. By means of osteocalcin measurements, it is possible to monitor therapy with antiresorptive agents (bisphosphonates or hormone replacement therapy [HRT]) in, for example, patients with osteoporosis or hypercalcemia.(1) Decrease in osteocalcin is also observed in some disorders (eg, hypoparathyroidism, hypothyroidism, and growth hormone deficiency).

 

Immunochemical and chromatographic studies have demonstrated considerable heterogeneity for concentrations of circulating osteocalcin in normal individuals and in patients with osteoporosis, chronic renal failure, and Paget disease. Both intact osteocalcin (amino acids 1-49) and the large N-terminal/midregion (N-MID) fragment (amino acids 1-43) are present in blood. Intact osteocalcin is unstable due to protease cleavage between amino acids 43 and 44. The N-MID fragment, resulting from cleavage, is considerably more stable. This assay detects both the stable N-MID fragment and intact osteocalcin.

Interpretation

Elevated levels of osteocalcin indicate increased bone turnover.

 

In patients taking antiresorptive agents (bisphosphonates or hormone replacement therapy: HRT), a decrease of 20% or less from baseline osteocalcin level (ie, prior to the start of therapy) after 3 to 6 months of therapy suggests effective response to treatment.(2)

 

Patients with diseases such as hyperparathyroidism, which can be cured, should have a return of osteocalcin levels to the reference range within 3 to 6 months after complete cure.(3)

Analytic Time

Same day/1 day

Day(s) and Time(s) Performed

Monday through Friday; 5 a.m.-12 a.m.

Saturday; 6 a.m.-6 p.m.

Clinical Reference

1. Chen JT, Hosoda K, Hasumi K, et al: Serum N-terminal osteocalcin is a good indicator for estimating responders to hormone replacement therapy in postmenopausal women. J Bone Miner Res. 1996 Nov;11(11):1784-1792 

2. Delmas PD, Eastell R, Garnero P, et al: The use of biochemical markers of bone turnover in osteoporosis. Committee of Scientific Advisors of the International Osteoporosis Foundation. Osteoporos Int. 2000;11(6):S2-S17

3. Harris SS, Soteriades E, Dawson-Hughes B, et al: Secondary hyperparathyroidism and bone turnover in elderly blacks and whites. J Clin Endocrinol Metab. 2001 Aug;86(8):3801-3804

4. Fraser W: Bone and mineral metabolism. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier;2018:1422-1491

Method Name

Electrochemiluminescence Immunoassay

Specimen Type

Serum


Specimen Required


Patient Preparation:

1. For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

2. Patient should be fasting for 12 hours.

Supplies: Aliquot Tube, 5 mL (T465)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 14 days
  Refrigerated  72 hours

Reference Values

Males

<5 years: 19-75 ng/mL

5-9 years: 21-108 ng/mL

10-15 years: 19-159 ng/mL

16-17: 12-114 ng/mL

≥18 years: 9-42 ng/mL

 

Females

<5 years: 14-126 ng/mL

5-9 years: 16-152 ng/mL

10-15 years: 15-151 ng/mL

16-17 years: 9-70 ng/mL

≥18 years: 9-42 ng/mL

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

83937

LOINC Code Information

Test ID Test Order Name Order LOINC Value
OSCAL Osteocalcin, S 2697-1

 

Result ID Test Result Name Result LOINC Value
OSCAL Osteocalcin, S 2697-1
Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

mml-bone-minerals