Osteocalcin | Laboratory research

Osteocalcin is a non-collagenous, 49 amino acid polypeptide bone protein with a molecular weight of 5800 kilodaltons. Osteoblasts produce osteocalcin and incorporate it into the bone matrix.

Osteocalcin is released into the serum during bone resorption and is thus used to assess bone turnover during antiresorptive treatment (bisphosphonates and hormone replacement therapy) in patients with osteopenia, osteoporosis, bone metastases from tumors, Paget's disease, and elevated serum osteocalcin levels and hypercalcemia. Serum osteocalcin level also increases in hyperparathyroidism, thyrotoxicosis, renal osteodystrophy, fractures, acromegaly.

Determination of osteocalcin is ineffective in diagnosing osteoporosis.

Osteocalcin makes up about 1% of human bone proteins. Its production depends on vitamin K and is stimulated by exposure to 1,25-dihydroxyvitamin D.

Osteocalcin is synthesized by osteoblasts (bone cells) and is a marker of osteoblastic activity.

A decrease in the activity of osteocalcin in the serum is observed in hypoparathyroidism, hypothyroidism, growth hormone deficiency and other pathologies.

Immunochemical and chromatographic studies revealed heterogeneity of osteocalcin levels, both in healthy people and in patients with osteoporosis, kidney failure, and Paget's disease.

Interpretation

An increase in serum osteocalcin level indicates increased bone turnover.

In patients who are on resorptive therapy (with bisphosphonates or hormone replacement therapy), a 3% decrease in serum osteocalcin levels 6-20 months after the start of treatment indicates a positive response to treatment.

Research method: Electrochemiluminescent immunoassay

Material for examination: Serum

Preliminary preparation: The study is conducted on an empty stomach. Minerals, vitamins and nutritional supplements should be stopped for 12 hours before the study.

Indicators of the norm

<18 years: no study

After >18 years: 10,4 – 45,6