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C-terminal telopeptide in blood
Medical expert of the article
Last reviewed: 05.07.2025
Type I collagen accounts for more than 90% of the organic matrix of bone. As a result of constant remodeling of bone tissue, type I collagen is destroyed, and its fragments enter the blood. One of these fragments is the cross-linked C-terminal telopeptide (molecular weight less than 2000), which is not subsequently subject to catabolism and is excreted in the urine.
Reference values (norm) of C-terminal telopeptide in blood serum
Age |
C-terminal telopeptide, ng/ml |
Men |
|
30-50 years |
0.300-0.584 |
50-70 years |
0.304-0.704 |
Over 70 years old |
0.394-0.854 |
Women |
|
Premenopause |
0.299-0.573 |
Postmenopause |
0.556-1.008 |
With an increase in bone metabolism or its resorption, type I collagen is destroyed faster, and the content of collagen fragments in the blood increases accordingly.
The concentration of C-terminal telopeptide in the blood increases during menopause and normalizes after the administration of estrogens. In osteoporosis, the concentration of C-terminal telopeptide correlates well with the activity of the process (including osteoporosis caused by malignant tumors).
The study of C-terminal telopeptide in the blood is indicated not only to establish the activity of resorptive processes in bone tissue, but also to monitor the effectiveness of the treatment. Treatment is considered effective if the level of C-terminal telopeptide in the blood decreases within 3-6 months of therapy.
Hyperparathyroidism is accompanied by a significant increase in the concentration of C-terminal telopeptide in the blood serum, and its normalization serves as a good marker of the effectiveness of surgical treatment of adenoma or malignant tumor of the parathyroid glands.
Jaundice and lipidemia cause interference and overestimate the results of determination of C-terminal telopeptide in blood serum, and hemolysis (free hemoglobin in plasma above 0.5 g/dL) can lead to the opposite effect.
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