The bone profile is blood tests that allow you to assess the condition of the bones, but not only. The tests included in the bone profile are also performed, among others, by in people with chronic kidney disease. What are the indications for a bone profile? What are the standards? How to interpret the test results?
Bone profileare blood tests that assess the body's calcium and phosphate metabolism, such as assessing calcium, phosphorus, and alkaline phosphatase levels. They are the basis of every bone profile. Some laboratories also assess blood levels of albumin, total protein, vitamin D, and / or parathyroid hormone and calcitonin.
Bone profile - indications for the test
The bone profile is performed mainly to assess the condition of the skeletal system , i.e. in people with chronic bone diseases. It can also be performed in people with chronic kidney and nervous system diseases. Depending on what other tests - apart from assessing the concentration of calcium, phosphorus and alkaline phosphatase - make up the bone profile, thyroid diseases and decompensated diabetes may also be detected.
1. Calcium
Together with phosphorus, it participates in the mineralization of bones - it enables them to grow and ensures adequate density, and thus strength. Elevated calcium levels (hypercalcemia) may suggest malignant tumors, metastasis of malignant tumors to bone tissue, vitamin D overdose or hyperparathyroidism. Low calcium levels in the blood (hypocalcaemia) can be caused by, for example, Vitamin D deficiency or excessive accumulation of calcium in the tissues.
2. Phosphorus
Over 80 percent This element is found in bones and teeth, therefore, without it, the skeletal system cannot function properly. The cause of its excess may be, among others kidney disease. In turn, the decrease in its concentration in the blood may be due to the impaired absorption of phosphate from the gastrointestinal tract.
3. Alkaline phosphatase
Alkaline phosphatase is an enzyme found mainly in bones. An increase in its concentration may indicate bone diseases, e.g. rickets or osteomalacia (softening of the bones due to the loss of calcium and phosphorus), as well as vitamin D deficiency, calcium and phosphorus deficiency in the diet, or secondary hyperparathyroidism associated with impaired vitamin D metabolism.in turn, lowering its level may suggest, inter alia, lack of proper calcium deposition in bones.
4. Parathyroid hormone (PTH)
Parathyroid hormone is a hormone produced in the parathyroid glands. Its role is to regulate the hormonal calcium and phosphate metabolism in the body. PTH raises blood calcium levels if it is too low, releasing it from bones and teeth. It also influences the production of the active form of vitamin D (calcitriol).
An increase in PTH levels and a simultaneous increase in serum calcium levels may mean, inter alia, primary hyperparathyroidism. On the other hand, a decrease in PTH concentration and an increase in calcium level as a result of, inter alia, overactive thyroid gland. In contrast, decreased levels of both PTH and calcium indicate hypoparathyroidism.
5. Calcitonin
Calcitonin is mainly produced in the C cells of the thyroid gland. It lowers the level of calcium in the blood, binding excess calcium in the bones and limiting its absorption in the small intestine. It also regulates disorders of calcium and phosphate metabolism, influencing bone metabolism. Its elevated concentration may suggest vitamin D overdose, primary hyperparathyroidism or renal failure.
6. Vitamin D
Vitamin D in its active form (1,25-OH cholecalciferol) affects the absorption of calcium and phosphorus, and thus the maintenance of the body's calcium and phosphorus balance, as well as bone mineralization. In addition, vitamin D increases the secretion of parathyroid hormone (PTH).
Bone profile - norms
- calcium - 2.1-2.6 mmol / l (8.5-10.5 mg / dl)
- phosphorus - 0.81-1.62 mmol / l in adults and 1.3-2.26 mmol / l in children
- alkaline phosphatase (alkaline, ALP) - adults: 20-70 U / l, children: 20-150 U / l
- total protein - 60-80 g / l (6.0-8.0 g / dl)
- albumin - 35-50 g / l (3.5-5.0 g / dl) - makes up about 60 percent total protein
- parathyroid hormone - 1.1 - 6.7 pmol / l (10 - 60 pg / ml)
- calcitonin - less than 2.9 pmol / l (less than 10 ng / l)
- vitamin D (1.25-OH-D) - from 30 to 50 ng / ml