Parathyroid hormone (PTH, PTH, parathormone, parathyrin; in the information space there are also erroneous names - “hormone parade”, “thyroid hormone parade”) - this is a biologically active substance that is produced by the parathyroid (parathyroid) glands and is a single-chain peptide in chemical structure, as reported by the Internet edition for girls and women. net Parathyrin, or parathyroid hormone - the main regulator of calcium, the most important substance in the life support of the body. Parathyroid hormone antagonist is calcitonin, which is produced by C-cells of the thyroid gland..

The level of parathyroid hormone can be affected by the level of calcium, magnesium, phosphorus and vitamin D in the body. So, with an increase in the level of calcium in the blood, the secretion of parathyroid hormone decreases, and with a decrease, it increases, which allows maintaining a stable level of calcium in the blood..

What functions does it perform in the body Parathyroid hormone plays an important role in the regulation of calcium and phosphorus metabolism. The action of the hormone is carried out by binding to specific PTH receptors that are located on the surface of cells.. The main biologically active form of the substance is intact parathyroid hormone, consisting of 84 amino acids..

Functions of parathyroid hormone in the body:.

Inhibits bone formation by acting on osteocytes and osteoblasts, which in turn produce cytokines and insulin-like growth factor 1, which activate osteoclasts. The latter secrete collagenase and alkaline phosphatase, which destroy the bone matrix..

Involved in increasing calcium reabsorption in the renal tubules.

Stimulates the synthesis of calcitriol, which increases the absorption of calcium in the small intestine, and also regulates the excretion of phosphate by the kidneys.

Responsible for maintaining a stable level of calcium and phosphorus in the extracellular fluid.

Laboratory study for PTH In addition to the analysis for parathyrin, the patient is usually assigned to determine the content of ionized calcium in the blood, the hormone concentration is assessed along with this indicator.

The appointment of the analysis and the decoding of the result is carried out by the doctor, who will explain what the level of this or that indicator in a particular case can mean, and, if necessary, prescribe treatment.

Indications for analysis A study on parathyroid hormone is prescribed:.

in order to assess the work of the parathyroid glands;

to determine the causes of calcium metabolism disorders and monitor patients with this pathology;

for diagnosing hypoparathyroidism;

during the differential diagnosis of primary, secondary and tertiary hyperparathyroidism;

to evaluate the effectiveness of the treatment of parathyroid diseases.

Indications for research may be:.

an increase or decrease in the concentration of calcium in the blood;

concomitant symptoms of calcium metabolism disorders (abdominal pain, thirst, nausea, convulsions, tingling in the fingers);

osteoporosis;

chronic kidney disease, in which there is a decrease in the glomerular filtration rate;

performed surgeries in the neck;

increased neuromuscular excitability;

multiple caries;

cholelithiasis;

relapses of peptic ulcer of the stomach and duodenum 12.

Rules for preparing for the studyTo analyze for parathyrin, you need to properly prepare:.

For a day, you should exclude the use of alcoholic beverages, stop taking medications that may affect the performance (after agreement with the doctor).

On the eve of the analysis, exclude intense physical activity, excessive mental stress. Before taking blood, ensure a state of complete rest.

Smoking should be stopped 3 hours before blood sampling..

Donating blood is recommended in the morning on an empty stomach (at least 12 hours after the last meal), best around 08:00.

Some drugs can distort the result of the study, the introduction of a radioisotope drug for 1 week before the laboratory test. Estrogens, phosphates, anticonvulsants, anti-tuberculosis drugs can increase parathyroid hormone levels, and oral contraceptives, antibacterials, vitamin D can decrease.

If the patient consumed milk on the eve of the study, this may lead to underestimated results of the analysis for parathyroid hormone, a false decrease in the indicator is possible with Burnett's syndrome.

Norms of parathyroid hormone in women and men The level of parathyroid hormone varies depending on the time of day. So, the maximum content of this substance in the blood is observed at 14:00-16:00, the decrease to the basal level occurs by 08:00.

Normal values \u200b\u200bare presented in the table.

Patient group.

Reference values, pg/ml.

Women under 20.

12–95.

Women 20–70 years old.

9.5–75.

Women over 70.

4.7–117.

Men under 22.

12–95.

Men 22-70 years old.

9.5–75.

Men over 70.

4.7–117.

Different laboratories may use different methods for determining the level of PTH, norms and units of measurement. Therefore, if it is necessary to repeatedly determine the concentration of parathyroid hormone in the blood, it is recommended to take tests in the same medical institution..

Causes of deviation of PTH from the norm Increased concentration of parathyroid hormone is detected under the following conditions:.

decreased calcium levels in the blood;

hyperparathyroidism;

Albright's disease (pseudohypoparathyroidism);

rickets;

bone metastases;

chronic renal failure;

ulcerogenic adenoma of the pancreas;

multiple endocrine neoplasia.

Elevated levels of parathyrin can be determined in women during pregnancy and breastfeeding.

Decrease in the concentration of parathyroid hormone occurs in the following cases:.

hypercalcemia;

hypoparathyroidism;

excess in the body of vitamins A, D;

autoimmune pathologies in which autoantibodies to calcium receptors are formed in the body;

severe form of thyrotoxicosis;

hepatocerebral dystrophy;

sarcoidosis;

multiple myeloma;

lack of magnesium in the body.

neboleem. net.