What Is Plasma Cortisol?
Plasma: 8-9 am (442 ± 276) nmol / L, 3-4 pm (221 ± 166) nmol / L.
- Cortisol is secreted by the adrenal cortex fascia and exists in the blood in both bound and free forms. Cortisol in the free state only accounts for about 10%, is biologically active, and can be filtered from the kidney; those in the binding state are mainly combined with glucocorticosteroid-binding protein (CBG), and a small amount of albumin, have no biological activity and are not affected by Hepatocytes are damaged and cannot be filtered from the glomeruli. The secretion of cortisol is mainly regulated by the adrenocorticotropic hormone secreted by the pituitary gland. The secretion of cortisol has a clear circadian rhythm. The secretion reaches a peak around 8 am, and then gradually decreases, and it is lowest at midnight. Cortisol has very important effects on the body's material metabolism, immune function, and physiological functions of various organs.
- Name
- Cortisol
- category
- endocrine
Normal plasma cortisol
- Plasma: 8-9 am (442 ± 276) nmol / L, 3-4 pm (221 ± 166) nmol / L.
Clinical significance of plasma cortisol
- (1) Cortisol in patients with adrenal cortex due to hyperplasia, adenoma, carcinogenesis, etc., the content of cortisol in plasma, 24-hour urine and saliva were significantly increased, and circadian rhythm disappeared. Patients with pituitary ACTH cancer and ectopic ACTH syndrome can increase plasma cortisol due to increased ACTH secretion. Cortisol levels in hyperglucocorticosteroid-binding protein (CBG) blood were significantly increased for various reasons. Cortisol can also increase in obesity and critical diseases such as myocardial infarction, cerebrovascular accident, shock. (2) Diseases with decreased cortisol concentration include: primary or secondary hypocortical adrenal insufficiency, familial glucocorticoid-binding protein (CBG) deficiency, Graves disease, hypoalbuminemia, severe liver disease, or kidney disease Wait. Long-term use of drugs such as glucocorticoids, sedatives, and central antihypertensive drugs can also reduce cortisol levels.
Cortisol precautions
- Due to the large physiological fluctuations of cortisol in the blood, it is highest in the morning and gradually decreases in the future, and decreases to the lowest level after falling asleep. Clinically, blood samples are taken for examination at around 8 am.
Cortisol- related diseases
- Nelson syndrome, secondary adrenal insufficiency, pregnancy with cortisol, chronic adrenal insufficiency, adrenal insufficiency