Использование ультрачувствительного метода определения биологически активного свободного кортизола в слюне для оценки глюкокортикоидной функции коры надпочечников

Abstract

Comparative studies were conducted to define the informative value of the noninvasive technique for determining free Cortisol in saliva and daily urine, by applying ultrasensitive immunoassay technologies, and for evaluating total Cortisol in blood from healthy individuals and patients with Cushing's syndrome. The studies were made during functional tests and glucocorticoid replacement therapy before and after treatment. To evaluate the pattern of diurnal rhythm, the level of total Cortisol in the blood and that of its free form in the saliva were simultaneously measured in the morning, in the afternoon, and in the evening. The normal daily salivary free Cortisol values were established in healthy individuals in the morning (6.8-25.9 nmol/l) and in the evening (0.6-3.3 nmol/l). There is evidence that salivary free Cortisol is highly sensitive in the assessing functional tests with adrenocorticotropic hormone and dexamethasone. The noninvasiveness, accessibility, and easiness-to-use of obtaining salivary samples in combination with the high analytical sensitivity and specificity of the technique in determining the free biologically active fraction of Cortisol make it promising in evaluating adrenal hormonal function.