SALIVARY CORTISOL - AN ALTERNATIVE TO SERUM CORTISOL DETERMINATIONS IN DYNAMIC FUNCTION-TESTS

Salivary cortisol was measured as an alternative to serum cortisol as a marker for adrenocortical function following insulin tolerance test, corticotropin-releasing-hormone stimulation and adreno-corticotrophic hormone stimulation. During insulin tolerance test and corticotropin- releasing-hormone stimulation adreno-corticotrophic hormone was also m easured. The tests were performed on healthy control subjects as well as on patients under investigation for various disturbances in the hyp othalamic-pituitary-adrenocortical axis (insulin tolerance test: 3 con trols on two occasions and 14 patients; corticotropin-releasing-hormon e stimulation: 4 controls and 18 patients; adreno-corticotrophic hormo ne stimulation: 6 controls and 10 patients). Five patients underwent b oth insulin tolerance test and corticotropin-releasing-hormone stimula tion. Using criteria for adequate cortisol response in serum, the pati ents were classified as good or poor responders. In 42 of the 45 tests performed the same conclusion as to cortisol status was drawn when ba sed on serum and salivary cortisol responses. In healthy subjects and good responders the mean cortisol relative increase was greater in sal iva than in serum in all three tests (p < 0.05). Characteristic of the results for the insulin tolerance test was a significant initial mean decrease (p < 0.05), not found in serum, and the highest observed sal ivary cortisol value was delayed for at least 30 minutes compared to t hat in serum. Plasma adreno-corticotrophic hormone correlated signific antly with the cortisol concentrations determined 15 minutes later in serum (r = 0.54-0.64) and in saliva (r = 0.76-0.85). The more pronounc ed cortisol response in saliva than in serum and its closer correlatio n with adreno-corticotrophic hormone offer advantages over serum corti sol, suggesting salivary cortisol measurement may be used as an altern ative parameter in dynamic endocrine tets.