Salivary corticosteroids in the study of adrenal function.

Salivary corticosteroids (SCC) and plasma corticosteroids (PCC) were studied under basal conditions, after dexamethasone (DXM) and in the ACTH stimulation test in a reference group (RG) of 33 adults, in three groups with non-adrenal pathology and in a group of 4 patients with hypercortisolaemia. SCC and PCC were measured using a non-extraction RIA method using [3H]cortisol. The results for SCC in the RG and in the groups with non-adrenal pathology were similar to those obtained for PCC in terms of percentage of decrease in the circadian rhythm or DXM suppression. However, the responsiveness to ACTH in saliva was twice that obtained in plasma. In patients with hypercortisolism, SCC were in closer agreement with the adrenal hyperfunction than PCC. From the previous results the following conclusions may be drawn: (a) SCC differentiate adrenal gland normal function from hyperfunction as clearly or even better than PCC does; (b) SCC were in a closer agreement with the symptomatology of adrenal hyperfunction than were PCC; and (c) the responses to ACTH obtained with SCC were clearly higher than those obtained with PCC.