Dynamics of salivary cortisol in chronic kidney disease patients at stages 1 through 4.

Context: End-stage renal disease has been associated with derangement of the HPA function. The dynamics of this axis in early stages of renal disease (CKD) has not been assessed.

Objectives: To evaluate in patients with CKD at stages 1-4 (KDOQI): the diurnal variation of salivary cortisol; the suppressibility of cortisol in saliva and serum after an overnight oral 1 mg dexamethasone suppression test (1 mg DST) with simultaneous measurement of circulating dexamethasone.