Pituitary adrenal responsiveness to corticotropin-releasing hormone in chronic uremic patients

We investigated the effect of exogenous ovine corticotropin-releasing hormone (oCRH) on plasma levels of adrenocorticotropic hormone (ACTH) and cortisol in 24 chronic renal failure patients: 8 nondialysis (NDCRF), 8 on hemodialysis (HD), and 8 on continuous ambulatory peritoneal dialysis (CAPD). In all groups the acute administration of oCRH caused a further increase (less pronounced in NDCRF patients) in the already elevated levels of cortisol. Following oCRH administration, plasma ACTH rose significantly in CAPD patients, but there was a blunted response of the hormone in the NDCRF and HD groups. The patterns of the ACTH and cortisol response in the last two groups, resemble those observed in chronic stress. We conclude that the hypothalamic-pituitary-adrenal axis in chronic uremic patients, retains the ability to respond to exogenous oCRH. Patients on CAPD, however, display a better, identical to normal response, which can be due to less chronic stress and/or to the more effective clearance of uremic toxins.