August 1982

Evaluation of the Hypothalamic Hypophyseal Adrenal Axis in Patients Receiving Long-term Hemodialysis

Author Affiliations

From the Divisions of Nephrology (Dr Ramirez) and Endocrinology (Dr Gomez-Sanchez), Department of Internal Medicine, University of South Florida, Tampa; the Division of Metabolism, University of Utah, Salt Lake City (Drs Meikle and Jubiz); and the Division of Nephrology, the Veterans Administration Hospital, Tampa, Fla (Dr Ramirez).

Arch Intern Med. 1982;142(8):1448-1452. doi:10.1001/archinte.1982.00340210040010

Several alterations are present in the hypothalamic hypophyseal regulation of many hormones in patients with chronic renal failure. Evaluation of the hypothalamic hypophyseal adrenal axis in these groups of patients demonstrated normal levels of plasma cortisol. Dexamethasone suppression is abnormal after administration of 1 mg of oral dexamethasone, but normal after 3 mg. Dexamethasone blood levels were lower than the control after administration of 1 mg of oral dexamethasone. A dexamethasone metabolic clearance showed a similar half-life between the patients and controls. Oral absorption study showed poor absorption of the drug. Therefore, there is a problem of gastrointestinal absorption producing the abnormal dexamethasone suppression test in patients with renal failure. Results of metyrapone tests were normal. Corticotropin stimulation tests elicited a normal response. Insulin-induced hypoglycemia does not produce an increment in plasma cortisol or adrenocorticotropic hormone levels.

(Arch Intern Med 1982;142:1448-1452)