Pituitary-adrenal axis responsiveness to ovine corticotropin releasing hormone in patients with rheumatoid arthritis treated with low dose prednisone.
Ovine corticotropin-releasing hormone (oCRH) stimulation tests were performed in 8 female patients with active rheumatoid arthritis treated chronically with daily low dose prednisone and 16 age matched female controls. Patients were tested on the day of treatment, 12 h after their last prednisone dose, and after withholding prednisone for 36 h. Basal levels of plasma ACTH and to a lesser extent plasma cortisol levels were elevated before each test, and significant increases in ACTH and cortisol were induced with oCRH. The dose response relationship between total ACTH and total cortisol was shifted to the right, suggesting that the patient group had mildly deficient adrenocortical responsiveness compensated for by elevated basal evening ACTH concentrations. It is not known whether the neuroendocrine abnormalities demonstrated are due to an intrinsic preexisting abnormality, active disease, drug therapy or all these factors.