Hypothalamo-pituitary-adrenal axis and growth hormone axis in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic disease and is associated with cytokines (IL-1, IL-6, TNF-alpha) production. There is little information on hypothalamo-pituitary-adrenal (HPA) axis and growth hormone (GH) axis in the patients with RA. We have, therefore, investigated these systems in twenty patients with confirmed RA. Ten of the patients had active and 10 patients remitted RA. Serum cortisol, ACTH and GH levels were measured in the basal state and after insulin induced hypoglycaemia. Cortisol, adrenocorticotropic hormone (ACTH) and GH responses were impaired in 65%, 85% and 30% of the patients, respectively. The basal and peak hormone levels were similar between the patients with active RA and the patients in remission. These findings indicate that there is an impairment in HPA and GH axis in patients with active and remitted RA. The site of this impairment is probably hypothalamus and/or pituitary gland.