Abnormal hypothalamic-pituitary-adrenal axis function in rheumatoid arthritis. Effects of nonsteroidal antiinflammatory drugs and water immersion

OBJECTIVE: To investigate the effects of nonsteroidal antiinflammatory drug (NSAID) therapy and water immersion on hypothalamic-pituitary-adrenal (HPA) axis function in rheumatoid arthritis (RA). METHODS: Plasma levels of adrenocorticotropic hormone (ACTH) and serum and urine levels of cortisol were compared in untreated RA patients, NSAID-treated RA patients, and healthy control subjects. RESULTS: ACTH levels were significantly higher in untreated RA patients (mean +/- SEM integrated area 11,377 +/- 5,246 hours ng/liter) than in NSAID-treated RA patients (2,285 +/- 388 hours ng/liter) or healthy controls (1,845 +/- 35.5 hours ng/liter) (P < 0.001). Serum and urine cortisol levels were not significantly different between groups. Two-hour head-out water immersion had no effect. CONCLUSION: Elevated ACTH levels without hypercortisolemia occur in untreated RA. NSAID therapy alters HPA axis response, but immersion has no effect.