[Introduction] The aim of this study is to investigate the status of cortisol and adrenocorticotropic hormone (ACTH) in patients with the rheumatic diseases.
[Methods] We obtained 58 blood samples from 40 patients treated with low doses of corticosteroids：31 samples from 23 patients with rheumatoid arthritis (RA), 16 samples from 10 patients with polymyalgia rheumatica (PMR), and 11 samples from 7 patients with remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome.
[Results]A significantly decreased cortisol/ACTH ratio due to increased ACTH was detected in RA patients with positive CRP when compared to those with negative CRP. The CRP levels of patients with RA in the cortisol/ACTH ratio ≤ 1st quartile group were significantly higher than those of the ＞ 1st quartile group. In contrast, the CRP levels of patients with PMR & RS3PE syndrome were significantly lower in the cortisol/ACTH ratio ≤ 1st quartile group than in the ＞ 1st quartile group. The multivariate logistic regression analysis revealed that CRP positivity was a significantly independent factor associated with the decreased cortisol/ACTH ratio in RA patients.
[Conclusions] This study demonstrates that the decreased cortisol/ACTH ratio detected in RA patients with high CRP may be related to the disease activity of this disorder.