Objectives: To determine the correlation between inflammatory cytokines and adrenal hormones in patients with polymyalgia rheumatica (PMR) and to compare the ratio of serum cortisol and androstenedione (ASD) or dehydroepiandrosterone sulphate (DHEAS) in normal subjects with PMR patients.
Methods: In 102 patients with PMR (32 beginning and 70 chronic disease) and 31 age-matched and sex-matched healthy subjects, ASD, cortisol, DHEAS, interleukin-6 (IL-6), and tumour necrosis factor (TNF) were measured by immunometric assays.
Results: Serum levels of IL-6 were elevated in patients with PMR as compared with normal subjects (10.0 +/- 1.6 vs 2.1 +/- 0.1 pg/ml, P = 0.01), which was not found for TNF. In PMR patients, serum levels of IL-6 were positively correlated with serum levels of ASD (P < 0.001), cortisol (P < 0.001), and DHEAS (P = 0. 038) irrespective of corticosteroid treatment. Serum levels of cortisol in relation to IL-6 were significantly lower in patients with chronic disease and long-standing corticosteroid administration as compared with patients with recent onset of the disease and without corticosteroid therapy (P < 0.01).
Conclusions: In PMR, as expected, there was an increase in IL-6 serum levels that was associated with elevated serum levels of ASD, DHEAS, and cortisol which was more marked in patients with recent-onset disease and without corticosteroids. However, serum levels of cortisol in patients with and without corticosteroids were lower than expected by considering the inflammatory status (increased IL-6). This may indicate a change in the hypothalamic-pituitary-adrenal (HPA) axis responsiveness to inflammatory stimuli such as IL-6 during chronic disease. Furthermore, there seems to be a shift of biosynthesis to cortisol in relation to DHEAS or ASD in chronic disease.