Objective: Acute stress in patients with rheumatoid arthritis (RA) should stimulate a strong stress response. After cryotherapy, we expected to observe an increase of hormones of the adrenal gland and the sympathetic nervous system.
Methods: A total of 55 patients with RA were recruited for whole-body cryotherapy at -110 degrees C and -60 degrees C, and local cold therapy between -20 degrees C and -30 degrees C for 7 days. We measured plasma levels of steroid hormones, neuropeptide Y (sympathetic marker), and interleukin (IL)6 daily before and after cryotherapy.
Results: In both therapy groups with/without glucocorticoids (GC), hormone and IL6 levels at baseline and 5 h after cold stress did not change over 7 days of cryotherapy. In patients without GC, plasma levels of cortisol and androstenedione were highest after -110 degrees C cold stress followed by -60 degrees C or local cold stress. The opposite was found in patients under GC therapy, in whom, unexpectedly, -110 degrees C cold stress elicited the smallest responses. In patients without GC, adrenal cortisol production increased relative to other adrenal steroids, and again the opposite was seen under GC therapy with a loss of cortisol and an increase of dehydroepiandrosterone. Importantly, there was no sympathetic stress response in both groups. Patients without GC and -110 degrees C cold stress demonstrated higher plasma IL6 compared to the other treatment groups (not observed under GC), but they showed the best clinical response.
Conclusions: We detected an inadequate stress response in patients with GC. It is further shown that the sympathetic stress response was inadequate in patients with/without GC. Paradoxically, plasma levels of IL6 increased under strong cold stress in patients without GC. These findings confirm dysfunctional stress axes in RA.