Does exercise affect the antioxidant system in patients with ankylosing spondylitis?

We aimed to investigate the effect of regular supervised exercise program on functional status, disease activity, and total antioxidant status (TAS) level in patients with ankylosing spondylitis (AS). Thirty-two patients (mean age: 44 years) with AS were included in the study and divided into two groups. Group 1, the exercise group (n = 16), attended a supervised exercise program that consisted of aerobic, strengthening, and stretching exercises for 1 h a day, five times a week for 3 weeks. Group 2, the control group, received a home exercise program (n:16). Bath AS Activity Index (BASDAI) and Bath AS Functional Index (BASFI) were calculated and serum TAS levels were measured for each patient at 0 and 3 weeks. There was no significant difference in patients' baseline characteristics (age, disease duration, BASFI, and BASDAI scores) between exercise and control groups. In the exercise group, there were significant improvements between pre-exercise and post-exercise assessments in BASFI (2.8 +/- 1,8; 1.7 +/- 1,40, p = 0.004) and BASDAI scores (2.1 +/- 1.7; 1.2 +/- 1.3, p = 0.01). Mean TAS levels were significantly decreased after supervised exercise program (1.48 +/- 0.16 mmol/L; 1.36 +/- 0.20 mmol/L, p = 0.03). In the control group, BASFI score (2.4 +/- 1.7; 2.9 +/- 2.1, p = 0.19), BASDAI score (2.6 +/- 2.2; 3.1 +/- 2.6, p = 0.33), and mean TAS levels (1.38 +/- 0.23 mmol/L; 1.39 +/- 0.20 mmol/L, p = 0.66) did not differ significantly between 0 and 3 weeks. Short-term, supervised exercise program improved functional status and decreased disease activity. However, the mechanism of this beneficial clinical effect does not seem to be through antioxidant activity.