Effect of aerobic exercise program on disease activity, symptoms, quality of life, spinal mobility and serum calprotectin, visfatin, leptin values ​​in patients with ankylosing spondylitis: An ultrasonographic study

Objectives: The aim of our study is to investigate the effects of the combination of stretching exercises and high-intensity interval aerobic exercise applied in bicycle ergometry on disease activity, quality of life, spinal mobility, USG parameters and calprotectin, visfatin, leptin, IL-33 serum values in patients with Ankylosing Spondylitis (AS). Materials and Methods: A total of 56 patients between the ages of 20-60 who were diagnosed with AS according to the 2009 ASAS criteria were included in the study. The patients were randomized into two treatment groups as aerobic + stretching exercise group (28 patients) and stretching exercise only group (28 patients). Both groups were given a total of 20 sessions of cervical, thoracic and lumbar spine range of motion and stretching exercises, 5 days a week for 4 weeks under supervision. In addition the first group underwent a high-intensity interval aerobic exercise program on bicycle ergometry in our cardiopulmonary rehabilitation unit. Exercise intensity of the patients who received aerobic exercise was determined by the formula Wmax (W) = (0.122 x 6MWT) + (72.683 x height [m]) - 117.109; patients were applied the entire load determined in 4×4 minute intervals, followed by 50% of the load determined in 3x3 minute intervals; for a total of 25 minutes. The patients perceived degree of exertion was monitored according to the Borg scale with values between 15-17 for high-intensity intervals and 12-14 for low-intensity intervals. The patients were evaluated three times before treatment (T0), at the end of treatment (T1: 4th week), and 12th week after treatment (T2). The patients demographic data (age, gender, height, weight, body mass index (BMI), education status, presence of additional comorbidities, disease duration, previous treatments and medications) and HLA-B27 status were recorded. Acute phase reactants were evaluated with CRP (mg/L) and ESR (mm/hour), disease activity with BASDAI and ASDAS-CRP, functional status with BASFI, quality of life with ASQoL, spinal mobility with BASMI and subparameters (right and left lateral flexion, right and left cervical rotation, maximal intermalleolar distance, tragus wall distance and modified schober test (MST)) and ultrasonographic evaluation parameters (T11-12 prone, T11-12 max flexion, T11-12 difference, L4-5 prone, L4-5 max flexion, L4-5 difference), aerobic capacity with 6MWT, body weight and composition with BIA method using TANITA BC 418. Additionally, chest expansion was evaluated. Serum calprotectin (ng/ml), visfatin (ng/ml), leptin (ng/ml) and IL-33 (ng/L) levels were measured as biomarkers at T0, T1 and T2 using ELISA kits and the results were recorded. Results: Of the 56 patients who completed the study, 18 (32.1%) were female and 38 (67.9%) were male. There was no statistically significant difference between the groups in terms of demographic data at baseline (p>0.05). Improvement in BASDAI, ASDAS-CRP, ASQoL and 6DYT at T1 and T2 in the aerobic + stretching exercise group was superior to the improvement in the stretching exercise only group (p<0.05). Significant improvements were observed in both groups in terms of BASFI, BASMI and its sub-parameters, ultrasonographic evaluation parameters (T11-12 prone, T11-12 max flexion, T11-12 difference, L4-5 prone, L4-5 max flexion, L4-5 difference) at T1 and T2 (p<0.05), but no statistically significant difference was found between the groups (p>0.05). Improvement in chest expansion was superior in the aerobic + stretching exercise group compared to the other group (p<0.05). The improvement in intragroup chest expansion measurements was significant at T2 in both groups, and was also significant at T1 in the aerobic + stretching exercise group (p<0.05). In terms of biomarkers, improvement was observed in calprotectin and leptin levels in the aerobic + stretching exercise group at T1 and T2 (p<0.05); improvement in calprotectin was superior in the aerobic + stretching group (p<0.05). There was no significant difference between the groups after treatment in terms of changes in leptin (p>0.05). No significant changes were observed in CRP, ESR, Visfatin and IL-33 levels in both groups after treatment (p>0.05). Body weight and BMI improved only in the aerobic + stretching exercise group at T1; body fat mass improved in the aerobic + stretching exercise group at T1 and T2 (p<0.05). There was no significant difference in body weight, BMI and fat mass between the groups after treatment (p>0.05). Correlation analysis showed a moderate to strong positive correlation between serum calprotectin and visfatin, leptin and IL-33 at T1 and T2 (p<0.05). There was no correlation between serum calprotectin level and disease-specific parameters, CRP and ESR after treatment. Ultrasonographic evaluation parameters (T11-12 max flexion, T11-12 difference, L4-5 max flexion, L4-5 difference) were negatively correlated with BASMI at mild to moderate level and positively correlated with MST at mild to moderate level (p<0.05). Conclusions: In patients with AS, it has been observed that the combination of high-intensity interval aerobic exercises provides additional benefits in terms of disease activity, quality of life and functional exercise capacity compared to stretching exercises alone. In addition, both aerobic and stretching exercises were found to be effective in improving spinal mobility. It was determined that ultrasonographic measurements, as well as metric measurements, could reflect clinical improvement in the assessment of spinal mobility. In addition, it was concluded that serum calprotectin levels, one of the inflammatory biomarkers, may contribute to the assessment of disease activity in AS. Adding aerobic exercises to exercise prescriptions as part of non-pharmacological treatment methods in AS patients may provide important contributions to treatment management. In order to evaluate the effect of aerobic exercises on inflammatory biomarkers more comprehensively, studies with larger populations and longer follow-up periods are needed. Key Words: Ankylosing spondylitis, Aerobic exercise, Calprotectin, High intensity interval training, Ultrasonography