Evaluation of anaerobic exercise capacity in patients with ankylosing spondylitis

Objective: This study aimed to evaluate anaerobic exercise capacity in Ankylosing Spondylitis (AS) patients by measuring anaerobic power and anaerobic capacity with the wingate anaerobic power test, and to determine the relationship between anaerobic exercise capacity and disease-related variables and to detect differences with healthy controls. Materials and Methods: 50 patients who diagnosed as Ankylosing spondylitis according to modified New York criteria, aged 18-65 years, and 50 healthy controls were included in the study. The participants included in the study were questioned about their age, gender, education level, occupational information, smoking and exercise habits. The patients's illness duration, morning stiffness duration, non-steroidal anti-inflammatory drug (NSAID) and biological drug usage status were questioned. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were recorded to evaluate inflammation activity. HLA B27 positive and negative status of the patients was recorded. Patient and physician global assessment scores were used to evaluate the effect of ankylosing spondylitis on the well-being of patients. Mobility of AS patients was evaluated by measuring finger-to-ground distance, tragus wall distance, occiput wall distance, modified Schober test, intermalleolar distance, lumbar lateral flexion, cervical rotation degree, mouth opening, chin manubrium distance and chest expansion. The life quality of AS patients was assesed by Short form-36 (SF-36). Bath AS functional index (BASFI) was used to evaluate functional status in AS patients, Bath AS disease activity scale (BASDAI) was used to evaluate disease activity, and Bath AS metrology index (BASMI) was used to evaluate axial skeletal mobility. Wingate anaerobic power test was applied to all participants using a Wattbike pro exercise bike to evaluate anaerobic exercise capacity. In the anaerobic power test, maximum anaerobic power (Pmax), maximum anaerobic capacity (Pavg), Pmax/kg, Pavg/kg, Pmin (minimum anaerobic power), Fatigue index, maximum heart rate (beats/min), average heart rate (beats/min) values were recorded. Results: The mean age of AS patients was 40.5 ±7.55 meanwhile the mean age of healthy subjects was 40.78 ± 8.71. When the data on the demographic characteristics of both groups were compared, no significant difference was observed between the two groups. HLA B27 was positive in 76% of AS patients participating in the study. In the anaerobic power test applied to all participants, maximum anaerobic power (Pmax), maximum anaerobic capacity (Pavg), Pmax/kg, Pavg/kg, Pmin values were found to be significantly lower in the patient group than in the control group (p<0.05). Maximum heart rate and mean heart rate in AS patients were significantly higher than the control group (p<0.05). When comparing AS and control groups, no significant difference was observed between fatigue index values. Negative correlation was found between Pmax/kg and Pavg/kg values and BASDAI and BASFI in AS patients. Negative correlation was found between Maximum heart rate, Average heart rate and BASMI. When the Maximum anaerobic power (Pmax), Maximum anaerobic capacity (Pavg), Pmax/kg, Pavg/kg, Pmin values were compared in the patient and control groups, they were found to be significantly higher in men than in women (p<0.05). No significant difference was observed between fatigue index, maximum heart rate and average heart rate according to gender. No significant difference was observed in the evaluation of anaerobic power parameters in AS patients according to smoking status, exercise status and medication usage status. No significant difference was observed in the evaluation of anaerobic power parameters in AS Patients according to HLA B27 positive and negative status. Negative correlation was detected between anaerobic power parameters, peak heart rate and mean heart rate, and age in AS patients. No significant correlation was detected between disease duration and anaerobic power parameters. There was no significant difference between the smoker and non-smoker groups in all parameters in the anaerobic power test of the participants in the control group. Pmax/kg and Pavg/kg values of the control group participants who exercised regularly were found to be significantly higher than those who did not exercise. In the control group, a negative correlation was found between maximum anaerobic power (Pmax), Maximum anaerobic capacity (Pavg), Pmax/kg, Pavg/kg values and age. Concluisons: In our study where anaerobic exercise capacity, which is an important measure of physical performance, was evaluated, better results were obtained in the healthy control group than in Ankylosing Spondylitis patients in many parameters in the anaerobic power test applied to all participants. Maximum anaerobic power (Pmax), Maximum anaerobic capacity (Pavg), Pmax/kg, Pavg/kg, Pmin values were found to be significantly lower in AS patients. The reason for the decrease in anaerobic exercise capacity in AS patients is attributed to the effects of the disease on the cardiovascular and respiratory systems, especially the musculoskeletal system. More studies are needed to determine the factors affecting anaerobic exercise capacity in ankylosing spondylitis and to improve anaerobic exercise capacity. Keywords: ankylosing spondylitis, anaerobic power, anaerobic capacity, physical performance