Aerobic and anaerobic exercise capacity in adolescents with juvenile idiopathic arthritis

OBJECTIVE: To examine the aerobic and anaerobic exercise capacity in adolescents with juvenile idiopathic arthritis (JIA) compared with age- and sex-matched healthy individuals, and to assess associations between disease-related variables and aerobic and anaerobic exercise capacity.METHODS: Of 25 patients enrolled in a JIA transition outpatient clinic, 22 patients with JIA were included in this study (mean +/- SD age 17.1 +/- 0.7 years, range 16-18 years). Aerobic capacity was examined using a Symptom Limited Bicycle Ergometry test. Anaerobic capacity was assessed with the Wingate Anaerobic Test. Functional ability was assessed with the Childhood Health Assessment Questionnaire. Pain and overall well-being were measured using a visual analog scale. Disease duration and disease activity were also assessed.RESULTS: Absolute and relative maximal oxygen consumption in the JIA group were significantly impaired (85% and 83% for boys, respectively; 81% and 78% for girls, respectively) compared with healthy controls. Mean power was also significantly impaired (88% for boys and 74% for girls), whereas peak power was significantly impaired for girls and just failed significance for boys (67% for girls and 92% for boys). A post hoc analysis correcting for underweight and overweight demonstrated that body composition did not influence the results substantially.CONCLUSION: This study demonstrated that adolescents with JIA have an impaired aerobic and anaerobic exercise capacity compared with healthy age- and sex-matched peers. The likely cause for this significant impairment is multifactorial and needs to be revealed to improve treatment strategies.