Aerobic and anaerobic capacity in Juvenile Idiopathic Arthritis: evaluation of the cardiorespiratory response

Abstract

Objectives: To compare the cardiac response during maximal aerobic exercise in JIA with healthy children. Methods: Thirteen children aged 10 to 17 years with JIA and 9 controls (CON) participated. All performed maximal VO2 and Wingate tests on a cycle ergometer. Cardiac output (CO) was measured during exercise with Doppler echocardiography. Arterial – mixed venous oxygen index (A-VO2) and systemic vascular resistance (SVR) were calculated. Results: JIA subjects had decreased aerobic fitness (VO2 31.3, CON 47.9 ml/kg/min p = 0.013]. There was no significant difference in CO, A-VO2 or SVR but we observed trends towards lower CO and higher SVR in JIA. During anaerobic exercise JIA subjects completed less total work. Conclusions: Children with JIA have moderate impairment in aerobic fitness. CO and A-VO2 during aerobic exercise did not differ between JIA subjects and CON. Further research with is required to determine factors contributing to limited fitness in JIA. CONTRIBUTING INSTITUTIONS Divisions of Rheumatology and Cardiology, British Columbia Children's Hospital, Department of Pediatrics, University of British Columbia, Vancouver, Canada. School of Human Kinetics, University of British Columbia, Vancouver, Canada.