FRI0470 CARDIORESPIRATORY FITNESS IN JUVENILE IDIOPATHIC ARTHRITIS IN 6 – 17-YEAR-OLD CHILDREN- CROSS-SECTIONAL STUDY

Abstract

Background:Children with juvenile idiopathic arthritis (JIA) have been found to have reduced cardiorespiratory fitness and lower physical activity. Poor cardiorespiratory fitness is associated with a risk of cardiometabolic diseases.Objectives:The aim of this study was to study the levels of cardiorespiratory fitness, respiratory function and hemodynamic responses during and after maximal cycle ergometer exercise test in children with JIA aged 6-17 years and compare the results with healthy controls.Methods:Study group in this analysis consisted of 43 patients with JIA who were treated in Department of Pediatrics in Kuopio University Hospital, Finland and 40 healthy age- and sex matched controls. Maximal exercise tests were carried out with an electromagnetic cycle ergometer using a pediatric saddle module. Maximal workload per kilogram (Wmax/kg) was used as a measure of cardiorespiratory fitness and was presented relative to bodyweight. In addition the peak values of VO2per kilogram (VO2max/kg) were used as a measure of highest amount of oxygen that an individual can consume during exercise. Values of VO2maxwere collected from respiratory gases measured directly from breath by breath method and was presented relative to body weight.Physical activity and sedentary behavior (minutes per day) was assessed by the PANIC (Physical activity and nutrition in children -study) Physical Activity Questionnaire which the participants filled.Results:Statistical analyses were performed for 43 children with JIA and 40 controls. Mean age in JIA group was 12.09 years (95%Cl 11.04-13.14), and 11.72 years (95%CI 10.52-12.93) in controls (p=0.572). Mean body mass index for age (BMI) was 22.58 kg/m2(95%CI 21.54-23.62) in JIA and 18.95 kg/m2(95%CI 17.73-20.16) in controls (p<0.05). In JIA group BMI was 19.18 % higher compared to controls. Mean physical activity in JIA group was 94.11 minutes per day (95% Cl 81.09-107.13), and 122.54 minutes per day (95% CI 102.84-142.24) in controls, thus JIA group was 23.20 % less physically active than controls (p=0.015).Mean Wmax/kg was 2.65 W/kg (95% CI 2.49-2.82) in JIA and 3.01 W/kg (95%CI 2.86-3.15) in controls thus Wmax/kg in JIA was 0.36 W/kg (11.8 %) lower than in controls, (p = 0.002). VO2max/kg was 37.00 (95%CI 33.96-40.84) ml/kg/min in JIA and 43.30 (95%CI 40.79-45.82) ml/kg/min in controls thus in JIA group mean VO2max/kg was 6.3 ml/kg/min (14.4 %) lower than in controls (p=0.001).Conclusion:Children with JIA were found to have significantly lower cardiorespiratory fitness. In addition, BMI in JIA patients was higher compared to healthy age- and sex-matched controls. Impaired cardiorespiratory fitness and higher BMI may predispose children with JIA to cardiometabolic comorbidities later in life. In addition to disease-control, more attention should be paid to maintaining good cardiorespiratory fitness and normal BMI in these patients already before adulthood.