Background Aerobic fitness may serve as an important health-related outcome measure in JIA. A reduced aerobic fitness is associated with cardiovascular morbidity, mortality and osteoporosis in adult patients with chronic diseases. However, in adolescents and young adults, long-term outcome data of aerobic fitness are unknown. Reduced aerobic fitness was described in cross-sectional studies in children and adolescents with JIA, and was more impaired in active disease
Objectives Our objectives are to describe course of the aerobic fitness in a longitudinal cohort of adolescents and young adult JIA-patients who are intensively treated including the possibility of biologics and to identify the association of clinical variables with aerobic fitness.
Methods In a longitudinal cohort, all consecutive JIA patients aged 10–24 years were included after informed consent. Annual examinations were obtained from demographic and disease-related items. At baseline and end of the study, aerobic fitness (VO2peak) was assessed using a graded cardiopulmonary exercise test (CPET) to volitional exhaustion performed on an electronically braked cycle ergometer. Absolute and relative VO2-peak values were measured and related to healthy controls (Z-scores), using one-sample T-tests. Non-parametric tests were used to evaluate results
Results Paired Z-scores were available from 27 patients. 44% were male, median age at baseline was 13,0yrs (IQR 4,3), disease duration 7,6yrs (6,7), JADAS27 4,0 (5,9), DAS28 2,2 (1,2). 76% of the patients were in DAS28-remission. 11% had systemic JIA, 7% persistent oligoarticular and 82% had a polyarticular course. Baseline and end Z-scores were reduced compared to healthy controls (ZAbs_base -0,68, IQR2,3 p=0,01; Zrel_base -1,33, IQR 2,0, p<0,01; Zabs_end -0,23, IQR 1,7, p=0,06; Zrel_end -0,87, IQR 2,2, p=0,01) and did not change significantly over time (change Zabs_change 0,45, p=0,34; Zrel_change 0,46, p=0,31). At baseline, MTX-use (p=0,04) and a higher DAS28 (p=0,015) and ESR (p=0,013) are associated with a worse outcome of aerobic fitness. The greatest improvement of aerobic fitness over time was seen in patients with a higher ESR (p<0,01) and thrombocytes (p<0,01) at baseline. Multivariate analysis showed that a higher DAS28 and male gender were the most important variables for worse aerobic fitness at baseline, a higher ESR at baseline was the most important predictor for improving aerobic fitness over time
Conclusions Aerobic fitness is significantly reduced in adolescents and young adults with JIA and does not improve over time, despite intensive treatment. Be aware of a reduced quality of life due to a persistent reduced aerobic fitness during disease course of JIA, despite low disease activity
Aerobic capacity and disease activity in children, adolescents and young adults with juvenile idiopathic arthritis (JIA). Ph.A. van Pelt MD, T. Takken PhD, M.van Brussel PhD, M. de Witte. A.A. Kruize*, MD, N.M.Wulffraat* MD, PhD. Pediatr Rheumatol Online J. 2012 Aug 27;10(1):27. doi: 10.1186/1546–0096–10–27.
Disclosure of Interest None declared