Background Previous studies indicate that juvenile idiopathic arthritis (JIA) patients have lower levels of physical activity (PA), spend more time in sedentary PA and less time in moderate and vigorous PA than controls. Associations between PA and disease variables in JIA patients are inconclusive. To our knowledge, this study is the first to compare objectively measured PA in JIA patients treated in the era of biologics with healthy controls whose data collection were conducted at the same time as the patients.
Objectives To compare objectively measured levels and intensity of PA in JIA patients who have had access to biological treatment from disease onset with age- and sex-matched controls from the general population. Furthermore, to compare PA between JIA patients with persistent oligo- and poly-articular disease, and to examine associations between PA and disease variables in patients.
Methods Patients, 10–16 years, with persistent oligo- or poly-articular disease (extended oligoarthritis and polyarticular RF +/-), were recruited consecutively at Oslo University Hospital in 2015. Age- and sex-matched controls were selected randomly from the Norwegian Population Registry. PA was measured with accelerometers during 7 consecutive days. The general level of PA was determined by counts per minute (cpm) and steps daily. Cut-off points for different PA categories of intensity were used as described by Evenson1. Present pain, and pain and fatigue during the previous week were assessed in all participants. Disease activity, functional ability, diasease duration, use of medication and lower extremity joints with active arthritis were registered in patients. Differences between study groups were analyzed with paired or unpaired analyses as appropriate.
Results Acceptable data from the accelerometers were retrieved in 53 matched pairs, of which 45 (85%) were female. Mean age was 13.3±2.2 years in patients and 13.2±2.6 years in controls, p=0.55. 26 (49%) patients had polyarticular disease. No significant differences were found in cpm or steps daily, or in time spent in sedentary PA, light PA or moderate PA in patients vs controls (Table 1). However, patients spent significantly less time in vigorous PA than controls. No significant differences in PA variables were found between JIA subgroups. The use of biologic medication correlated weakly with cpm, r=0.30, p=0.03, while no other disease variables correlated significantly with cpm or with vigorous PA (all r<0.30, p=NS).
Conclusions General level of physical activity and time spent in sedentary PA, light PA and moderate PA in JIA patients treated in the biological era are comparable with controls. However, patients spend less time in vigorous PA. Even though these results are promising regarding PA in JIA patients, the results indicate that patients still need to be encouraged to be physically active, with emphasis on increasing vigorous PA.
Evenson et al 2008.
Disclosure of Interest None declared