Abstract

Background: Physical inactivity and screen-based media (SBM) use are different aspects of sedentary behavior, independently related to poor health outcomes [1,2], and not yet (sufficiently) evaluated in adolescents with juvenile idiopathic arthritis (JIA). In addition, none of the previous studies examined SBM use and physical activity (PA) behavior during disease course and with consideration of health-related quality of life (HRQoL). Objectives: This study aimed to longitudinally investigate possible differences in daily time spent with SBM and levels of weekly PA between adolescents with JIA and controls from the general population. Methods: Data from JIA patients and controls enrolled in the German multicenter Inception COhort of Newly diagnosed patients with JIA (ICON) at 11 German centers were analyzed. Individuals aged 13 and over were followed prospectively with questionnaires concerning clinical data, PA level, SBM use, and HRQoL (PedsQL) at a two-year interval (Baseline, T1; follow-up, T2). While group by time interactions were analyzed using linear mixed models, multinomial logistic regression was performed to estimate the association between SBM use/PA levels/HRQoL and sociodemographic factors as well as clinical parameters. Results: Data of 214 patients (T1 mean age 14.4 ± 0.9 years, female 63%, polyarthritis 33%, oligoarthritis 26%) and 141 controls could be considered. At T1, 52% of the patients were treated with a DMARD, 59% at T2. In contrast to controls, PA levels of patients increased over time (OR 3.69; 95% CI: 1.01-13.50, p=0.048), however, they remained below the level of controls (OR 0.13; 95% CI: 0.04-0.38, p<0.001). Increasing PA levels were associated with decreasing disease activity (cJADAS-10), increasing use of biologics and improved HRQoL (PedsQL) over time. Although mean screen time did not differ significantly between patients and controls (T1: 3.5h vs. 3.0h, p=0.194; T2: 3.6h vs. 3.3h, p=0.364), patients more frequently spent more than 4 hours a day with SBM (T2: p=0.046). Male patients and controls displayed significantly higher total screen time than females both at T1 and at T2 and were also more likely to be heavy screen users (>4h/day). In contrast, males in both groups more frequently achieved the current WHO recommended PA level of 60 minutes per day than girls. While low socioeconomic status (OR 14.40; 95%-CI: 2.84-73.15) and higher cJADAS-10 score (OR 1.31; 95%-CI: 1.03-1.66) increased the likelihood for high SBM use (≥4.5h/d), higher PedsQL psychosocial health score (OR 0.93; 95%-CI: 0.88-0.99) was associated with a decreased likelihood. Conclusion: Adolescents with JIA became more physically active over the course of their disease, but remained more frequently physically inactive and were more likely to be heavy screen users than controls. To help prevent negative effects of excessive screen time and pronounced physically inactivity, pediatric rheumatologists, pediatricians and other healthcare professionals should inform patients and parents about its dangers and advise them to reduce sitting time to act as a stepping-stone to increase other aspects of PA. The ICON study was funded by the Federal Ministry of Education and Research (BMBF, FKZ 01ER0812, FKZ 01ER1504A-C). REFERENCES: [1] Lee IM, et al. Effect of physical inactivity on major non-communicable diseases worldwide: An analysis of burden of disease and life expectancy. Lancet 2012;380:219–229. [2] Proper KI, et al. Sedentary behaviors and health outcomes among adults: A systematic review of prospective studies. Am J Prev Med 2011;40:174–182. Acknowledgements: We thank all patients and their parents as well all physicians and study nurses for their participation in ICON. Disclosure of Interests: None declared.