Objectives: To assess the prevalence of overweight in patients with juvenile idiopathic arthritis (JIA) between 2003 and 2012 and to determine correlates of overweight relevant to the change in the overweight rate.
Method: Annual overweight prevalence was determined in the National Paediatric Rheumatological Database (NPRD) between 2003 and 2012. The prevalence of overweight in JIA was compared to representative data from Germany in 2005.
Results: The median age of JIA patients was 11.5 years and the mean disease duration 4 years. Almost 50% of JIA patients had persistent oligoarthritis, followed by rheumatoid factor (RF)-negative polyarthritis (14%). The overweight prevalence decreased significantly from 14.2% in 2003 to 8.3% in 2012 [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.89-0.95]. Higher levels of physical activity and less frequent treatment with high-dose glucocorticoids (GCs) were associated with decreasing overweight rates. Systemic JIA had the highest decrease in the overweight rate over time. Patients with JIA had an overweight rate comparable to that of children and adolescents in the general population. However, systemic JIA and enthesitis-related arthritis were more likely to be associated with overweight. The use of high-dose GCs, lower functional limitations, and a lower level (or lack) of participation in school sports were significant predictors of overweight in multivariable analyses.
Conclusions: The prevalence of overweight in JIA was comparable to the general population and decreased significantly over time. The decrease was associated with higher functional ability and JIA patients should be encouraged to be more physically active. The role of an elevated body mass index (BMI) in the long-term outcome of JIA needs to be addressed in future studies.