gms | German Medical Science

Background: Overweight and obesity are considered to have a negative impact on Rheumatoid Arthritis in adults and there is less information regarding the correlation in juvenile idiopathic arthritis (JIA).

Methods: This is a longitudinal retrospective study design. We collected data of 164 patients suffering from JIA from three consecutive visits. Treatment was conducted between 2012 and 2015 at our centre in accordance to current guidelines. Remission was defined by cJADAS10 score ≤0,5 in Oligoarthritis and ≤0,7 in Polyarthritis. Patients were categorized by weight-for-age percentiles as heavily underweight (less than 3rd percentile) underweight (4th up to 10th percentile) healthy (11th up to 90th percentile) overweight (91th up to 96th percentile) and obese (97th up to 100th percentile). We compared the cJADAS10 of normal-weighted children with the cJADAS10 of the overweight and the obese patients, respectively.

Results: Of all patients, 13 were “underweight” (7,9%), 109 were defined as “normal weight” (66,5%) and 42 patients were categorized as “overweight” (25,6%) of which 16 children (9,8%) were “obese”. 95 (57.9%) reached a remission during follow-up visits. Overweight was associated with higher disease activity compared to healthy weight children at the first visit (mean 9,5 vs. 8,5) and a wider range of the cJADAS10 score (0-22 vs.0-20,5). Results from the 3-months-follow-up revealed an overall good response to the prescribed medication. At 6-months-follow-up, overweight children couldn’t stabilize the improvement since cJADAS10 range rises while it stays stable in healthy weight children. At the same time, while interpreting the disease activity of “overweight” and “obese” children separately, obese children show significantly less disease activity than overweight children, especially at the 3- and 6-months-follow-ups.

Conclusion: Overweight seems to have a negative influence on the disease activity and remission of JIA patients but it is most likely not the only influencing factor since obese patients show a better result regarding the cJADAS10 score than overweight patients. In the future, factors like socioeconomic status, BMI of the parents or physical activity level of the patient should be included in the evaluation. Also, the 7 subtypes of JIA should be analyzed individually since they show heterogeneous etiology, phenotype and prognosis.