Determinants of physical activity level in children and adolescents with juvenile idiopathic arthritis

One of the most frequently discussed physical parameters in juvenile idiopathic arthritis (JIA) is physical activity level. There is limited evidence about determinants of physical activity level in JIA. In this study, we aimed to investigate the determinants of physical activity level in children and adolescents with JIA.

Thirty-two JIA patients and 18 age- and sex-matched healthy individuals were included in the study. The age range was 8-18 years. Sociodemographic and clinical data of the participants were recorded. In both groups, anthropometry, fatigue, pain, knee extension muscle strength, gait variables, functional exercise capacity assessed by six-minute walk test (6MWT), and arterial stiffness were evaluated. Physical activity level was assessed by an accelerometer.

The disease activity level of the patients was low. Pain and fatigue scores were significantly higher in the JIA group compared to healthy controls (p < 0.05). Walking speed, physical activity level, time spent in low-intensity physical activity, time spent in moderate-to-vigorous-intensity physical activity, and 6MWT distance were significantly lower than in healthy controls (p < 0.05). Quadriceps muscle strength and arterial stiffness assessment results were similar in both groups (p > 0.05). In the JIA group, there was a positive correlation between physical activity and age, height, fat-free body mass, quadriceps muscle strength, and 6MWT distance (p < 0.05). Also, there was a negative correlation between physical activity and pain, fatigue, and cadence. Physical activity level was independently associated with 6MWT distance (42.9% of the variability).

In mildly affected JIA patients, gait speed, functional exercise capacity, and physical activity level are affected. Functional exercise capacity is a determinant of physical activity level in JIA.