Objective: To assess aerobic fitness (AF) and physical activity (PA) in patients with HLA-B27 positive juvenile spondyloarthropathy (JSpA) in remission at the time of testing.
Methods: Twenty-one previous patients (12 male, 9 female), age 6-26 years (median age 17.8), and 21 healthy controls matched for age, sex, height, and weight participated. AF was determined by measuring maximal power and peak oxygen uptake (VO2 peak) during a continuous incremental cycling task. PA was assessed by Seven-Day Recall and Lipid Research Clinic questionnaire.
Results: There was only a tendency for a lower maximal power and O2 peak in the 21 patients compared to controls for the total group (median/range: 191/49-306 W vs 219/41-337 W; 2385/998-3962 ml x min(-1) vs 2761/10434221 ml x min(-1); both p < 0.10). However, patients who were older than 18 years had a significantly lower maximal power and VO2 peak than their controls (median/range: 199/126-306 W vs 255/194-337 W; 2785/1570-3962 ml x min(-1) vs 3308/2049-4221 ml x min(-1); both p < 0.05). Many of the older patients had also had arthritis for longer than 2 years and felt limited in their AF or PA. PA was not significantly different between patients and controls.
Conclusion: These data suggest that some patients have an impairment of their AF long after arthritis has ceased, which is likely attributable to psychological factors. Changes in the heart and skeletal muscle might also contribute to the lower AF. Participation in physical exercise is encouraged especially in older or "anxious" patients with inactive JSpA.