Impact of Disease Activity on Physical Activity in Patients With Psoriatic Arthritis.

Objective: The purpose of this study was to compare physical activity (PA) in a group of patients with psoriatic arthritis (PsA) versus healthy controls and to determine whether the mobility of these patients is affected by disease activity.

Methods: A group of 52 patients with PsA and 53 controls were included in this case-control study. PA was assessed by accelerometry in both groups and additionally with the International Physical Activity Questionnaire (IPAQ) in patients with PsA. Multiple regression analysis was used to compare PA between groups and to determine the relationship between PA and PsA features, including disease activity, as assessed by the 28-joint Disease Activity Score (DAS28) and the Disease Activity Index for Psoriatic Arthritis (DAPSA) score. In a group of 36 patients, a test-retest study was carried out after 6 months.

Results: The time engaged in moderate-to-vigorous physical activity (MVPA) per day, as evaluated by accelerometry, and adjusted by confounders, proved similar in patients with PsA and controls. In patients with PsA, disease activity was inversely related to PA as assessed either by IPAQ or accelerometry. When PA was compared in patients with PsA between the 2 visits, a significant difference in the amount of time doing MVPA was found (42 ± 33 versus 30 ± 22 minutes/day; P = 0.004). Interestingly, in the test-retest study, variations in disease activity over time based on DAPSA scores (r = -0.49, P = 0.002) and DAS28 using the C-reactive protein level (r = -0.4, P = 0.017) were inversely correlated with changes in PA, as determined by accelerometry.

Conclusion: Patients with PsA show levels of PA like healthy controls. In patients with PsA, disease activity and PA are inversely correlated and the evaluation of PA by accelerometry is sensitive to changes in disease activity.