Do Patients with Rheumatoid Arthritis Have an (In)Adequate Level of Physical Activity? A Latent Class Analysis Approach.

Introduction: Regular physical activity (PA) has a beneficial effect on joint pain, stiffness, strength, flexibility, and aerobic capacity in patients with rheumatoid arthritis (RA).

Objective: The aim of this study was to assess the level of PA in patients with rheumatoid arthritis and to identify potential barriers to this activity.

Material And Methods: The study involved 132 patients with RA. Participants completed the International Physical Activity Questionnaire (IPAQ), the Functional Assessment of Chronic Illness Therapy-Fatigue Scale (FACIT-F), the Tampa Scale for kinesiophobia (TSK), Strength, Ambulation, Rising from a chair, Stair climbing and history of Falling questionnaire (SARC-F) for sarcopenia assessment, and the Patient Health Questionnaire-9 (PHQ-9) for depression. Basic socio-epidemiological data, disease activity score in 28 joints (DAS), duration of disease, and therapy information were retrieved from electronic patient records. Latent class analysis (LCA) was used to identify subpopulations of patients.

Results: The study included 109 women (82.6%) and 23 men (17.4%). Low levels of PA were observed in 16 patients (12%), moderate levels in 70 patients (53%), and high levels in 42 patients (35%). Symptoms of pronounced fatigue were significantly associated with low PA (28.5 ± 11.3 vs. 37 ± 7 vs. 37 ± 10; = 0.002). The risk of sarcopenia was significantly higher in RA patients with low PA ( = 0.05). Kinesiophobia was present in all three groups (65.2%). LCA identified two classes. In the first class, patients were more likely to be non-exercisers compared to the second class. Patients in the first class were characterized by a higher probability of being female, obese, with lower education levels. Patients in the first class had pronounced fatigue, kinesiophobia and more frequent symptoms of depression. The second class (65% of the total population) included patients who exercised moderately to frequently (93%) and were middle-aged. They were less obese, highly educated, employed, and majority of them achieved low disease activity or remission. In addition, they had lower risks for sarcopenia, depression, fatigue, and kinesiophobia.

Conclusions: This study showed that RA patients with moderate and high levels of PA have better disease control, fewer symptoms of fatigue and depression, and a lower risk of sarcopenia. However, kinesiophobia was significantly present in all three groups, indicating a need for further promotion of this non-pharmacological treatment.