Efficacy of personalized exercise program on physical function in elderly patients with rheumatoid arthritis at high risk for sarcopenia: study protocol for a randomized controlled trial

Background: Patients with rheumatoid arthritis (RA) are prone to muscle atrophy due to inflammatory cytokines and corticosteroid use and immobility due to joint pain and deformity. Although resistance training is effective and safe in reversing muscle atrophy in RA, some patients are unable to perform a conventional high-load exercise program due to disease-related limitations. This study aims to examine the efficacy of individualized exercise therapy on physical function in elderly patients with RA who are at a high risk for sarcopenia.

Methods: This study is a single-center, parallel-group, two-arm, healthcare provider- and outcome assessor-blinded, superiority randomized controlled trial with a 1:1 allocation ratio. A total of 160 participants with RA between 60 and 85 years of age with a positive screening test for sarcopenia will be included. The intervention group will receive nutritional guidance and a four-month individualized exercise program in addition to the usual treatment. The control group will receive nutritional guidance in addition to the usual care. The primary endpoint will be physical function assessed using the Short Physical Performance Battery (SPPB) at 4 months. The data on outcome measures will be collected at baseline and at the two- and four-month follow-ups. Linear mixed-effects models for repeated measures will be conducted using the modified intention-to-treat analysis population.

Discussion: This study will provide evidence on whether a personalized exercise program can improve physical function and quality of life in elderly patients with RA. Some limitations include limited generalizability due to the single-center study and lack of blinding of the patients to the intervention assignment because of the nature of the exercise. Physical therapists may use this knowledge in their daily practice to improve RA treatment. Tailored exercise may enhance the health outcomes of the RA population and contribute to a reduction in healthcare costs.

Trial registration: The study protocol was retrospectively registered at the University hospital Medical Information Network-Clinical Trial Repository (UMIN-CTR) (registration number: UMIN000044930, https://www.umin.ac.jp/ctr/index-j.htm ) on January 4, 2022.