The aim of this study is to investigate respiratory muscle strength, respiratory muscle endurance, muscle oxygenation, upper extremity and lower extremity exercise capacity in rheumatoid arthritis patients compared with healthy individuals.

Rheumatoid arthritis (RA) is a chronic progressive autoimmune disease of unknown etiology with symmetric erosive synovitis and multisystem involvement. The disease causes significant long-term morbidity, reduced functional capacity, and increased mortality rates. Patients with rheumatoid arthritis avoid physical activity due to pain and fatigue. Despite the advances in pharmacological treatments in recent years, functional losses due to rheumatic diseases the resulting deterioration in quality of life, and loss of work continue. Physical inactivity is known to have detrimental effects on the cardiovascular and pulmonary systems by reducing muscle strength and aerobic capacity. The physiological reasons underlying skeletal muscle oxygenation that may cause muscle dysfunction in rheumatoid arthritis have not been investigated. In these patients, decreased arterial oxygen may reduce exercise capacity and cause muscle deoxygenation.

In rheumatoid arthritis patients, decreases in respiratory muscle strength, lung volumes, oxygen consumption, and six minute walk test distance cause cardiopulmonary deconditioning. Decreased exercise capacity increases the risk of cardiovascular disease and causes mortality in patients with RA.

This study aimed to, the effects of respiratory muscle strength, respiratory muscle endurance, upper and lower extremity muscle oxygenation, and upper and lower extremity exercise capacity in patients with stable disease activity.

Rheumatoid Arthritis Group

Inclusion Criteria:

• Patients diagnosed with rheumatoid arthritis,
• The ages of 18-65 years,
• Volunteer to participate in the study will be included in the study.

Exclusion Criteria:

• Serious cardiopulmonary, neurological, neuromuscular, orthopedic and other systemic diseases or other diseases affecting physical functions,
• Participated in a planned exercise program in the last three months,
• Cognitive impairment that will cause difficulty in understanding and following exercise test instructions,
• Contraindications to exercise testing or exercise training according to the American Sports Medicine Association will not be included in the study.

Control Group

Inclusion Criteria:

• The ages of 18-65 years,
• Volunteer to participate in the study will be included in the study.

Exclusion Criteria:

• Diagnosed chronic or systemic disease,
• Regular exercise (physical activity) 3 days a week, 150 minutes/week of moderate intensity
• Smoking 10 packs x years or more,
• Pneumonia or any acute infection,
• Healthy individuals with any psychiatric disorder will not be included in the study.

Rheumatoid arthritis patients (diagnosed according to American College of Rheumatology/European Alliance of Associations for Rheumatology ACR/EULAR 2022 diagnostic criteria) aged between 18-65 years, with a Disease Activity Score (DAS)-28 score below 2.6 in disease remission and followed up at the Rheumatology Polyclinic of the Department of Physical Medicine and Rehabilitation at Kirsehir Ahi Evran University will be included in the study.

As a control group, healthy individuals between the ages of 18-65, who are similar to the patients in terms of age and gender, without any disease, will be included in the study.

All data will be stored in a locked cabinet.