Background: RA affects not only the joints but also other organs such as the lungs. Lung involvement occurs in 60-80% of patients with RA and can contribute significantly to morbidity and mortality by affecting all components of the lungs. Although the involvement of the respiratory system in RA can be quite variable, the most common is RA-associated interstitial lung disease (RA-ILD).

Objectives: The aim of this study was to examine the relationship between respiratory muscle strength and grip strength, muscle strength, oxygen saturation of peripheral muscles, dyspnea and respiration, cough, and health-related quality of life in individuals with rheumatoid arthritis-related interstitial lung disease.

Methods: Twenty-four volunteers with RA-ILD (19 female, 5 male) with a mean age of 65.17 ± 8.71 years were included in the study. Participants’ respiratory muscle strength was assessed with maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), grip strength with Baseline Digital Hand Dynanometer, muscle strength (m biceps brachii and m quadriceps femoris) with Commander Echo brand manual muscle testing device, oxygen saturation of peripheral muscles (m biceps brachii and calf muscles) with MOXY device, dyspnea with Modified Borg Scale, Modified Medical Research Council Dyspnea Scale and Visual Analog Scale, respiratory-related quality of life with St. George Respiratory Questionnaire, cough-related quality of life with Leicester Cough Questionnaire and health-related quality of life with Short Form-36 (SF-36).

Results: As a result of the correlation analysis, MIP and SF-36 physical functionality (r:0.555; p:0.009); SF-36 pain (r:0.560; p:0.008); There were significant correlations between left grip strength (r:0.729; p<0.001); right grip strength (r:0.706; p<0.001); left biceps brachii muscle strength mean (r:0.590; p:0.005) and maximum (r:0.596; p:0.004); right biceps brachii muscle strength mean (r:0.568; p:0.007) and maximum (r:0.575; p:0.006); left quadriceps femoris muscle strength mean (r:0.625; p:0.002) and maximum (r:0.594; p:0.004); right quadriceps femoris muscle strength mean (r:0.628; p:0.002) and maximum (r:0.591; p:0.005). MEP and SF-36 physical functionality (r:0.448; p:0.042); left grip strength (r:0.633; p:0.002); right grip strength (r:0.496; p:0.019); left biceps brachii muscle strength average (r:0.449; p:0.041) and maximum (r:0.442; p:0.045); right biceps brachii muscle strength average (r:0.546; p:0.011) and maximum (r:0.545; p:0.011); left quadriceps femoris muscle strength average (r:0.525; p:0.015) and maximum (r:0.534; p:0.013); There was a significant relationship between right quadriceps femoris muscle strength mean (r:0.538; p:0.012) and maximum (r:0.519; p:0.016); right biceps brachii oxygen saturation maximum (r:0.537; p:0.012) and mean maximum (r:0.447; p:0.042); right calf muscle oxygen saturation maximum (r:0.484; p:0.030) and mean maximum (r:0.505; p:0.023).

Conclusion: In individuals with RA-ILD, inspiratory and expiratory muscle strength is associated with handgrip strength, upper and lower extremity muscle strength and physical functionality subparameter of quality of life. In addition, expiratory muscle strength was found to be correlated with right-sided upper and lower extremity oxygen saturation. It is recommended that future studies examine the effects of respiratory exercises on extremity muscles or extremity exercises on respiratory muscles.

REFERENCES: [1] Spagnolo, P., Lee, J. S., Sverzellati, N., Rossi, G., & Cottin, V. (2018). The lung in rheumatoid arthritis: Focus on interstitiallung disease. Arthritis & Rheumatology, 70(10), 1544--1554. https://doi.org/10 . 1002/art.40574.

[2] Tanaka, A., Kurasawa, K., Soda, S., Takamura, Y., Miyao, T., Hasegawa, A., Hiyama, T., Yamazaki, R., Arai, S., Owada, T., Arima, M., Arakawa, H., & Maezawa, R. (2023). Changing patterns of pulmonary abnormalities in rheumatoid arthritis.Respiratory Investigation, 61(1), 27--39. https://doi.org/10.1016/j.resinv.2022.09.002 .

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.