POS0413-HPR EXERCISE CAPACITY BY THE 6MWD IN A PROSPECTIVE RMD-ILD COHORT FOLLOWED OVER 12 MONTHS; IMPACT OF DISEASE CHARACTERISTICS AND PATIENT REPORTED MEASURES
Authors: M. L. Ramsli, T. Garen, P. P. Diep, H. Didriksen, E. V. Langballe, H. Andersson, Ø. Molberg, H. Mangseth, M. Durheim, A. M. Hoffmann-Vold
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Interstitial lung disease (ILD) is a frequent and severe manifestation in multi-organ rheumatic musculoskeletal diseases (RMD). The six-minute walking test (6MWT) is a inexpensive, readily available tool in clinical practice for the monitoring of exercise capacity in patients with RMD-ILD. It is however unclear whether the underlying disease or lung involvement correlates with reduced exercise capacity. <h3>Objectives:</h3> To assess the impact of patient reported disease activity and disability, lung specific characteristics and the sensitivity to change of exercise capacity by the 6 minutes walking distance (6MWD) in patients with RMD-ILD and to compare 6MWD performance in the patients compared to age- and gender-specific reference values [1]. <h3>Methods:</h3> We followed 109 RMD-ILD patients in our prospective cohort study at Oslo University Hospital. Patients were assessed at baseline and 52 weeks. Exercise capacity using the 6MWD was assessed together with lung function by forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO), overall physical capacity by New York Heart association (NYHA) functional class and self-reported symptoms and disability by validated PROMs. We calculated standardized references values of the 6MWD (1). Changes in the scores values were analyzed by Wilcoxon signed rank test. All correlations were assessed using Spearman correlation. <h3>Results:</h3> The study population consisted of 38 rheumatoid arthritis (RA), 30 idiopathic inflammatory myopathies (IIM), 24 systemic sclerosis (SSc), 12 primary Sjogren's syndrome (pSS) and 5 mixed connective tissue disease (MCTD)-ILD patients (Table 1). Clinical characteristics and patients reported measures did not differ significantly across the individual RMD-ILD subsets (Table 1). In comparison with the calculated reference values, the RA-ILD patients had reduced 6MWD, with a difference of 175 meters (P&lt;0.001) (Figure 1A). We identified significant correlation between NYHA class and 6MWD, but could not identify any other common variables impacting exercise capacity (Figure1B). Lower lung function impacted exercise capacity only in IIM-ILD patients. While in RA-ILD patients exercise capacity was lower in patients reporting increased fatigue, disability and overall impaired health status, this had no impact in pSS-ILD and only limited impact on patients with IIM and SSc/MCTD-ILD. <h3>Conclusion:</h3> RA-ILD patients have a lower than expected exercise capacity and this appears to be more strongly influenced by fatigue, overall health status and disability than lung involvement. In the other RMD-ILD patients, we found only minor impact of patient reported outcomes on exercise capacity. <h3>REFERENCES:</h3> [1] Enright, P. L. &amp; Sherrill, D. L. (1998). <i>Reference equations for the Six-minute Walk in Healthy adults.</i> AM J RESPIR CRIT CARE MED 1998;158:1384-1387. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Mona-Lovise Ramsli: None declared, Torhild Garen: None declared, Phuong Phuong Diep Boehringer-Ingelheim., Yes (to my institution): Boehringer-Ingelheim., Henriette Didriksen: None declared, Emily Violette Langballe Boehringer-Ingelheim, Helena Andersson: None declared, Øyvind Molberg: None declared, Henrik Mangseth: None declared, Michael Durheim Pfizer and AstraZeneca, Yes, (to my institution): Roche and Boehringer Ingelheim, Anna-Maria Hoffmann-Vold Boehringer Ingelheim, Boehringer Ingelheim, Janssen, Medscape, Merck Sharp &amp; Dohme, Novartis and Roche, ARXX, BMS, Boehringer Ingelheim, Genentech, Janssen, Medscape, Merck Sharp &amp; Dohme and Roche, Boehringer Ingelheim, Janssen.