Objective The 6-min walk test (6MWT) is a simple test widely used to assess sub-maximal exercise capacity in chronic respiratory diseases. We explored the relationship of 6-min walk distance (6MWD) with measurements of physiological, clinical, radiographic measures in patients with myositis-associated interstitial lung disease (MA-ILD). Method We analysed data from the Abatacept in Myositis Associated Interstitial Lung Disease (Attack My-ILD) study, a 48-week multicentre randomized trial of patients with anti-synthetase antibodies and active MA-ILD. 6MWD, forced vital capacity (FVC), diffusing capacity (DLCO), high-resolution CT and various physician-/patient-reported outcome measures were obtained during the trial. Spearman’s correlations and repeated-measures analysis with linear mixed-effects models were used to estimate the associations between 6MWD and various physiologic, clinical and radiographic parameters both cross-sectionally and longitudinally. Results Twenty participants with a median age of 57 years, 55% male and 85% white were analysed. Baseline 6MWD did not associate with baseline pulmonary function tests. Repeated-measures analysis showed 6MWD over time associated with FVC over time, but not with DLCO. 6MWD over time also correlated with University of California San Diego Shortness of Breath questionnaire dyspnoea score, Borg scores, as well as global disease activity and muscle strength over time. Emotional role functioning, vitality, general health and physical functioning scores by Short Form 36 also correlated with 6MWD over time. Conclusions Exploratory work in a small cohort of MA-ILD demonstrated 6MWD over time associated with parallel changes in FVC and patient-reported outcomes of dyspnoea, but not with DLCO. Larger studies are needed to validate the reliability, responsiveness and utility of the 6MWT in MA-ILD. Trial registration ClinicalTrials.gov, http://clinicaltrials.gov, NCT03215927.

中文翻译：

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肌炎相关间质性肺病 6 分钟步行距离与生理指标及临床结局的关联


目的 6 分钟步行测试 （6MWT） 是一种简单的测试，广泛用于评估慢性呼吸系统疾病的次极限运动能力。我们探讨了肌炎相关间质性肺病 （MA-ILD） 患者 6 分钟步行距离 （6MWD） 与生理、临床、影像学测量的关系。方法 我们分析了阿巴西普治疗肌炎相关间质性肺病 （Attack My-ILD） 研究的数据，这是一项为期 48 周的多中心随机试验，针对具有抗合成酶抗体和活动性 MA-ILD 的患者。试验期间获得了 6MWD 、用力肺活量 （FVC） 、弥散量 （DLCO） 、高分辨率 CT 和各种医生/患者报告的结果测量。Spearman 的相关性和线性混合效应模型的重复测量分析用于估计 6MWD 与各种生理、临床和影像学参数之间的横截面和纵向关联。结果 对 20 名中位年龄为 57 岁的参与者进行了分析，其中 55% 为男性，85% 为白人。基线 6MWD 与基线肺功能测试无关。重复测量分析显示，随时间推移的 6MWD 与 FVC 随时间推移相关，但与 DLCO 无关。随时间推移的 6MWD 还与加州大学圣地亚哥分校呼吸急促问卷呼吸困难评分、Borg 评分以及随时间推移的整体疾病活动和肌肉力量相关。Short Form 36 的情绪角色功能、活力、一般健康和身体机能评分也与随着时间的推移的 6MWD 相关。结论 在一小群 MA-ILD 队列中的探索性工作表明，随着时间的推移，6MWD 与 FVC 的平行变化和患者报告的呼吸困难结局相关，但与 DLCO 无关。 需要更大规模的研究来验证 6MWT 在 MA-ILD 中的可靠性、响应性和实用性。试验注册 ClinicalTrials.gov、http://clinicaltrials.gov NCT03215927。