Six-minute walk test as a tool for functional assessment of patients with pneumoconiosis

BACKGROUND AND AIM: Pneumoconiosis can impair lung functions and the exercise capacities of patients. The six -minute walk test (6MWT) is a submaximal cardiopulmonary exercise test. In cases of pneumoconiosis, it may serve as a reliable functional tool for medical, social, and legal assessments. Considering this, we aimed to investigate the value of the 6MWT in pneumoconiosis patients experiencing dyspnea despite normal pulmonary function tests (PFTs). METHODS: This cross-sectional study, conducted from September to December 2015, investigated 85 inpatients with pneumoconiosis who showed symptoms of dyspnea despite having normal results in PFTs. Data on sociodemographic features, occupational history, functional and radiological assessments, and 6MWT results were evaluated. Radiological assessment were performed according to International Labour Organization (ILO) categorization. RESULTS: All patients were male. The mean age of the patients were 41.65 +/- 10.8. The majority had q opacity (51.8%) and were in category 1 (67%). 11 (13.0%) patients had a large opacity, and 6 of these were classified as having A opacity in ILO classification. The mean distance in the 6MWT was 488.54 +/- 87.54 meters, with 18 (21.1%) patients developing desaturation of more than 4%. A moderate negative correlation was observed between chest X-ray profusion and walking distance (p=0.001, r=-0.365). Walking distance was significantly lower in patients with a profusion of 2/1 or higher (452.29 +/- 94.36 m vs. 506.35 +/- 78.8 m; p=0.021). Receiver operating curve analysis indicated a cut-off value of 414 meters for category 2 or worse radiology. CONCLUSIONS: This study evaluated pneumoconiosis patients with dyspnea and normal PFT results, showing that the 6MWT is moderately correlated with radiological findings. More extensive disease was associated with a lower walking distance. These results suggest the potential role of the 6MWT in the routine evaluation of pneumoconiosis patients. The 6MWT may be a valuable tool in occupational health for monitoring pneumoconiosis patients.