Dyspnea, respiratory muscle strength, cough capacity, and sleep quality in individuals with substance use disorder.

There is evidence that substance use and smoking cause some adverse effects on the respiratory system. The aim of this study was to assess dyspnea severity, respiratory muscle strength, cough capacity, and sleep quality in people with substance use disorder (SUD). Forty eight individuals with SUD and 28 active cigarette smokers participated in the study. Participants' dyspnea severity was assessed using the Modified Medical Research Council Scale, respiratory muscle strength was measured with a portable electronic mouth pressure device, peak cough flow was assessed with a Peak Flow Meter, and sleep quality was determined using the Pittsburgh Sleep Quality Index (PSQI). The amount of daily cigarette smoking and dyspnea severity were significantly higher in individuals with SUD ( < .001). Peak cough flow values, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), MIP (%predicted), and MEP (%predicted) were not significantly different between the SUD patients and the active cigarette smokers ( > .05). However, PSQI sub-parameters such as subjective sleep quality, sleep latency, habitual sleep efficiency, use of sleeping medication, and total scores showed significant differences between the SUD patients and the active cigarette smokers ( < .05,  < .001,  = .03,  < .001,  < .001, respectively). Individuals with SUD were found to have higher dyspnea and poorer sleep quality than active smokers. However, respiratory muscle strength and cough capacities were similar.