Impact of COVID-19 severity on sleep parameters, exercise tolerance, respiratory muscle strength, pulmonary function, and quality of life: a cross-sectional study

To investigate the impact of post-COVID-19 infection severity on lung function, exercise tolerance, sleep parameters, and quality of life. A cross-sectional study with 30 individuals (age 44.27±14.88 years; 70% women) affected by COVID-19 (23.37±3.49 months after acute infection) was divided into 3 groups: control, mild, and moderate/severe. Evaluations included: submaximal aerobic capacity, respiratory muscle strength, lung function, sleep parameters and quality of life. The moderate/severe group showed lower results for the predicted percentage of FEV1/FVC (p=0.004) and significant differences in sustained maximum inspiratory pressure (SMIP) and fatigue index (FIT) (p<0.05). They also showed reduced exercise tolerance with shorter walking distances (p<0.001), poorer sleep quality, excessive daytime sleepiness, lower sleep efficiency (p=0.032), longer sleep latency (p<0.001), and more awakenings (p=0.006). Quality of life was reduced in three of the eight domains assessed. Individuals with moderate/severe COVID-19 exhibited impaired pulmonary function, reduced sleep efficiency, more awakenings, and lower quality of life compared to those with asymptomatic or mild cases.