ABSTRACTBackground Post-COVID-19 syndrome may impair respiratory function, inspiratory muscle performance, and sleep quality; however, the interaction between inspiratory muscle fatigue, regional deposition/perfusion, and sleep disturbances remains unclear. Objective To analyze associations between inspiratory muscle fatigue, pulmonary radiopharmaceutical activity, and sleep disturbances in symptomatic and asymptomatic post-COVID-19 individuals. Methods This cross-sectional study included 33 post-COVID-19 individuals classified as symptomatic (n=23) or asymptomatic (n=10) according to symptom severity. Inspiratory muscle performance was assessed using maximal inspiratory pressure (MIP), sustained maximal inspiratory pressure (SMIP), and the inspiratory fatigue index (FIT) obtained from an incremental respiratory resistance test. Sleep was assessed by actigraphy, the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS). Pulmonary aerosol deposition and perfusion were assessed by gamma scintigraphy using 99ᵐTc-DTPA and 99ᵐTc-MAA, respectively; total radiopharmaceutical activity was quantified for both lungs combined and for the right and left lungs separately. Results Symptomatic individuals had lower MIP (73 37 vs 114 22.50 cmH2O), SMIP (502 222 vs 935.50 215 PTU), and FIT (22.30 9.20 vs 46.25 20.28; all pConclusions Long COVID is associated with reduced inspiratory muscle performance, impaired ventilation/perfusion, and worse sleep, supporting FIT and pulmonary scintigraphy as potential functional markers for assessment and rehabilitation monitoring.
Junior et al. (Fri,) studied this question.