Sarcopenia and Comorbidity Burden Independently Predict Cough Impairment in Hospitalized Patients: A Cross-Sectional Study

Background and Objectives: Peak Cough Flow (PCF) is an objective measure of cough effectiveness, traditionally used in patients with neuromuscular disorders. Sarcopenia may also impair respiratory muscles, but its relationship with cough efficacy in hospitalized patients with respiratory diseases is not well established. This study investigated the correlation between PCF and sarcopenia indicators and evaluated the influence of comorbidities, anthropometric variables, and body position on PCF. Methods: A cross-sectional observational study was performed. PCF was measured using a portable peak flow meter in seated and supine positions. Sarcopenia was assessed through handgrip strength and validated questionnaires. Comorbidity burden was quantified using the Charlson Comorbidity Index (CCI). Nutritional status and sleep apnea risk were evaluated with the Mini Nutritional Assessment–Short Form (MNA-SF) and STOP-BANG questionnaire. Correlation analyses and linear regression were performed. Results: 53 patients were enrolled (mean age 72.6 ± 15.2 years; 64% male). Men showed significantly higher PCF values than women in both seated (p < 0.001) and supine positions (p < 0.001). Sarcopenic patients exhibited reduced PCF compared to non-sarcopenic subjects (p = 0.037). Handgrip strength was strongly correlated with PCF in seated and supine positions (p < 0.0001). CCI was negatively correlated with PCF (seated r2 = 0.17, p = 0.0021; supine r2 = 0.16, p = 0.0027). No significant associations were observed with BMI, MNA-SF, or STOP-BANG. Postural change resulted in comparable PCF reduction in men and women (ΔPCF: 20 ± 37.9 vs. 17 ± 37.9 L/min). Conclusions: Sarcopenia and comorbidity burden are significantly associated with reduced cough efficacy. Handgrip strength is a strong predictor of PCF, supporting routine PCF assessment beyond neuromuscular populations.