Objective
To evaluate the relationship between respiratory muscle strength, diaphragm thickness (DT), and indices of sarcopenia.
Methods
This study included 45 healthy elderly volunteers (21 male and 24 female) aged 65 years or older. Sarcopenia indices, including hand grip strength (HGS) and body mass index-adjusted appendicular skeletal muscle (ASM/BMI), were measured using a hand grip dynamometer and bioimpedance analysis, respectively. Calf circumference (CC) and gait speed were also measured. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were obtained using a spirometer, as a measure of respiratory muscle strength. DT was evaluated through ultrasonography. The association between indices of sarcopenia, respiratory muscle strength, and DT was evaluated using Spearman’s rank correlation test, and univariate and multiple regression analysis.
Results
ASM/BMI (r=0.609, p<0.01), CC (r=0.499, p<0.01), HGS (r=0.759, p<0.01), and gait speed (r=0.319, p<0.05) were significantly correlated with DT. In the univariate linear regression analysis, MIP was significantly associated with age (p=0.003), DT (p<0.001), HGS (p=0.002), CC (p=0.013), and gait speed (p=0.026). MEP was significantly associated with sex (p=0.001), BMI (p=0.033), ASM/BMI (p=0.003), DT (p<0.001), HGS (p<0.001), CC (p=0.001) and gait speed (p=0.004). In the multiple linear regression analysis, age (p=0.001), DT (p<0.001), and ASM/BMI (p=0.008) showed significant association with MIP. DT (p<0.001) and gait speed (p=0.050) were associated with MEP.
Conclusion
Our findings suggest that respiratory muscle strength is associated with DT and indices of sarcopenia. Further prospective studies with larger sample sizes are needed to confirm these findings.

Citations

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Objective
To analyze the factors influencing the capacity of cough, the relationships between maximal respiratory pressure, lung compliance, capacity of cough, and assisted cough techniques were evaluated in tetraplegics. Method: The vital capacity (VC) in seated and supine position, maximum insufflation capacity (MIC), maximum inspiratory (MIP) and expiratory (MEP) pressure in seated position were measured. Unassisted and assisted peak cough flow (PCF) at two different conditions (a volume assisted method by the mechanical insufflation [PCFmic] and the manual assistance by abdominal compression [MPCF]) were evaluated in 44 tetraplegic patients. Results: The mean value of VC in supine was greater than that of seated position (p＜0.01). The MICs of the subjects were significantly higher than VCs in a same position (＜0.01). Both volume and manual assisted method showed significantly higher PCF than unassisted PCF (p＜0.01). MIP (r=0.53) correlated with UPCF as well as MEP (r=0.68), although MEP was better correlated with MPCF. Conclusion: Generally the therapists apply manual pressure only to increase capacity of cough, which assist the expulsive phase. The results of this study showed that both inspiratory and expulsive phases should be assisted to enhance the effectiveness of cough. (J Korean Acad Rehab Med 2002; 26: 704-708)