Decreased Tongue Strength is Related to Skeletal Muscle Mass in COPD Patients

Dysphagia is frequently observed in patients with chronic obstructive pulmonary disease (COPD). Decreased tongue strength is one of the causes of dysphagia, and it is often observed in patients with sarcopenia. Sarcopenia is also frequently observed in COPD patients. We hypothesized that tongue strength is lower in COPD patients compared to normal subjects. This was a single-center, observational, cross-sectional study. Maximum tongue pressure (MTP) was measured in 27 patients with COPD and 24 age-matched control subjects. We also evaluated handgrip strength, gait speed, and appendicular skeletal muscle mass to define subjects as having sarcopenia. We used bioelectrical impedance analysis to assess body composition. The eating assessment test-10 was used to diagnose dysphagia. MTP was significantly lower in COPD patients than in control subjects (33.8 ± 8.4 vs 38.0 ± 5.3; p = 0.032). All measures of muscle and fat free body mass, handgrip strength, and gait speed were also significantly lower in COPD patients compared to control subjects (p < 0.01). The prevalence of sarcopenia in COPD patients was higher than that in control subjects (6/27 versus 0/24; p = 0.007), but the prevalence of dysphagia was not different between groups (COPD: 5/27, versus control: 1/24; p = 0.112). MTP was moderately correlated with skeletal muscle mass index (r = 0.56, p = 0.003) and handgrip strength (r = 0.43, p = 0.027) in COPD patients. Tongue strength was lower in COPD patients compared to normal subjects, and decreased tongue strength may be correlated with sarcopenia in COPD patients.