Effect of daily swallowing frequency on swallowing-related muscle mass in individuals with severe motor and intellectual disability.

BACKGROUND

Among the causes of dysphagia in individuals with severe motor and intellectual disability (SMID), addressing disuse atrophy of swallowing-related muscles are expected to improve patient outcomes. Disuse atrophy is associated with a reduced frequency of muscle activity, and swallowing frequency may be associated with the atrophy of swallowing-related muscles.

OBJECTIVE

We aimed to investigate the relationship between swallowing frequency and swallowing-related muscle mass in individuals with SMID.

METHODS

This cross-sectional study included 62 individuals with SMID (31 men and 31 women; mean age: 46.9 [standard deviation, 13.2] years) admitted to our center. Swallowing frequency was measured using a laryngeal microphone, and swallowing-related muscle mass was estimated by measuring the cross-sectional area of the geniohyoid muscle (GHM) using an ultrasonic diagnostic device.

RESULTS

Increased swallowing frequency and body weight corresponded to a larger cross-sectional area of the GHM. Moreover, women had a smaller GHM cross-sectional area than men. Multiple regression analysis showed that the swallowing frequency, body weight, and sex were significantly and independently associated with the GHM cross-sectional area (p < 0.01).

CONCLUSIONS

Swallowing frequency and body weight significantly affect swallowing-related muscle mass in individuals with SMID.