Cutoff value of the geniohyoid muscle mass to identify sarcopenic dysphagia by ultrasonography

Key summary points Aim In this study, the cross-sectional area of the geniohyoid muscle was investigated using ultrasonography to determine the normative and cut-off values. Findings The cut-off values of the ultrasonographic cross-sectional area of the geniohyoid muscle were found as 172.5 mm 2 for women and 194.7 mm 2 for men. Message This cut-off values could help detect loss of swallowing muscle mass and contribute to the diagnosis of sarcopenic dysphagia. Purpose Determining the strength and area of the swallowing muscles is important in patients with sarcopenic dysphagia. Although the normative data on the strength of the swallowing muscles have been reported, those of the area of the geniohyoid muscle are poorly investigated. We investigated the cross-sectional area of the geniohyoid muscle in Japanese subjects without dysphagia using ultrasonography to determine the normative and cut-off values. Methods 142 subjects without dysphagia were included. The older group (age ≥ 65 years) included 36 (women 27/men 9) subjects, and the younger group (age ≤ 39 years) included 106 (women 54/men 52) subjects. The cross-sectional area of the geniohyoid muscle was measured by ultrasound. The mean of the younger group-2 standard deviation (SD) was calculated and used as a cut-off value for low swallowing muscle mass. Results The mean (SD) of the area of the geniohyoid muscle of each group was as follows: older women group 167.2 (32.6) mm 2 , older men group 193.2 (49.5) mm 2 , younger women group 247.3 (37.4) mm 2 , younger men group 313.1 (59.2) mm 2 . The mean 2SD of the geniohyoid muscle area in the younger women group was 172.5 mm 2 and in the younger men group 194.7 mm 2 . Conclusion We found that the cut-off value of the ultrasonographic cross-sectional area of the geniohyoid muscle was 172.5 mm 2 for women and 194.7 mm 2 for men. These values could be used as cut-off values for the mass of the geniohyoid muscle to identify patients with sarcopenic dysphagia.