The relationship between masseter muscle thickness and appendicular skeletal muscle mass in Japanese community-dwelling elders: A cross-sectional study

Purpose of the study: Sarcopenia has been identified as a health hazard in elderly people. Although the association between sarcopenia and a decrease in masticatory function has been reported, the mechanism underlying this association has not been widely reported. Therefore, in order to elucidate the relationship between sarcopenia and masticatory function, we examined whether the masseter muscle thickness (MMT), which is a factor influencing masticatory function, in community-dwelling elders is associated with the appendicular skeletal muscle index (SMI), a diagnostic criterion for sarcopenia. Materials and methods: MMT was measured in 774 community-dwelling elders aged 65 years or older at resting state via ultrasonography, and SMI was measured with the bioelectrical impedance method. The relationships were investigated by calculating Pearson's correlation coefficients. Multiple regression analyses adjusted for age and sex, SMI, and oral-related items were performed to determine the association between these factors. Results: There was a significant correlation between the MMT and the SMI. The multiple regression analysis indicated that SMI was significantly associated with a decrease in MMT. Conclusions: The reduction in whole-body skeletal muscle mass in sarcopenia may be involved in the reduction in MMT. Prevention of sarcopenia may be an important factor for maintaining masticatory function in the elderly.