Ultrasonographic Measurement of Masseter Muscle Thickness Associates with Oral Phase Dysphagia in Institutionalized Elderly Individuals

Abstract

Background & aims: Oral phase dysphagia is dependent on ability to chew. As people age, general muscle atrophy contributes to decreased masseter strength. The main objective of this study was to assess the relationship between the thickness of the masseter muscle measured by ultrasonography and the presence of dysphagia in a group of institutionalized elderly people. As a secondary objective, we aimed to establish cutoff points of masseters muscle thickness (MMT) to identify elderly individuals at risk of oral dysphagia.

Methods: Cross-sectional study of all residents from 3 nursing homes. All individuals underwent ultrasonographic measurements of left and right MMT and were classified according to the presence of dysphagia assessed by both the EAT-10 screening questionnaire and the volume-viscosity swallow test (V-VST).

Results: 469 patients (69% women, mean age 84.7 yrs) were recruited. Dysphagia was present in 41.6% and 26% of individuals according the EAT-10 and V-VST, respectively. Multivariate logistic regression showed that 1 mm increase in MMT reduced the risk of dysphagia by 21% according to the EAT-10 tool and by 30% using the V-VST after adjusting for age, sex, mini-nutritional assessment score, and body mass index. We used receiver operative characteristic (ROC) curves to identify cutoff points of MMT to detect dysphagic individuals according to either EAT-10 or V-VST.

Conclusions: The MMT measured by ultrasonography is reduced in elderly individuals with dysphagia. Based on MMT, clinicians may be better informed about the patients'´ ability to masticate solid foods and identify potential nutrient deficiencies in geriatric settings.

Keywords: Malnutrition; Mastication; ROC; Severe dependency; Swallowing.