Relationship between chewing ability and malnutrition, sarcopenia, and frailty in older adults

Background Several studies reported that impaired nutrition is associated with reduced muscle mass, muscle strength, and physical performance. Chewing ability is essential to maintain balanced oral nutrient intake. The study was designed to define the possible relationship between chewing ability and nutrition-related problems (malnutrition, sarcopenia, and frailty) in a holistic perspective. Methods This cross-sectional study recruited adults aged >= 65 years. All patients were evaluated with comprehensive geriatric assessment. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People criterion. Malnutrition was determined according to body mass index, calf circumference, and Mini Nutritional Assessment short form (MNA-SF). Frailty status was diagnosed with the Clinical Frailty Scale. Masseter and gastrocnemius muscle thicknesses (MTs) were measured via ultrasonography imaging. Oral examinations were carried out by a dentist, and chewing performance was examined with a color-changeable chewing gum. Results Overall, 135 older adults (76 females) were analyzed. Mean +/- SD age was 75.7 +/- 7.2 years; 37.0% of the patients were frail, 3.7% were malnourished, 12.6% were sarcopenic, and 20.0% had poor chewing function. In the poor chewing function group, age and frailty scores were increased and the MNA-SF scores, handgrip strength, skeletal muscle index, and masseter MT were reduced (all P < 0.05). After adjusting for confounders, regression analysis showed that low grip strength and low gastrocnemius MT were independently associated with poor chewing ability. Conclusions Chewing ability was related to sarcopenia. Age and low grip strength in females and low cognitive scores and having low gastrocnemius MT in males were independent variables affecting chewing ability.