Sex Differences in the Association Between Masticatory Function and Sarcopenia Components: The Shizuoka Study.

Background/

Objectives

Low masticatory function has been proposed as a risk factor for sarcopenia. This study investigated its potential association with body composition and physical performance in community-dwelling older adults.

Methods

Participants included adults aged ≥65 years (643 men; 797 women) who volunteered for a longitudinal cohort study. Masticatory function was objectively assessed using gummy jelly and subjectively evaluated via a structured questionnaire. The skeletal muscle mass, body mass index, waist circumference, handgrip strength, gait speed, and five-time chair-stand test were assessed.

Results

Objectively measured masticatory function was classified as low (12.6%), moderate (38.0%), or high (49.4%). In men, masticatory function was significantly associated with skeletal muscle mass index (low, moderate, and high: 7.4, 7.7, and 7.7 kg/m2; p = 0.005), handgrip strength (31.8, 34.2, and 35.5 kg; p < 0.001), and gait speed (1.3, 1.4, and 1.4 m/s; p = 0.003). In women, low masticatory function was linked to a higher body mass index (22.9, 22.0, and 21.9 kg/m2; p = 0.028) and waist circumference (82.9, 80.8, and 80.4 cm; p = 0.041). Moreover, these significant associations persisted after adjusting for covariates. Discrepancies were observed between objective and subjective measures of masticatory function, with approximately 40% of participants showing low objective masticatory function, perceiving their chewing ability as normal. Subjective masticatory function exhibited no significant associations with anthropometric measures or sarcopenia components.

Conclusions

In men, objectively measured low masticatory function was associated with reduced skeletal muscle mass and poor physical performance; in women, it was linked to higher body mass index.