Sex-difference in chewing difficulty and the risk of obstructive sleep apnea among middle-aged and older adults.

PURPOSE: Chewing difficulty may reflect orofacial factors linked to obstructive sleep apnea (OSA) risk, yet evidence remains limited, especially regarding sex differences. This study examined the association between perceived chewing difficulty and OSA risk according to sex. METHODS: The study used five-year (2019-2023) data from the Korean National Health and Nutrition Examination Survey, including 16,105 participants aged ≥ 40 years (6,965 males and 9,140 females). Chewing difficulty was assessed on a five-level scale, and OSA risk was determined using the STOP-Bang questionnaire. A significant interaction between sex and chewing difficulty (p = 0.0387) in the model prompted sex-stratified analyses. Multivariable and multinomial logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among participants, 62.7% of males and 18.5% of females were classified as having middle-to-high risk of OSA. In adjusted models, chewing difficulty was significantly associated with higher OSA risk (OR: 1.28, 95% CI: 1.11-1.48) in females but not in males, with stronger associations observed at higher OSA risk levels (middle-risk, OR: 1.26, 95% CI: 1.09-1.46; high-risk, OR: 1.86, 95% CI: 1.09-3.18). This association persisted when chewing difficulty was analyzed as a graded variable, showing a trend of increasing association with greater severity (p < 0.0001 for trend). CONCLUSIONS: In females, higher levels of chewing difficulty were associated with increased OSA risk. These findings suggest that chewing difficulty could be explored as a potential factor in identifying individuals at higher risk of OSA.