Self-Assessed Kyphosis and Chewing Disorders Predict Disability and Mortality in Community-Dwelling Older Adults

Objective

It is clear that each trend of kyphosis with increased age and the ability to eat firm foods with the back teeth (chewing ability) has a strong influence on both the physical and mental condition of older people. Thus, this study aimed to examine whether the combination of kyphosis and chewing disorders was associated with mortality or the need for care under the new long-term care insurance (LTCI) service requirement, over 3 years in community-dwelling older Japanese adults.

Design

A prospective cohort study.

Setting and Participants

We analyzed the cohort data for older adults (65 years or older) from a prospective study in Kami town. The response rate was 94.3%, and we followed 5094 older individuals for 3 years. Thus, we analyzed 5083 older adults using multiple imputation to manage missing data.

Outcome

The outcomes were mortality or new certifications for LTCI services in a 3-year period.

Measurements

We developed 3 groups by asking 2 self-reported questions on both “no kyphosis” and “good chewing ability.” The groups were no kyphosis and good chewing ability (GG), kyphosis and poor chewing ability (BB), and kyphosis and good chewing ability or no kyphosis and poor chewing ability (GB/BG).

Results

The prevalence of BB, BG/GB, and GG were 8.9%, 40.3%, and 50.8%, respectively, in our survey. During the 3-year follow-up period, 5.2% (n = 262) died and 13.9% (n = 708) individuals were newly certified as needing LTCI services. As determined by multivariate analyses, BG/GB older adults (adjusted hazard ratio: 1.3 [95% CI 1.1–1.6]) and BB older adults (adjusted hazard ratio: 2.0 [95% CI 1.5–2.4]) had a significantly higher risk of needing LTCI services than GG older adults. Similarly, BG/GB older adults (adjusted hazard ratio: 1.5 [95% CI 1.1–2.0]) and BB older adults (adjusted hazard ratio: 2.3 [95% CI 1.5–3.3]) had a significantly higher risk of mortality than GG older adults did.

Conclusion

The presence of kyphosis or poor chewing ability was related to mortality and new certifications for LTCI services, and we found an additive effect of these 2 factors related to frailty.