Background Chewing disability is associated with impaired quality of life, potentially leading to depression and cognitive impairment. While the chewing-ability-cognition relationship has been explored, examining whether depression mediates this relationship remains unclear. We investigated the association between chewing disability and cognitive impairment development and a potential mediation via depression among older persons. Methods Older persons without cognitive impairment at baseline (n=973) from the three waves of the Panel on Health and Ageing of Singaporean Elderly (PHASE) were investigated. The outcome was incident cognitive impairment by the end of the study, while the exposure was chewing disability over the study period. Time-varying depression was the mediator. Time-fixed confounders included sex, ethnicity, education, marital status, living arrangement, and housing type, and time-varying confounders were age, smoking, cardiovascular diseases, diabetes, number of teeth, and denture wearing. We used marginal structural modeling to evaluate the effect of chewing disability on cognitive impairment development. Results After six years, 11% developed cognitive impairment and chewing disability was reported by 33%. Chewing disability was associated with higher odds of developing cognitive impairment (OR 1.43, 95% CI 1.09, 1.87), of which 85.3% was explained by the controlled direct effect of chewing disability, whereas the remaining 14.7% could be eliminated if there was no depression. Conclusions Our findings indicate an association between chewing disability and cognitive impairment, while the role of depression could not be fully elucidated. Oral health should be incorporated as part of older persons’ care for its potential to assess the risk for other systemic conditions.

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咀嚼障碍与老年人认知障碍相关：一项基于人群的队列研究

背景 咀嚼障碍与生活质量受损有关，可能导致抑郁和认知障碍。虽然咀嚼能力与认知的关系已经被探索，但检查抑郁症是否介导这种关系仍不清楚。我们研究了咀嚼障碍与认知障碍发展之间的关联以及通过老年人抑郁症进行的潜在调节。方法 对来自新加坡老年人健康与老龄化小组 (PHASE) 的三轮基线时没有认知障碍的老年人 (n=973) 进行了调查。结果是研究结束时发生认知障碍，而暴露是研究期间的咀嚼障碍。随时间变化的抑郁是中介因素。时间固定的混杂因素包括性别、种族、教育、婚姻状况、居住安排和住房类型，时变的混杂因素包括年龄、吸烟、心血管疾病、糖尿病、牙齿数量和假牙佩戴。我们使用边缘结构模型来评估咀嚼障碍对认知障碍发展的影响。结果 六年后，11% 的人出现认知障碍，33% 的人出现咀嚼障碍。咀嚼障碍与发生认知障碍的较高几率相关（OR 1.43，95% CI 1.09，1.87），其中 85.3% 是由咀嚼障碍的受控直接影响解释的，而其余 14.7% 如果没有沮丧。结论 我们的研究结果表明咀嚼障碍与认知障碍之间存在关联，而抑郁症的作用尚不能完全阐明。口腔健康应纳入老年人护理的一部分，因为它有可能评估其他全身性疾病的风险。