Occlusal force is correlated with cognitive function directly as well as indirectly via food intake in community-dwelling older Japanese: From the SONIC study.

Kazunori Ikebe,Mai Kabayama,Hirochika Ryuno,Yuko Kurushima,Yasuyuki Gondo,Motoyoshi Fukutake,Ryosuke Oguro,Shinya Murakami,Yoshinobu Maeda,Yukie Masui,Yoichi Takami,Ken Sugimoto,Yasumichi Arai,Kaori Enoki,Hitomi Okubo,Taturo Ishizaki,Kei Kamide,Hiromi Rakugi,Kohdai Hatta,Masahiro Kitamura,Yasushi Takeya,Taiji Ogawa,Hiroki Inagaki,Yusuke Mihara,Chisato Inomata,Hitoshi Takeshita ,Kōichi Yamamoto ,Takeshi Nakagawa ,Ken Matsuda ,Noriyuki Itoh

doi:10.1371/journal.pone.0190741

Abstract

BackgroundGrowing evidence suggests that oral health may be an important factor associated with cognitive function in aged populations. However, many previous studies on this topic used insensitive oral indicators or did not include certain essential covariates. Thus, we examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors.MethodsIn this cross-sectional study of older community-dwelling Japanese adults, we examined data collected from 994 persons aged 70 years and 968 persons aged 80 years. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were evaluated according to the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between MoCA-J scores and occlusal force were investigated via bivariate and multivariate analyses.ResultsEducation level, financial status, depression score, and intake of green and yellow vegetables, as well as number of teeth and occlusal force, were significantly correlated with MoCA-J scores in both age groups. Among individuals aged 80 years, CRP and periodontal status were weakly but significantly associated with MoCA-J score. After controlling for all significant variables via bivariate analyses, the correlation between maximal occlusal force and cognitive function persisted. A path analysis confirmed the hypothesis that cognitive function is associated with occlusal force directly as well as indirectly via food intake.ConclusionsAfter controlling for possible factors, maximal occlusal force was positively associated with cognitive function directly as well as indirectly through dietary intake.

Highlights

Cognitive impairment is a substantial health concern for rapidly aging societies, where it is a major cause of severe disability
We examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors
A path analysis confirmed the hypothesis that cognitive function is associated with occlusal force directly as well as indirectly via food intake

Summary

Introduction

Cognitive impairment is a substantial health concern for rapidly aging societies, where it is a major cause of severe disability. In the last year of life, 68% of patients with advanced dementia were labeled as having a persistently severe disability, a value that far exceeds the percentage of those with frailty (25%) or organ failure (18%) [1]. A Japanese survey conducted in 2012 indicated that 15% of the older population (65 year and older) had been diagnosed with dementia, while 13% had mild cognitive impairment (MCI). Half of individuals with MCI progress to dementia within 5 years of the initial diagnosis. Strategies for preventing or delaying the onset of dementia, even marginally, are extremely important. Growing evidence suggests that oral health may be an important factor associated with cognitive function in aged populations. We examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors

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