Cognitive function and oral health among ageing adults

Objectives There is inconclusive evidence that cognitive function is associated with oral health in older adults. This study investigated the association between cognitive function and oral health among older adults in England. Methods This longitudinal cohort study included 4416 dentate participants aged 50 years or older in the English Longitudinal Study of Ageing during 2002-2014. Cognitive function was assessed at baseline in 2002/2003 using a battery of cognitive function tests. The self-reported number of teeth remaining and self-rated general oral health status was reported in 2014/2015. Ordinal logistic regression was applied to model the association between cognitive function at baseline and tooth loss or self-rated oral health. Results Cognitive function at baseline was negatively associated with the risk of tooth loss (per each 1 standard deviation lower in cognitive function score, OR: 1.13, 95% CI: 1.05-1.21). When cognitive function score was categorized into quintiles, there was a clear gradient association between cognitive function and tooth loss (P-trend = 0.003); people in the lowest quintile of cognitive function had higher risk of tooth loss than those in the highest quintile (OR: 1.39, 95% CI: 1.12-1.74). A similar magnitude and direction of association were evident between cognitive function and self-rated oral health. Conclusion This longitudinal study in an English ageing population has demonstrated that poor cognitive function at early stage was associated with poorer oral health and higher risk of tooth loss in later life. The gradient relationship suggests that an improvement in cognitive function could potentially improve oral health and reduce the risk of tooth loss in the ageing population.