Association of cognitive function with tooth loss and mitochondrial variation in adult subjects: a community-based study in Beijing, China.

Abstract

Cognitive impairment is a common neurological problem in elderly people. In this study, we investigated whether tooth loss, periodontal parameters, and gene variations in the mitochondrial DNA displacement loop region are potential influencing factors on cognitive function. We employed a linear regression model to estimate cross-sectional association between number of teeth lost, periodontal parameters and Mini-mental State Examination score, adjusting for demographic factors, socioeconomic factors, general health status, smoking, drinking, and life habits. A total of 905 Han Chinese people, ≥50years of age, with complete data, were enrolled. Blood samples of 567 of the subjects were analyzed for correlation between mitochondrial DNA variants and Mini-mental State Examination score. The number of teeth lost (β=-0.042, 95% CI: -0.061, -0.024, P<0.001), two single nucleotide polymorphism (SNP) points: A189G (β=-1.540, 95% CI: -2.818, -0.263, P=0.018) and A16164G (β=-1.053, 95% CI: -2.054, -0.052, P=0.039) in the mitochondrial DNA displacement loop region, and haplogroup Y (β=-2.152, 95% CI: -4.062, -0.242, P=0.027) were found to be negatively associated with Mini-mental State Examination scores in the fully adjusted model. No correlation was found between periodontal parameters and Mini-mental State Examination scores. Number of teeth lost, mitochondrial SNPs, and haplogroup Y were correlated with cognitive function in this study population.