Predicting cognitive decline and dementia in elderly twins from indicators of early life oral health

UnrestrictedThe purpose of this dissertation was to explore the relationship between tooth loss in young adulthood and dementia and cognitive decline in older adulthood in a sample of elderly twins. The study had two specific aims. The first aim was to determine whether tooth loss is associated with risk of developing dementia after accounting for low SES and other possible covariates. The second aim was to determine whether tooth loss is associated with baseline cognitive performance and cognitive decline on the modified Telephone Interview for Cognitive Status (TICS-m) after accounting for low SES and other possible covariates.; A theoretical model is advanced proposing several possible mechanisms by which oral health may relate to dementia and cognitive decline. The literature review discusses how infectious pathogens and systemic inflammation may play a role in AD with regard to known pathologies including senile plaques, neuron death, neurofibrillary tangles, and cerebrovascular changes. A model of proposed pathways between periodontal infection and AD is presented including three possible mechanisms: a) direct effects of infectious pathogens, b) inflammatory response to pathogens, and c) the effects on vascular integrity. The role of gene polymorphisms is discussed.; The study was conducted using military induction data from members of the NAS-NRC Registry of World War II Veterans who are members of the Duke Twins Study of Memory in Aging (N = 6,352). In case-control analyses, tooth loss in young adulthood did not significantly predict dementia. Tooth loss did predict poor baseline cognitive scores, although the effect was explained by the relationship between tooth loss and low educational attainment. Due to a low rate of tooth loss, the power to detect a relationship between tooth loss and dementia was .20 to .40 in our sample. Thus, results do not rule out a relationship between tooth loss and dementia in the population. Co-twin control analysis techniques were planned, although the low power effectively precluded meaningful co-twin control analyses. Consistent with previous research, older age and lower levels of educational attainment were associated with increased risk of dementia and poorer baseline cognitive scores. Additionally, low education predicted earlier age of dementia onset