SAN ANTONIO -- The fewer teeth someone has in middle age, the greater the risk seems to be for dementia later in life, data from an ongoing study of women's health suggest.
SAN ANTONIO, July 13 -- The fewer teeth someone has in middle age, the greater the risk seems to be for dementia later in life, data from an ongoing study of women's health suggest.
Poor dental health increased the likelihood of dementia by 30% to 40% over a 32-year period, regardless of cardiovascular status, according to a report at the International Society of Vascular Behavioral and Cognitive Disorders meeting here.
After adjustment for multiple demographic and clinical factors, the association between tooth count and dementia remained significant.
Previous studies have suggested an association between poor dental health and cardiovascular disease, possibly linked by the common thread of lower socioeconomic status. However, the two seemingly disparate health conditions also have some intriguing potential biological links, said Robert Stewart, M.D., of King's College London, England.
"Inflammation is a particularly interesting area," Dr. Stewart said. "Someone with poor dental health often has chronic infections in their teeth and gums. This gives rise to circulating inflammatory markers, and circulating inflammatory markers are potentially related to cardiovascular disease, dementia, and a host of other diseases that people are very interested in studying whether inflammatory pathways are involved."
To look at a dental health/dementia correlation, Dr. Stewart and colleagues analyzed data from the Women's Health Study of Goteborg, Sweden. The study includes women born in 1908, 1914, 1918, 1922, and 1930. The women had clinical examinations in 1968, 1974, 1980, 1992, and 2000. Dental exams took place in 1968, 1980, and 1992, and diagnostic evaluations for dementia were conducted in 2000.
Dr. Stewart and colleagues conducted a nested analysis of 638 surviving women who had dental exams in 1968 and dementia evaluations. The study group included 84 women who met criteria for dementia.
As compared with dementia-free participants, women with dementia were older (more than 90% were 78 or older), were less likely to have a high school education, and more likely to have a history of myocardial infarction.
Comparison of dental status and prevalence of dementia revealed a clear inverse association between tooth count and dementia in 1968, 1980, and 1992 (years when dental exams occurred). For example, about 25% of women with dementia had fewer than nine teeth at the 1968 dental exam, compared with a dementia prevalence of about 5% in women who had 25 or more teeth.
In an analysis adjusted only for age, declining tooth count was associated with an odds ratio of 1.3 for dementia. Adjustment for education and a variety of cardiovascular risk factors had minimal impact on the association. Adjustment for weight change between 1968 and 1992 resulted in an odds ratio of 1.4.
"Dental health is a prospective predictor of dementia which does not appear to be accounted for by cardiovascular comorbidity," Dr. Stewart concluded. "It may in part be a marker of cognitive reserve or education but inflammatory and nutritional causal pathways require investigation."
Future investigations will focus on finding other cohorts with data from dental and cognitive assessments, he added, but very few have been identified thus far.