Canadian researchers have found an association between dementia and the combined impact of 19 other health problems. The "frailty index" used by the researchers to assess dementia risk included arthritis, skin problems, difficulties with hearing and vision, and whether or not dentures fit properly.
The research team, based in Halifax, drew on data from the Canadian Study of Health and Aging, a 10-year epidemiological study of dementia that began in 1991. They followed the health outcomes of 7,239 men and women aged 65 and over, all of whom were cognitively healthy at the start of the study. At five-year intervals, each participant underwent an evaluation for the onset of Alzheimer's disease or any other form of dementia. They also answered questions about many health problems common among elderly people.
By the end of the study period, nearly 3,000 participants had died; 883 maintained their cognitive health, while about 600 had developed Alzheimer's or some other form of dementia.
Dementia and health
Age and age-related health problems such as stroke, heart disease, high blood pressure, and diabetes are among the most commonly recognized risk factors for the onset of Alzheimer's. But according to the study, the various health conditions listed in the frailty index also appear to be at play in the development of the disease.
"We evaluated several health deficits that are not known to be risks for dementia, and found that, combined in an index variable, they were significantly associated not just with survival, but also with the incidence of [Alzheimer's disease] and dementia of all types over 5-year and 10-year intervals," the authors write. "Accumulating any health deficit seemingly remote to dementia increases the risk of dementia by over 3%."
That leads the authors of the study, published today in the online edition of the journal Neurology, to conclude that maintaining overall health could play a significant role in keeping Alzheimer's and other forms of dementia at bay.
"Our study suggests that rather than just paying attention to already known risk factors for dementia, such as diabetes or heart disease, keeping up with your general health may help reduce the risk for dementia," study co-author Kenneth Rockwood, MD, of Dalhousie University in Halifax, Nova Scotia, Canada, says in a news release.
By Matt McMillen
Reviewed by Laura J. Martin, MD