New tool assesses dementia risk for seniors
Some items on the 15-point scale (e.g., older age, low scores on cognitive tests, and having a particular gene) are well-established risk factors. Others are less conventional (e.g., being underweight, abstaining from alcohol, a history of coronary bypass surgery).
The NIH-funded study involved 3,375 participants in the Cardiovascular Health Cognition Study, which is nested within a larger prospective, population-based project. All were aged 65 years or older at baseline with no evidence of dementia; 59% were women, and 15% were black (Neurology. 2009; published online ahead of print).
During six years of follow-up, 14% developed some type of dementia. Of these, 51% were diagnosed with Alzheimer's disease, 13% with vascular dementia, 31% with mixed dementia, and 5% with some other form. Overall risk correlated with index scores, as 4.2% of subjects with low scores (0-3 points) developed dementia compared with 22.8% of those with moderate scores (4-7points) and 56.0% of those with high scores (8-15 points).
The researchers looked at many factors associated with mental decline before culling a final "late-life dementia risk index." It includes age, poor cognitive test performance, BMI <18.5, one or more apolipoprotein E-ε4 alleles, cerebral MRI findings of white matter disease or ventricular enlargement, internal carotid artery thickening on ultrasound, history of coronary bypass surgery, slow physical performance (of tasks such as buttoning a shirt), and lack of alcohol consumption.
"This tool could be used in clinical settings to target prevention and intervention strategies toward high-risk individuals," the researchers conclude. "The index could also be used to reassure those individuals whose risk is low or moderate."