Diabetes mellitus is a risk factor for vascular dementia, but not for Alzheimer's disease: a population-based study of the oldest old.
BACKGROUND
The purpose of this study was to examine if Type 2 diabetes mellitus is a risk factor for dementia in very old age, specifically for Alzheimer's disease (AD) and vascular dementia (VaD).


METHODS
We evaluated the risk of dementia in relation to Type 2 diabetes using a population-based sample of 702 individuals aged 80 years and older (mean age 83 years). A total of 187 persons received a dementia diagnosis. Thirty-one individuals had a diabetes diagnosis prior to onset of the dementia.


RESULTS
Cox proportional hazard analyses, adjusted for age, gender, education, smoking habits, and circulatory diseases, indicated an elevated risk to develop VaD (relative risk = 2.54, 95% confidence interval 1.354.78) in individuals with diabetes mellitus. No association was found between diabetes and AD.


CONCLUSIONS
Type 2 diabetes is selectively related to the different subtypes of dementia. There is no increased risk of AD but more than a twofold risk of VaD in persons with diabetes.
Hassing
Linda B
LB
Department of Psychology, Göteborg University, Göteborg, Sweden. Linda.Hassing@psy.gu.se
Johansson
Boo
B
Nilsson
Sven E
SE
Berg
Stig
S
Pedersen
Nancy L
NL
Gatz
Margaret
M
McClearn
Gerald
G
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology*; D015140:Dementia, Vascular / Q000453:epidemiology*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors