OBJECTIVE: Associations between metabolic syndrome and its individual components 
with risk of incident dementia and its different subtypes are inconsistent.
RESEARCH DESIGN AND METHODS: The 7,087 community-dwelling subjects aged > or =65 
years were recruited from the French Three-City (3C) cohort. Hazard ratios (over 
4 years) of incident dementia and its subtypes (vascular dementia and 
Alzheimer's disease) and association with metabolic syndrome (defined according 
to the National Cholesterol Education Program Adult Treatment Panel III 
criteria) and its individual components (hypertension, large waist 
circumference, high triglycerides, low HDL cholesterol, and elevated fasting 
glycemia) were estimated in separate Cox proportional hazard models.
RESULTS: Metabolic syndrome was present in 15.8% of the study participants. The 
presence of metabolic syndrome increased the risk of incident vascular dementia 
but not Alzheimer's disease over 4 years, independent of sociodemographic 
characteristics and the apolipoprotein (apo) Eepsilon4 allele. High triglyceride 
level was the only component of metabolic syndrome that was significantly 
associated with the incidence of all-cause (hazard ratio 1.45 [95% CI 
1.05-2.00]; P = 0.02) and vascular (2.27 [1.16-4.42]; P = 0.02) dementia, even 
after adjustment of the apoE genotype. Diabetes, but not impaired fasting 
glycemia, was significantly associated with all-cause (1.58 [1.05-2.38]; P = 
0.03) and vascular (2.53 [1.15-5.66]; P = 0.03) dementia.
CONCLUSIONS: The observed relation between high triglycerides, diabetes, and 
vascular dementia emphasizes the need for detection and treatment of vascular 
risk factors in older individuals in order to prevent the likelihood of clinical 
dementia.