Individuals with the metabolic syndrome, which is known to increase the risk of cardiovascular disease, and diabetes may also have an increased risk of vascular dementia, but not Alzheimer’s disease.
“If metabolic syndrome were also associated with increased risk of developing dementia, the screening and management of its components might offer avenues for prevention of cardiovascular disease and dementia as well,” lead author Dr. Christelle Raffaitin of University Hospital Bordeaux, Pessac, France, and colleagues reported. “However, the association between metabolic syndrome, or its individual components, and dementia has received little attention.”
The researchers examined the association between the individual components of metabolic syndrome (hypertension, large waist circumference, high triglycerides, low HDL cholesterol, and elevated fasting glycemia) and the risk of incident dementia and its subtypes (Alzheimer’s disease and vascular dementia).
Over the 4-year study, 7087 community-dwelling adults without dementia at baseline completed at least one follow-up examination. The subjects were at least 65 years of age. The researchers report that 15.8% of the participants had the metabolic syndrome, which increased the risk of incident vascular dementia, but not Alzheimer’s disease, independent of sociodemographic characteristics and the apolipoprotein E-epsilon-4 allele.
However, the only component of the metabolic syndrome that was significantly associated with the incidence of all-cause (hazard ratio 1.45; p = 0.02) and vascular (hazard ratio 2.27; p = 0.02) dementia was high triglyceride levels. The association remained significant after adjustment for apoE genotype.
A significant association was also observed between diabetes and all-cause (hazard ratio 1.58; p = 0.03) and vascular (hazard ratio 2.53; p = 0.03) dementia. Impaired fasting glucose was not associated with any type of dementia.
The relationship among high triglycerides, diabetes and vascular dementia “emphasizes the need for detection and treatment of vascular risk factors in older persons in order to prevent the likelihood of clinical dementia,” Dr. Raffaitin said in an interview with Reuters Health. “Our next step is to study the associations between cognitive decline — the stage before dementia — and metabolic syndrome and its components.”
Diabetes Care Jan. 2009;32:169-174.