| Several lines of evidence suggest Alzheimer's disease (AD) and vascular dementia (VaD) are an impending public health catastrophe. Treatment for dementia has thus far been insufficient and, therefore, many scientists have turned their focus towards prevention. Multiple studies have implicated vascular factors as possible risk factors for both AD and VaD. The overall aim of this thesis was to extend this line of research by examining blood-related risk factors of vascular diseases and their relation to dementia and biomarkers of dementia. In chapter 2 we review these blood-related factors, including homocysteine, cholesterol, triglycerides, fatty acids, potassium, antioxidants, and C-reactive protein. For each of these factors we provide background information, suggest possible biological mechanisms, and review epidemiological studies that have examined their relationship with dementia.; In chapter 3 we examine total cholesterol and triglyceride levels in relation to incident dementia in an 18-year follow-up of a 70-year-old birth cohort in Sweden. Multiple studies have examined mid-life cholesterol and dementia risk, but few have examined late-life cholesterol and incident dementia. We found low cholesterol was associated with an increased risk of dementia. Upon examination of cholesterol in quartiles, the risk reduction was apparent only among the highest quartile. Triglyceride levels were not associated with dementia.; In chapter 4 we examine potassium and incident VaD using the same dataset as in chapter 3. This is the first prospective study to examine the association between potassium and dementia. We initially examined both AD and VaD but since potassium was only associated with VaD, this dementia subtype is the emphasis of the current chapter. Importantly, we show low potassium is associated with an increased risk of VaD, independent of blood pressure and stroke.; Finally, in chapter 5 we examine potassium and CSF Abeta(1--42) in a 24-year follow-up of women from Sweden, first interviewed in 1968. Decreasing potassium in 1968 and 1974, but not 1980 and 1992, was associated with decreasing CSF Abeta(1--42) levels in 1992. Associations remained after controlling for blood pressure and other factors. These findings, along with those of chapter 4, offer intriguing evidence that potassium is involved in dementia pathogenesis. |
