Chris MacKnight, MD, MSc, FRCPC
Division of Geriatric Medicine,
Dementia and hypertension are two of the most common conditions affecting older adults. A number of recent studies suggest that dementia is one of the long-term complications of hypertension. Studies also suggest that the treatment of hypertension may prevent dementia. This brief review will focus on the relationship between hypertension and dementia in older adults.
Epidemiology of Dementia
Eight percent of Canadians who are over the age of 65 suffer from dementia, with Alzheimer's disease being the most common cause (approximately 60% of cases).1 Dementia is age-related, with the prevalence increasing from 2.4% of those from 65-74 years of age, to 34.5% of those 85 and older. Sixty thousand new cases occur each year in Canada.2 The cost of providing care to these patients is substantial, at 3.9 billion dollars/year, in 1991 dollars.3 Vascular dementia is the second most common cause of dementia in Canada, accounting for 20% of cases. When discussing vascular dementia, it is important to recognize that the classic pattern of multiple infarcts is found only in approximately 1/3 of the cases. The other cases consist of patients who have changes in their white matter (likely on the basis of small vessel ischemia) with or without lacunar infarcts, or, rarely, single strategic strokes.