Heart disease risk factors raise risk of Alzheimer's disease too, says a US study.
The Kaiser Permanente Northern California Medical Group (healthcare delivery organization) formed the database for the study. The 9,844 participants underwent detailed health evaluations during 1964-1973 at ages 40-45 years; they were still members of the health plan in 1994. Alzheimer's and vascular disorders were ascertained by medical records between 1 January 1994 and 1 June 2007.
The study appears in the journal Dementia and Geriatric Cognitive Disorders.
Among those whose cholesterol was "desirable" during middle age (below 200 mg/dl), 4% developed Alzheimer's in old age; among those with high cholesterol (240 mg/dl or above), 5.6% developed Alzheimer's. After adjusting for other variables, the researchers found that people with high cholesterol were 57% more likely than those with desirable levels to develop Alzheimer's.
Physicians tend to confine Alzheimer's and vascular problems to geriatric age borders, and address symptoms as they occur. Our study, along with others, points out the importance of addressing risk factors as early as midlife, before the underlying disease(s) or the symptoms appear, the researchers said.
Elevated midlife serum total cholesterol increases the risk of both Alzheimer's and vascular disorders, a finding that adds to the existing body of evidence on a degree of overlap between the two dementia types in terms of risk factors, symptoms and neuropathology.
Moreover, dementia and cardiovascular disease are common major health problems, share several risk factors and often occur simultaneously, interacting with one another. Effective management of such disorders thus warrants a transdisciplinary approach, the study concludes.
Researchers have been looking for a while at whether cardiovascular risk factors also increase the risk of Alzheimer's and other forms of dementia. The Alzheimer's Association has an overview of more than a dozen published studies that looked at cholesterol as well as blood pressure, diabetes and smoking — all key risk factors for heart disease that may play a role in cognitive decline as well.