Findings Support Role of Vascular Disease in Development of Alzheimer’s Disease

Among adults who entered a study more than 25 years ago, an increasing number of midlife vascular risk factors, such as obesity, high blood pressure, diabetes, high cholesterol and smoking, were associated with elevated levels of brain amyloid (protein fragments linked to Alzheimer’s disease) later in life, according to a study published by JAMA.

Midlife vascular risk factors have been associated with late-life dementia. Whether these risk factors directly contribute to brain amyloid deposits is less well understood. Rebecca F. Gottesman, M.D., Ph.D., of the Johns Hopkins University School of Medicine, Baltimore, and colleagues examined data from 346 participants without dementia at study entry who have been evaluated for vascular risk factors and markers since 1987-1989 and with PET scans in 2011-2013. Rsk factors included body mass index 30 or greater, current smoking, hypertension, diabetes, and total cholesterol 200 mg/dL or greater and were evaluated in models that included age, sex, race, genotype, and educational level.

The researchers found that a cumulative number of midlife vascular risk factors were associated with elevated brain amyloid. Relationships between vascular risk factors and brain amyloid did not differ by race. There was no significant difference among people who were or were not carriers of an APOE ε4 allele (a variant of a gene associated with increased risk for Alzheimer’s disease). Late-life vascular risk factors were not associated with late-life brain amyloid deposition.

“These data support the concept that midlife, but not late-life, exposure to these vascular risk factors is important for amyloid deposition,” the authors write. “These findings are consistent with a role of vascular disease in the development of Alzheimer’s Disease.”