Middle-aged individuals with risk factors for heart attacks and stroke are also more likely to develop changes in the brain that can precede the development of Alzheimer's disease, according to a study led by the Johns Hopkins University School of Medicine.
The Atherosclerosis Risk in Communities (ARIC)–PET Amyloid Imaging Study, a prospective cohort investigation, evaluated 346 participants without dementia who had been assessed for vascular risk factors and markers since 1987–1989 in three U.S. communities (Washington County, Maryland; Forsyth County, North Carolina; and Jackson, Mississippi). Positron emission tomography (PET) scans were performed in 2011–2013 and were analyzed in 2015. Standardized uptake value ratios (SUVRs) were calculated from the PET scans, and a mean global cortical SUVR was calculated. Elevated florbetapir (defined as an SUVR greater than 1.2) was the dependent variable.
Among 322 participants without dementia and with midlife vascular risk factors at baseline (mean age, 52 years; 58% female; 43% black), the SUVR (elevated in 164 participants [50.9%]) was measured more than 20 years later (median follow-up, 23.5 years) when the participants were between 67 and 88 years of age (mean, 76 years).
An elevated body mass index in midlife was associated with an elevated SUVR (odds ratio [OR], 2.06). At baseline, 65 participants had no vascular risk factors; 123 had one; and 134 had two or more. A higher number of midlife risk factors was associated with elevated amyloid SUVR at follow-up (30.8% [n = 20], 50.4% [n = 62], and 61.2% [n = 82], respectively). Late-life vascular risk factors were not associated with late-life brain amyloid deposition.
“In our study, we found an association between the number of risk factors that people without dementia had when they were middle-aged and the risk of having amyloid in their brain when they were older,” lead author Dr. Rebecca Gottesman, of Johns Hopkins University School of Medicine, told Reuters. “Each alone may not be enough to increase the risk of Alzheimer’s disease, but having a number of these risk factors appears to be associated with an even higher risk. Although this doesn’t prove causation, it suggests that vascular risk factors might directly impact Alzheimer’s changes in the brain.”
The results add to the evidence suggesting that people who focus on heart health earlier in life may also be safeguarding their brains, said Dr. Hannah Gardener, a neurology researcher at the University of Miami who wasn’t involved in the study.
“Patients and physicians need to work together to monitor and minimize the burden of vascular health factors like smoking, obesity, blood pressure, cholesterol, and diabetes with the goal of protecting both heart and brain health decades before Alzheimer’s disease typically manifests,” Gardener told Reuters.