To investigate risk factors for Amyloid-beta deposition in cognitively healthy middle-aged and older adults, the authors studied individuals with hypertension, in combination with the APOE4 genetic risk factor for Alzheimer’s disease. 118 cognitively normal adults, aged 47 to 89 years were studied. Participants were classified in the hypertension group if they reported a medical diagnosis of hypertension or if blood pressure exceeded 140 mm Hg systolic/90 mm Hg diastolic, as measured across 7 occasions at the time of study. Participants underwent Aβ positron emission tomography imaging with radiotracer fluorine 18-labeled florbetapir. Participants were genotyped for apolipoprotein E and were classified as APOE4+ or APOE4-. Participants in the hypertension group with at least 1 APOE4 allele showed significantly greater amyloid burden than those with only 1 risk factor or no risk factors. Increased pulse pressure was strongly associated with increased mean cortical amyloid level for subjects with at least 1 APOE4 allele. The authors suggest that control of risk factors such as hypertension earlier in the life span may be one potential mechanism to ameliorate or delay neuropathological brain changes with aging.
Rodrigue KM, Rieck JR, Kennedy KM, Devous MD, Diaz-Arrastia R, Park DC: Risk Factors for β-Amyloid Deposition in healthy Aging: Vascular and Genetic Effects. JAMA Neurology [Epub ahead of print, March 18, 2013; doi: 10.1001/jamaneurol.2013.1342].