Alzheimer's hits 'younger elderly' hardest

Although age is the greatest risk factor for Alzheimer's the disease hits the "younger elderly" -- those in their 60s and 70s -- hardest, U.S. researchers say. First author Dominic Holland of the University of California, San Diego Health Sciences, said by age 85, the likelihood of developing Alzheimer's disease is roughly 50 percent, but those who get Alzheimer's in their 60s and 70s might show faster rates of brain tissue loss and cognitive decline than those patients age 80 and older. Holland and colleagues used imaging and biomarker data from participants in the Alzheimer's Disease Neuroimaging Initiative, a multi-institution effort coordinated at University of California, San Diego. They examined 723 people, ages 65-90, who were categorized as either cognitively normal, mildly cognitively impairment or suffering from full-blown Alzheimer's disease. "We found that younger elderly show higher rates of cognitive decline and faster rates of tissue loss in brain regions that are vulnerable during the early stages of Alzheimer's disease," Holland said in a statement. "Additionally cerebrospinal fluid biomarker levels indicate a greater disease burden in younger than in older individuals." Holland said it's not clear why Alzheimer's disease is more aggressive among younger elderly. The findings were published in the journal PLOS One.