Midlife Plasma Levels of Amyloid Beta May Predict Future Dementia or Mild Cognitive Impairment 

Data from the Arthritis in Communities study (NCT00005131) published in Neurology showed midlife plasma levels of amyloid beta 42 (Aβ₄₂) correlated with development of dementia or mild cognitive impairment (MCI) 25 years later. In contrast, there was no correlation between Aβ₄₂  plasma level in late life and dementia or MCI. 

Midlife was defined as baseline in this study, at which point participants were mean age 59 with no cognitive impairments. For every 10 pg/ml increase of plasm Aβ₄₂, there was a 13% lower likelihood of dementia or MCI at mean age 77.

“A doubling of this ratio under the threshold at midlife was associated with a 37% lower risk of MCI or dementia, which is comparable to about 5 years of younger age, and a doubling of this ratio under the threshold at late life was comparable to about 3 years younger age,” said Kevin J. Sullivan, PhD, MPH, of the University of Mississippi Medical Center. “Amyloid in the blood may be useful as a biomarker for risk of future cognitive impairment. These new results suggest that there is utility in using simple blood draws that would be less expensive and much less invasive for people.”

Participants were given thinking and memory tests over the 25 years of the study to determine whether they developed dementia or MCI. A total of 502 people developed dementia and 832 developed MCI.