(HealthDay News) – The ratio of two plasma amyloid-β (Aβ) biomarkers is associated with the development of Alzheimer’s disease (AD) and dementia.

Alain Koyama, of the University of California at San Francisco, and colleagues conducted a systematic review and meta-analysis to determine whether plasma levels of Aβ peptides have any predictive value with regard to the development of AD, dementia, or overall cognitive decline.

The researchers identified 13 studies involving 10,303 subjects. Although plasma levels of either Aβ42 or Aβ40 alone were not associated with the development of AD or dementia, the ratio of Aβ42 to Aβ40 was predictive. Subjects with a lower Aβ42:Aβ40 ratio were significantly more likely to develop AD (summary risk ratio, 1.6) or dementia (risk ratio, 1.67). For both summary estimates, there was significant heterogeneity.

“Despite the limitations of existing research and heterogeneity across the studies considered, this systematic review and meta-analysis suggests that the ratio of plasma Aβ42:Aβ40 may have value in predicting the risk for later development of dementia or AD and merits further investigation,” the authors write.

One of the authors disclosed financial ties to Elan.

Full Text (subscription or payment may be required)