Elevated early tau more common in women than men on Alzheimer’s trajectory

Women are at a greater risk than men for early tau deposition, a marker of pre-symptomatic Alzheimer’s disease identifiable on PET imaging, according to a study published online in JAMA Neurology.

In introducing their findings, Rachel Buckley, PhD, of Harvard and colleagues noted the mounting evidence pointing to differences between the sexes in how Alzheimer’s progresses. To concentrate on the association of sex with regional tau deposition in clinically normal older adults, the team analyzed data on two cohorts of individuals who were scanned with PET for both tau depositions and amyloid plaques.

One cohort drew from data on 193 participants in the Harvard Aging Brain Study (age range 55 to 92 years; 61 percent women) who underwent carbon 11-labeled Pittsburgh Compound B and flortaucipir F18 PET.

The other cohort comprised 103 clinically normal individuals from the Alzheimer’s Disease Neuroimaging Initiative (age range 63 to 94 years; 51 percent women) who underwent florbetapir and flortaucipir F18 PET.

Buckley and colleagues found no unambiguous association of sex with regional tau. However, in both cohorts, clinically normal women had elevated tau vs. men in the entorhinal cortex, a part of the medial temporal lobe that’s crucial to memory and other cognitive functions. The elevation was particularly pronounced in women with higher amyloid burden.

Early tau deposition, the authors concluded, “may be accelerated in women compared with men, with our findings lending support to a growing body of literature that exposes a biological underpinning for sex differences in Alzheimer’s disease risk.”