HRT Shrinks the Brain
Jan. 13 -- MONDAY, Jan. 12 (HealthDay News) -- Two studies looking at the same group of women found that while hormone therapy is linked with brain shrinkage, it does not seem to be associated with early signs of cerebrovascular disease.
This suggests that hormone therapy's effect on brain volume, not its effect on the brain lesions that indicate "silent strokes," is the mechanism by which hormones increase the risk for dementia in women over 65.
"These are a nice companion to cognitive studies reported earlier. This is now neuroradiological evidence that, together, suggest that the effect [of hormones] may be more degeneration than vascular," said Miriam Weber, an assistant professor of physical medicine and rehabilitation and of neurology at the University of Rochester Medical Center.
These papers, both published in the Jan. 13 issue of Neurology, are the latest in a parade of analyses resulting from the hormone therapy arm of the landmark, government-sponsored Women's Health Initiative study.
Previous results included an increased risk of stroke and cerebrovascular disease in women over 65 taking hormone replacement therapy (HRT). Another offshoot of the WHI, the WHI Memory Study, found an increased risk of dementia and memory problems in this group of women.
Both papers set out to understand the mechanisms behind this increased risk for dementia in women taking conjugated equine estrogens (either estrogen alone or estrogen plus progestin).
In the primary paper, researchers analyzed brain scans on about 1,400 women in the WHI Memory Study, who had been on hormone therapy for about four to six years.
They found no relationship between vascular lesions in the brain or an increased risk of dementia.
"The main message is that women over 65 years of age who took CEE-based hormone therapy [either estrogen alone or estrogen plus progestin] through the WHI clinical trials and who agreed to have an MRI scan did not experience increases in brain lesion volume," said study author Laura H. Coker, an assistant professor of public health sciences at Wake Forest University School of Medicine in Winston-Salem, N.C.
