Women at greater risk for dementia than men

Jul 21, 2015, 4:18 PM EDT
A person holds the hands of an elderly woman at a EHPAD, a housing centre for dependant elderly persons, in Limoges on June 30, 2015 as thermometers were set to reach nearly 40 degrees.

Women suffering from mild cognitive impairment -- a precursor to dementia -- appear to mentally degenerate twice as quickly as men. A new study suggests that women decline mentally at a far faster rate, showing that women are at a greater risk for dementia. Telegraph UK reports:

Researchers also discovered that women are far more susceptible to developing dementia in the first place.
Figures presented at the Alzheimer’s Association’s Annual Conference in Washington showed that around two thirds of older people living with Alzheimer’s disease are women.
At the age of 65 women have a one in six chance of developing Alzheimer’s disease compared with a 1 in 11 chance for men.
“Women are disproportionately affected by Alzheimer’s, and there is an urgent need to understand if differences in brain structure, disease progression, and biological characterises contribute to higher prevalence and rates of cognitive decline,” said Dr Heather Snyder, the Director of Medical and Scientific Operations at the Alzheimer’s Association.
“To intervene and help reduce the risk of Alzheimer’s it’s critical to understand the reason for these differences.”
There are 850,000 people currently suffering from dementia in the UK, with Alzheimer's disease being the most common type. The disease kills at least 60,000 people each year.
"Women are really at the epicenter of the Alzheimer's disease crisis," said Dr. Kristine Yaffe of the University of California, San Francisco. "We don't really understand what this is all about."
A series of studies presented Tuesday at the Alzheimer's Association International Conference uncovered signs of that vulnerability well before Alzheimer's symptoms hit.
First, Duke University researchers compared nearly 400 men and women with mild cognitive impairment, early memory changes that don't interfere with everyday activities but that mark an increased risk for developing Alzheimer's. They measured these people's cognitive abilities over an average of four years and as long as eight years for some participants.
The men's scores on an in-depth test of memory and thinking skills declined a point a year while the women's scores dropped by two points a year.
Age, education levels and even whether people carried the ApoE-4 gene that increases the risk of late-in-life Alzheimer's couldn't account for the difference, said Duke medical student Katherine Lin, who coauthored the study with Duke psychiatry professor Dr. P. Murali Doraiswamy. The study wasn't large or long enough to tell if women were more at risk for progressing to full dementia.
Nor could it explain why the women declined faster, but the researchers said larger Alzheimer's prevention studies should start analyzing gender differences for more clues. And two other studies presented Tuesday offered additional hints of differences in women's brains:
—A sample of 1,000 participants in the large Alzheimer's Disease Neuroimaging Initiative compared PET scans to see how much of a sticky protein called beta-amyloid was building up in the brains of a variety of men and women, some healthy, some at risk and others with full-blown Alzheimer's. Amyloid plaques are a hallmark of Alzheimer's, and growing levels can help indicate who's at risk before symptoms ever appear.