WASHINGTON (AP) â€” Older women with mild memory impairment worsened approximately twice as swift as men, according to research that illustrates the especially complex toll that Alzheimer's takes on women.
Nearly two-thirds of Americans with Alzheimer's are women.
At age 65, seemingly healthy women have approximately a 1 in 6 chance of developing Alzheimer's during the rest of their lives, compared with a 1 in 11 chance for men. Scientists once thought the disparity was just because women tend to live longer â€” yet there's increasing agreement that something else makes women more vulnerable.
p>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 & women with mild cognitive impairment, early memory changes that don't interfere with everyday activities yet that mark an increased risk for developing Alzheimer's. They measured these people's cognitive abilities over an average of four years â€” & as long as eight years for some participants.
The men's scores on an in-depth test of memory & thinking skills declined a point a year while the women's scores dropped by two points a year.
Age, education levels & 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.
The study couldn't explain why the women declined faster, yet scientists need to explore that further for clues into the gender difference. But two other studies presented Tuesday offered additional hints of differences in women's brains:
â€”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 & women, some healthy, some at risk & others with full-blown Alzheimer's. Amyloid plaques are a hallmark of Alzheimer's, & growing levels can assist indicate who's at risk before symptoms ever appear.
"Overall, women have more amyloid than men," even among the cognitively normal group, said Dr. Michael Weiner of the University of California, San Francisco. The study couldn't explain why, although it didn't appear due to the risky ApoE-4 gene, which seemed to make a difference for men with Alzheimer's yet not women.
â€”Some seniors who undergo surgery with general anesthesia suffer lasting cognitive problems afterward, often expressed to doctors as, "Grandma was never the same after that operation." Tuesday, researchers reported that here again, women are at higher risk of getting worse.
Dr. Katie Schenning of the Oregon Health & Science University tracked records of more than 500 participants in two long-term studies of cognitive aging, which included a battery of brain tests. About 180 participants underwent 331 procedures involving general anesthesia.
Over seven years, people who had undergone surgery with general anesthesia declined faster on measures of cognition, their ability to function & even brain shrinkage than people who hadn't had surgery. But women declined at a significantly faster rate than men, Schenning said.
"It is worth letting our older patients know that they should perhaps talk approximately this with their practitioner, that this is a possibility & consider whether or not they need to undergo procedures that are considered to be elective," she said.
Schenning didn't have amyloid measurements for these people; other studies have suggested that the people most at risk may have brewing cognitive problems already.
The anesthesia alone isn't the culprit, she cautioned. Indeed, other research presented Tuesday showed that surgery in general can spur inflammation-causing molecules to cross into the brain & impair how nerve cells communicate, regardless of gender.
Together, the studies show how much more research is needed into gender differences that may increase the risk of Alzheimer's, said Dr. Kristine Yaffe of UCSF, who wasn't involved in Tuesday's studies yet was part of a recent Alzheimer's Association meeting to start determining those next steps.
"It's not just that women are living to be older. There's something else going on in terms of the biology, the environment, for women compared to men that may make them at greater risk, or if they have some symptoms, alter the progression," Yaffe said.
Source: “Associated Press”