Women bear the burden of Alzheimer's disease; researchers are trying to find out why

At the International Conference of the Alzheimer's Association in Chicago this week, researchers are exploring the biological and social differences that could explain why more women than men develop Alzheimer's and Alzheimer's disease. of other types of dementia

. link between a lower risk of dementia and the number of births that a woman has. According to preliminary results of the study of nearly 15,000 women, women with three or more children had a 12% risk of developing cognitive problems that was lower than that of a woman who had only Only one child. Pregnancy failures, however, increased the risk of a woman, according to Kaiser Permanente's study. Compared to women who never lost a pregnancy, women with three or more spontaneous abortions had a 47% higher risk of dementia.

This is only one of several studies on pregnancy, female hormones, age of menarche and menopause. Alzheimer's disease is a progressive mental deterioration of the brain that destroys memory and thinking skills until the person is unable to do the simplest thing. Tasks. It is believed that the disease is caused by accumulation in the brain of beta-amyloid plaques and neurofibrillary tangles called tau.

Of the more than 50 million people with dementia and Alzheimer's in the world, most are women. In the United States alone, two-thirds of the 5.7 million Americans with Alzheimer's are women. Women age 60 and older are twice as likely to be diagnosed with Alzheimer's disease as breast cancer.

The results are devastating. The World Health Organization considers dementia as one of the top 10 causes of death among women. In the United States, Alzheimer's disease is now the sixth leading cause of death, killing more seniors than breast cancer and prostate cancer combined. In England, Wales and Australia, 2016 Demographic Statistics Show That Dementia and Alzheimer's Disease Kill More Women Than Heart Disease

Yet Experts Say Science Does Not Concentrate not why the disease affects women more than men. "Age is the biggest predictor of Alzheimer's disease, so for a long time, there was this notion that women are more at risk than because they live longer," he said. Pauline Maki, Professor of Psychology and Psychiatry at the University of Illinois. . "No one paid attention to what was happening in the brains of women throughout a woman's life."

"I was asking for money to do estrogen research, and the commentators asked me, "Why are you doing this? & # 39; & # 39; "Presenter Carey Gleason from the Wisconsin Alzheimer's Disease Research Center."

"We are at a very exciting time on the ground," said Rachel Whitmer, professor of public health science at UC Davis School of Medicine. "Rather than repel it as" women live longer and it's the end of history, "science is now breaking it down to a deeper level to understand where, when, why and how. "

19659005] The Kaiser Permanente study, which looked at the number of births and risk of dementia, followed women who used care Most of their lives, this allowed researchers to access each woman's medical records between 1964 and 1973, then from 1996 to 2017.

This was important , say the researchers, because they're not relying on the memory of a woman d e his reproductive and medical history, "

" I myself sometimes find it hard to remember what happened last week, "said Whitmer, who co-directed the company. ;study. "But we actually have the questionnaires that they filled in the '60s and' 70s."

"We could then compare that to their risk factors in midlife like hypertension, stroke, diabetes and heart disease" Paola Gilsanz, a staff member of Kaiser Permanente who co-directed l & # 39; study. "In that sense, it's very, very powerful."

When the study began in 1964, all women were between 40 and 55 years old. Their medical records documented the history of reproduction, education, race and quarantine. when every woman started menstruating, when she entered menopause and the length of those reproductive years. The diagnosis of dementia and chronic diseases later, such as heart failure and diabetes, were drawn from the records between 2016 and 2017.

In addition to finding that multiple pregnancies protect against dementia, but the multiple abortions are not, the study found that were fertile for only 21 to 30 years had a risk of dementia 33% higher than women who were fertile for a longer period. They also found that women who started their first menstrual cycle at age 16 or older were 31% more likely to have cognitive problems than women who started at age 13.

What do all these results mean? It's too early to tell, Whitmer says.

"This is an observational study," she said. "It does not tell you the mechanisms, but it tells you who is at higher risk and lower.This information allows basic scientists to take the next step and do more experimental work."

L & # 39; Kaiser's study was at odds with recently published research that found that South Korean and Greek women who gave birth five or more times "Korean, Greek, and American women are very different genetically," he said. Dr. Richard Isaacson, researcher on Alzheimer's disease, who has not taken part in any studies. "You must be very careful with the generalization of these studies. Take for example the studies done in China on stroke. You can not generalize these results to stroke patients in the United States unless they are Chinese-Americans or born in China and moved here.

"Alzheimer's disease is a disease of life, in my opinion. Alzheimer's Disease Prevention Clinic at NewYork-Presbyterian Medical Center / Weill Cornell. "The risk begins in the womb and is then affected by your genes, your early risk factors for life, your level of education, your diet and exercise, and so much more."

Best Cognitive Assessment

Another study presented at the conference focused on the need for more accurate screening tests for Alzheimer's disease – tests that would consider the innate advantage of a woman compared to men in verbal memory.

"If you go to the store without your grocery list, a woman will do the best job of remembering," said Maki, who led the study. "A man will be better off at visual-spatial things, like finding the way home. "

Cognitive tests used to diagnose Alzheimer's disease heavily rely on recalling word lists, stories, and other verbal materials This means that women who have mild cognitive decline can achieve normal results, said Maki, thus preventing them from starting to take medication and adopting appropriate lifestyle changes. Some men might have a false positive on the memory test, she says, and be diagnosed with brain changes when they are normal.

Using Data from Alzheimer's Disease Neuroimaging Initiative, a Multicenter study designed to develop biomarkers for Alzheimer's disease, Maki found that women performed better even when they had the same level of illness as a man. It also required high levels of disease for this benefit to be eliminated. This could explain, she says, why women seem to deteriorate faster than men after diagnosis: they are more advanced in the disease.

Maki then tested a new scoring mechanism for the memory test of Alzheimer's disease. "Pass grade" while making it easier for men. She found that 10% of women who had shown the pathology of Alzheimer's disease on brain scans could now be identified; She also found that 10% of men who would have been found to be cognitively impaired were now considered normal.

"Further research is needed to apply these results to larger populations, but this shows the need for a reassessment of the tests we use to diagnose Alzheimer's disease, men and women. and women can get the help they need. "

The Role of Estrogen

A third study of the conference, presented by Gleason of the Wisconsin Alzheimer's Disease Research Center, to more recent studies on the cognitive effects of hormone replacement therapy, a topic with a controversial story.

"We recognize that our models were too simplistic," she says, "and that there are many more things to pay attention to, including the underlying health of women." a woman's genetic profile and when hormone replacement therapy is started and stopped. "

For years, science believed that giving women hormone replacement therapy, or HRT, at menopause, was beneficial to the aging brain and would help prevent heart disease." Women's Health Initiative, a long-term national study aimed at preventing heart disease, osteoporosis and breast and colon cancer in women, has been reported

a combination of HRT progesterone. actually increased the risk of heart disease as well as strokes, blood clots, dementia and breast cancer.

The use of HRT dropped.Then, 10 years later, the I & # 39; Women's Health Initiative reversed its findings because the original analysis focused on older women, who were already at risk for heart attack, blood clots and A & E. VC, the initial findings were wrong because they did not take into account the age of a woman at the beginning of the replacement treatment.

This hormone therapy may be useful for controlling menopausal symptoms when most women undergo change in their late forties and early fifties when their risk of chronic disease is lower.

the risk of blood clots, stroke and cancer is higher, should examine their risk factors and discuss the option with their doctor.

HRT could also not help the older brain: women who start hormone therapy, showed persistent declines in cognition, working memory and the ability to organize and get things done, which is called executive functioning.

For younger women, Gleason said, more recent research has found no cognitive harm or benefit from multiple forms of HRT if they start in a few years of menopause, unless the woman has diabetes-type 2.

"If you're diabetic, you're at increased risk of progressing to dementia, period," she says. "But the risk is greater if you follow hormonal treatment."

It is complex and often confusing, but field researchers say that all signs suggest more definitive answers in the next five years.

A Personalized Medicine Approach to Menopausal Hormone Therapy, "Gleason said." We are going through a very exciting time to understand the complexities of estrogen, menopausal and menopausal hormone therapy and how all of these things are combining. "

" No size fits all, "agreed Isaacson." We need to use imaging, biomarkers, blood biomarkers, clinical history, such as when they started their menstrual period, when they have stopped. Different women are going to need different therapeutic interventions. It will be precision medicine at its best. "

The-CNN-Wire