Advertisement
  1. Health

New questions about why more women than men have Alzheimer's

Amy Shives speaks about her experience with Alzheimer's disease, which she was diagnosed with in 2011, at her house, Wednesday, June 3, 2015, in Spokane, Wash. Nearly two-thirds of Americans with Alzheimer's disease are women, and now some scientists are questioning the long-held assumption that it's just because women tend to live longer than men. [Associated Press]
Published Jun. 28, 2015

WASHINGTON — Nearly two-thirds of Americans with Alzheimer's disease are women, and now some scientists are questioning the long-held assumption that it's just because they tend to live longer than men.

What else may put woman at extra risk? Could it be genetics? Biological differences in how women age? Maybe even lifestyle factors?

Finding out might affect treatments or preventive care.

One worrisome hint is that research shows a notorious Alzheimer's-related gene has a bigger impact on women than men.

"There are enough biological questions pointing to increased risk in women that we need to delve into that and find out why," said Maria Carrillo, chief science officer for the Alzheimer's Association.

Last month, the association brought 15 leading scientists together to ask what's known about women's risk. Later this summer, Carrillo said it plans to begin funding research to address some of the gaps.

"There is a lot that is not understood and not known. It's time we did something about it," she added.

A recent Alzheimer's Association report estimates that at age 65, women have about a 1 in 6 chance of developing Alzheimer's during the rest of their lives, compared with a 1 in 11 chance for men.

The tricky part is determining how much of the disparity is due to women's longevity or other factors.

"It is true that age is the greatest risk factor for developing Alzheimer's disease," said University of Southern California professor Roberta Diaz Brinton, who presented data on gender differences at a meeting of the National Institutes of Health this year.

But, she said, "on average, women live four or five years longer than men, and we know that Alzheimer's is a disease that starts 20 years before the diagnosis." That's how early cellular damage can quietly begin.

Brinton researches if menopause can be a tipping point that leaves certain women vulnerable.

However it starts brewing, there's some evidence that once Alzheimer's is diagnosed, women may worsen faster; scans show more rapid shrinkage of certain brain areas.

But gene research offers the most startling evidence of a sex difference.

Stanford University researchers analyzed records of more than 8,000 people for a form of a gene named ApoE-4, long known to increase Alzheimer's risk.

Women who carry a copy of that gene variant were about twice as likely to eventually develop Alzheimer's as women without the gene, while men's risk was only slightly increased, Stanford's Dr. Michael Greicius reported last year.

It's not clear why. It may be in how the gene interacts with estrogen, Brinton said.

Amy Shives, 57, of Spokane, Washington, recalls when her mother began showing symptoms of Alzheimer's. But it wasn't until after her own diagnosis a few years ago that Shives looked up the gender statistics.

"That was alarming," said Shives, who is in the early stages of Alzheimer's, which struck at a younger-than-usual age and forced her retirement as a college counselor. "The impact on our lives and that of our families is extraordinary."

She points to another disproportionate burden: About 60 percent of caregivers for Alzheimer's patients are women.

"My daughters are in their 20s and I'm already ill," Shives worries. "It's very stressful for them to think about when their mother's going to need their help."

What drives the difference in Alzheimer's cases isn't clear, said Dr. Susan Resnick of the National Institutes of Health, pointing to conflicting research.

"We really have had a tough time understanding whether or not women really are more affected by the disease, or it's just that they live longer," Resnick said.

Data from the long-running Framingham, Massachusetts, health study suggests that because more men die from heart disease in middle age, those who survive past 65 may have healthier hearts that in turn provide some brain protection. Many of the same factors — obesity, high cholesterol, diabetes — that damage arteries also are Alzheimer's risks.

What about hormones? That's been hard to pin down. Years ago, a major study found that estrogen therapy after 65 might increase risk of dementia, although later research showed hormone replacement around the onset of menopause wasn't a problem.

Brinton studies how menopause changes the brain. Estrogen helps regulate the brain's metabolism, how it produces the energy for proper cognitive function, and it must switch to a less efficient backup method as estrogen plummets, she explained.

"It's like the brain is a little bit diabetic," said Brinton, who is studying whether that may relate to menopausal symptoms in women who later experience cognitive problems.

Carrillo notes that 40 years ago, heart disease was studied mainly in men, with little understanding of how women's heart risks can differ.

"How do we make sure we're not making that mistake when it comes to Alzheimer's?" she asked.

ALSO IN THIS SECTION

  1. Pharmacist Wendy Sullivan gives a flu shot to Luz Acevedo at the Town 'N Country Senior Center in 2012. The 2019-20 flu season is expected to be a hard one, with Hillsborough County already leading the state in outbreaks. Associated Press
    The county leads the state in flu outbreaks so far this season, prompting an official call for parents to get their kids vaccinated.
  2. An opened capsule containing Kratom. The Clearwater City Council was confronted by dozens of concerned citizens at a recent meeting who urged them not to ban the herbal supplement. Tampa Bay Times
    “I think there was a misunderstanding."
  3. Dr. Philip Adler treated generations of Tampa children, including Hannah Millman, who was 2 years old at the time of this visit. Times (1985)
    The Tampa pediatrician also played a prominent role in desegregating local hospital care.
  4. Reginald Ferguson, center, a resident of the Kenwood Inn in St. Petersburg, talks with Rachel Ilic, an environmental epidemiologist, left, and Fannie Vaughn, right, a nurse with the Florida Department of Health in Pinellas County. The health team was encouraging residents to get vaccinated against hepatitis A, part of a larger effort to address an outbreak of the virus in Florida. SCOTT KEELER  |  Tampa Bay Times
    The effort started in Pinellas, where health department “foot teams” are knocking on doors in neighborhoods at higher risk for the virus.
  5. A nurse at Tampa General Hospital holds a special stethoscope used for critical patients in the Jennifer Leigh Muma Neonatal Intensive Care Unit there. The hospital received a C grade from Leapfrog, an independent nonprofit which ranks hospitals nationally for patient safety. Times (2018)
    Leapfrog, an independent nonprofit, rated hospitals based on hand washing, infection rates, patient falls and other factors.
  6. Most of the time (55%), older spouses are caregiving alone as husbands or wives come to the end of their lives, without help from their children, other family members or friends or paid home health aides, according to research published earlier this year. [Times (2011)]
    Compared to adult children who care for their parents, spouses perform more tasks and assume greater physical and financial burdens when they become caregivers.
  7. “Coming out,” as providers call it, is not easy. But when people ask her specialty, Dr. Jewel Brown of Tampa owns it. She wants to be an abortion provider. Becoming one, she has found, takes determination at every step of the way. MONICA HERNDON  |  Times
    Florida providers seek training and work extra hours to give patients anything they might need.
  8. Nurses at Tampa General Hospital came up with the idea to turn sterile mats used in the operating room into sleeping bags for the homeless. From left are: Lucy Gurka, Claudia Hibbert, Karley Wright and Nicole Hubbard. Courtesy of Tampa General Hospital
    The paper-thin material is waterproof and holds heat, “like an envelope that you can slide into.”
  9. Tampa City Hall. TIM NICKENS  |  Times
    City attorneys intend to appeal a U.S. district judge’s ruling last month overturning Tampa’s ban of a treatment that has been deemed harmful and ineffective.
  10. Messiah Davis, 19 months old, choked on hamburger meat while at a South Tampa child care center and lost oxygen to his brain. He died four days later. His mother has filed a wrongful death suit. Facebook
    Felicia Davis has filed a wrongful death suit, saying Kiddie Kollege failed to save her child and questioning why he was fed hamburger.
Advertisement
Advertisement
Advertisement