Women who begin taking hormone therapy within five years of starting menopause cut their risk for Alzheimer’s disease, a study found.
Those who took treatments such as Pfizer Inc.’s estrogen pill Premarin within five years of menopause lowered their chance of Alzheimer’s by 30 percent, according to research released today in the journal Neurology.
While some prior observational studies have shown that hormone therapy helps lower the chance of developing Alzheimer’s disease, an earlier randomized trial showed an increase risk, the authors said. Today’s data also found that those who started the pills later than five years saw no benefit, adding to the debate and suggesting more analysis is needed before doctors can recommend women take hormone therapy right after menopause to prevent Alzheimer’s, said study author Peter Zandi.
“This is just another piece of evidence that suggests timing might be important,” Zandi, an associate professor in the Department of Mental Health at the Johns Hopkins Bloomberg School of Public Health in Baltimore, said in an Oct. 22 telephone interview. “As a result of our study, I don’t think women should change their behaviors just yet. They shouldn’t think that they’re going to take hormone therapies to protect against Alzheimer’s disease.”
Menopausal women take hormone treatments to relieve hot flashes, night sweats and vaginal symptoms. The hormone replacement therapies should be taken at the lowest dose and for the shortest duration needed to relieve symptoms, according to U.S. recommendations. Some of the treatments may increase a woman’s risk of breast cancer, heart disease and stroke.
More than 6 million women took New York-based Pfizer’s Premarin and Prempro, a combination of estrogen and progestin, to treat their menopausal symptoms before they were linked in 2002 to health concerns such as breast cancer. The drugmaker has paid about $1.1 billion to settle lawsuits and set aside another $532 million to resolve the remaining cases, according to an August filing with the U.S. Securities and Exchange Commission.
Researchers in today’s study followed 1,768 women ages 65 and older for 11 years. The women provided their use of hormone therapies and the date when their menopause began. In the study, 1,105 women used estrogen or estrogen in combination with progestin.
Of the women taking hormone therapy, 87 developed Alzheimer’s disease, while 89 of 663 who didn’t take the treatments got the disease.
The researchers found that women who started hormone therapy within five years of menopause had a significantly lower risk of developing Alzheimer’s disease, while those who started the treatments later in life had no such benefits. Women who took hormone therapies for 10 or more years saw the most benefit, the authors said.
Estrogen may be helpful to neurons in the brain, protecting them and helping them to grow, Zandi said. It may also help with blood flow in the brain. Preventing a sudden drop in estrogen around menopause by taking hormone therapies may be why the treatments help prevent Alzheimer’s disease, he said.
Victor Henderson, who wrote an accompanying editorial, said that women should be somewhat relieved by these findings if they are taking the treatments for menopausal symptoms. He said though that more studies are needed before changes to hormone therapy recommendations are made.
Today’s findings give “additional evidence that hormone therapy use close to the time of menopause may not be associated with the same risks seen with later initiation of hormone therapy,” said Henderson, a professor of health and policy and neurology and neurological sciences, at Stanford University in California, in an Oct. 22 telephone interview.
The Johns Hopkins Bloomberg School of Public Health is named for Michael Bloomberg, New York City’s mayor and the founder and majority owner of Bloomberg News parent Bloomberg LP.