Erin LeBlanc at Kaiser.jpg
Dr. Erin LeBlanc, lead author of the study showing an increased risk of diabetes associated with menopause timing, consults with a colleague at the Kaiser Permanente Center for Health Research in Portland.
When researchers dug into the data from a national study of women age 50 to 79, they expected to find that those who went through menopause early would face a greater risk of diabetes.
But they also got a surprise: Women who had their final period late also faced a higher risk of diabetes, a serious disease that can cut life short.
It's not clear why lifetime estrogen levels might lead to diabetes, said Dr. Erin LeBlanc, a researcher at Kaiser Permanente Center for Health Research in Portland.
After menopause, estrogen levels drop. Appetites increase, metabolism slows and fat accumulates, especially around the belly. That's also a risk factor for diabetes.
LeBlanc suspects the hormone has a sweet spot. Too much or too little appears to increase the diabetes risk, she said.
"My belief is that there is an optimal window for how much estrogen is healthy for women's bodies," Le Blanc said.
Though women can't control when they go through menopause, they can reduce their risk of getting diabetes by eating a low-sugar diet with lots of fruits and vegetables and getting plenty of exercise, she said.
For their study, LeBlanc and other scientists pored over data from the Women's Health Initiative, a trial focused on preventing disease in post-menopausal women. The initiative enrolled more than 124,000 women between 1993 and 1998 and followed them for about 12 years.
LeBlanc said they found that women who went through menopause before age 46 faced a 25 percent higher risk of developing type 2 diabetes. Women who had their last period after age 55 faced an increased risk of 12 percent.
The average age for menopause is 51, according the North American Menopause Society. The study was published in the society's journal, Menopause.
Diabetes stems from a lack of insulin, which is produced by the pancreas. Maintaining insulin is crucial for ensuring that cells are fed glucose from the blood to use for energy.
When insulin levels are low, sugar stays in the blood and the cells don't have enough fuel for the body. That, in turn, can cause a number of serious problems associated with diabetes, such as blindness, stroke and damage to nerves and kidney.
People with diabetes also face shorter lives: At 50, they live nearly nine years less than the average, LeBlanc said. At age 60, longevity is cut by about five years.
Estrogen therapy has been shown to reduce some ill effects of menopause but for diabetes, the results are mixed.
Some studies have associated estrogen alone with an onset of diabetes. LeBlanc said combined with progestin, estrogen therapy could reduce the risk of getting diabetes.
"The issue with that is that we know that there are other potentially adverse effects of estrogen and progestin," LeBlanc said.
They include breast cancer, stroke and heart disease.
She doesn't advise women to take estrogen and progestin after menopause to avoid diabetes.
"I don't want anyone to be anxious or worried," she said. "We want women to be aware that if they do have an early or late menopause that they talk to their doctor to reduce the risk for diabetes."
She said more work needs to be done on the effect of estrogen on insulin and the relationship between estrogen and diabetes.
-- Lynne Terry