Earlier menopause tied to earlier death (Reuters)

NEW YORK (Reuters Health) - Women who go through menopause in their early 40s may have a slightly higher risk of death later in life compared with their peers, a large U.S. study suggests.

The risk stems mainly from higher rates of death from heart disease, respiratory illnesses and kidney dysfunction after the age of 75, researchers at the American Cancer Society in Atlanta found.

However, one of the study authors told Reuters Health, the risk associated with earlier menopause is only "modest," and many other, controllable factors are involved in a woman's health and longevity.

The study results, published in the American Journal of Epidemiology, are based on data from more than 68,000 U.S. women followed for 20 years.

Overall, the researchers found, women who went through menopause between the ages of 40 and 44 had a 4-percent higher risk of death from any cause compared with those who had their last menstrual period in their early 50s.

Further analysis showed that the link was limited to women age 75 or older -- apparently because, at younger ages, women with an earlier menopause had lower rates of death from breast and ovarian cancers. Before age 75, cancer was the top cause of death among all women, while in younger women, heart disease and other conditions were more common.

Several past studies have linked earlier menopause to a slightly shorter lifespan, but unlike those, the current study looked at a range of causes of death.

The findings offer some insight into why age at menopause matters in a woman's longevity, according to study co-author Dr. Carmen Rodriguez.

As expected, earlier menopause was linked to heart disease deaths later in life. This, Rodriguez noted in an interview, is in line with what experts believe about the protective effect of estrogen on the heart and blood vessels. The longer a woman menstruates, the greater her exposure to estrogen and the greater the cardiovascular benefit.

On the other hand, lower lifetime estrogen exposure is thought to lower the risk of breast and ovarian cancers -- another relationship supported by this study. However, heart disease is the number-one killer of U.S. women, and the slightly higher risk of heart disease death among women with early menopause -- 9 percent higher -- contributed to their overall higher mortality.

It's not clear why earlier menopause was tied to deaths from respiratory illnesses and diseases of the genitourinary system, such as kidney disease. But Rodriguez said that one possible factor is the bone-thinning disease osteoporosis.

Estrogen loss after menopause often leads to osteoporosis, and women who sustain bone fractures are at risk of complications such as pneumonia and urinary tract infections, Rodriguez explained.

She stressed, however, that the study found only a "very modest increase" in death risk for women who go through earlier menopause. And while women may not be able to change their age at menopause, Rodriguez said, they can significantly affect their health and longevity by eating well, exercising, maintaining a healthy weight and avoiding smoking.

"There are a lot of things that can be done to modify your risk," she said.

SOURCE: American Journal of Epidemiology, December 1, 2005.