At the beginning of the study in July 2000, women were ages 45 to 84. Nearly 28 percent of the women reported early menopause; 446 women had natural menopause and 247 had surgical menopause. Women not yet past menopause were included in the group that did not have early menopause. Follow-up tracked whether participants had a cardiovascular disease event, which included a heart attack, nonfatal cardiac arrest (a suddenly stopped heart), angina (chest pain due to narrowed or blocked arteries), probable angina followed by angioplasty or bypass surgery, a stroke or death due to stroke, heart attack or other cardiovascular disease.

No one had any such event before age 55. After that, women who had early menopause were more likely to have had a cardiovascular disease event than women who had not gone through menopause before age 46.

Even when the researchers' statistical analysis controlled for current or previous use of hormone replacement therapy or for major cardiovascular risk factors, it did not change the results. Early menopause remained a risk factor on its own, although it is unclear why, Wellons reported.

"Our study is observational; therefore, we cannot conclude that early menopause somehow causes future cardiovascular disease," Wellons said. "However, our findings do support the possible use of age at menopause as a marker of future heart and vascular disease risk."

SOURCE The Endocrine Society