Researchers from the U-M School of Public Health and Medical School found that women who are younger than 45 when they first notice changes in their monthly cycles and other symptoms can have a longer menopausal transition than those who begin it at age 51 or later. The length of the transition can be nearly double for younger women than for those who enter the transition later, 8.57 versus 4.37 years.
"The duration of the menopausal transition—the time from when a woman notices a distinct change in the frequency or regularity of her menstrual cycles to the time of her last menstrual period—varies from just a couple of years up to 8-10 years," said Sioban Harlow, professor of epidemiology at the U-M School of Public Health. "Understanding that age at onset of the menopausal transition influences how long the transition will last can help inform women's health care decisions related to symptom management, contraception and preventive care."
Menopausal transition symptoms include irregular periods, mood swings, hot flashes, night sweats and difficulty sleeping. Some women also suffer from emotional issues, vaginal dryness and decreased sex drive. Some research suggests long-term health considerations include bone loss and changes in cardiovascular risk.
During the multi-ethnic study published in the online version of the journal Menopause, 1,145 women participating in the Study of Women's Health Across the Nation tracked their monthly cycles and symptoms from 1996 to 2006. The women were recruited from Boston, southeastern Michigan, Los Angeles, and Oakland, Calif.
The study found this age-of-onset difference across four racial/ethnic groups: white, Chinese, Japanese and African-American women. The only difference researchers found unique to the groups was that African-American women had a longer transition than white women.
"As the duration and amount of menstrual bleeding increases significantly during the menopausal transition, a longer transition may signify that women with fibroids or with abnormal uterine bleeding may have increased difficulty in coping effectively with their blood loss," Harlow said. "This issue may be particularly salient for African-American women who had longer transitions and are also at greater risk of having fibroids."
The researchers say their findings can inform physicians and their patients about how best to manage the symptoms of menopausal transition. The decision regarding the use of hormones, for instance, is one that women and their doctors wrestle with because the treatments are not without side effects.
"Women with an earlier onset may opt for intervention in anticipation of a longer duration of concerns, whereas women with a later onset may forego therapy with the expectation of a shorter timeframe of change," said Dr. John Randolph, professor of obstetrics and gynecology at the U-M Health System. "The relative risks, benefits and costs of medical therapy versus surgery can be discussed with greater confidence by knowing how long a treatment may be required."
Also noteworthy in the research is that cigarette smoking was associated with an earlier onset of menopausal symptoms and shorter duration, and obesity was linked to a later start but no difference in duration.