Age-related decline in women's lung function may speed up during and after menopause, a recent study suggests.
Past research has shown that young women can boost their lung function through their mid-twenties by following a healthy lifestyle that includes getting plenty of aerobic exercise and avoiding cigarettes. After that, lung function declines gradually, and the process can be sped up when people smoke or carry excess fat around their midsection.
"Our study adds, that with increasing reproductive age slope of decline becomes steeper and the decline becomes faster, and it accelerates beyond the age-related expectations," said lead study author Kai Triebner, a researcher at the University of Bergen in Norway.
The good news for women is they can take steps to manage their respiratory health early in life to limit the potential for declines in lung function with menopause to lead to meaningful health problems, Triebner added by email.
"Generally speaking you cannot build up lung function again unless the loss was due to a medical condition, but you can manage the decline," Triebner added.
Women go through menopause when they stop menstruating, which typically happens between ages 45 and 55. As the ovaries curb production of the hormones estrogen and progesterone in the years leading up to menopause and afterwards, women can experience symptoms ranging from irregular periods and vaginal dryness to mood swings and insomnia.
For the current study, researchers examined data on 1,438 women who were followed for 20 years starting when they were between 25 and 48 years old.
None of the women had started going through menopause when they joined the study. By the end, they had either started or completed the process of going through menopause.
To assess shifts in lung function tied to menopause, researchers examined what's known as forced vital capacity (FVC), a measure of lung size, as well as forced expiratory volume (FEV1), or how much air can be pushed out of the lungs in one second.
Lung function decline was faster during the transition to menopause and sped up even further after menopause, compared to when women were still menstruating, researchers report in the American Journal of Respiratory and Critical Care Medicine.
For example, transitional women lost about 10 milliliters of forced vital lung capacity more per year than pre-menopausal women, and after menopause women lost a mean of 12 ml/year more.
For forced vital capacity, the decline after menopause was comparable to smoking 20 cigarettes a day for 10 years, the study found.
With forced expiratory volume, the decline after menopause was comparable to smoking 20 cigarettes a day for two years.
The more pronounced decline in forced vital capacity compared to forced expiratory volume suggests that menopause may be more likely to lead to what's known as restrictive breathing problems, such as sarcoidosis, that make it difficult to fully expand the lungs when inhaling, rather than breathing problems such as chronic obstructive pulmonary disorder (COPD) that make it difficult to exhale air from the lungs, the authors conclude.
The study is observational and doesn't prove menopause directly causes breathing problems, the authors note.
While the findings don't explain why lung function dropped for women after menopause, it's possible that hormonal changes during this time that are linked to systemic inflammation may also trigger lung function declines, the authors point out.
Hormonal changes are also implicated in osteoporosis, which shortens the height of the chest vertebrae and may, in turn, limit the amount of air a person can inhale.
Both before and after menopause, though, the rate of decline in lung function is slow, and may only be significant in women with lung disease, said Dr. David Jacoby, a researcher at Oregon Health and Science University in Portland who wasn't involved in the study.
"Someone with lungs damaged by smoking who has no symptoms at age 30 may have symptoms of her lung disease later in life as her lung function declines with age," Jacoby said by email. "The message, an obvious one, is to avoid smoking to avoid damaging your lungs, and if you have chronic lung disease, take your medications to keep your lung function as good as possible."