Later menopause and the greater risk for asthma

Many studies suggest that an earlier age at menopause is more detrimental to a woman’s health, leading to an increased risk for adverse health conditions such as heart disease, diabetes, osteoporosis, and depression, among others. However, a new Canadian study is linking a later age at natural menopause with a greater risk for asthma.

Asthma is a common, chronic disease affecting more than 300 million people worldwide. The prevalence of asthma has been increasing over recent years, creating a substantial economic impact because it is one of the highest diseases for healthcare use. Adult-onset asthma is typically more severe and more difficult to treat than childhood asthma.

Multiple studies have suggested a possible link between asthma and sex hormones. Most notable is the fact that adult-onset asthma is more common in women than men. In childhood, asthma is more prevalent in boys. After puberty, however, asthma occurs more often in girls. Women also tend to have more severe asthma and are less likely to have remission of the disease.

Some studies have found a peak incidence of asthma at around age 40 years, which is commonly the age of the menopause transition, whereas other studies found a peak at the average age at menopause, which is 51 years. Both natural oestrogen and synthetic oestrogen, such as used in hormone therapy, offer similar risk profiles. Women using hormone therapy were shown to have a 63% increased risk of asthma, whereas women who stopped hormone therapy were two times more likely to quit asthma treatment. Higher body mass index also is shown to be a risk factor for women, but not men, because fat produces oestrogen.

Unfortunately, research on the association between menopause and asthma incidence is limited and has yielded conflicting results. That is why this newest study, based on 10 years of follow-up data from more than 14,000 postmenopausal women, was designed to investigate the association between the age at natural menopause and incidence of asthma in nonsmoking postmenopausal women. The study researchers found that women with early menopause (which occurs between 40 and 44 years of age) are at a reduced risk of asthma, which led them to suggest a role of oestrogen with asthma risk. Study results are published in the article “The association between age at natural menopause and risk of asthma among postmenopausal women from the Canadian Longitudinal Study on Aging.”

Abstract

Objective 

This study aimed to investigate the association between age at natural menopause and incidence of asthma among postmenopausal Canadian women.

Methods 

Women between the ages of 45-85 yr were followed for a 10-yr period. Analysis was restricted to naturally postmenopausal women who are nonsmokers and did not have asthma prior to menopause. Age at natural menopause was examined using the following categories: 40-44, 45-49, 50-54 (reference), and ≥55. Survival analysis was utilized to determine time to onset of asthma. Multivariable Cox regression analysis was performed to assess the relationship between age at natural menopause and asthma after adjusting for covariates.

Results 

The multivariable Cox regression analysis showed a 30% decreased risk of asthma in women with age at natural menopause of 40-44 yr compared with age at natural menopause of 50-54 yr with a hazard ratio of 0.7 (95% confidence interval: 0.49-0.95).

Conclusion 

Women with later ages at natural menopause may be at increased risk for asthma.

Reference