MADRID – Menopause is blamed for many things, but it’s unlikely to be the reason for the increased risk of severe asthma or worse quality of life in elderly asthmatic women, a study suggests.
"The increased unadjusted asthma severity and need for health care utilization in postmenopausal women are more likely due to other factors like age and other comorbidities rather than menopause per se," Dr. Joe Zein said at the world congress of the American College of Chest Physicians.
Dr. Joe Zein
The investigators used a propensity score matching method to analyze the effect of menopause on asthma severity, quality of life, and health care utilization in 166 menopausal and 538 premenopausal women enrolled in the Severe Asthma Research program from 2002 to 2011. Subsequent multivariate logistic regression analyses were used to adjust for the covariates of age at enrollment, hypertension, gastroesophageal reflux disease (GERD), and hormone therapy, which was used in only 35 menopausal women.
Compared with premenopausal women, menopausal women were older and reported less atopy and more comorbidities, such as higher body mass index, diabetes mellitus, hypertension, GERD, obstructive sleep apnea, sinusitis, and nasal polyps, said Dr. Zein, a pulmonologist at Cleveland Clinic.
Menopausal women also had lower lung function and higher neutrophil percentage in both induced sputum and bronchoalveolar lavage fluid.
Severe asthma was present in 31% (167/538) of premenopausal and 72% (119/166) of menopausal women.
In unadjusted analysis, the risk of severe asthma was almost sixfold higher in menopausal women (odds ratio, 5.62; 95% confidence interval 3.83-8.26), but dropped dramatically in the adjusted analysis (OR, 1.46), he said.
Menopausal women also had lower average scores than did premenopausal women (4.06 vs. 4.56) on the 7-point Asthma Quality of Life Questionnaire, with 7 being "not impaired at all" and 1 being "severely impaired." The mean difference between groups pointed to worse quality of life among menopausal women in unadjusted analysis (–0.5), but again this faded after multivariate adjustment (0.31; 95% C.I. –0.30 to 0.93).
Similar trends were observed for health care utilization including emergency department visits (unadjusted OR, 1.33; adjusted OR, 1.15) and hospitalization (unadjusted OR, 2.93; adjusted OR, 0.70), Dr. Zein said.
Finally, an analysis stratified by menopausal status that looked at the association between enrollment age and the probability of severe asthma, suggested a rise in severe asthma among premenopausal women and those in early menopause, followed by a steady decline around age 55 years. Two possible hypotheses are that insulin resistance is higher during the period around menopause and thus may worsen asthma and that estrogen levels initially rise during early menopause before declining and also may increase asthma severity, Dr. Zein said.
"We don’t know exactly, but I think we should not look at menopause as one entity."
Several studies have tried to tease out the effects of menopause and aging on asthma severity, with conflicting results.
A recent study reported that menopausal women in their fifties and sixties are more than twice as likely to be hospitalized for asthma as men the same age (Ann. Allergy Asthma Immunol. 2013;111:176-81).
The Harvard Nurses Health Study, however, found that postmenopausal women who never used hormone therapy had a significantly lower age-adjusted risk of asthma than premenopausal women (Am. J. Respir. Crit. Care Med. 1995;152:1183-8).
The role of estrogen in asthma remains controversial, Dr. Zein observed. The incidence of asthma is twice as high among boys during childhood, but this switches during puberty when girls have a higher incidence of asthma as well as asthma-related hospitalizations and health care utilization, he noted.
Dr. Zein reported no financial disclosures; a coauthor reported grant monies from the National Institutes of Health.