Hormone replacement therapy (HRT) may increase the risk of severe asthma exacerbations in peri- and post-menopausal asthmatic women, an observational study suggests. Dr. Bright Nwaru of the University of Gothenburg told Reuters Health by email, "Starting from around puberty, asthma becomes more common and more severe in women than in men, and this continues until around menopause. Sex hormones have long been suspected to, at least in part, explain these gender differences." "We know that more than 40% of women who have asthma experience increased exacerbations during their menstrual cycle, which points to the role of sex hormones," he noted. "Some anecdotal evidence suggests that some women get relief if they take hormonal contraceptives. However, the impact of exogenous sex steroids on clinical outcomes of asthma remained uncertain." "Our findings do not suggest any changes in current management guidelines of asthma," he said, "but indicate the need for mechanistic studies uncovering the biological processes through which HRT may impact on clinical outcomes of asthma. In addition, confirmatory studies - e.g., clinical trials - are required." As reported in the Journal of Allergy and Clinical Immunology: In Practice, Dr. Nwaru and colleagues analyzed data from a longitudinal primary cared database in the UK to construct a 17-year cohort (2000 through 2016) of peri- and post-menopausal women. More than 30,000 patients between the ages of 46-70 were included: 11% used combined HRT, 11% used estrogen-only, and 78% did not use HRT. Sixteen percent had experienced a severe asthma exacerbation. Compared to non-use, previous, but not current, use of any HRT was associated with an increased risk of severe asthma exacerbation (incidence rate ratio,1.24). The IRR for combined HRT was 1.28, and for estrogen-only, 1.18. IRRs for longer duration were 1.16 for 1-2 years; 1.43 for 3-4 years; and 1.48 for five years or more. Risk estimates were greater among lean (BMI <25 kg/m2) than among heavier women (BMI 25-29.9 and 30 or more), and higher among smokers than non-smokers. Dr. Jonathan Bernstein, Professor in the Division of Immunology/Allergy at the University of Cincinnati College of Medicine and a clinician at the Bernstein Allergy Group and Bernstein Clinical Research Center, commented by email, "It is clear that some women have worsening of a number of health issues peri-menstrual when there are estrogen and/or progesterone surges, including asthma, migraines, urticaria and hereditary angioedema, among other conditions." In agreement with Dr. Nwaru, he told Reuters Health, "I don't think the message is not to prescribe HRT in asthma patients but rather to be aware of risk factors for worsening asthma if starting HRT (lean body habitus, duration of HRT and smoking history) - and if an asthma patient is having worsening asthma, to consider HRT as a potential contributing cause, especially if there are no other explanations for their asthma decline." —Marilynn Larkin Source
