Hormone Replacement Therapy May Increase Risk of Severe Asthma Exacerbation in Women

Takeaway

• Previous but not current use of hormone replacement therapy (HRT) and its subtypes (oestrogen-only and combined oestrogen/progestogen) and long-term use were associated with an increased risk of severe asthma exacerbation in peri- and postmenopausal women with asthma.

Why this matters

• Although current findings do not suggest changes in asthma management in peri-menopausal and postmenopausal women, studies uncovering the mechanisms through which HRT impact on clinical outcomes of asthma are needed.

Study design

• Researchers used the population-based, Optimum Patient Care Research Database to construct a 17-year retrospective cohort of peri-menopausal and postmenopausal (age, 46-70 years; n=31,656) women with asthma. The 17-year follow-up resulted in 366,678 person-years of follow-up time.
• Association of HRT use, its subtypes and duration of use with severe asthma exacerbation was evaluated.
• Funding: Asthma UK and Health Data Research UK.

Key results

• At baseline, 22% of women were using any HRT, 11% combined HRT and 11% oestrogen-only HRT.
• Compared with non-HRT use, previous use of any HRT (adjusted incidence rate ratio [aIRR], 1.24; 95% CI, 1.22-1.26), combined oestrogen/progestogen HRT (aIRR, 1.28; 95% CI, 1.25-1.31) and oestrogen-only HRT (aIRR, 1.18; 95% CI, 1.14-1.21) was associated with an increased risk of severe asthma exacerbation.
• Current use of any HRT was associated with a small increased risk of severe asthma exacerbation (aIRR, 1.07; 95% CI, 1.04-1.09) while combined oestrogen/progestogen and oestrogen-only HRT showed no significant association.
• Compared with non-HRT use, any duration of HRT use was associated with an increased risk of severe asthma exacerbation:
  • 1-2 years (aIRR, 1.16; 95% CI, 1.13-1.19);
  • 3-4 years (aIRR, 1.43; 95% CI, 1.38-1.48); and
  • >5 years (aIRR, 1.32; 95% CI, 1.28-1.36).
• The risk estimates were greater in lean women (body mass index [BMI], <25 kg/m²) than heavier women (BMI, 25-29.9 kg/m² and ≥30 kg/m²) and higher in smokers than non-smokers.

Limitations

• Risk of confounding.

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.