HealthDay News — Previous and current use of any and combined hormonal contraceptives is associated with a reduction in the risk for severe asthma exacerbation, according to a study published online Nov. 23 in Thorax.
Bright I. Nwaru, Ph.D., from the University of Gothenburg in Goteborg, Sweden, and colleagues examined the correlation between use of hormonal contraceptives and risk for severe asthma exacerbation in reproductive-aged women with asthma. A 17-year retrospective cohort was constructed, including 83,084 women aged 16 to 45 years, with 456,803 person-years of follow-up.
The researchers found that 34, 25, and 9 percent of women were using any hormonal contraceptives, combined estrogen/progestogen, and progestogen-only contraceptives, respectively. Compared with nonuse, a reduced risk for severe asthma exacerbation was seen for previous and current use of any (incidence rate ratios [IRRs], 0.94 and 0.96, respectively), previous and current use of combined (IRRs, 0.92 and 0.93, respectively), and longer duration of use (three to four years: IRR, 0.95; five or more years: IRR, 0.91) of hormonal contraceptives; risk was not reduced with progestogen-only contraceptive use.
“I don’t think this finding will end up in clinical guidelines or advice. But … the signal we’ve got from the study gives us the confidence to progress to designing more studies to try to understand the mechanisms through which hormonal contraceptives may influence asthma,” Nwaru commented in a linked podcast.