Hormonal contraceptive use may reduce severe asthma exacerbations in women

Previous and current use of hormonal contraceptives was associated with a small beneficial effect on asthma exacerbations in reproductive-aged, according to data published in Thorax.

Researchers noted that the beneficial effect was relatively small and does not include progestogen-only hormonal contraceptives.

“Deciphering the role of hormonal contraceptives on clinical outcomes of asthma is essential in resolving the current uncertainty in the underlying evidence,” Bright I. Nwaru, PhD, associate senior lecturer at the Krefting Research Centre Institute of Medicine and the Wallenberg Centre for Molecular and Translational Medicine at the University of Gothenburg, Sweden, and colleagues wrote. “This is also essential in evaluating any potential benefit or harm of exogenous sex steroids in the management of asthma.”

Researchers analyzed the population-based, longitudinal Optimum Patient Care Research Database to identify 83,084 women aged 16 to 45 years with asthma. Severe asthma exacerbations were defined as asthma-related hospitalization, accident and ED visits due to asthma and/or oral corticosteroid prescriptions. Hormonal contraceptive use, subtypes and duration of use were assessed using Read Clinical Classification System codes.

The researchers reported findings on the association between contraceptive use and asthma exacerbation over 17-year follow-up.

At baseline, 34% of women were using any hormonal contraceptives, 25% were using combined hormonal contraceptives (estrogen/progestogen) and 9% were using progestogen-only contraceptives.

Compared with no use of hormonal contraceptives, the following were associated with reduced risk for severe asthma exacerbations:

previous use of any hormonal contraceptives (incidence rate ratio [IRR] = 0.94; 95% CI, 0.92-0.97);

current use of any hormonal contraceptives (IRR = 0.96; 95% CI, 0.94-0.98);

previous use of combined hormonal contraceptives (IRR = 0.92; 95% CI, 0.87-0.97);

current use of combined hormonal contraceptives (IRR = 0.93; 95% CI, 0.91-0.96);

longer duration of 3 to 4 years of use (IRR = 0.94; 95% CI, 0.92-0.97); and

longer duration of 5 or more years of use (IRR = 0.91; 95% CI, 0.89-0.93).

Use of progestogen-only contraceptives was not associated with reduced risk for severe asthma exacerbations (previous use: IRR = 1.09; 95% CI, 1-1.18; current use: IRR = 1.04; 95% CI, 1.01-1.06).

“We observed that the use of hormonal contraceptives is associated with a small beneficial effect on severe asthma exacerbation,” the researchers wrote. “Further longitudinal studies are required to confirm these findings, as well as mechanistic studies investigating the underlying biological processes through which exogenous sex steroids influence the pathogenesis of asthma in women.”