Menstrual irregularity and asthma and lung function.

Background: Oligomenorrhea was associated with more asthma (Respiratory Health in Northern Europe study), but a possible association with lung function has not been investigated previously. Objective: To investigate whether oligomenorrhea was related to lung function and asthma, and whether body mass index and physical activity modified associations. Methods: Women age 28 to 44 years (n = 1631) participating in the European Community Respiratory Health Survey were included. Women who were taking exogenous sex hormones, were pregnant, or had recently given birth were excluded. Results: Long or irregular menstrual cycles were reported by 313 women (19%). Oligomenorrhea was significantly associated with more asthma symptoms (odds ratio [OR], 1.76; 95% CI, 1.29-2.40), allergic asthma (OR, 2.46; 95% CI, 1.43-4.23), and lower forced vital capacity (FVC; adjusted difference, 63 mL; 95% CI, −124 to −1). When excluding women using asthma medication, very lean women, or women exercising daily, these associations remained significant. Effects of oligomenorrhea were additive to those of body mass index (BMI) on asthma and FVC. Asthma symptoms increased significantly with BMI. FVC and FEV₁ increased with BMI until 25 kg/m² and thereafter decreased with increasing BMI. Excluding women exercising daily, asthma symptoms increased significantly with decreasing physical activity (OR, 1.09; 95% CI, 1.001-1.19) per category of physical activity) independently of oligomenorrhea. Among women exercising daily, oligomenorrhea predicted very high risk for asthma symptoms (OR, 12.6; 95% CI, 3.7-43). Conclusion: Women with oligomenorrhea have reduced lung function and more asthma, particularly allergic asthma, independent of BMI and physical activity. Airways pathology may have not only a hormonal but also a metabolic component. Clinical implications: Women with oligomenorrhea should be investigated with regard to asthma and lung function. Underlying metabolic disturbance should be considered in asthma. [Copyright &y& Elsevier]