Menstrual variation in BHR may affect lung function test results
MedWire News: Study results indicate that there is significant variation in bronchial hyper-responsiveness (BHR) among women during the menstrual cycle.
The findings, published in the Journal of Allergy and Clinical Immunology, have implications for the timing of respiratory tests in women with suspected asthma or established disease, say Julia Dratva (Swiss Tropical Institute, Basel, Switzerland) and team.
The researchers studied data on 571 premenopausal women, aged 28–58 years, who participated in the Swiss cohort study on Air Pollution And Lung Disease In Adults (SAPALDIA), and who were not taking hormone therapy.
All the women underwent lung function tests and methacholine challenge to identify BHR, including 143 who underwent methacholine challenge in a pre-defined “window of risk” of 3 days before to 3 days after the first day of the menstrual cycle.
The researchers found that 13% of the participants had BHR, defined as at least a 20% fall in FEV1 up to a maximal methacholine cumulative dose of 2 mg, and 6% had asthma.
Analysis revealed that there was as a significant increase in BHR during the window of risk compared with at other times of the menstrual cycle, at an odds ratio of 2.3.
The researchers also found that there was significantly less menstrual cycle-associated variation in BHR among women taking oral contraceptives than among those who were not, and more variation among those diagnosed with asthma than in those without the condition.
Dratva and team conclude: “The data provide evidence of a systematic variation in BHR during the menstruation cycle, supporting the hypothesis of a hormonal influence.”
They add: “Menstrual cyclicity of BHR may be of importance for future screening and diagnostic testing recommendations. In women with menstrual cyclicity, an adaptation of medication prescriptions might prove useful.”
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By Mark Cowen