Respiratory symptoms tend to get worse during the mid-luteal to mid-follicular phases of the menstrual cycle - between days 10 to 22 of the cycle - the authors reported. The Follicular Phase is from day 1 to 14, and the Luteal Phase is from day 14 to 28.
Lead author Ferenc Macsali, MD, said:
"The effects of the menstrual cycle on respiratory symptoms in the general population have not been well studied. In a cohort of nearly 4,000 women, we found large and consistent changes in respiratory symptoms according to menstrual cycle phase, and, in addition, these patterns varied according to body mass index (BMI), asthma, and smoking status."
Dr. Macsali and team enrolled 3,926 women whose cycles were regular and who were not taking exogenous sex hormones. They were all sent postal questionnaires which asked them about their body mass index (BMI), menstrual cycles, respiratory symptoms, and smoking status.
They found considerable variations over the menstrual cycle for each symptom.
- Wheezing symptoms were most severe on cycles day 10 to 22
- The participants reported a mid-cycle dip in wheezing symptoms during ovulation (days 14 to 16)
- Shortness of breath symptoms were most severe on days 7 to 21. In a subgroup, shortness of breath symptom severity dipped on days 14 to 16
- There were more coughs just after putative ovulation (days 14 to 16) in participants with asthma, regular smokers and those whose BMIs were at least 23
"Our finding that respiratory symptoms vary according to the stage of the menstrual cycle is novel, as is our finding that these patterns vary according to BMI and smoking status. These relationships indicate a link between respiratory symptoms and hormonal changes through the menstrual cycle."
The authors emphasized that there were some limitations in the study: 1. Questionnaires were used to gather data (not face to face). 2. There were variations in the length of menstrual cycles, which may have affected the accuracy in determining menstrual cycles stages.
Dr. Macsali concluded:
"Our results point to the potential for individualizing therapy for respiratory diseases according to individual symptom patterns. Adjusting asthma medication, for example, according to a woman's menstrual cycle might improve its efficacy and help reduce disability and the costs of care."
Written by Christian Nordqvist