Lung function changes in relation to menstrual cycle in females with cystic fibrosis

Oestrogen and progesterone have been shown to have impact on cystic fibrosi s transmembrane conductance regulator (CFTR) gene expression, tone of smoot h muscle in the airways, immune response, exhaled nitric oxide and cytology in the tracheobronchial epithelium. The aim of this investigation was to s tudy the influence of menstrual cyclicity on airway symptoms among cystic f ibrosis (CF) females. Twelve CF women (mean age 30 years, mean Shwachman score 85) kept daily rec ords during three menstrual cycles of lung function, sputum quality and nee d for intravenous antibiotics. Paired t-test was used as a statistical meth od to compare the airway symptoms between the time of ovulation (high level s of oestrogen and low levels of progesterone), the luteal phase (high leve ls of oestrogen and progesterone) and menstruation (low levels of oestrogen s and progesterone). Forced expiratory volume in 1 sec (FEV1) was significantly higher during th e luteal phase (66% of predicted) compared to during ovulation (63%) and me nstruation (61%) (P<0.01). Forced vital capacity (FVC) showed the same patt ern, being significantly higher during the luteal phase compared with durin g menstruation (mean 75% vs. 70%. P<0.01). In conclusion, lung function changes were found during menstrual cycles in women with cystic fibrosis. These changes are probably related to changes i n progesterone levels during the menstrual cycles. This result warrants fur ther studies to understand the complexity of CF lung disease in women.