A Prospective Study of the Effects of Sex Hormones on Lung Function and Inflammation in Women with Cystic Fibrosis.

Rationale: Epidemiologic studies demonstrate worse outcomes in women with cystic fibrosis (CF) than men. Women are colonized earlier with respiratory pathogens and have increased rates of pulmonary exacerbations after puberty and near ovulation. The etiology of this disparity is unclear, but sex hormones may contribute to these differences.

Objectives

We sought to explore whether natural hormonal fluctuations and hormonal contraception associate with changes in lung function, respiratory symptoms, or inflammatory markers.

Methods

We prospectively followed women with CF who were not on hormonal contraceptives and reported regular menstrual cycles. We captured study visits at points that corresponded with menses, ovulation, and the luteal phase. A subset of subjects were subsequently placed on a standard oral estrogen/progesterone combination contraceptive pill, ethinyl estradiol/norethindrone (loestrin), and reevaluated. Measurements included lung function, symptom questionnaires, sweat tests, blood for hormone concentrations, and sputum for inflammatory markers, bacterial density, and cytology.

Results

Twenty-three women participated in this study. Hormone concentrations were as expected on and off hormonal contraception. At times of peak estrogen (ovulation), there was a significant increase in sputum proinflammatory cytokines (neutrophil-free elastase) and a corresponding pattern of decrease in lung function. Proinflammatory cytokines (IL-8, TNF-α, and neutrophil-free elastase) improved when placed on hormone contraception.

Conclusions

Our results show that there are potentially important fluctuations in inflammatory biomarkers in the lungs that correlate with changes in lung function in women with CF. Larger studies evaluating the impact of sex hormones on airway inflammation and immune response are necessary to better understand the clinical impact of these responses.