Background: Changes in asthma activity, in part related to the female hormonal profile, have been observed during pre-menstrual periods and during pregnancy. Estrogen replacement therapy (ERT) is an accepted routine treatment for post-menopausal women. The effect of ERT on disease activity in post-menopausal asthmatic women has not been investigated in the past and is the subject of the present study.
Methods: Fifteen post-menopausal women with mild to moderate asthma completed two 30-day periods in which they measured peak expiratory flow (PEF) at home and filled in a daily diary of asthma-related symptoms. The first monitoring period was pre-ERT and the second was during ERT. In addition spirometry was performed on each woman three times, twice pre-ERT and once during ERT.
Results: The average daily PEF decreased from 241 (57.9, S.D.) l/min pre-ERT to 226.7 (62.7) l/min during ERT (P < 0.004). Significant differences between the two study periods were also found in morning and evening PEF values. Diurnal variation, measured as the difference between morning and evening PEF values, decreased significantly from 22.3 (26.7) l/min pre-ERT to 17.5 (26.8) l/min during ERT (P < 0.007). The average daily consumption of bronchodilator inhalers increased significantly from 3.7 puffs/day pre-ERT to 4.3 puffs/day during ERT (P < 0.006). Although the differences in spirometry between the two periods did not reach statistical significance, a trend towards a worsening of the obstructive disorder during ERT was observed. However, the general feeling of well-being of the asthmatics did not change during the two periods.
Conclusions: During ERT a sub-clinical worsening of disease activity was found in postmenopausal women with mild to moderate asthma. We also detected a decrease in diurnal variation. Our findings should be substantiated by additional studies.