Study objective: Lymphangioleiomyomatosis (LAM), a disease affecting women and causing cystic lung lesions, and, in some instances, leading to respiratory failure and death, appears to be exacerbated by estrogens. Hence, hormonal therapy with progesterone is frequently employed; however, efficacy has not been demonstrated. Our aim was to determine whether progesterone administration slowed the decline in lung function in LAM.
Design: Retrospective study.
Setting: National Institutes of Health, Bethesda, MD.
Design and subjects: The study population comprised 348 patients with LAM participating in a longitudinal research protocol. Declines in diffusion capacity of the lung for carbon monoxide (Dlco) and FEV1 were measured in 275 patients observed for approximately 4 years. The declines in Dlco and FEV1 of patients treated with progesterone, po (n = 67) or IM (n = 72), were compared with those of untreated patients (n = 136).
Measurements and results: Overall yearly rates of decline in Dlco and FEV1 were 2.4 ± 0.4% predicted (0.69 ± 0.07 mL/min/mm Hg) and 1.7 ± 0.4% predicted (75 ± 9 mL), respectively (mean ± SEM). The most significant predictors of functional decline were initial lung function and age. After adjusting for initial FEV1, age, and duration of disease, patients treated with IM progesterone tended to have lower rates of decline in FEV1 than patients treated po (1.9 ± 0.6% predicted vs 3.2 ± 0.8% predicted, respectively; p = 0.081). However, there was no significant difference in rates of decline in FEV1 between patients treated with IM progesterone and untreated patients (1.9 ± 0.6% predicted vs 0.8 ± 0.5% predicted, respectively; p = 0.520), and patients treated with po progesterone and untreated patients (3.2 ± 0.8% predicted vs 0.8 ± 0.5% predicted, respectively; p = 0.064). After adjusting for initial Dlco, rates of decline in Dlco were significantly higher in patients treated with po progesterone (3.6 ± 0.7% predicted, p = 0.002) and IM progesterone (2.8 ± 0.5% predicted, p = 0.022) than in untreated patients (1.6 ± 0.6% predicted).
Conclusions: Within the limitations of a retrospective study, our data suggest that progesterone therapy does not slow the decline in lung function in LAM.