Journal of Korean Medical Science · Nov 2, 2026

Lifetime Endogenous Estrogen Exposure Predicts Idiopathic Pulmonary Fibrosis Risk in Postmenopausal Women Based on a Nationwide Population Study

By Kim BG, Han K, Seo HT et al.

BACKGROUND: Conflicting results exist regarding the association between endogenous estrogen exposure and the risk of idiopathic pulmonary fibrosis (IPF). We aimed to investigate the relationship between lifetime endogenous estrogen exposure and the development of IPF among postmenopausal women. METHODS: Using the Korean National Health Insurance Service database for the period between 1 January 2009 and 31 December 2022, we analyzed a total of 1,388,645 postmenopausal women without previous history of IPF in 2009. The exposure was lifetime endogenous estrogen exposure (duration between the age of menarche and the age of menopause). The primary outcome was new-onset IPF. Participants were followed until the date of new IPF diagnosis, death, or 31 December 2022. RESULTS: During the median follow-up period of 12.4 (interquartile range, 12.1-12.7) years, 0.13% of postmenopausal women developed IPF, with an incidence rate of 0.109 per 1,000 person-years. There was a dose-dependent inverse relationship between endogenous estrogen exposure and the incidence of IPF (0.144/1,000 person-years for < 30 years, 0.104/1,000 person-years for 30-39 years and 0.101/1,000 person-years for ≥ 40 years). Multivariable Cox-regression analysis showed that the risk of developing IPF was dose-dependently decreased as endogenous estrogen exposure increased (adjusted hazard ratio [aHR], 0.85; 95% confidence interval [CI], 0.75-0.96 for 30-39 years; aHR, 0.77; 95% CI, 0.61-0.96 for ≥ 40 years compared to < 30 years). CONCLUSION: Among postmenopausal women, lifetime endogenous estrogen exposure showed a protective role from developing IPF.

doi.org/10.3346/jkms.2026.41.e269Open accessPubMed 42978134Populations