Study of the associations between short telomeres, sex hormones and pulmonary fibrosis

Abstract Background Pulmonary fibrosis (PF) is an incurable fibrotic lung disease with limited treatment options and a high mortality. Evidence is growing that short telomeres cause both heritable and idiopathic pulmonary fibrosis (IPF). Based on survival data, we hypothesised that sex hormones are protective against premature telomere(definition) attrition and could influence PF disease onset and/or progression. Methods Associations between IPF, sex hormone concentrations and measured leukocyte telomere length (LTL) were examined for unrelated UK Biobank participants of European ancestry with a diagnosis of IPF (415 females, 718 males) against controls (204,321 females, 174,254 males). Polygenic risk scores were used to explore causality between sex hormone indices, LTL and disease. Findings Strong associations were found between IPF and LTL. For females, higher odds of having IPF was associated with early menopause and premature ovarian failure. Menopause age correlated positively with both age of IPF diagnosis and age of death. For males, IPF prevalence and stages of disease were associated with serum bioavailable testosterone concentrations. For both sexes, evidence of lower concentrations of sex hormones was associated with shorter LTL. Genetic analysis also inferred bi-directional causal links between sex hormone binding globulin concentration, which impacts free testosterone concentration, and LTL in males. Interpretation Our findings suggest that higher sex hormone concentrations protect against IPF onset and progression, possibly by slowing telomere shortening. Hormonal supplementation may delay or prevent disease onset for those with telomere-associated PF risk and improve disease prognosis. This warrants further exploration in a randomised controlled trial. Funding Medical Research Council.