Gender differences at presentation of idiopathic pulmonary fibrosis in Sweden

Background Idiopathic pulmonary fibrosis (IPF) is a disease with poor prognosis mainly affecting males. Differences in clinical presentation between genders may be important both for the diagnostic work-up and for follow-up. In the present study, we therefore explored potential gender differences at presentation in a Swedish cohort of IPF-patients. Methods We studied patients included in the Swedish IPF- registry over a three-year period from its launch in 2014. A cross-sectional analysis was performed for data concerning demographics, lung function, 6- min walking test (6MWT) and quality of life (QoL) (King's Brief Interstitial Lung Disease (K-BILD) score). Results Three hundred forty- eight patients (250 (72%) males, 98 (28%) females, median age 72 years in both genders) were included in the registry during the study period. Smoking history (N = 169 (68%) vs. N = 53 (54%), p < 0.05), baseline lung function (Forced vital capacity, % of predicted (FVC%): 68.9% +/- 14.4 vs. 73.0% +/- 17.7, p < 0.05; Total lung capacity, % of predicted (TLC%): 62.2% +/- 11.8 vs. 68.6% +/- 11.3%, p < 0.001) were significantly different at presentation between males and females, respectively. Comorbidities such as coronary artery disease (OR: 3.5-95% CI: 1.6-7.6) and other cardiovascular diseases (including atrial fibrillation and heart failure) (OR: 3.8-95% CI: 1.9-7.8) also showed significant differences between the genders. The K- BILD showed poor quality of life, but no difference was found between genders in total score (54 +/- 11 vs. 54 +/- 10, p = 0.61 in males vs. females, respectively). Conclusions This study shows that female patients with IPF have a more preserved lung function than males at inclusion, while males have a significant burden of cardiovascular comorbidities. However, QoL and results on the 6MWT did not differ between the groups. These gender differences may be of importance both at diagnosis and follow- up of patients with IPF.