RESUMO
Background: Idiopathic pulmonary fibrosis (IPF) is characterized by a male predominance. The aim of the study was to explore gender differences in a well-designed French multicentre prospective IPF cohort (COhorte FIbrose, COFI) with a 5-year follow-up. Methods: Between 2007 and 2010, 236 patients with incident IPF were included in COFI. Gender characteristics were compared using a t-test, Chi-squared test and ANOVA, as appropriate. Survival analyses were performed. Results: Fifty-one (22%) females and 185 (78%) males with an average age at diagnosis of 70.1 ± 9.20 and 67.4 ± 10.9 years, respectively, were included in the cohort. Women were significantly less exposed to tobacco smoke [never n = 32 (62.7%) vs. n = 39 (21.1%), p < 0.001] and to occupational exposure [n = 7 (13.7%) vs. n = 63 (34.1%), p = 0.012]. Baseline forced vital capacity, % of predicted (FVC%) was significantly better in women compare to men (83.0% ± 25.0 v. 75.4% ± 18.7 p = 0.046). At presentation honeycombing and emphysema on CT scan were less common in women [n = 40 (78.4%) vs. n = 167 (90.3%) p = 0.041] and [n = 6 (11.8%) vs. n = 48 (25.9%) p = 0.029], respectively. During follow-up fewer women were transplanted compared to men [n = 1 (1.96%) vs. n = 20 (10.8%) p = 0.039]. Medians of survival were comparable by gender [31 months (CI 95%: 28-40) vs. 40 months (CI 95%: 33-72) p = 0.2]. After adjusting for age and FVC at inclusion, being a woman was not associated to a better survival. Conclusions: Women appear to have less advanced disease at diagnosis, maybe due to less exposure history compare to men. Disease progression and overall survival remains comparable regardless gender, but women have less access to lung transplantation.
RESUMO
INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) has an unpredictable course corresponding to various profiles: stability, physiological disease progression and rapid decline. A minority of patients experience acute exacerbations (AEs). A recent study suggested that ozone and nitrogen dioxide might contribute to the occurrence of AE. We hypothesised that outdoor air pollution might influence the natural history of IPF. METHODS: Patients were selected from the French cohort COhorte FIbrose (COFI), a national multicentre longitudinal prospective cohort of IPF (n=192). Air pollutant levels were assigned to each patient from the air quality monitoring station closest to the patient's geocoded residence. Cox proportional hazards model was used to evaluate the impact of air pollution on AE, disease progression and death. RESULTS: Onset of AEs was significantly associated with an increased mean level of ozone in the six preceding weeks, with an HR of 1.47 (95% CI 1.13 to 1.92) per 10 µg/m3 (p=0.005). Cumulative levels of exposure to particulate matter PM10 and PM2.5 were above WHO recommendations in 34% and 100% of patients, respectively. Mortality was significantly associated with increased levels of exposure to PM10 (HR=2.01, 95% CI 1.07 to 3.77) per 10 µg/m3 (p=0.03), and PM2.5 (HR=7.93, 95% CI 2.93 to 21.33) per 10 µg/m3 (p<0.001). CONCLUSION: This study suggests that air pollution has a negative impact on IPF outcomes, corroborating the role of ozone on AEs and establishing, for the first time, the potential role of long-term exposure to PM10 and PM2.5 on overall mortality.
