Idiopathic pulmonary fibrosis: Clinical behavior and aging associated comorbidities

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible and usually lethal lung disease of unknown etiology. Once considered as a relatively homogeneous, slowly progressive disease, is now recognized that the clinical behavior shows substantial heterogeneity, including an accelerated variant, and the presence of acute exacerbations. In addition, since IPF largely affects individuals over 60 years of age, the patients are at increased risk of several comorbidities that in turn have a remarkable clinical impact on the disease and increases mortality rate. Among others, combined pulmonary fibrosis and emphysema, secondary pulmonary arterial hypertension, lung cancer, and cardiovascular diseases are frequently associated with IPF and impact survival. For these reasons clinical phenotypes and comorbidities should be timely identified and managed. The aim of this review is to describe the common pulmonary and extra-pulmonary comorbidities in IPF, as well as the putative mechanisms involved.