Risk factors for idiopathic pulmonary fibrosis in a Mexican population. A case-control study

Summary The etiology of idiopathic pulmonary fibrosis (IPF) remains poorly understood, but some studies have suggested that cigarette smoking or other occupational or environmental exposures, diabetes mellitus, or gastroesophageal reflux may play a role. In this study we evaluated the clinical records of a group of 97 consecutive patients with IPF, and 560 patients suffering 5 different respiratory disorders that were examined as controls: asthma ( n =111), chronic obstructive pulmonary disease ( n =132), squamous cell lung carcinoma ( n =118), lung adenocarcinoma ( n =101) and patients with otorhinolaryngology problems but without lung disease ( n =98). In bivariate analyses male sex, diabetes mellitus and being former cigarette smoker were associated with IPF. After adjusting by these variables, multivariate analysis revealed that type 2 diabetes mellitus [11.3% in IPF patients vs 2.9% in controls, OR=4.3 (95% CI: 1.9–9.8), p