How common is sleep-disordered breathing in patients with idiopathic pulmonary fibrosis?

Background and aim The frequency of obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with idiopathic pulmonary fibrosis (IPF) remains controversial. The aim of this study was to assess the frequency of OSAHS in newly diagnosed IPF patients and to identify possible correlations with body mass index and pulmonary function testing parameters. Materials and methods Thirty-four newly diagnosed IPF patients were included. All subjects underwent attended overnight PSG. None of the included subjects was under any of the currently available IPF treatments or nocturnal supplemental oxygen therapy. Results Total apnea-hypopnea index (AHI) was <5, 5-15, and >= 15/h of sleep in 14(41%), 15 (44%), and five patients (15%), respectively. REM AHI was statistically significant correlated with TLC [Total lung capacity] (p=0.03, r=-0.38). Diffusing capacity of the lung for carbon monoxide was correlated with mean oxygen saturation during sleep (p=0.02, r=0.39). Conclusions Sleep-disordered breathing seems frequent, although remains usually under diagnosed in IPF patients. A decrease in TLC, reflecting the severity of pulmonary restriction, might predispose IPF patients in SDB, especially during the vulnerable REM sleep period.