Sleep Quality and Health-Related Quality of Life in Idiopathic Pulmonary Fibrosis

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder resulting in irreversible scarring of the lung parenchyma. Although fatigue is a prominent symptom for patients with IPF, little is known about sleep quality in patients with IPF. In this cross-sectional study of 41 patients with IPF from a prospectively designed cohort, we ascertained sleep quality by means of the Pittsburgh sleep quality index (PSQI) and the Epworth sleepiness scale. Health status, baseline demographics, and physiologic parameters were also assessed. Patients with IPF reported extremely poor sleep quality and high frequency of daytime sleepiness, which differs significantly from normal control populations. Further, poor sleep quality was not associated with body mass index, age, gender, or lung function. This population also demonstrated extremely poor health status in a number of domains, including physical function and vitality. Poor sleep quality (by the global PSQI) was significantly associated with decreased quality of life (QOL) in several domains, including role of physical function (r = - 0.58, p = 0.001), vitality (r = - 0.43, p = 0.015), and role of emotions (r = - 0.40, p = 0.023). Poor sleep quality is extremely common in patients with IPF and is not predicted by variables traditionally associated with sleep-disordered breathing. Further, poor sleep quality is associated with poor QOL. These findings suggest that systematic evaluation of the cause of poor sleep quality in IPF is merited.