Commentary on How common is sleep-disordered breathing in patients with idiopathic pulmonary fibrosis? Mermigkis C. et al.

Abstract

There are few recent studies on the issue of quality of sleep in interstitial lung disease [idiopathic pulmonary fibrosis (IPF)]. Early studies [1,2] showed that the patients developed significant desaturation during sleep, especially during REM sleep. In a comparative study with a healthy control group using PSG monitoring, SaO2 was reduced below 90% during 30% of sleep time. Furthermore, increased arousal, decreased sleep efficiency, and reduced Delta-sleep was found. These sleep disturbances had an effect on the subjective state/functionality, as measured by FOSQ and Pittsburgh (PSQI) [3]. Only recently, polysomnographic studies on the incidence of obstructive sleep apnea (OSA) in pulmonary fibrosis have been published [4,5].Data by Lancaster et al. [5] show an increased incidence of OSA in IPF patients. Forty-four of 50 subjects (88%) had OSA as defined by an AHI of >5 events per hour. Twenty percent of subjects had mild OSA (AHI, five to15 events per hour), and 68% had moderate-to-severe OSA (AHI >15 events per hour). The mean BMI of the whole group with OSA was 33. OSA was noted only in a small percentage of 11% of patients with normal BMI.In this issue of SLBR, Mermigkis et al. [6] analyzed the frequency of OSA in 34 IPF patients. In a prospective study, they investigated Sleep Disordered Breathing isorders (SRBD) in a newly diagnosed IPF population group before the start of any treatment and tried to identify correlations with pulmonary function testing parameters. They found a high prevalence of SDB and a statistically significant correlation of REM AHI with TLC. The BMI was only moderately increased and at least in mild to moderate OSA (AHI 5-15) not different from the BMI of the IPF patients without OSA (AHI <5). Thus, other additional factors should be responsible for the higher incidence of SRBD in IPF. Studies suggest that the mechanism underlying this association is probably a decrease in upper airway stiffness with lower lung volume caused by reduced caudal traction from the trachea.The results demonstrate that sleep-disordered breathing in IPF is more frequent than previously suspected .These patients currently have very limited therapeutic options concerning the fibrosing alveolitis. We need to turn greater attention to the association between IPF and OSAS because applying CPAP sleep and quality of life can eventually be ameliorated. We should not defer sleep testing.

Obstructive sleep apnea in patients with interstitial lung diseases: past and future

“…Prior polysomnographic studies in the mid-1980s demonstrated alterations in sleep architecture and oxygen desaturation, especially during REM sleep, but not OSA, even in morbidly obese patients with ILDs [3,4]. The results of the study by Pihtili et al related to IPF patients are similar to recent studies that report increased incidence of OSA and pointed the need for high clinical suspicion for possible underlying OSA in this population [5][6][7][8]. Prior studies dating back 10-20 years probably underestimated hypopneas by using only thermal sensors and not nasal pressure transducers which are recognized as the sensitive devices for hypopnea detection that represents the majority of the observed respiratory events in IPF patients based on the newer studies.…”

CPAP treatment in patients with idiopathic pulmonary fibrosis and obstructive sleep apnea—therapeutic difficulties and dilemmas

“…Recently published studies [1][2][3][4] report an increased incidence of obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF). Underlying and usually underdiagnosed OSA in these patients may be a reason for impaired sleep quality and may consequently have a negative influence on their daily activities and overall quality of life [5][6][7].…”

“…Underlying and usually underdiagnosed OSA in these patients may be a reason for impaired sleep quality and may consequently have a negative influence on their daily activities and overall quality of life [5][6][7]. The absence of any effective treatment for IPF so far indicates that the recognition and treatment of generally underdiagnosed OSA in IPF patients should be a primary goal [1,2,5]. A major diagnostic problem in this population is related to the fact that the clinical presentation of OSA is often not typical, while generally accepted screening tools, such as the Epworth sleepiness scale or OSA-specific questionnaires, have several limitations to their diagnostic sensitivity [1,3].…”

Pulmonary Overlap Syndromes, with a Focus on COPD and ILD

“…111,112 Briefly, in patients without lung disease, a decrease in lung volumes leads to increased upper airway resistance, increased collapsibility, and worse OSA severity. 113,114 However, whether this relationship still holds when compliance of the lung is altered in not clear, and no formal measurement of airway resistance or collapsibility has been made in IPF patients to test this hypothesis.…”