Effects of obstructive sleep apnea on sleep quality, cognition, and driving performance in patients with cirrhosis

Abstract

Background & aims: In patients with cirrhosis, sleep disturbances are assumed to result from hepatic encephalopathy (HE). The effects of obstructive sleep apnea (OSA) on cognition, sleep parameters, or driving in patients with cirrhosis are unclear.

Methods: We performed a cross-sectional and prospective study of 118 subjects. Subjects were assigned to 1 of 4 groups: those with OSA and cirrhosis (without hepatic encephalopathy or ascites, n = 34), those with cirrhosis only (n = 30), those with OSA only (n = 29), and those without OSA or cirrhosis (controls, n = 25). None of the OSA patients were receiving continuous positive airway pressure (CPAP) therapy. Subjects underwent cognitive testing (paper-pencil tests for psychomotor speed and attention, as well as executive function tests), sleep assessment (daytime sleepiness and night-time sleep quality), and a monotonous driving simulation (worsening lane deviations over time indicated poor performance). We also tested patients with OSA, with cirrhosis (n = 10) and without cirrhosis (n = 7), before and after CPAP therapy.

Results: Daytime sleepiness and sleep quality were worse in subjects in the OSA groups (with or without cirrhosis) than subjects with cirrhosis alone or controls. Of subjects with only OSA, 36% had impaired psychomotor speed and attention, compared with more than 60% of subjects in both cirrhosis groups. In contrast, executive function was uniformly worse in subjects with OSA, with or without cirrhosis, than groups without OSA. Simulator performance (lane deviations) worsened over time in both OSA groups. CPAP therapy significantly increased executive function and sleep quality, and reduced simulator lane deviations and sleepiness, in OSA subjects with and without cirrhosis. After CPAP therapy, performance on the paper-pencil test improved significantly only in subjects with OSA without cirrhosis.

Conclusions: OSA should be considered in evaluating sleep impairment in patients with cirrhosis. In patients with cirrhosis and OSA, psychomotor speed and attention issues likely are related to cirrhosis, whereas executive function and simulator performance are affected by OSA. CPAP therapy improves executive function and simulator performance in patients with OSA, regardless of cirrhosis.

Keywords: CPAP; Chronic Liver Disease; Covert Hepatic Encephalopathy; Minimal Hepatic Encephalopathy.

Figure 1

Flow of patients through the study

Figure 2. Overarching title: Sleep and cognitive differences between subject groups. Ctrl: control, OSA: obstructive sleep apnea alone, OSA+Cirrhosis: both cirrhosis and OSA

Figure 2A: Cognitive impairment between groups: Cirrhotic patients had a higher proportion of cognitive impairment compared to OSA and controls. Figure 2B: Sleep questionnaires between groups: There was a significant worsening of daytime sleepiness and sleep quality in OSA patients with cirrhosis compared to other groups. ESS: Epworth Sleepiness Scale, PSQI: Pittsburgh Sleep Quality Index. Boxplots demonstrate median and inter-quartile range of scores. Controls were significantly better compared to all disease groups (p<0.0001) on ESS and PSQI.

Figure 3. Overarching title: Change in lane deviations between 1^st and 2^nd half of simulation before and after CPAP in patients with OSA

Figure 3A: In cirrhosis+OSA, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3B: In cirrhosis+OSA, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation. Figure 3C: In OSA only patients, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3D: In OSA only patients, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation.

Figure 3. Overarching title: Change in lane deviations between 1^st and 2^nd half of simulation before and after CPAP in patients with OSA

Figure 3A: In cirrhosis+OSA, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3B: In cirrhosis+OSA, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation. Figure 3C: In OSA only patients, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3D: In OSA only patients, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation.

Figure 3. Overarching title: Change in lane deviations between 1^st and 2^nd half of simulation before and after CPAP in patients with OSA

Figure 3A: In cirrhosis+OSA, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3B: In cirrhosis+OSA, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation. Figure 3C: In OSA only patients, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3D: In OSA only patients, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation.

Figure 3. Overarching title: Change in lane deviations between 1^st and 2^nd half of simulation before and after CPAP in patients with OSA

Figure 3A: In cirrhosis+OSA, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3B: In cirrhosis+OSA, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation. Figure 3C: In OSA only patients, there was a significant increase in lane deviations in the 2^nd half compared to the 1^st half before CPAP initiation. Figure 3D: In OSA only patients, there was no significant change in lane deviations in the 2^nd half compared to the 1^st half after CPAP initiation.