This prospective ongoing study is the first to assess sleep disorders among Romanian patients with CLDs by using actigraphy and correlate its results with subjective tools for sleep quality and HRQOL.

Sleep disorders have been previously described in patients with CLDs in several studies [8,10,11,20,21,22], where their prevalence varies widely from 47% to 81%, mainly due to different assessment methods, heterogenous population, and cumulative influencing/bias factors (e.g., coffee intake, alcohol, sleep medication, presence of hepatic encephalopathy, associated comorbidities, etc.). We reported in our study, among CLD patients, a prevalence of 48.21% of nighttime disturbances and 39.29% of daytime sleepiness, evaluated by PSQI and ESS, respectively. The scores for both questionnaires were significantly higher in decompensated patients, showing a direct relationship between impaired sleep quality and daytime somnolence, and complicated, severe liver disease. Excessive daytime sleepiness has been considered a feature of hepatic encephalopathy, since ESS score has been shown to correlate with the degree of hepatic encephalopathy [16,23,24,25]. Still, it's demonstrated that daytime somnolence is present in a high percentage even in pre-cirrhotic patients. This finding may indicate a possible early minimal hepatic encephalopathy (HE) before becoming clinically evident in patients with cirrhosis, however, of course, further prospective studies are needed to confirm this hypothesis.

In addition to the subjective data of sleep quality, objective measures of sleep characteristics were added by using actigraphy. Studies from the literature show that patients with cirrhosis, in particular, experience “delayed sleep phase syndrome” [26], with prolonged onset latency, poor sleep efficacy, and fragmented sleep with frequent awakenings [16,20,26]. This information is also supported by our study, which showed delayed bedtime and get-up hours, lower sleep efficacy, and also more awakenings in patients with cirrhosis compared to pre-cirrhotic ones. Controversially, our study failed to reveal significant differences of onset latency and total sleep time between pre-cirrhotic and cirrhotic patients, as the periods were similar. Moreover, our evidence shows that the difference in sleep parameters is even more important when comparing decompensated stages with compensated forms.

HRQOL in patients with CLDs is influenced by various factors. On one hand, patients experience multiple symptoms related to liver disease, such as itching, fatigue, weight loss, and “fuzzy-thinking”, which can also interfere with their social life. On the other hand, psychological distress strains on patients with advanced stages, when concerns regarding disease progression tremendously impact their QOL [27]. All these factors are also contributors to sleep abnormalities. However, researchers investigated the relationship between sleep impairment in patients with cirrhosis and HRQOL independently of other factors [11,16]. An important finding of our study showed that, besides cirrhotics, patients in pre-cirrhotic stages also experience reduced QOL, directly influenced by poor sleep quality.