Induced hyperammonemia may compromise the ability to generate restful sleep in patients with cirrhosis

Sleep disturbance in patients with cirrhosis and transjugular intrahepatic portosystemic shunt

BACKGROUND

Sleep disturbance (SD) is a common occurrence in individuals with cirrhosis and significantly impacts their quality of life. Datas regarding post transjugular intrahepatic portosystemic shunt (TIPS) SD are scarce. This study aimed to explore the incidence and outcomes of post-TIPS SD.

METHODS

From August 2018 to November 2019, 73 patients who underwent TIPS were prospectively recruited for the study. Sleep quality was evaluated via the Pittsburgh Sleep Quality Index (PSQI), and the presence of hepatic encephalopathy was evaluated according to the West Haven criteria before and after the TIPS procedure.

RESULTS

Nineteen patients (26%) experienced new-onset SD after TIPS, with a median latency of 67 (40-98) days from the procedure. The median time from TIPS creation to occurrence was 67 (40-98) days. Minimal hepatic encephalopathy (MHE) post-TIPS emerged as an independent predictor of SD, with an odds ratio of 3 (95% CI: 1.04-8.78, P = 0.046). Notably, five of the six (83%) patients with SD experienced improvement after being administered eszopiclone. Ten of the thirteen (77%) patients with SD improved spontaneously without treatment. Furthermore, the prevalence of MHE was significantly greater among patients with SD than among those without SD (58% vs. 31%, P = 0.04).

CONCLUSIONS

SD is prevalent in patients who undergo TIPS. MHE is an independent risk factor for the development of SD post-TIPS. Eszopiclone may be a safe and effective treatment option for patients with SD after TIPS. The study was registered with ClinicalTrials.gov under the identifier NCT03685994, with a registration date of September 23, 2018.

Circadian rhythms and the liver

This narrative review briefly describes the mammalian circadian timing system, the specific features of the liver clock, also by comparison with other peripheral clocks, the role of the liver clock in the preparation of food intake, and its relationship with energy metabolism. It then goes on to provide a chronobiological perspective of the pathophysiology and management of several types of liver disease, with a particular focus on metabolic-associated fatty liver disease (MAFLD), decompensated cirrhosis and liver transplantation. Finally, it provides some insight into the potential contribution of circadian principles and circadian hygiene practices in preventing MAFLD, improving the prognosis of advanced liver disease and modulating liver transplantation outcomes.

Hyperammonaemia disrupts daily rhythms reversibly by elevating glutamate in the central circadian pacemaker

Patients with cirrhosis exhibit features of circadian disruption. Hyperammonaemia has been suggested to impair both homeostatic and circadian sleep regulation. Here, we tested if hyperammonaemia directly disrupts circadian rhythm generation in the central pacemaker, the suprachiasmatic nuclei (SCN) of the hypothalamus. Wheel-running activity was recorded from mice fed with a hyperammonaemic or normal diet for ~35 days in a 12:12 light-dark (LD) cycle followed by ~15 days in constant darkness (DD). The expression of the clock protein PERIOD2 (PER2) was recorded from SCN explants before, during and after ammonia exposure, ±glutamate receptor antagonists. In LD, hyperammonaemic mice advanced their daily activity onset time by ~1 h (16.8 ± 0.3 vs. 18.1 ± 0.04 h, p = .009) and decreased their total activity, concentrating it during the first half of the night. In DD, hyperammonaemia reduced the amplitude of daily activity (551.5 ± 27.7 vs. 724.9 ± 59 counts, p = .007), with no changes in circadian period. Ammonia (≥0.01 mM) rapidly and significantly reduced PER2 amplitude, and slightly increased circadian period. The decrease in PER2 amplitude correlated with decreased synchrony among circadian cells in the SCN and increased extracellular glutamate, which was rescued by AMPA glutamate receptor antagonists. These data suggest that hyperammonaemia affects circadian regulation of rest-activity behaviour by increasing extracellular glutamate in the SCN.

Systematic Review and Meta-Analysis on the Effects of Lactulose and Rifaximin on Patient-Reported Outcomes in Hepatic Encephalopathy

INTRODUCTION

Patients with hepatic encephalopathy (HE) suffer from significant symptoms and impaired quality of life. Improved understanding on the potential benefits of first-line HE therapies may aid patient-provider discussions regarding expected benefits of HE treatments. We aimed to perform a systematic review to assess the effects of lactulose and rifaximin on patient-reported outcomes (PROs).

METHODS

We searched MEDLINE, EMBASE, and Cochrane Library databases for randomized trials or prospective cohort studies using lactulose and/or rifaximin for the management of HE and assessing changes in PRO using PRO instruments. Physician reviewers independently reviewed titles, abstracts, and full texts and extracted data independently. We performed random-effects meta-analyses to examine the effects of lactulose and rifaximin on PROs.

RESULTS

We identified 16 studies representing 1,376 patients that met inclusion criteria. Most studies assessed treatment of covert HE. In patients with covert HE, lactulose significantly improved overall patient-reported health-related quality of life measured by the Sickness Impact Profile with an estimated pooled mean difference of 6.92 (95% confidence interval: 6.66-7.18) and showed improvements in several subscales. Conversely, rifaximin demonstrated a nonstatistically significant mean difference in the total Sickness Impact Profile of 4.76 (95% confidence interval: -4.23 to 13.76), with strong evidence of heterogeneity between these studies. Studies examining other PRO instruments showed improvements in overall health-related quality of life, social functioning, and sleep from both lactulose and rifaximin.

DISCUSSION

Patients with HE treated with lactulose or rifaximin reported improvements in important PROs. These results may inform provider-patient communication and help manage patient expectations regarding the potential benefits of HE therapies.

Minimal Hepatic Encephalopathy Affects Daily Life of Cirrhotic Patients: A Viewpoint on Clinical Consequences and Therapeutic Opportunities

Minimal hepatic encephalopathy (MHE) is a frequent complication of hepatic encephalopathy (HE) and can affect up to 80% of patients with liver cirrhosis. It is characterized by the lack of obvious clinical signs and the presence of alterations detectable using psychometric or electrophysiological testing focused on attention, working memory, psychomotor speed and visuospatial ability. Ideally, each patient should be tested for this condition because, despite the absence of symptoms, it has severe repercussions on daily life activities. It may be responsible for an inability to drive, sleep disturbances, risk of falls and inability to work. Some studies have highlighted its prognostically unfavorable role on mortality and risk of "overt" HE (OHE). Finally, MHE severely affects the lives of patients and caregivers, altering their quality of life and their socioeconomic status. Several treatments have been proposed for MHE treatment, including non-absorbable disaccharides, poorly absorbable antibiotics, such as rifaximin, probiotics and branched-chain amino acids, with promising results. For this reason, early diagnosis and intervention with appropriate measures is essential, with the aim of improving both performance on psychometric tests, as well as clinical aspects related to this condition.

The effect of induced hyperammonaemia on sleep and melanopsin-mediated pupillary light response in patients with liver cirrhosis: A single-blinded randomized crossover trial

Background & aims

Sleep disturbances are related to hepatic encephalopathy and hyperammonaemia in patients with cirrhosis. The circadian rhythm is regulated by light stimulation of the retina via melanopsin-containing ganglion cells. The study aimed to investigate whether induced hyperammonaemia affects the pupillary light response and sleep efficiency in patients with cirrhosis.

Methods

The study was a single-blinded crossover trial including nine patients with cirrhosis. Sleep was evaluated by Pittsburgh Sleep Quality Index (PSQI) and monitored for twelve nights with wrist accelerometers and sleep diaries. On two experimental days, separated by one week, patients were randomized to ingest either an oral amino acid challenge (AAC) or an isocaloric glucose solution (GS). We measured pupillary light response, capillary ammonia, the Karolinska Sleepiness Scale (KSS), and two neuropsychological tests on both experimental days.

Results

The patients had poor self-assessed sleep quality. The amino acid challenge led to a significant increase in capillary ammonia and KSS. The time spent in bed sleeping after AAC was longer and with a reduced movement index compared to baseline but not different from GS. We found no difference in the pupillary light response or neuropsychiatric tests when comparing the effect of AAC with GS.

Conclusions

Patients with cirrhosis had impaired sleep quality. Induced hyperammonaemia led to increased sleepiness but had no acute effect on pupillary light response or the neuropsychiatric tests.

Trial registration

Registration number: NCT04771104.

Sleep and liver disease: a bidirectional relationship

Sleep is a complex, highly regulated process essential for human health and wellbeing. Increasingly, sleep-wake disturbance has been implicated in the pathogenesis of chronic liver disease, particularly the development and progression of non-alcoholic fatty liver disease and alcohol-related liver disease. Patients with cirrhosis also have a high burden of sleep abnormalities with substantial implications for their quality of life and physical health. This Review summarises the epidemiology and pathophysiology of sleep-wake disturbance in liver disease and discusses the multiple converging pathways leading to abnormal sleeping patterns in patients with cirrhosis. This includes contributions from altered melatonin metabolism, neuromuscular complications, and aberrant thermoregulation. In turn, a vicious cycle is established whereby disrupted sleep can further contribute to liver disease progression. We also begin to unravel the complex, interlinking relationship between sleep-wake disturbance and hepatic encephalopathy, discussing both overlapping and distinct mechanisms and clinical features. Finally, we summarise the current and future therapeutic approaches aiming to improve sleep quality in patients with cirrhosis.

New Therapies of Liver Diseases: Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common complication of advanced liver disease which has profound implications in terms of the patients’ ability to fulfil their family and social roles, to drive and to provide for themselves. Recurrent and persistent HE is still a serious management challenge, translating into a significant burden for patients and their families, health services and society at large. The past few years have been characterized by significantly more attention towards HE and its implications; its definition has been refined and a small number of new drugs/alternative management strategies have become available, while others are underway. In this narrative review we summarize them in a pragmatic and hopefully useful fashion.

The role of astrocytes in generating circadian rhythmicity in health and disease

Evidence is accumulating that the mammalian circadian clock system is considerably more complex than previously believed, also in terms of the cell types that actually contribute to generating the oscillation within the master clock, in the suprachiasmatic nuclei of the hypothalamus. Here we review the evidence that has lead to the identification of a bona fide astrocytic circadian clock, and that of the potential contribution of such clock to the generation of circadian and seasonal rhythmicity in health and in neurodegenerative disorders. Finally, we speculate on the role of the astrocytic clock in determining some of the clinical features of hepatic encephalopathy, a reversible neuropsychiatric syndrome associated with advanced liver disease, which is characterized by transient, profound morphological and functional astrocytic abnormalities, in the absence of significant, structural neuronal changes.

Sleep Disturbance Is Associated With the Presence of Portosystemic Collaterals in Patients With Compensated Cirrhosis

Disturbed sleep is common among patients with cirrhosis. The extent to which this is associated with the different stages of compensated cirrhosis is unknown. This study examines whether the presence of portosystemic collaterals, an indicator of clinically significant portal hypertension, is associated with sleep disturbance in compensated cirrhosis. We conducted a cross-sectional study among patients with compensated cirrhosis, comparing sleep characteristics, sleep quality, and excessive daytime sleepiness between 21 patients without and 21 patients with portosystemic collaterals. Patients were assessed with wrist actigraphy, Pittsburgh Sleep Quality Index, and the Epworth Sleepiness Scale. Collateral presence was determined by imaging and esophagogastroduodenoscopy. Differences in sleep characteristics were analyzed using t tests and computed effect sizes. Multivariable linear regression analysis was used to evaluate the association between collaterals and sleep disturbance while controlling for possible confounders. The group of patients with collaterals had greater beta-blocker and tobacco use, lower albumin, and higher international normalized ratio compared to the group without collaterals. Patients with collaterals had more sleep fragmentation (Cohen's d = -0.86), lower sleep efficiency (Cohen's d = 0.59), and lower total sleep time (Cohen's d = 0.75) than patients without collaterals. The presence of collaterals was independently associated with greater sleep fragmentation (P = 0.046) and greater daytime sleepiness (P = 0.030). Conclusion: Patients with compensated cirrhosis complicated by portosystemic collaterals experienced more sleep disturbance than those without collaterals.

Comprehensive Overview of Sleep Disorders in Patients with Chronic Liver Disease

The impact of sleep disorders (SDs) on patients with chronic liver diseases (CLD) is tremendous. SDs are frequently encountered among these patients and interfere with their quality of life. This review aims to present the data available so far about the prevalence, phenotypes, and proposed pathophysiological mechanisms of SDs in CLD. Moreover, we proposed to search the literature regarding the most reliable methods to assess SDs and the possible therapeutic options in patients with CLD. The main results of this review show that when it comes to prevalence, the percentages reported vary widely between studies performed among populations from the USA or Europe and those coming from Asian countries. Furthermore, it has been proven that SDs may also be present in the absence of neurocognitive disorders attributable to hepatic encephalopathy (HE), which contradicts traditional suppositions where SDs were considered part of the clinical scenario of HE. Currently, there are no specific recommendations or protocols to assess SDs in CLD patients and data about the therapeutic management are limited. Taking into consideration their impact, a protocol for diagnosing and managing SDs should be developed and included in the daily practice of hepatologists.

Prevalence of and Factors Associated with Sleep-Wake Abnormalities in Patients with Cirrhosis

BACKGROUND & AIMS

Sleep-wake abnormalities [poor nighttime sleep and excessive daytime sleepiness (EDS)] are common in patients with cirrhosis. The aim of this study was to assess the prevalence of sleep-wake abnormalities and clinical factors associated with these abnormalities in a group of patients with cirrhosis.

METHODS

1098 patients with cirrhosis [Child Turcotte Pugh (CTP) class A, 22.2%; CTP class B, 29.2% and CTP class C, 48.6%], with either no ascites or mild ascites controlled on diuretics, and no history of or current overt hepatic encephalopathy were included in the study.

RESULTS

Poor nighttime sleep and EDS were found in 569 (51.8%) and 489 (44.5%) patients respectively. On multivariate analysis, factors associated with poor nighttime sleep were CTP class C (vs. class A), presence of minimal hepatic encephalopathy (MHE), intermediate or evening type of diurnal preference category (vs. morning type), high risk for obstructive sleep apnea (OSA), diuretic use, presence of major depression, and presence of generalized anxiety disorder (GAD). Factors associated with EDS on multivariate analysis were CTP class B and C (vs. class A), intermediate or evening type of diurnal preference category (vs. morning type), high risk for OSA, presence of major depression, and presence of GAD.

CONCLUSIONS

Sleep-wake abnormalities are common in patients with cirrhosis. CTP status, diurnal preference chronotype, risk of OSA, major depression and GAD are associated with both poor nighttime sleep and EDS. MHE and diuretic use are associated with poor nighttime sleep, but not with EDS.

Sleep disorder in patients with chronic liver disease: a narrative review

Sleep disturbance is a common feature of chronic liver disease (CLD) with impact on health-related quality of life; 60-80% of patients with CLD report subjective poor sleep; frequent presentations of sleep disturbance include insomnia, reduced sleep efficiency, increased sleep latency, reduced time in rapid eye movement (REM) sleep, restless leg syndrome and excessive daytime sleepiness (EDS). Key contributors to sleep disturbance include hepatic encephalopathy (HE) and circadian rhythm imbalance due to altered melatonin metabolism. Specific conditions causing CLD, such as non-alcoholic fatty liver disease (NAFLD), chronic viral hepatitis and primary biliary cholangitis (PBC) result in different types of sleep disturbance, and the treatment of these conditions can often also lead to sleep disturbance. There are currently limited management options for sleep disturbance in CLD. Obstructive sleep apnoea (OSA) is a common condition that causes chronic intermittent hypoxia due to airway collapse during sleep. This chronic intermittent hypoxia appears to contribute to the development of NAFLD. The presence of reactive oxygen species and the overexpression of hypoxia inducible factor 1-alpha secondary to hypoxia may be responsible for the second 'hit' of the 'two-hit' hypothesis of NAFLD. Treatment of the intermittent hypoxia with continuous positive airway pressure therapy has limited efficacy against liver dysfunction. There remain many outstanding areas of investigation in the management of sleep disturbance in CLD, and of liver dysfunction in OSA.

Predictive value of induced hyperammonaemia and neuropsychiatric profiling in relation to the occurrence of post-TIPS hepatic encephalopathy

Hepatic encephalopathy (HE) occurs in 20-50% of patients after transjugular intrahepatic portosystemic shunt (TIPS) placement. Older age, HE history and severe liver failure have all been associated with post-TIPS HE but it remains difficult to identify patients at risk. The aim of the present pathophysiological, pilot study was to assess the role of induced hyperammonaemia and associated neuropsychological and neurophysiological changes as predictors of post-TIPS HE. Eighteen TIPS candidates with no overt HE history (56 ± 8 yrs., MELD 11 ± 3) underwent neurophysiological [Electroencephalography (EEG)], neuropsychological [Psychometric Hepatic Encephalopathy Score (PHES) and Scan tests], ammonia and sleepiness assessment at baseline and after the induction of hyperammonaemia by an oral amino acid challenge (AAC). Pre-AAC, 17% of patients had abnormal EEG, 5% abnormal PHES, and 33% abnormal Scan performance. Post-AAC, 17% had abnormal EEG, 0% abnormal PHES, and 17% abnormal Scan performance. Pre-AAC, ammonia concentrations were 201 ± 73 μg/dL and subjective sleepiness 2.5 ± 1.2 (1-9 scale). Post-AAC, patients exhibited the expected increase in ammonia/sleepiness. Six months post-TIPS, 3 patients developed an episode of HE requiring hospitalization; these showed significantly lower pre-AAC fasting ammonia concentrations compared to patients who did not develop HE (117 ± 63 vs. 227 ± 57 μg/dL p = 0.015). They also showed worse PHES/Scan performance pre-AAC, and worse Scan performance post-AAC. Findings at 12 months follow-up (n = 5 HE episodes) were comparable. In conclusion, baseline ammonia levels and both pre- and post-AAC neuropsychiatric indices hold promise in defining HE risk in TIPS candidates with no HE history.

Impact of Hepatic Encephalopathy in Cirrhosis on Quality-of-Life Issues

Hepatic encephalopathy (HE) has a major impact on health-related quality of life (HRQOL) in patients, which has clinical and psychosocial consequences. HRQOL in cirrhosis has been measured by generic and liver-specific instruments, with most studies indicating a negative impact of HE. HRQOL abnormalities span daily functioning, sleep–wake cycle changes, and the ability to work. Of these, sleep–wake cycle changes have a major effect on HRQOL, which remains challenging to treat. The personal effect of HRQOL is modulated by the presence of HE, the etiology of cirrhosis, and cognitive reserve. Patients with higher cognitive reserve are able to tolerate HE and its impact on HRQOL better than those with a poor cognitive reserve. The impact of HRQOL impairment is felt by patients (higher mortality and poor daily functioning), as well as by caregivers and families. Caregivers of patients with HE bear a major financial and psychological burden, which may affect their personal health and longevity.

Sleep disturbances in patients with liver cirrhosis: prevalence, impact, and management challenges

Sleep-wake disturbances are common in liver cirrhosis and associated with impaired quality of life. The most common abnormalities are insomnia (difficulties falling asleep and maintaining sleep, or unrefreshing sleep), excessive daytime sleepiness, and sleep-wake inversion (disturbances of circadian rhythmicity). The underlying pathophysiological mechanisms for sleep disturbances in cirrhosis are complex and may include disturbed metabolism of melatonin and glucose, alterations in thermoregulation, and altered ghrelin secretion profiles. Sleep-wake abnormalities are related to the presence of hepatic encephalopathy (HE) and improvement in sleep parameters can be observed when HE is properly managed. A few non-specific treatments for sleep-wake abnormalities have been tried with encouraging results for hydroxyzine and modafinil. However, due to the potential for medication toxicity in these disabled patients, further studies are needed to address the potential role of non-drug therapies in this population (eg, cognitive behavioral therapy, mindfulness, yoga) that have demonstrated usefulness in insomnia disorders.

Assessment and Management of Sleep Disturbance in Cirrhosis

Purpose of Review

This review presents an in-depth overview of the sleep–wake phenotype of patients with cirrhosis, together with available pharmacological and non-pharmacological treatment strategies. A set of simple, practical recommendations is also provided.

Recent Findings

The understanding of the pathophysiology of sleep disorders in this patient population has improved over the past decade, especially in relation to the interplay between homeostatic and circadian sleep regulation. In addition, new tools have been utilised for both screening and in-depth investigation of the sleep–wake profile of these patients. Finally, a number of studies have evaluated the efficacy of novel treatment strategies, often with encouraging results.

Summary

Since sleep disturbances are common in patients with cirrhosis, more so than in patients with other chronic diseases of similar severity, their assessment should become routine hepatological practice, along with the initiation of adequate treatment.

Abnormalities in the 24-hour rhythm of skin temperature in cirrhosis: Sleep-wake and general clinical implications

BACKGROUND & AIMS

Sleep preparation/onset are associated with peripheral vasodilatation and a decrease in body temperature. The hyperdynamic syndrome exhibited by patients with cirrhosis may impinge on sleep preparation, thus contributing to their difficulties falling asleep. The aim of this study was the assessment of skin temperature, in relation to sleep-wake patterns, in patients with cirrhosis.

METHODS

Fifty-three subjects were initially recruited, and 46 completed the study. Of the final 46, 12 were outpatients with cirrhosis, 13 inpatients with cirrhosis, 11 inpatients without cirrhosis and 10 healthy volunteers. All underwent baseline sleep-wake evaluation and blood sampling for inflammatory markers and morning melatonin levels. Distal/proximal skin temperature and their gradient (DPG) were recorded for 24 hours by a wireless device. Over this period subjects kept a sleep-wake diary.

RESULTS

Inpatients with cirrhosis slept significantly less well than the other groups. Inpatients and outpatients with cirrhosis had higher proximal temperature and blunted rhythmicity compared to the other groups. Inpatients with/without cirrhosis had higher distal temperature values and blunted rhythmicity compared to the other groups. Inpatients and outpatients with cirrhosis had significantly lower DPG values compared to the other groups, and DPG reached near-zero values several hours later. Significant correlations were observed between temperature and sleep-wake variables and inflammatory markers.

CONCLUSIONS

Alterations of distal/proximal skin temperature, their gradient and their time-course were observed in patients with cirrhosis, which may contribute to their sleep disturbances.

Abnormalities in the Polysomnographic, Adenosine and Metabolic Response to Sleep Deprivation in an Animal Model of Hyperammonemia

Patients with liver cirrhosis can develop hyperammonemia and hepatic encephalopathy (HE), accompanied by pronounced daytime sleepiness. Previous studies with healthy volunteers show that experimental increase in blood ammonium levels increases sleepiness and slows the waking electroencephalogram. As ammonium increases adenosine levels in vitro, and adenosine is a known regulator of sleep/wake homeostasis, we hypothesized that the sleepiness-inducing effect of ammonium is mediated by adenosine. Eight adult male Wistar rats were fed with an ammonium-enriched diet for 4 weeks; eight rats on standard diet served as controls. Each animal was implanted with electroencephalography/electromyography (EEG/EMG) electrodes and a microdialysis probe. Sleep EEG recording and cerebral microdialysis were carried out at baseline and after 6 h of sleep deprivation. Adenosine and metabolite levels were measured by high-performance liquid chromatography (HPLC) and targeted LC/MS metabolomics, respectively. Baseline adenosine and metabolite levels (12 of 16 amino acids, taurine, t4-hydroxy-proline, and acetylcarnitine) were lower in hyperammonemic animals, while putrescine was higher. After sleep deprivation, hyperammonemic animals exhibited a larger increase in adenosine levels, and a number of metabolites showed a different time-course in the two groups. In both groups the recovery period was characterized by a significant decrease in wakefulness/increase in NREM and REM sleep. However, while control animals exhibited a gradual compensatory effect, hyperammonemic animals showed a significantly shorter recovery phase. In conclusion, the adenosine/metabolite/EEG response to sleep deprivation was modulated by hyperammonemia, suggesting that ammonia affects homeostatic sleep regulation and its metabolic correlates.

Most Individuals With Advanced Cirrhosis Have Sleep Disturbances, Which Are Associated With Poor Quality of Life

BACKGROUND & AIMS

Sleep disturbances are common in patients with cirrhosis, but their determinants and effects on health-related quality of life are not well-understood. We investigated the prevalence of disturbed sleep in these patients, factors associated with sleep disruption, and effects on quality of life.

METHODS

We performed a prospective, cross-sectional study of 193 stable ambulatory patients with cirrhosis (154 with decompensated cirrhosis). Participants completed the Pittsburgh Sleep Quality Index (to assess sleep quality), the Chronic Liver Disease Questionnaire (CLDQ), and muscle cramp questionnaires and underwent neurocognitive testing. Actigraphy was performed in a subset of patients with normal and disturbed sleep. We collected serum samples from subjects with normal and disturbed sleep and performed non-targeted metabolomic analyses.

RESULTS

Of the study subjects, 157 (81%) had disturbed sleep, with Pittsburgh Sleep Quality Index scores >5. Disturbed sleep was associated with muscle cramps, daytime somnolence, and decreased quality of life on the basis of CLDQ scores. Factors independently associated with disturbed sleep in logistic regression analysis included hypoalbuminemia, opiate therapy, and muscle cramps. Disturbed sleep was independently associated with CLDQ score (correlation parameter, -36.6; 95% confidence interval, -24 to -49; P < .001) on linear regression. Disturbed sleep was associated with neurocognitive impairment and with significantly delayed bedtime and decreased total sleep time, measured by actigraphy. Disturbed sleep was associated with metabolome signatures of alterations to the intestinal microbiome and lipid, arginine, and urea cycle metabolism.

CONCLUSIONS

Most patients with advanced cirrhosis (81%) have disturbed sleep. This has negative effects on quality of life and is associated with disruptions of several metabolic pathways, including metabolism by the intestinal microbiota.

Sleep disturbances in patients of liver cirrhosis with minimal hepatic encephalopathy before and after lactulose therapy

Sleep disturbances are common in patients of cirrhosis with minimal hepatic encephalopathy (MHE) and affect health related quality of life (HRQOL). No study has evaluated effect of lactulose on sleep disturbances and correlation with HRQOL in patients with MHE. We assessed sleep disturbances in cirrhosis with MHE and effect of lactulose on sleep disturbances and HRQOL. One hundred patients of cirrhosis [MHE; (n = 50, age 45.3 ± 11.2 years, 45 males) no-MHE (n = 50, age 46.3 ± 10.4 years, 44 males)] were included. MHE was diagnosed with psychometric hepatic encephalopathy score (PHES) ≤ -5. All patients underwent laboratory parameters including arterial ammonia and critical flicker frequency (CFF) Sleep disturbances were measured with Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and polysomnography. HRQOL was measured with SF-36(v2) questionnaire. Patients with MHE were given lactulose therapy for 3 months and all the parameters were repeated. Poor quality of sleep and excessive day time sleepiness were more common in patients with MHE, compared to without MHE. With lactulose therapy there was improvement in MHE in 21 patients and arterial ammonia levels (93.74 ± 14.8 vs. 71.44 ± 18.8 μmol/L: p < 0.001), CFF (34.83 ± 3.54 vs. 39.44 ± 4.95 Hz: p < 0.001), PHES (-7.64 ± 2.1 vs. -5.58 ± 2.09: p < 0.001), PSQI (8.6 ± 3.3 vs. 5.2 ± 1.5: p < 0.001), ESS (12.52 ± 3.01 vs. 9.24 ± 2.27: p < 0.001) and HRQOL (p = 0.01). Excessive day time sleepiness and impaired sleep quality are common in patients with MHE and correlate with neuropsychiatric impairment. Improvement in MHE with lactulose also leads to improvement in sleep disturbances and HRQOL.

Improvement of sleep architecture parameters in cirrhotic patients with recurrent hepatic encephalopathy with the use of rifaximin

BACKGROUND AND AIM

Sleep disorders are frequently reported in patients with cirrhosis and hepatic encephalopathy (HE). This study assessed the effect of rifaximin on sleep architecture parameters in patients with recurrent HE.

PATIENTS AND METHODS

This sequential, prospective, and exploratory study involved all patients with cirrhosis and recurrent HE admitted between June 2014 and September 2015. HE was assessed according to the West-Haven Classification. Patients underwent 24-h polysomnography (PSG) and 7-day actigraphy. Rapid eye movement (REM) sleep was considered to be an indicator of good sleep quality. Patients completed questionnaires assessing the quality of sleep and sleepiness. After a 28-day course of rifaximin, the same assessment was repeated.

RESULTS

Fifteen patients were included (nine men, mean age: 57±11 years). Child-Pugh scores ranged from B7 to C15. Before rifaximin, the mean HE score was 2.7±0.7. Data from PSG analysis indicated long total sleep time (TST): 571±288 min, and limited REM sleep: 2.5% TST (0-19). Seven-day actigraphy showed an impaired number of steps: 1690/24 h (176-6945). Questionnaires indicated that patients experienced impaired sleep quality and excessive daytime sleepiness. After rifaximin, HE scores decreased to 1.7±0.6 (P<0.001). REM sleep increased to 8.5% TST (0-25) (P=0.003). No changes were observed for TST, number of steps, and on questionnaires.

CONCLUSION

Patients with recurrent HE suffer from poor sleep quality and excessive daytime sleepiness. On 24-h PSG, rifaximin improves objective sleep architecture parameters with no changes in the subjective quality of sleep and sleepiness.

Vigilance and wake EEG architecture in simulated hyperammonaemia: a pilot study on the effects of L-Ornithine-L-Aspartate (LOLA) and caffeine

Hyperammonaemia/mild hepatic encephalopathy (HE) can be simulated by the oral administration of a so-called amino acid challenge (AAC). This study sought to assess the effects of the AAC alone and in combination with either ammonia-lowering [L-ornithine-L-aspartate (LOLA)] or vigilance-enhancing medication (caffeine). Six patients with cirrhosis (5 males; 61.3 ± 9.2 years; 5 Child A, 1 Child B) and six healthy volunteers (5 males; 49.8 ± 10.6 years) were studied between 08:00 and 19:00 on Monday of three consecutive weeks. The following indices were obtained: hourly capillary ammonia, hourly subjective sleepiness, paper & pencil/computerized psychometry and wake electroencephalography (EEG) at 12:00, i.e. at the time of the maximum expected effect of the AAC.

RESULTS

On average, patients had worse neuropsychological performance and slower EEG than healthy volunteers in all conditions but differences did not reach significance. In healthy volunteers, the post-AAC increase in capillary ammonia levels was contained by both the administration of LOLA and of caffeine (significant differences between 10:00 and 14:00 h). The administration of caffeine also resulted in a reduction in subjective sleepiness and in the amplitude of the EEG on several frontal/temporal-occipital sites (p < 0.05; paired t-test). Changes in ammonia levels, subjective sleepiness and the EEG in the three conditions were less obvious in patients. In conclusion, both LOLA and caffeine contained the AAC-induced increase in capillary ammonia, especially in healthy volunteers. Caffeine also counteracted the AAC effects on sleepiness/EEG amplitude. The association of ammonia-lowering and vigilance-enhancing medication in the management of HE is worthy of further study.

Hepatic encephalopathy and sleepiness: an interesting connection?

Sleep-wake abnormalities in patients with cirrhosis have been traditionally associated with hepatic encephalopathy (HE). In recent years, a certain amount of work has been devoted to the study of this relationship. This has lead to a modified picture, with weakening of the association between HE and poor night sleep, and the emergence of stronger links between HE and excessive daytime sleepiness. This brief review focuses on the evidence in favor of the interpretation of HE as a sleepiness syndrome, and on the diagnostic, therapeutic and social implications of such an interpretation.

Acute hyperammonaemia induces a sustained decrease in vigilance, which is modulated by caffeine

Hyperammonaemia is observed after prolonged, intense exercise, or in patients with hepatic failure. In the latter, it is associated with a set of neurological and psychiatric abnormalities termed hepatic encephalopathy.

THE AIMS OF OUR STUDY WERE

1. to measure vigilance in a condition of induced hyperammonaemia; 2. to assess whether caffeine modulates the effects of hyperammonaemia on vigilance, if any. Ten healthy volunteers (28.5 ± 5 years; 5 males) underwent three experimental sessions consisting of two-hourly measurements of capillary ammonia, subjective sleepiness (Karolinska Sleepiness Scale) and vigilance (Psychomotor Vigilance Task, PVT), in relation to the intake of breakfast (+/-coffee), an amino acid mixture which induces hyperammonaemia (amino acid challenge; AAC), and AAC+coffee (only for participants who had coffee with their standard breakfast). The AAC resulted in: 1. the expected increase in capillary ammonia levels, with highest values at approximately 4 h after the administration; 2. a significant increase in subjective sleepiness ratings; 3. a sustained increase in PVT-based reaction times. When caffeine was administered after the AAC, both subjective sleepiness and the slowing in RTs were significantly milder than in the AAC-only condition. In conclusion, acute hyperammonaemia induces an increase in subjective sleepiness and a sustained decrease in vigilance, which are attenuated by the administration of a single espresso coffee.

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

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.

Brain oscillatory activity during sleep shows unknown dysfunctions in early encephalopathy

Electroencephalographic recordings in cirrhotic patients without overt hepatic encephalopathy (HE) have mainly been performed during wakefulness. Our aim was to quantify their alterations in nocturnal sleep electroencephalogram (EEG). In 20 patients and 20 healthy volunteers, we recorded a nocturnal digital polysomnography. Different sleep parameters were measured. Besides, we performed quantitative analysis of EEG (qEEG) as follows: spectral power in the different sleep stages was calculated in the frequency bands low δ, δ, θ, α, and σ. Also, the mean dominant frequency and Sleep Indexes were obtained. In comparison with controls, the group of patients showed (1) different alterations in both the microstructure and the macrostructure of sleep; (2) an increase in, both, θ band power and the average mean dominant frequency during rapid eye movement (REM); (3) in all sleep stages, a decrease of sleep electroencephalogram spectral power in low δ band and an increase in δ band: and (4) in stages N3 and REM, significant increases in the minimum of mean dominant frequency and in the respective sleep indexes. Therefore, in cirrhotic patients without overt HE, and likely having minimal hepatic encephalopathy, we found different alterations in both the microstructure and the macrostructure of nocturnal sleep. Also, sleep qEEG showed a brain dysfunction in slow oscillatory mechanisms intrinsic of sleep stages, with an increase in the frequency of its maximal electroencephalogram synchronization, from low δ to δ band. These alterations may reflect the onset of encephalopathy; sleep qEEG may, thus, be an adequate tool for its brain functional evaluation and follow-up.

Risk of obstructive sleep apnea with daytime sleepiness is associated with liver damage in non-morbidly obese patients with nonalcoholic fatty liver disease

Background

A high prevalence of obstructive sleep apnea syndrome (OSAS) has been reported in severely obese patients with nonalcoholic fatty liver disease (NAFLD), but few studies have evaluated OSAS in non-morbidly obese NAFLD patients.

Aims

To determine the prevalence of risk for OSAS with or without daytime sleepiness in non-morbidly obese patients with NAFLD and evaluate the association with the severity of liver damage.

Methods

We considered 159 consecutive patients with histological NAFLD and body mass index (BMI) <35 Kg/m², and 80 controls without ultrasonographic steatosis matched for age, sex, and BMI. OSAS risk was determined by positivity for Berlin questionnaire (BQ), and daytime sleepiness by the Sleepness Epworth Scale (ESS). Liver damage was evaluated according to the NAFLD activity score.

Results

In NAFLD patients, BQ alone was positive in 39 (25%), ESS in 8 (5%), and both in 13 (8%, OSAS with sleepines); p = ns vs. controls without steatosis. In NAFLD patients at risk for OSAS with (but not in those without) sleepiness, we observed a higher prevalence of nonalcoholic steatohepatitis (NASH; 11/13, 85% vs. 72/146, 49%; p = 0.018), and of clinically significant fibrosis (stage>1; 9/13, 69% vs. 39/146, 27%; p = 0.003). At multivariate logistic regression analysis, OSAS with sleepiness was strongly associated with NASH and fibrosis>1 independently of known clinical risk factors such as age, gender, BMI, diabetes, and ALT levels (OR 7.1, 95% c.i. 1.7–51, p = 0.005 and OR 14.0, 95% c.i. 3.5–70, p = 0.0002, respectively).

Conclusions

A proportion of NAFLD patients without severe obesity is at risk for OSAS with daytime sleepiness, which is associated with the severity of liver damage independently of body mass and other cofactors.

Sleep-wake abnormalities in patients with cirrhosis

A considerable proportion of patients with cirrhosis exhibit insomnia, delayed sleep habits, and excessive daytime sleepiness. These have been variously attributed to hepatic encephalopathy and impaired hepatic melatonin metabolism, but the understanding of their pathophysiology remains limited and their treatment problematic. Sleep is regulated by the interaction of a homeostatic and a circadian process. The homeostatic process determines sleep propensity in relation to sleep-wake history, thus the need to sleep increases with the duration of the waking period. The circadian process, which is marked by the 24-hour rhythm of the hormone melatonin, is responsible for the alternation of high/low sleep propensity in relation to dark/light cues. Circadian sleep regulation has been studied in some depth in patients with cirrhosis, who show delays in the 24-hour melatonin rhythm, most likely in relation to reduced sensitivity to light cues. However, while melatonin abnormalities are associated with delayed sleep habits, they do not seem to offer a comprehensive explanation to the insomnia exhibited by these patients. Fewer data are available on homeostatic sleep control: it has been recently hypothesized that patients with cirrhosis and hepatic encephalopathy might be unable, due to excessive daytime sleepiness, to accumulate the need/ability to produce restorative sleep. This review will describe in some detail the features of sleep-wake disturbances in patients with cirrhosis, their mutual relationships, and those, if any, with hepatic failure/hepatic encephalopathy. A separate section will cover the available information on their pathophysiology. Finally, etiological treatment will be briefly discussed.

Excessive daytime sleepiness and hepatic encephalopathy: it is worth asking

The relationship between hepatic encephalopathy (HE) and the sleep-wake disturbances exhibited by patients with cirrhosis remains debated. The aim of this study was to examine the usefulness of sleep-wake interview within the context of HE assessment. One-hundred-and-six cirrhotic patients were asked three yes/no questions investigating the presence of difficulty falling asleep, night awakenings and daytime sleepiness. All underwent formal HE assessment, quantitative electroencephalography and standardised psychometry. Fifty-eight were monitored for 8 ± 6 months in relation to the occurrence of HE. Patients complaining of daytime sleepiness (n = 75, 71 %) had slower EEGs than those who did not report it (relative alpha power: 37 ± 19 vs. 48 ± 17 %, p < 0.05). In addition, daytime sleepiness was associated with the presence of portal-systemic shunt (79 vs. 57 %, p < 0.05) and HE history (72 vs. 45 %, p < 0.05). Finally, the absence of excessive daytime sleepiness had a Negative Predictive Value of 92 % (64-100) in relation to the development of HE during the follow-up period. These data support the appropriateness of adding a yes/no question on the presence of excessive daytime sleepiness to routine assessment of patients with cirrhosis, to help identify those who do not need further, formal HE screening.

Correlation between degree and quality of sleep disturbance and the level of neuropsychiatric impairment in patients with liver cirrhosis

Sleep disturbances are common in patients of cirrhosis and has a significant effect on their health related quality of life (HRQOL). Thus far, no study has demonstrated a systematically studied significant correlation between the sleep disturbance observed and the neuropsychiatric impairment status of patients of cirrhosis. On the basis of PHES, we divided 100 cirrhotics into those having minimal hepatic encephalopathy (MHE) (PHES≤-5) and those not (NMHE). Now, in these MHE (n=46) and NMHE (n=54) patients, sleep disturbance was measured with Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) and HRQOL with SF-36(v2) questionnaire. Sixty (60 %) patients were found to be 'poor sleepers' (PSQI>5) while 38 (38 %) patients had excessive daytime sleepiness (ESS≥11). Univariate and multivariate analyses showed MHE has significant effect among 'poor sleepers' (P<0.0001) as well as on those with EDS (P<0.0001). Significant correlation existed between PHES and both the sleep parameters of PSQI (r = -0.518, P <0.0001) as well as ESS (r = -0.383, P <0.0001), implying independently strong correlation between poor cognition and the presence of night time sleep disturbance and excessive daytime sleepiness among cirrhotics. Significant correlation existed between PSQI and ESS and the various scales and component scores of SF-36(v2) signifying the negative impact of sleep disturbance on the HRQOL. In conclusion, both night time sleep disturbance and excessive daytime sleepiness have significant relation with the neuropsychiatric impairment in patients of cirrhosis and are significantly associated with the observed impairment in HRQOL.

Neuropsychological tools in hepatology: a survival guide for the clinician

Neuropsychological assessment has three main applications in clinical hepatology: (i) to detect, grade and monitor liver failure-related cognitive alterations in end-stage liver disease (hepatic encephalopathy), (ii) to substantiate complaints of attention or concentration difficulties in patients with non-cirrhotic chronic hepatitis C viral infection, and (iii) to screen patients who are being considered for liver transplantation for early signs of dementia. However, there is limited agreement on how cognitive assessment should be conducted in these patients, and how results should be interpreted and used to implement clinical decisions. In this review, we summarize the available literature on neuropsychological dysfunction in patients with cirrhosis and with chronic hepatitis C viral infection and provide some guidance on how to utilize neuropsychological assessment in practice.