Autonomic dysfunction in chronic liver disease

Cardiovascular Autonomic Dysfunction in Hospitalized Patients with a Bacterial Infection: A Longitudinal Observational Pilot Study in the UK

PURPOSE

A temporal reduction in the cardiovascular autonomic responses predisposes patients to cardiovascular instability after a viral infection and therefore increases the risk of associated complications. These findings have not been replicated in a bacterial infection. This pilot study will explore the prevalence of cardiovascular autonomic dysfunction (CAD) in hospitalized patients with a bacterial infection.

METHODS

A longitudinal observational pilot study was conducted. Fifty participants were included: 13 and 37 participants in the infection group and healthy group, respectively. Recruitment and data collection were carried out during a two-year period. Participants were followed up for 6 weeks: all participants' cardiovascular function was assessed at baseline (week 1) and reassessed subsequently at week 6 so that the progression of the autonomic function could be evaluated over that period of time. The collected data were thereafter analyzed using STATA/SE version 16.1 (StataCorp). The Fisher Exact test, McNemar exact test, Mann-Whitney test and Wilcoxon test were used for data analysis.

RESULTS

32.4% of the participants in the healthy group were males (n = 12) and 67.6% were females (n = 25). Participants' age ranged from 33 years old to 76 years old with the majority being 40-60 years of age (62.1%) (Mean age 52.4 SD = 11.4). Heart rate variability (HRV) in response to Valsalva Maneuver, metronome breathing, standing and sustained handgrip in the infection group was lower than in the healthy group throughout the weeks. Moreover, both the HRV in response to metronome breathing and standing up showed a statistically significant difference when the mean values were compared between both groups in week 1 (p = 0.03 and p = 0.013). The prevalence of CAD was significantly higher in the infection group compared to healthy volunteers, both at the beginning of the study (p = 0.018) and at the end of follow up (p = 0.057), when all patients had been discharged.

CONCLUSIONS

CAD, as assessed by the HRV, is a common finding during the recovery period of a bacterial infection, even after 6 weeks post-hospital admission. This may increase the risk of complications and cardiovascular instability. It may therefore be of value to conduct a wider scale study to further evaluate this aspect so recommendations can be made for the cardiovascular autonomic assessment of patients while they are recovering from a bacterial infectious process.

Intraoperative Factors Modifying the Risk of Postoperative Pulmonary Complications After Living Donor Liver Transplantation

BACKGROUND

The relationship between intraoperative anesthetic management and postoperative pulmonary complications (PPCs) after liver transplantation is not fully understood. We aimed to determine the intraoperative contributors to PPC.

METHODS

The retrospectively collected cohort included 605 patients who underwent living donor liver transplantation. PPCs comprised respiratory failure, respiratory infection, pulmonary edema, atelectasis (at least moderate degree), pneumothorax, and pleural effusion (at least moderate degree). The presence and type of PPC were evaluated by 2 pulmonary physicians. Logistic regression analysis was performed to determine the association between perioperative variables and PPC risk.

RESULTS

Of the 605 patients, 318 patients (52.6%) developed 486 PPCs. Multivariable analysis demonstrated that PPC risk decreased with low tidal volume ventilation (odds ratio [OR] 0.62 [0.41-0.94], P  = 0.023) and increased with greater driving pressure at the end of surgery (OR 1.08 [1.01-1.14], P  = 0.018), prolonged hypotension (OR 1.85 [1.27-2.70], P  = 0.001), and blood albumin level ≤3.0 g/dL at the end of surgery (OR 2.43 [1.51-3.92], P  < 0.001). Survival probability at 3, 6, and 12 mo after transplantation was 91.2%, 89.6%, and 86.5%, respectively, in patients with PPCs and 98.3%, 96.5%, and 93.4%, respectively, in patients without PPCs (hazard ratio 2.2 [1.3-3.6], P  = 0.004). Graft survival probability at 3, 6, and 12 mo after transplantation was 89.3%, 87.1%, and 84.3%, respectively, in patients with PPCs and 97.6%, 95.8%, and 92.7%, respectively, in patients without PPCs (hazard ratio 2.3 [1.4-3.7], P  = 0.001).

CONCLUSIONS

We found that tidal volume, driving pressure, hypotension, and albumin level during living donor liver transplantation were significantly associated with PPC risk. These data may help determine patients at risk of PPC or develop an intraoperative lung-protective strategy for liver transplant recipients.

The Association between Inflammatory Biomarkers and Cardiovascular Autonomic Dysfunction after Bacterial Infection

Heart rate variability (HRV) is a known measure of cardiac autonomic function. A cardiovascular autonomic dysfunction (CAD), measured as changes in HRV, is usually presented after an infectious process. The aim of the present study is to assess the association between serum inflammatory markers and CAD. For this purpose, 50 volunteers (13 of them recovering from an infection) were recruited and followed-up for 6 weeks. Their serum inflammatory biomarkers (CRP, IL1, IL4, IL6, IL10, and TNFalpha) were quantified throughout those weeks, along with their HRV resting, in response to the Valsalva maneuver, metronome breathing, standing and sustained handgrip. The correlation of within-subject changes in both HRV and inflammatory biomarkers was assessed to evaluate the concurrent changes. An inverse within-subject correlation was found between CRP and HRV in response to the Valsalva maneuver (rho (95% CI): −0.517 (−0.877 to −0.001); p = 0.032) and HRV standing (rho (95% CI): −0.490 (−0.943 to −0.036); p = 0.034). At the beginning, increased values of CRP are found along with reduced levels of HRV. Then, the CRP was reduced, accompanied by an improvement (increase) in HRV. These results suggest that CRP is a potential marker of CAD. Whether it is the cause, the consequence or a risk indicator non-causally associated is still to be determined.

NAFLD in the Elderly

Non-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent disease globally. Current estimates are that 24% of the adult population, thus, one billion individuals worldwide, are affected. Interestingly, the prevalence of fatty liver seems to peak between 40─50 years of age in males and 60─69 years in females, often slightly decreasing in older (>70 years) cohorts. Furthermore, several risk factors for NAFLD development, such as hypertension, diabetes, hyperlipidemia, and obesity are higher in older adults. The diagnosis and management strategies in older adults are sometimes challenging, and certain age-specific factors have to be taken into account by healthcare professionals. In this review, we provide an overview of considerations relevant to the management and diagnosis of NAFLD in older adults (age >65 years) and discuss the types of pharmacological interventions available for the management of non-alcoholic steatohepatitis (NASH) in the aging population.

I drank too much and now I can't walk: a case of alcohol-induced dysautonomia

Dysautonomia is a dysfunction of the autonomic nervous system, which mediates both sympathetic and parasympathetic functions of the human body. Alcohol has been established to affect the autonomic function through liver injury and accumulation of vasodilators. Alcohol can induce peripheral neurological diseases as well. This case report describes a patient who had a chronic history of alcoholism and uncontrolled diabetes mellitus presenting for orthostatic hypotension and peripheral neuropathy without underlying liver disease or other endocrinopathies. Although diabetes mellitus was controlled pharmacologically and risk factors for orthostatic hypotension were managed conservatively, his symptoms did not improve which indicated an alcohol-related autonomic dysfunction, shedding light on one of long-term complications of alcoholism.

Heart Rate Turbulence Predicts Survival Independently From Severity of Liver Dysfunction in Patients With Cirrhosis

Background

Reduced heart rate variability (HRV) is an independent predictor of mortality in patients with cirrhosis. However, conventional HRV indices can only be interpreted in individuals with normal sinus rhythm. In patients with recurrent premature ventricular complexes (PVCs), the predictive capacity of conventional HRV indices is compromised. Heart Rate Turbulence (HRT) represents the biphasic change of the heart rate after PVCs. This study was aimed to define whether HRT parameters could predict mortality in cirrhotic patients.

Materials and Methods

24 h electrocardiogram recordings were collected from 40 cirrhotic patients. Turbulence Onset was calculated as HRT indices. The enrolled patients were followed up for 12 months after the recruitment in relation to survival and/or transplantation.

Results

During the follow-up period, 21 patients (52.5%) survived, 12 patients (30%) died and 7 patients (17.5%) had liver transplantation. Turbulence Onset was found to be strongly linked with mortality on Cox regression (Hazard ratio = 1.351, p < 0.05). Moreover, Turbulence Onset predicted mortality independently of MELD and Child-Pugh's Score.

Conclusion

This study provides further evidence of autonomic dysfunction in cirrhosis and suggests that HRT is reliable alternative to HRV in patients with PVCs.

Autonomic and diastolic dysfunction association with quality of life impairment in cirrhotic patients

BACKGROUND AND STUDY AIMS

Cirrhosis is a multisystem disorder characterized by hyperdynamic circulation which can progress to multiple organ dysfunctions. Recent studies have demonstrated autonomic dysfunction and cirrhotic cardiomyopathy including diastolic dysfunction, systolic dysfunction with electrophysiologic abnormalities in patients with cirrhosis. Due to the long and complicated course of the disease, health related quality of life is affected. We aimed to evaluate the frequency of diastolic dysfunction and autonomic dysfunction in cirrhosis, and the effects on health-related quality of life.

PATIENTS AND METHODS

Hundred cirrhotic patients were enrolled in the study. According to the Child-Pugh classification 35 patients were of Child A, 36 of Child B and 29 of Child C. The proportion of autonomic dysfunction was 52%, and diastolic dysfunction 51%. Autonomic dysfunction was diagnosed using bedside maneuvers and tests; diastolic dysfunction was diagnosed using the E/A ratio in echocardiographic findings. Health-related quality of life measurements was obtained from an SF-36 questionnaire.

RESULTS

Patients with advanced Child-Pugh classifications were found to have significantly lower health-related quality of life values (p < 0.05). Likewise, health-related quality of life values were observed to be significantly lower in patients with autonomic dysfunction (p < 0.05). No significant difference was found in health related quality of life measurements between patients with and without diastolic dysfunction.

CONCLUSION

Our study showed that autonomic dysfunction and diastolic dysfunction are found in patients with cirrhosis. Further studies are needed to assess the effects of autonomic dysfunction and diastolic dysfunction on health-related quality of life.

The degree of hepatic steatosis associates with impaired cardiac and autonomic function

BACKGROUND & AIMS

Cardiovascular disease is the principle cause of death in patients with elevated liver fat unrelated to alcohol consumption, more so than liver-related morbidity and mortality. The aim of this study was to evaluate the relationship between liver fat and cardiac and autonomic function, as well as to assess how impairment in cardiac and autonomic function is influenced by metabolic risk factors.

METHODS

Cardiovascular and autonomic function were assessed in 96 sedentary individuals: i) non-alcoholic fatty liver disease (NAFLD) (n = 46, hepatic steatosis >5% by magnetic resonance spectroscopy), ii) Hepatic steatosis and alcohol (dual aetiology fatty liver disease [DAFLD]) (n = 16, hepatic steatosis >5%, consuming >20 g/day of alcohol) and iii) CONTROL (n = 34, no cardiac, liver or metabolic disorders, <20 g/day of alcohol).

RESULTS

Patients with NAFLD and DAFLD had significantly impaired cardiac and autonomic function when compared with controls. Diastolic variability and systolic variability (LF/HF-sBP [n/1]; 2.3 (1.7) and 2.3 (1.5) vs. 3.4 (1.5), p <0.01) were impaired in patients with NAFLD and DAFLD when compared to controls, with DAFLD individuals showing a decrease in diastolic variability relative to NAFLD patients. Hepatic steatosis and fasting glucose were negatively correlated with stroke volume index. Fibrosis stage was significantly negatively associated with mean blood pressure (r = -0.47, p = 0.02), diastolic variability (r = -0.58, p ≤0.01) and systolic variability (r = -0.42, p = 0.04). Hepatic steatosis was independently associated with cardiac function (p ≤0.01); TNF-α (p ≤0.05) and CK-18 (p ≤0.05) were independently associated with autonomic function.

CONCLUSION

Cardiac and autonomic impairments appear to be dependent on level of liver fat, metabolic dysfunction, inflammation and fibrosis staging, and to a lesser extent alcohol intake. Interventions should be sought to moderate the excess cardiovascular risk in patients with NAFLD or DAFLD.

LAY SUMMARY

Increased levels of fat in the liver impair the ability of the cardiovascular system to work properly. The amount of fat in the liver, metabolic control, inflammation and alcohol are all linked to the degree that the cardiovascular system is affected.

Falls in Patients With Liver Cirrhosis

Health-related quality of life (HRQOL) has become an important outcome for patients with liver cirrhosis as the number of transplantation candidates increases by the progression of treatment strategies. Falls and fall-related injuries are common in patients with liver cirrhosis and negatively affect HRQOL. Many factors increase the risk for falls such as minimal hepatic encephalopathy, psychoactive drugs, muscle strength, autonomic dysfunction, hyponatremia, and sleep problems. It is important to understand the underlying mechanisms for falls in cirrhotic patients to prevent severe injuries such as fractures, decrease healthcare costs, and improve HRQOL. Healthcare professionals, including physiotherapists and nurses, should be aware of the higher risk for falls in this population and therapeutic interventions must be designed for patients, especially those waiting on the transplant list.

Cirrhotic cardiomyopathy

During the course of cirrhosis, there is a progressive deterioration of cardiac function manifested by the disappearance of the hyperdynamic circulation due to a failure in heart function with decreased cardiac output. This is due to a deterioration in inotropic and chronotropic function which takes place in parallel with a diastolic dysfunction and cardiac hypertrophy in the absence of other known cardiac disease. Other findings of this specific cardiomyopathy include impaired contractile responsiveness to stress stimuli and electrophysiological abnormalities with prolonged QT interval. The pathogenic mechanisms of cirrhotic cardiomyopathy include impairment of the b-adrenergic receptor signalling, abnormal cardiomyocyte membrane lipid composition and biophysical properties, ion channel defects and overactivity of humoral cardiodepressant factors. Cirrhotic cardiomyopathy may be difficult to determine due to the lack of a specific diagnosis test. However, an echocardiogram allows the detection of the diastolic dysfunction and the E/e′ ratio may be used in the follow-up progression of the illness. Cirrhotic cardiomyopathy plays an important role in the pathogenesis of the impairment of effective arterial blood volume and correlates with the degree of liver failure. A clinical consequence of cardiac dysfunction is an inadequate cardiac response in the setting of vascular stress that may result in renal hypoperfusion leading to renal failure. The prognosis is difficult to establish but the severity of diastolic dysfunction may be a marker of mortality risk. Treatment is non-specific and liver transplantation may normalize the cardiac function.

Association between non-alcoholic fatty liver disease and autonomic dysfunction in a Chinese population

BACKGROUND

Autonomic dysfunction (AD) accompanying with chronic liver disorders led to an increased risk of mortality. However, researches that investigated the association between non-alcoholic fatty liver disease (NAFLD) and AD were insufficient.

AIMS

To study the association of NAFLD with AD in middle-aged and elderly Chinese adults.

DESIGN

Four thousand nine hundred seventy-four adults aged 40 years or older were enrolled in this cross-sectional study. NAFLD was diagnosed by hepatic B-mode ultrasonography. Autonomic function was assessed using a simple EZSCAN test by measuring sudomotor function, with an AD index > 50% defined as a manifestation of AD.

METHODS

Pearson correlation, multiple stepwise linear regression, univariate and multivariate logistic regression was employed to examine the relationship between NAFLD and AD, controlling for potential confounders.

RESULTS

The prevalence of AD was significantly higher in participants with NAFLD than those without (40.75 vs. 26.86%, P < 0.0001). Age, body mass index, status of diabetes, sex, diastolic blood pressure and prevalent NAFLD, were positively correlated with AD index in multiple stepwise linear regression analysis (all P < 0.05), whereas total cholesterol was negatively related to it (P = 0.0043). Compared with the participants without NAFLD, those with NAFLD had an increased odds of the prevalent AD (odds ratio 1.38; 95% confidence interval 1.15-1.64; P = 0.0004) after controlling for multiple confounders.

CONCLUSIONS

The presence of NAFLD was significantly associated with AD, as indicated by abnormal sudomotor function. The association was independent from various conventional risk factors.

Neuropathies in hepatitis C-related liver cirrhosis

INTRODUCTION

Neurological complications occur in a large number of patients with chronic hepatitis C virus (HCV) infection and range from peripheral neuropathy to cognitive impairment. We studied the association between neuropathy and HCV-related chronic liver disease.

METHOD

Fifty patients with HCV-related chronic liver disease were enrolled in this prospective case-control study. Patients were classified into two groups: mild and severe corresponding to a model for end-stage liver disease (MELD) score <14 and a MELD score >14, respectively. Complete neurological examination and nerve conduction studies have been done for all patients. All patients in addition to 25 healthy control subjects were tested for their serum B12 levels.

RESULTS

Twenty-two percent of patients had sensory abnormality, 18 % had motor abnormality, while 10 % had both sensory and motor abnormalities. Autonomic function tests and nerve conduction studies revealed that 23 patients (46 %) had evidence of neuropathy and 10 patients (20 %) had both peripheral and autonomic neuropathy. Neuropathies were not related to the severity of the liver disease. Serum B12 level had a very wide range among patients with no relation between its level and neuropathy. Vitamin B12 level was significantly and directly correlated to MELD score and age.

CONCLUSION

Peripheral and autonomic neuropathy has high prevalence in patients with HCV-related chronic liver disease. On the other hand, vitamin B12 level is high in those patients and there is no role for vitamin B12 in the liver cirrhosis-related neuropathy.

Nonalcoholic fatty liver disease and aging: Epidemiology to management

Nonalcoholic fatty liver disease (NAFLD) is common in the elderly, in whom it carries a more substantial burden of hepatic (nonalcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma) and extra-hepatic manifestations and complications (cardiovascular disease, extrahepatic neoplasms) than in younger age groups. Therefore, proper identification and management of this condition is a major task for clinical geriatricians and geriatric hepatologists. In this paper, the epidemiology and pathophysiology of this condition are reviewed, and a full discussion of the link between NAFLD and the aspects that are peculiar to elderly individuals is provided; these aspects include frailty, multimorbidity, polypharmacy and dementia. The proper treatment strategy will have to consider the peculiarities of geriatric patients, so a multidisciplinary approach is mandatory. Non-pharmacological treatment (diet and physical exercise) has to be tailored individually considering the physical limitations of most elderly people and the need for an adequate caloric supply. Similarly, the choice of drug treatment must carefully balance the benefits and risks in terms of adverse events and pharmacological interactions in the common context of both multiple health conditions and polypharmacy. In conclusion, further epidemiological and pathophysiological insight is warranted. More accurate understanding of the molecular mechanisms of geriatric NAFLD will help in identifying the most appropriate diagnostic and therapeutic approach for individual elderly patients.

Evaluation of Tp-e interval and Tp-e/QT ratio in patients with chronic hepatitis B

Chronic hepatitis B (CHB) is a chronic inflammatory viral disorder. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarisation and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. Impaired autonomic function has been described in patients with CHB. The aim of this study was to evaluate ventricular repolarisation by using Tp-e interval and Tp-e/QT ratio in patients with CHB, and to assess the relation with inflammation. Fifty-five patients with CHB and 50 controls were included. Tp-e interval and Tp-e/QT ratio were measured from the 12-lead electrocardiogram, and Tp-e interval corrected for heart rate. These parameters were compared between groups. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in CHB patients compared to the controls (38.3 ± 10.9 vs. 28.5 ± 7.3 milliseconds and 39.5 ± 11.2 vs. 29.6 ± 7.6 milliseconds, P=0.01 and P<0.001, respectively). cTp-e interval and Tp-e/QT ratio were also significantly higher in CHB patients (85.3 ± 8.2 vs. 74.5 ± 7.4 milliseconds and 0.24 ± 0.02 vs. 0.18 ± 0.02, all P-value < 0.001). Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in CHB patients.

Alteration of the QT variability index in end-stage liver disease

Background

A prolonged QT interval can lead to malignant ventricular arrhythmias and sudden cardiac death, and has frequently been found in end-stage liver disease (ESLD). However, myocardial repolarization lability has not yet been fully investigated. We evaluated the QT variability index (QTVI), a marker of temporal inhomogeneity in ventricular repolarization and an abnormality associated with re-entrant malignant ventricular arrhythmias. We determined whether QTVI is affected by the head-up tilt test in ESLD.

Methods

We assessed 36 ESLD patients and 12 control subjects without overt heart disease before and after the 70-degree head-up tilt test. The electrocardiography signal (lead II) was recorded on a computer with an analog-to-digital converter. The RR interval (RRI) and QT interval were measured after recording 5 min of the digitized electrocardiography. Then, the QT intervals were corrected with Bazett's formula (QTc). QTVI was calculated through the following formula: QTVI = log10 [(QTv/QTm2)/(RRIv/RRIm2)], QTv/RRIv: variance of QTI/RRI, QTm/RRIm: mean of QT interval/RRI.

Results

Cirrhotic patients exhibited an elevated QTVI. In particular, Child class C patients had a significantly increased QTVI compared to Child class A patients and the control subjects in the supine position. However, the head-up tilt test did not cause a significant difference in QTVI in relation to the severity of ESLD.

Conclusions

Myocardial repolarization lability was significantly altered in end-stage liver disease. Our data suggest that the severity of ESLD is associated with the degree of the alteration in the QT variability index.

Functional impairment in alcoholic liver disease and non-alcoholic fatty liver disease is significant and persists over 3 years of follow-up

BACKGROUND AND AIMS

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are common and increasing in prevalence. We examined prevalence and predictors of functional impairment in biopsy-proven ALD and NAFLD. Change in function over 3 years was explored.

METHODS

Validated functional, cognitive, autonomic, and fatigue symptom assessment tools were completed by patients who had attended our liver clinic.

RESULTS

Totals of 224 NAFLD and 107 ALD patients returned the assessment tools. NAFLD and ALD demonstrated comparable functional difficulties, which were significantly worse than controls (p < 0.001) with the proportion of participants experiencing difficulty significantly higher [x (2) 8.93(3), (p = 0.01)]. No significant functional difficulty was demonstrated between those participants who were pre-cirrhotic or cirrhotic. Independent associations were present between difficulty with function in ALD and higher burden of autonomic and cognitive symptoms (p = 0.02) and in NAFLD-increased cognitive difficulty (p < 0.0001), age (p = 0.001), fatigue (p = 0.01), lower albumin (p = 0.02), and bilirubin (p = 0.04). PHAQ scores increased 21 % 2008-2011 {(3.2/15.6) [15.6 (0-93.8)] to 18.75 (0-90.6)}. Functional difficulty of participants alive [15.6 (0-96.9)] was significantly less compared to those who died [40.6 (0-100)] (p = 0.02).

CONCLUSIONS

NAFLD and ALD patients experience significant functional impairment affecting activities of daily living that persists over time. This has implications for the management of liver disease and service provision.

Resistance exercise improves autonomic regulation at rest and haemodynamic response to exercise in non-alcoholic fatty liver disease

Autonomic dysfunction has been reported in patients with NAFLD (non-alcoholic fatty liver disease) and is associated with clinical presentations. To date, there are no therapies to improve autonomic regulation in people with NAFLD. The present study defines the impact of a short-term exercise programme on cardiac autonomic and haemodynamic regulation in patients with NAFLD. A total of 17 patients with clinically defined NAFLD [age, 55±12 years; BMI (body mass index), 33±5 kg/m²; liver fat, 17±9%] were randomized to 8 weeks of resistance exercise or a control group to continue standard care. Resting and submaximal exercise (50% of peak oxygen consumption) autonomic and cardiac haemodynamic measures were assessed before and after the intervention. Resistance exercise resulted in a 14% reduction in HR (heart rate) and 7% lower SBP (systolic blood pressure) during submaximal exercise (16 beats/min, P=0.03 and 16 mmHg, P=0.22). Sympathovagal balance, expressed as LF/HF (low-frequency/high-frequency) ratio of the mean HR beat-to-beat (R-R) interval, was reduced by 37% (P=0.26). Similarly sympathovagal balance of DBP (diastolic blood pressure) and SBP variability decreased by 29% (P=0.33) and 19% (P=0.55), respectively in the exercise group only. BRS (baroreflex sensitivity) increased by 31% (P=0.08) following exercise. The mean R-R interval increased by 23% (159 ms, P=0.09). Parasympathetic regulation was decreased by 17% (P=0.05) and overall sympathovagal balance in BP regulation (LF/HF ratio) increased by 26% (P=0.02) following resistance exercise. Resting haemodynamic measures remained similar between groups. Resistance exercise therapy seems to improve autonomic and submaximal exercise haemodynamic regulation in NAFLD. Further studies are required to define its role in clinical management of the condition.

Cardiac sympathetic imaging with mIBG in cirrhosis and portal hypertension: relation to autonomic and cardiac function

Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake, and in patients with cardiac failure it predicts outcome. In this study, we aimed to investigate cardiac sympathetic neuronal function in cirrhosis by mIBG scintigraphy in relation to cardiovascular function. Ten patients with alcoholic cirrhosis and 10 age- and sex-matched healthy controls participated in the study. Heart/mediastinum (H/M) ratios of mIBG uptake were calculated 15 and 230 min after intravenous injection of mIBG. Furthermore, washout rate (WOR) of mIBG was calculated. The patients underwent a liver vein catheterization with determination of splanchnic and systemic hemodynamics and measurement of HRV and BRS. mIBG-scintigraphy revealed significantly increased WOR in patients with cirrhosis compared with controls (P < 0.005), whereas H/M uptakes were equal in the groups. Forty percent of the patients had reduced uptake of mIBG in the infero-lateral segment of the left ventricle. WOR correlated significantly with central circulation time, an estimate of central hypovolemia (r = -0.64, P < 0.05) and frequency-corrected QT(F) interval (r = 0.71, P = 0.01). Patients with cirrhosis had significantly decreased HRV and BRS correlating with indicators of abnormal cathecholamine uptake by mIBG although the catecholamine level was normal in the patients. In conclusion, in alcoholic cirrhosis, mIBG scintigraphy reveals autonomic dysfunction and impaired myocardial distribution of sympathetic nervous activity. It is associated to indicators of central hypovolemia, QT interval, and decreased HRV and BRS. Measurement of myocardial catecholamine uptake by mIBG may add important information on autonomic and cardiac dysfunction in cirrhosis.

Falls and fall-related injury are common in older people with chronic liver disease

BACKGROUND

Improved survival with chronic liver disease (CLD) and increased incidence in the older has led to a rapidly expanding population which faces similar "geriatric syndromes" as the general population. With risk factors such as autonomic dysfunction, cognitive impairment, and muscle abnormalities in CLD it is expected that falls and injury will be common.

AIM

To determine prevalence of falls and injury in chronic liver disease and to identify potential modifiable fall associations.

METHODS

Falls prevalence was estimated by providing patients aged ≥ 65 years with CLD a falls data collection tool, via the post or in the clinic. A younger CLD cohort and age-matched and sex-matched community controls was used for comparison. A sub-group underwent multidisciplinary falls assessment to identify modifiable fall associations.

RESULTS

Falls were significantly more common in older people with CLD (47 % in previous year) than in controls; incidence of injury did not differ. Regression identified orthostatic symptoms, lower-limb strength, and fear of falling as being independently associated with falls in CLD. Those who had fallen had significantly greater difficulty with daily activities.

CONCLUSION

Falls are prevalent in older people with CLD, and are potentially preventable with multifactorial intervention. Services must prepare for expansion in the older CLD population; here we demonstrate how this expansion may affect falls services and provide a potential therapeutic target.

Managing systemic symptoms in chronic liver disease

Improved medical management and the changing disease demographic mean that the majority of patients with chronic liver disease are living with the disease rather than dying from it. Historically, the perception has been that the impact of chronic liver disease is related entirely to the consequences of endstage liver disease; however, more recently a number of systemic symptoms have been recognised that can occur at any point in the natural history of chronic liver disease and which can be associated with functional impairment and reduced quality of life. The most characteristic of these systemic symptoms is fatigue, which frequently associates with sleep disturbance and autonomic dysfunction, particularly manifest as abnormality of blood pressure regulation. Cognitive symptoms can occur even in non-cirrhotic patients. Falls can present in patients with autonomic dysfunction, complicated by the presence of peripheral muscle strength problems. Importantly for clinicians managing chronic liver disease, the severity of these systemic symptoms is typically not related to liver disease severity, and therefore despite optimal liver disease management, patients can often continue to experience debilitating symptoms. The similarity in systemic symptoms between different chronic liver diseases (and indeed chronic inflammatory conditions affecting other organs) suggests the possibility of shared pathogenetic processes and raises the possibility of common management strategies, although further research is urgently needed to confirm this. In primary biliary cirrhosis, where our understanding of systemic symptoms is arguably most developed, structured management strategies have been shown to improve the quality of life of patients. It is highly likely that similar approaches will have comparable benefits for other chronic liver disease groups. Here, we review the current understanding of systemic symptoms in chronic liver disease and offer recommendations regarding the successful management of these symptoms. Critical for successful treatment is use of a structured and systematic approach to management in which all contributing factors are addressed in an organised fashion. We believe that such a systematic approach, when applied to research as well as to clinical management, will allow us to reduce the overall burden of chronic liver disease, improve quality of life and enhance functional ability.

Reduced baroreflex sensitivity and pulmonary dysfunction in alcoholic cirrhosis: effect of hyperoxia

Patients with cirrhosis exhibit impaired regulation of the arterial blood pressure, reduced baroreflex sensitivity (BRS), and prolonged QT interval. In addition, a considerable number of patients have a pulmonary dysfunction with hypoxemia, impaired lung diffusing capacity (Dl(CO)), and presence of hepatopulmonary syndrome (HPS). BRS is reduced at exposure to chronic hypoxia such as during sojourn in high altitudes. In this study, we assessed the relation of BRS to pulmonary dysfunction and cardiovascular characteristics and the effects of hyperoxia. Forty-three patients with cirrhosis and 12 healthy matched controls underwent hemodynamic and pulmonary investigations. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. A 100% oxygen test was performed with the assessment of arterial oxygen tensions (Pa(O(2))) and alveolar-arterial oxygen gradient. Baseline BRS was significantly reduced in the cirrhotic patients compared with the controls (4.7 +/- 0.8 vs. 10.3 +/- 2.0 ms/mmHg; P < 0.001). The frequency-corrected QT interval was significantly prolonged in the cirrhotic patients (P < 0.05). There was no significant difference in BRS according to presence of HPS, Pa(O(2)), Dl(CO), or Child-Turcotte score, but BRS correlated with metabolic and hemodynamic characteristics. After 100% oxygen inhalation, BRS and the QT interval remained unchanged in the cirrhotic patients. In conclusion, BRS is significantly reduced in patients with cirrhosis compared with controls, but it is unrelated to the degree of pulmonary dysfunction and portal hypertension. Acute hyperoxia does not significantly revert the low BRS or the prolonged QT interval in cirrhosis.

Hemodynamics in the immediate post-transplantation period in alcoholic and viral cirrhosis

AIM: To study the hemodynamics in the immediate post transplant period and compare patients with alcoholic vs viral cirrhosis.

METHODS: Between 2000-2003, 38 patients were transplanted for alcoholic cirrhosis and 28 for postviral cirrhosis. Heart rate (HR), central venous pressure (CVP), mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), systemic vascular resistance index (SVRI), pulmonary artery pressure (PAP), and pulmonary vascular resistance index (PVRI) were measured immediately and 24 h post transplantation.

RESULTS: Hyperdynamic circulation persisted at 24 h following transplantation with an elevated CI of 5.4 ± 1.3 L/(min × m²) and 4.9 ± 1.0 L/(min × m²) in the viral and alcoholic groups, respectively, and was associated with a decreased SVRI. Within the first 24 h, there was a significant decrease in HR and increase in MAP; the extent of the change was similar in both groups. The CVP, PCWP, and SVRI increased, and CI decreased in the viral patients, but not the alcoholic patients. Alcoholics showed a lower PVRI (119 ± 52 dynes/(cm⁵× m²) vs 166 ± 110 dynes/(cm⁵× m²), P < 0.05) and PAP (20 ± 7 mmHg vs 24 ± 7 mmHg, P < 0.05) compared to the viral group at 24 h.

CONCLUSION: Hyperdynamic circulation persists in the immediate post-transplant period with a faster improvement in the viral group. Alcoholic patients have a more pronounced pulmonary vasodilatation.

Baroreceptor sensitivity and baroreceptor effectiveness index in cirrhosis: the relevance of hepatic venous pressure gradient

BACKGROUND

Autonomic dysfunction has been reported as one of the complications of cirrhosis.

AIMS

The aim of this study was to test autonomic dysfunction in cirrhotic patients by analysing the baroreflex sensitivity and the baroreceptor effectiveness index (BEI), in order to determine its correlation with the severity and the aetiology of liver disease. Moreover, we explored the relationship between baroreceptor function and mortality in our cohort of patients.

METHODS

Clinical and laboratory evaluation, hepatic venous pressure gradient (HVPG) and haemodynamic setting and baroreceptor function were assessed in 45 cirrhotic patients (median age 55, range 38-72 years) divided in groups according to the severity of their disease (26 patients Child A, 13 patients Child B and six patients Child C).

RESULTS

Baroreceptor sensitivity and BEI were impaired in more advanced cirrhotic patients compared with subjects with milder disease (P<0.001). HVPG was significantly, independently and inversely correlated with baroreceptor sensitivity (P=0.003). More severe impairment of baroreceptor function was associated with a higher mortality (P=0.04) and subjects with alcohol-related cirrhosis presented worse baroreceptor function (P=0.032) and poorer survival (P=0.003) compared with subjects with post-viral liver disease.

CONCLUSIONS

These data support the hypothesis that liver disease severity and particularly portal hypertension have an important role in the derangement of baroreceptor function. The aetiology of cirrhosis seems to be related to baroreceptor impairment as well. Mortality rate is higher in subjects with a more damaged autonomic system, strengthening the idea of a worse prognosis in cirrhotic patients with autonomic neuropathy.

Chronic hepatitis C virus infection associated with autonomic dysfunction

BACKGROUND

Impaired autonomic function has been described in patients with chronic liver diseases from different aetiologies, and has proven to be a poor prognostic indicator. To date, it is not known how chronic hepatitis C virus (HCV) infection affects the autonomic nervous system.

AIMS

In the present study, we compared cardiovagal autonomic function in patients with chronic HCV infection and healthy controls and examined the relation between autonomic function and serum levels of aminotransferases, HCV RNA, cryoglobulins, albumin and glucose.

METHODS

Autonomic function was assessed in 45 treatment-naïve patients with chronic HCV infection and in 40 healthy controls by determining spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV) indices. The R-R interval was determined by electrocardiogram recording; continuous radial artery pressure was monitored simultaneously by applanation tonometry. Laboratory analyses and quantitative polymerase chain reaction for serum HCV RNA level were performed by standard procedures.

RESULTS

BRS and HRV time and frequency domain indices were lower in patients with HCV infection compared with healthy controls [7.1+/-3.4 vs. 11.5+/-6.5 ms/mmHg for BRS, 168.5+/-160.9 vs. 370.7+/-349.4 ms(2) for low-frequency HRV (mean+/-SD); P<0.01]. Multivariate analysis showed that autonomic dysfunction in HCV-infected patients correlated with elevated alanine aminotransferase levels, but was not associated with serum HCV RNA levels and cryoglobulins.

CONCLUSION

Our results suggest that impaired autonomic function is caused by chronic HCV infection. Further studies are needed, however, to identify the underlying mechanisms.