Autonomic dysfunction in primary biliary cirrhosis correlates with fatigue severity

Neuroimmune modulation in liver pathophysiology

The liver, the largest organ in the human body, plays a multifaceted role in digestion, coagulation, synthesis, metabolism, detoxification, and immune defense. Changes in liver function often coincide with disruptions in both the central and peripheral nervous systems. The intricate interplay between the nervous and immune systems is vital for maintaining tissue balance and combating diseases. Signaling molecules and pathways, including cytokines, inflammatory mediators, neuropeptides, neurotransmitters, chemoreceptors, and neural pathways, facilitate this complex communication. They establish feedback loops among diverse immune cell populations and the central, peripheral, sympathetic, parasympathetic, and enteric nervous systems within the liver. In this concise review, we provide an overview of the structural and compositional aspects of the hepatic neural and immune systems. We further explore the molecular mechanisms and pathways that govern neuroimmune communication, highlighting their significance in liver pathology. Finally, we summarize the current clinical implications of therapeutic approaches targeting neuroimmune interactions and present prospects for future research in this area.

Neurosteroid Activation of GABA-A Receptors: A Potential Treatment Target for Symptoms in Primary Biliary Cholangitis?

Background and Aims

A third of patients with primary biliary cholangitis (PBC) experience poorly understood cognitive symptoms, with a significant impact on quality of life (QOL), and no effective medical treatment. Allopregnanolone, a neurosteroid, is a positive allosteric modulator of gamma-aminobutyricacid-A (GABA-A) receptors, associated with disordered mood, cognition, and memory. This study explored associations between allopregnanolone and a disease-specific QOL scoring system (PBC-40) in PBC patients.

Method

Serum allopregnanolone levels were measured in 120 phenotyped PBC patients and 40 age and gender-matched healthy controls. PBC subjects completed the PBC-40 at recruitment. Serum allopregnanolone levels were compared across PBC-40 domains for those with none/mild symptoms versus severe symptoms.

Results

There were no overall differences in allopregnanolone levels between healthy controls (median = 0.03 ng/ml (IQR = 0.025)) and PBC patients (0.031 (0.42), p = 0.42). Within the PBC cohort, higher allopregnanolone levels were observed in younger patients (r (120) = -0.53, p < 0.001) but not healthy controls (r (39) = -0.21, p = 0.21). Allopregnanolone levels were elevated in the PBC-40 domains, cognition (u = 1034, p = 0.02), emotional (u = 1374, p = 0.004), and itch (u = 795, p = 0.03). Severe cognitive symptoms associated with a younger age: severe (50 (12)) vs. none (60 (13); u = 423 p = 0.001).

Conclusion

Elevated serum allopregnanolone is associated with severe cognitive, emotional, and itch symptoms in PBC, in keeping with its known action on GABA-A receptors. Existing novel compounds targeting allopregnanolone could offer new therapies in severely symptomatic PBC, satisfying a significant unmet need.

Metabolic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Not Due to Anti-mitochondrial Antibodies

Metabolic profiling studies have recently indicated dysfunctional mitochondria in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This includes an impaired function of pyruvate dehydrogenase complex (PDC), possibly driven by serum factor(s), which leads to inadequate adenosine triphosphate generation and excessive lactate accumulation. A reminiscent energy blockade is likely to occur in primary biliary cholangitis (PBC), caused by anti-PDC autoantibodies, as recently proposed. PBC is associated with fatigue and post-exertional malaise, also signifying ME/CFS. We herein have investigated whether ME/CFS patients have autoreactive antibodies that could interfere with mitochondrial function. We found that only 1 of 161 examined ME/CFS patients was positive for anti-PDC, while all PBC patients (15/15) presented significant IgM, IgG, and IgA anti-PDC reactivity, as previously shown. None of fibromyalgia patients (0/14), multiple sclerosis patients (0/29), and healthy blood donors (0/44) controls showed reactivities. Anti-mitochondrial autoantibodies (inner and outer membrane) were negative in ME/CFS cohort. Anti-cardiolipin antibody levels in patients did not differ significantly from healthy blood donors. In conclusion, the impaired mitochondrial/metabolic dysfunction, observed in ME/CFS, cannot be explained by presence of circulating autoantibodies against the tested mitochondrial epitopes.

High occurrence of small intestinal bacterial overgrowth in primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease affecting mainly middle-aged women. An alteration in intestinal motility has been well documented in cirrhosis predisposing to small intestinal bacterial overgrowth (SIBO). Patients with PBC frequently complain of various gastrointestinal symptoms compatible with SIBO. No study has specifically been published to this day to determine the occurrence of SIBO in PBC. Our objective was to determine the prevalence of SIBO in patients with PBC.

METHODS

Retrospective study from 2010 to 2018. All patients diagnosed with PBC during this period had a systematic screening for SIBO in their diagnostic workup. The diagnosis of SIBO was made by a carbohydrate breath test (lactulose and/or glucose). Clinical and paraclinical factors of patients were compared with a control group of healthy subjects.

KEY RESULTS

Ninety-eight subjects were included in the study (mean age 49, range 21-88 years) including 58 patients with PBC and 40 healthy subjects. The PBC group was older than the control group (mean age 56, range 31-88 vs 39, range 21-62 years; P < .001), but identical for gender and body mass index. The prevalence of SIBO was higher in PBC versus controls (32.8% vs 2.5%; P < .001). The PBC group with SIBO had significantly more diarrhea (78.9% vs 35.9%; P < .05) than the PBC group without SIBO, but the prevalence of abdominal pain and bloating was similar.

CONCLUSIONS & INFERENCES

The high occurrence of SIBO in PBC may explain some of the frequently reported gastrointestinal symptoms. This study justifies the systematic screening for SIBO in PBC.

Coronary flow reserve in patients with primary biliary cholangitis

BACKGROUND

It is still not clear whether primary biliary cholangitis (PBC) is associated with abnormalities of the cardiovascular system. We aimed to assess the relationship between PBC and coronary flow reserve (CFR).

METHODS

Our inclusion criterion was a diagnosis of PBC with no clinical evidence of heart disease or metabolic syndrome. Coronary flow velocity in the left anterior descending coronary artery was measured using transthoracic Doppler echocardiography at rest (DFVr), and during adenosine infusion (DFVh). The corrected CFR (cCFR) was defined as the ratio of DFVh to DFVr corrected for cardiac workload (cDFVr). Microvascular resistance was also assessed in baseline (BMR) and hyperemic conditions (HMR).

RESULTS

37 PBC patients and 37 sex- and age-matched controls were considered. The cCFR was significantly lower in PBC patients (2.8 ± 0.7 vs. 3.7 ± 0.7, p < 0.0001), and abnormal (≤2.5) in 13 (35%) of them, but in none of the controls (p < 0.0001). The cDFVr was higher in patients with abnormal cCFR (29.0 ± 6.0 vs. 20.4 ± 4.5 cm/sec, p < 0.0001). The CFR and cCFR did not correlate with any characteristics of PBC, comorbidities or Framingham risk scores. The BMR and HMR correlated with time since PBC diagnosis and duration of symptoms.

CONCLUSION

The CFR is reduced in PBC, apparently due to mechanisms correlating with the time since diagnosis. In particular, the higher cDFVr with a lower basal resistance in patients with cCFR ≤ 2.5 suggests a compensatory mechanism against any cardiomyocyte bioenergetics impairment.

Fatigue in chronic liver disease: New insights and therapeutic approaches

The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.

Symptoms and health-related quality of life in Japanese patients with primary biliary cholangitis

Although patients with primary biliary cholangitis (PBC) experience a variety of symptoms that could impair health-related quality of life (HRQOL), no studies regarding symptoms and impact of PBC on HRQOL have been performed in Asian countries. Herein, we aimed to evaluate symptoms and HRQOL in Japanese PBC patients. We performed a multicenter, observational, cross-sectional study. The PBC-40 and the short form (SF)-36 were used as measures of symptoms and HRQOL. Four-hundred-ninety-six patients with PBC were enrolled. In the PBC-40, the average score was highest in the emotional domain, followed by the fatigue domain. The HRQOL measured using SF-36 was also impaired, especially in the physical and role-social components. After adjustments of variables, female sex, younger age at diagnosis, and lower serum albumin level were independently associated with fatigue scores, while a longer follow-up period and lower serum albumin levels were associated with itch scores.

General illness and psychological factors in patients with chronic nasal symptoms

OBJECTIVES

Only a minority of patients referred to specialists with sinonasal symptoms have clear evidence of chronic rhinosinusitis (CRS). This study aims to estimate the prevalence of and associations between (i) general illness factors (fatigue, autonomic dysfunction) and (ii) psychological factors (anxiety, depression, somatisation, personality traits) in patients presenting with sinonasal symptoms.

DESIGN

The following validated questionnaires were administered to patients: the Sino-Nasal Outcome Test-22 (SNOT-22) identifying symptom burden, Composite Autonomic Symptom Score-31 (COMPASS-31) measuring autonomic function, Chalder Fatigue Questionnaire, Patient Health Questionnaire-15 (PHQ-15) addressing somatisation symptoms, Hospital Anxiety and Depression Scale (HADS), and the International Personality Item Pool-50 (IPIP-50). Comparisons were made with normative and general population data, and relationships were analysed using nonparametric correlation.

SETTING

Secondary care ENT outpatients.

PARTICIPANTS

Adults referred with chronic sinonasal symptoms.

MAIN OUTCOME MEASURES

SNOT-22, COMPASS-31, Chalder, PHQ-15, HADS, and IPIP-50 questionnaire scores.

RESULTS

Sixty-one patients were included. There was a high prevalence of all general and psychological factors assessed compared with controls. Total SNOT-22 scores showed significant correlation with Chalder fatigue scores, total autonomic dysfunction score, anxiety, depression, somatisation tendencies and the emotionally unstable personality trait. Emotional instability and psychological dysfunction correlated significantly with sleep and psychological subscales of SNOT-22 but not the rhinological or ear/facial subscales.

CONCLUSION

Patients with sinonasal symptoms demonstrate high prevalence and complex associations of general illness factors, psychological distress and certain personality traits. The SNOT-22 is a valuable tool, but its utility is limited by correlations with these confounding factors (eg psychological factors) that may exaggerate the total score. The use of the SNOT-22 component subscales is likely to provide more clinically meaningful and discriminant information.

Understanding and Treating Fatigue in Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis

Fatigue is a significant problem for patients with primary biliary cirrhosis and although experienced less by patients with primary sclerosing cholangitis, a minority still report significant fatigue. Fatigue is the symptom with the greatest impact on quality of life, particularly when associated with social dysfunction. The pathogenesis of fatigue in cholestatic liver disease is complex, poorly understood, and probably has central and peripheral components. Managing fatigue in cholestatic liver disease presents a challenge for clinicians given the complexity and its numerous associations. This article presents a structured approach to managing fatigue in cholestatic liver disease to improve fatigue severity and quality of life.

Prospective evaluation of PBC-specific health-related quality of life questionnaires in patients with primary sclerosing cholangitis

BACKGROUND & AIMS

Primary biliary cirrhosis and Primary sclerosing cholangitis are autoimmune cholestatic liver diseases sharing a lot in common, including a significant impairment of patients' health-related quality of life HRQoL HRQoL in PBC is assessed with disease-specific PBC-40 and PBC-27 questionnaires. A PSC-specific questionnaire has not been developed. Neither PBC-40 nor PBC-27s applicability for PSC has been evaluated. We applied these three questionnaires for HRQoL assessment in a large homogenous cohort of PSC patients.

PATIENTS AND METHODS

This cross-sectional study enrolled 102 Caucasian PSCs and 53 matched healthy controls and measured HRQoL using generic SF-36, and disease-specific (PBC-40/PBC-27) questionnaires.

RESULTS

(i) SF-36. Most SF-36 domains were significantly lower in PSCs than controls. Physical Functioning and Mental Component Summary scores were significantly lower in female patients and correlated negatively with age but not with concurrent inflammatory bowel disease. Cirrhosis was associated with lower Physical Functioning, Role Physical, General Health, Vitality and Physical Component Summary. (ii) PBC-40 and PBC-27. Both tools showed similar HRQoL impairment scoring. Fatigue and Cognitive were impaired in female patients. Several correlations existed between HRQoL and laboratory parameters, including cholestatic tests and Itch. Cirrhosis correlated with Other symptoms and Fatigue PBC-40. (iii) PBC-40 vs PBC-27. Strong correlations among most domains of both questionnaires were seen, as well as between (iv) SF-36 vs PBC-40 or SF-36 vs PBC-27.

CONCLUSION

This is the first study directly comparing PBC-40, PBC-27 and SF-36 in PSC. PSC patients, especially females, show HRQoL impairment. PBC-40 and PBC-27 questionnaires could be of potential use for HRQoL assessment in PSC.

Fatigue in primary sclerosing cholangitis is associated with sympathetic over-activity and increased cardiac output

BACKGROUND & AIMS

Patients with primary sclerosing cholangitis (PSC) frequently highlight the impact of fatigue on their life quality. The study aims were to evaluate fatigue and its associations in PSC and investigate whether overt autonomic dysfunction contributes to the expression of fatigue.

METHODS

All PSC patients under active follow-up at a regional liver centre were sent disease- and symptom-assessment tools. Three control groups were utilized; unselected community controls, patients with inflammatory bowel disease (IBD) without PSC, and cholestatic controls with primary biliary cirrhosis (PBC). A representative subgroup of PSC patients and normal controls underwent formal autonomic assessment.

RESULTS

Symptom-assessment tools were returned by 40 non-transplanted patients. PSC patients had significantly worse fatigue than population controls (P = 0.005). Fatigue was significant compared to population controls whether or not patients had accompanying IBD, although was more marked in those with both PSC and IBD. In patients with PSC and IBD, fatigue severity and autonomic symptoms were significantly increased in those with prior significant surgical intervention. Clinically significant autonomic dysfunction was seen in 22.5% of PSC patients, and of those, 78% had significant fatigue. Neurally mediated hypotension was found in 60% of PSC patients compared to 8% in the control group. The PSC group had increased sympathetic activity and reduced parasympathetic activity.

CONCLUSION

Fatigue is a significant problem in a minority of PSC patients and appears to be associated with autonomic dysfunction. Fatigued PSC patients should be screened for autonomic dysfunction and targeting such dysfunction represents a potential approach to treatment which warrants further exploration.

Female gender in the setting of liver transplantation

The evolution of liver diseases to end-stage liver disease or to acute hepatic failure, the evaluation process for liver transplantation, the organ allocation decision-making, as well as the post-transplant outcomes are different between female and male genders. Women’s access to liver transplantation is hampered by the use of model for end-stage liver disease (MELD) score, in which creatinine values exert a systematic bias against women due to their lower values even in the presence of variable degrees of renal dysfunction. Furthermore, even when correcting MELD score for gender-appropriate creatinine determination, a quantifiable uneven access to transplant prevails, demonstrating that other factors are also involved. While some of the differences can be explained from the epidemiological point of view, hormonal status plays an important role. Moreover, the pre-menopausal and post-menopausal stages imply profound differences in a woman’s physiology, including not only the passage from the fertile age to the non-fertile stage, but also the loss of estrogens and their potentially protective role in delaying liver fibrosis progression, amongst others. With menopause, the tendency to gain weight may contribute to the development of or worsening of pre-existing metabolic syndrome. As an increasing number of patients are transplanted for non-alcoholic steatohepatitis, and as the average age at transplant increases, clinicians must be prepared for the management of this particular condition, especially in post-menopausal women, who are at particular risk of developing metabolic complications after menopause.

Fatigue correlates with the decrease in parasympathetic sinus modulation induced by a cognitive challenge

Background

It is known that enhancement of sympathetic nerve activity based on a decrease in parasympathetic nerve activity is associated with fatigue induced by mental tasks lasting more than 30 min. However, to measure autonomic nerve function and assess fatigue levels in both clinical and industrial settings, shorter experimental durations and more sensitive measurement methods are needed. The aim of the present study was to establish an improved method for inducing fatigue and evaluating the association between it and autonomic nerve activity.

Methods

Twenty-eight healthy female college students participated in the study. We used a kana pick-out test (KPT) as a brief verbal cognitive task and recorded electrocardiography (ECG) to measure autonomic nerve activity. The experimental design consisted of a 16-min period of ECG: A pre-task resting state with eyes open for 3 min and eyes closed for 3 min, the 4-min KPT, and a post-task resting state with eyes open for 3 min and eyes closed for 3 min.

Results

Baseline fatigue sensation, measured by a visual analogue scale before the experiment, was associated with the decrease in parasympathetic sinus modulation, as indicated the by ratio of low-frequency component power (LF) to high-frequency component power (HF), during the KPT. The LF/HF ratio during the post-KPT rest with eyes open tended to be greater than the ratio during the KPT and correlated with fatigue sensation. Fatigue sensation was correlated negatively with log-transformed HF, which is an index of parasympathetic sinus modulation, during the post-KPT rest with eyes open.

Conclusions

The methods described here are useful for assessing the association between fatigue sensation and autonomic nerve activity using a brief cognitive test in healthy females.

The impact of liver transplantation on the phenotype of primary biliary cirrhosis patients in the UK-PBC cohort

BACKGROUND & AIMS

Liver transplantation improves survival in end-stage primary biliary cirrhosis (PBC), but the benefit for systemic symptoms including fatigue is less clear. The aim of this study was to utilise the comprehensive UK-PBC Research Cohort, including 380 post-transplant patients and 2300 non-transplanted patients, to answer key questions regarding transplantation for PBC.

METHODS

Cross-sectional study of post-transplant PBC patients and case-matched non-transplanted patients. Detailed clinical information was collected, together with patient systemic symptom impact data using validated assessment tools.

RESULTS

Over 25% of patients in the transplant cohort were grafted within 2 years of PBC diagnosis suggesting advanced disease at presentation. Transplanted patients were significantly younger at presentation than non-transplanted (mean 7 years) and >35% of all patients in the UK-PBC cohort who presented under 50 years had already undergone liver transplantation at the study censor point (>50% were treatment failures (post-transplant or unresponsive to UDCA)). Systemic symptom severity (fatigue and cognitive symptoms) was identical in female post-transplant patients and matched non-transplanted controls and unrelated to disease recurrence or immunosuppression type. In males, symptoms were worse in transplanted than in non-transplanted patients.

CONCLUSIONS

Age at presentation is a major risk factor for progression to transplant (as well as UDCA non-response) in PBC. Although both confirmatory longitudinal studies, and studies utilising objective as well as subjective measures of function, are needed if we are to address the question definitively, we found no evidence of improved systemic symptoms after liver transplantation in PBC and patients should be advised accordingly. Consideration needs to be given to enhancing rehabilitation approaches to improve function and life quality after liver transplant for PBC.

Sex and age are determinants of the clinical phenotype of primary biliary cirrhosis and response to ursodeoxycholic acid

BACKGROUND, & AIMS: Studies of primary biliary cirrhosis (PBC) phenotypes largely have been performed using small and selected populations. Study size has precluded investigation of important disease subgroups, such as men and young patients. We used a national patient cohort to obtain a better picture of PBC phenotypes.

METHODS

We performed a cross-sectional study using the United Kingdom-PBC, patient cohort. Comprehensive data were collected for 2353 patients on diagnosis reports, response to therapy with ursodeoxycholic acid (UDCA), laboratory results, and symptom impact (assessed using the PBC-40 and other related measures).

RESULTS

Seventy-nine percent of the patients reported current UDCA, therapy, with 80% meeting Paris response criteria. Men were significantly less likely to have responded to UDCA than women (72% vs 80% response rate; P < .05); male sex was an independent predictor of nonresponse on multivariate analysis. Age at diagnosis was associated strongly and independently with response to UDCA; response rates ranged from 90% among patients who presented with PBC when they were older than age 70, to less than 50% for those younger than age 30 (P < .0001). Patients who presented at younger ages also were significantly more likely not to respond to UDCA therapy, based on alanine aminotransferase and aspartate aminotransferase response criteria, and more likely to report fatigue and pruritus. Women had mean fatigue scores 32% higher than men's (P < .0001). The increase in fatigue severity in women was related strongly (r = 0.58; P < .0001) to higher levels of autonomic symptoms (P < .0001).

CONCLUSIONS

Among patients with PBC, response to UDCA, treatment and symptoms are related to sex and age at presentation, with the lowest response rates and highest levels of symptoms in women presenting at younger than age 50. Increased severity of fatigue in women is related to increased autonomic symptoms, making dysautonomia a plausible therapeutic target.

Is chronic fatigue syndrome in older patients a different disease? -- a clinical cohort study

BACKGROUND

Chronic fatigue syndrome (CFS) is a disabling disorder characterised by persistent fatigue with a typical age of diagnosis of 35-50 years. CFS does present in those aged over 50 but whether this is a different disease in older age groups has not been considered. Therefore, we performed a clinical cohort study to examine and differentiate the clinical and autonomic features in CFS patients aged over 50.

DESIGN

A total of 179 Fukuda diagnosed CFS patients were recruited, and 25 older CFS patients (50 + years) were matched case by case for gender and length of history to 25 younger CFS patients (16-29 years). A range of symptomatic-based questionnaires were used in addition to heart rate variability and baroreceptor sensitivity to assess autonomic function.

RESULTS

Chronic fatigue syndrome can present for the first time in an older population. Older CFS patients demonstrate increased fatigue (Fatigue impact scale; 85 ± 33 vs. 107 ± 27, P = 0·02) (Chalder fatigue scale; 9 ± 3 vs. 11 ± 1, P = 0·002) and caseness for depression (Hospital Anxiety and Depression scale; 7 ± 3 vs. 10 ± 4; P = 0·005). There is a greater autonomic dysfunction in older CFS patients, with reduced parasympathetic function (HFnu; 49·1 ± 18 vs. 36·2 ± 18, P = 0·01, RR30 : 15; ± , P = 0·02) and increased sympathetic function (LFnu; 51·5 ± 17 vs. 63·8 ± 18, P = 0·01). Baroreflex sensitivity was substantially reduced (BRS; 19·7 ± 12 vs. 9·9 ± 5, P = 0·0004), and left ventricular ejection time prolonged (LVET; 274·6 ± 16 vs. 285·8 ± 9, P = 0·004).

CONCLUSIONS

Older CFS patients demonstrate a disease phenotype very different from younger patients. The combination of differing underlying pathogenic mechanisms and the physiological aspects of ageing result in a greater disease impact in older CFS patients.

Natural history and management of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic inflammatory autoimmune disease that mainly targets the cholangiocytes of the interlobular bile ducts in the liver. It is a rare disease with prevalence of less than one in 2000. Its prevalence in developing countries is increasing presumably because of growth in recognition and knowledge of the disease. PBC is thought to result from a combination of multiple genetic factors and superimposed environmental triggers. The contribution of the genetic predisposition is evidenced by familial clustering. Several risk factors, including exposure to infectious agents and chemical xenobiotics, have been suggested. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The prognosis of PBC has improved because of early diagnosis and use of ursodeoxycholic acid, the only established medical treatment for this disorder. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. However, some patients do not respond adequately to ursodeoxycholic acid and might need alternative therapeutic approaches.

Primary Sjogrens syndrome is associated with impaired autonomic response to orthostasis and sympathetic failure

BACKGROUND

Symptoms in keeping with autonomic dysfunction are commonly described by primary Sjögrens syndrome patients (pSS); whether objective abnormalities of autonomic function occur is unclear. This study set out to explore dynamic cardiovascular autonomic responses in pSS and their relationship with symptoms and quality of life.

METHODS

Twenty-one people from the UK pSS registry, 21 community controls and 21 patients with the autoimmune liver disease primary biliary cirrhosis (PBC) (matched case-wise for age and sex) attended for assessment of autonomic responses to orthostasis and Valsalva manoeuvre (VM). pSS patients also completed EULAR Sjögrens Syndrome patient-reported index (ESSPRI), EULAR Sjögren's syndrome disease activity index (ESSDAI), fatigue impact scale and EURO-QOL 5-dimension (EQ-5D).

RESULTS

Compared with controls, pSS patients had significantly lower baseline systolic blood pressure (SBP) (114 ± 13 vs. 127 ± 20; P = 0.02), which dropped to a significantly lower value (98 ± 22 vs. 119 ± 24, P = 0.009). When area under the curve (AUC) was calculated for when the SBP was below baseline this was significantly greater in pSS compared to both control groups (pSS vs. control vs. PBC: 153 ± 236 vs. 92 ± 85 vs. 1.2 ± 0.3, P = 0.005). Peak phase IV SBP during the VM was significantly lower in pSS (P = 0.007) indicating early sympathetic failure. Increased heart rate associated with fatigue (P = 0.02; r(2) = 0.2) and EQ-5D. A shift in sympathetic-vagal balance associated with overall symptom burden (ESSPRI) (P = 0.04, r(2) = 0.3) and EULAR sicca score (P = 0.016; r(2) = 0.3), the latter also correlated with baroreceptor effectiveness (P = 0.03; r(2) = 0.2) and diastolic blood pressure variability (P = 0.003; r(2) = 0.4).

CONCLUSION

pSS patients have impaired blood pressure response to standing. Dysautonomia correlates with PSS-associated symptoms and quality of life.

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.

HIV-associated fatigue in the era of highly active antiretroviral therapy: novel biological mechanisms?

OBJECTIVE

The aim of the study was to determine the prevalence and risk factors for HIV-associated fatigue in the era of highly active antiretroviral therapy (HAART).

METHODS

A cross-sectional survey of 100 stable HIV-infected out-patients was carried out. Severity of fatigue was measured using the Fatigue Impact Scale (FIS). Symptoms of orthostatic intolerance (dysautonomia) were evaluated using the Orthostatic Grading Scale (OGS). Data for HIV-infected patients were compared with those for 166 uninfected controls and 74 patients with chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (encephalopathy) (ME).

RESULTS

Ninety-one per cent of HIV-infected patients were on HAART and 78% had suppressed plasma HIV viral load (≤ 40 HIV-1 RNA copies/mL). Fifty-one per cent of HIV-infected patients reported excessive symptomatic fatigue (FIS ≥ 40), and 28% reported severe fatigue symptoms (FIS ≥ 80). The mean FIS score among HIV-infected patients was 50.8 [standard deviation (SD) 41.9] compared with 13.0 (SD 17.6) in uninfected control subjects, and 92.9 (SD 29.0) in CFS patients (P < 0.001 for comparison of HIV-infected patients and uninfected controls). Among HIV-infected patients, fatigue severity was not significantly associated with current or nadir CD4 lymphocyte count, HIV plasma viral load, or whether on HAART. Prior dideoxynucleoside analogue (d-drug) exposure (P = 0.016) and the presence of clinical lipodystrophy syndrome (P = 0.011) were associated with fatigue. Additionally, fatigue severity correlated strongly with symptomatic orthostatic intolerance (r = 0.65; P < 0.001).

CONCLUSIONS

Fatigue is very common and often severe in HIV-infected out-patients, despite viral suppression and good immune function. In a subgroup of patients, prior d-drug exposure may contribute to fatigue, suggesting a metabolic basis. Dysautonomia may also drive fatigue associated with HIV infection, as in other chronic diseases, and CFS/ME, and should be further evaluated with the potential for a shared therapeutic approach.

Cardiac torsion-strain relationships in fatigued primary biliary cirrhosis patients show accelerated aging: a pilot cross-sectional study

The autoimmune liver disease primary biliary cirrhosis (PBC) is associated with life-altering fatigue in ∼50% of patients. Previous work suggests that fatigued PBC subjects have evidence of autonomic dysfunction and may be at a higher risk of sudden cardiac death. The manifestation of this risk is not clear. This pilot study investigated whether alterations in cardiac torsion and strain could be detected in fatigued or nonfatigued early-stage PBC patients. We performed cardiac tissue tagging and anatomical cine-imaging in 13 early-stage PBC patients (including 7 with significant fatigue) and 10 control subjects to calculate cardiac torsion and strain throughout systole and diastole. From the cardiac tagging, we calculated the torsion-to-shortening ratio (TSR), a measure of subepicardial torsion exerting mechanical advantage over subendocardial shortening. Autonomic function testing was performed to evaluate baroreceptor effective index on standing. TSR was markedly increased in the fatigued PBC patients (0.70 ± 0.13) compared with both controls (0.46 ± 0.11, P = 0.002) and nonfatigued PBC patients (0.44 ± 0.12, P = 0.003). Decreased baroreceptor effective index on standing strongly correlated with increased TSR within the whole PBC group (r = −0.71, P = 0.007). Fatigued PBC patients demonstrate a redistribution of myocardial strain characteristic of a reduced relative contribution to contraction from the subendocardium. This is analogous to the changes found in healthy aging for subjects ∼16 yr older than the fatigued PBC patients. Hence the hearts of fatigued PBC patients may be subject to processes of accelerated aging.

Autonomic dysfunction in patients with advanced cancer; prevalence, clinical correlates and challenges in assessment

Background

The results of a small number of studies of autonomic function in patients with advanced cancer suggest that autonomic dysfunction (AD) is common. In other disease-specific groups this is associated with decreased survival, falls and symptoms such as postural hypotension, nausea, early satiety and fatigue. The contribution of AD to symptoms in advanced cancer is unknown.

Methods

We conducted a prospective cohort study designed to identify the risk factors for falls in patients with advanced cancer. Ambulant adult patients admitted consecutively to palliative care services were invited to participate. Participants underwent an assessment at baseline which included standard clinical tests of autonomic function, assessment of symptom severity, muscle strength, anthropometric measurements, walking speed, medication use, comorbidities and demographics. Information regarding survival was recorded ten months following cessation of recruitment. The clinical correlates of AD, defined as definite or severe dysfunction using Ewing's classification, were examined by univariate and multivariate logistic regression analysis. Survival analysis was conducted using Kaplan-Meier plots and the log rank test.

Results

Of 185 patients recruited, 45% were unable to complete all of the clinical tests of autonomic function. Non-completion was associated with scoring high on clinical indicators of frailty. It was possible to accurately classify 138/185 (74.6%) of participants as having either definite or severe versus normal, early or atypical AD: 110 (80%) had definite/severe AD. In logistic regression analysis, age (OR = 1.07 [95% CI; 1.03-1.1] P = 0.001) and increased severity of fatigue (OR = 1.26 [95% CI; 1.05-1.5] p = 0.016) were associated with having definite/severe AD. In analysis adjusted for age, median survival of participants with definite/severe AD was shorter than in those with normal/early/atypical classification (χ² = 4.3, p = 0.038).

Conclusions

Autonomic dysfunction is highly prevalent in patients with advanced cancer and is associated with increased severity of fatigue and reduced survival. Due to frailty, up to 45% of participants were unable to complete standard clinical tests of autonomic function. In order to further investigate the impact of AD and the therapeutic potential of treatment of AD in patients with advanced cancer, the validity of alternative novel methods of assessing autonomic function must be appraised.

In the mind or in the brain? Scientific evidence for central sensitisation in chronic fatigue syndrome

BACKGROUND

Central sensitisation entails several top-down and bottom-up mechanisms, all contributing to the hyperresponsiveness of the central nervous system to a variety of inputs. In the late nineties, it was first hypothesised that chronic fatigue syndrome (CFS) is characterised by hypersensitivity of the central nervous system (i.e. central sensitisation). Since then, several studies have examined central sensitisation in patients with CFS. This study provides an overview of such studies.

MATERIALS AND METHODS

Narrative review.

RESULTS

Various studies showed generalised hyperalgesia in CFS for a variety of sensory stimuli, including electrical stimulation, mechanical pressure, heat and histamine. Various tissues are affected by generalised hyperalgesia: the skin, muscle tissue and the lungs. Generalised hyperalgesia in CFS is augmented, rather than decreased, following various types of stressors like exercise and noxious heat pain. Endogenous inhibition is not activated in response to exercise and activation of diffuse noxious inhibitory controls following noxious heat application to the skin is delayed.

CONCLUSIONS

The observation of central sensitisation in CFS is in line with our current understanding of CFS. The presence of central sensitisation in CFS corroborates with the presence of several psychological influences on the illness, the presence of infectious agents and immune dysfunctions and the dysfunctional hypothalamus-pituitary-adrenal axis as seen in these severely debilitated patients.

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.

Autonomic nervous alterations associated with daily level of fatigue

BACKGROUND

Fatigue is a common symptom in both sick and healthy people. We examined autonomic nervous alterations associated with fatigue to clarify the mechanisms underlying fatigue.

METHODS

The study group consisted of 19 healthy participants who performed a 2-back test for 30 min as a fatigue-inducing mental task session. Before and after the session, they completed the advanced trail making test (ATMT) for 30 min for mental fatigue evaluation, subjective scales to measure fatigue sensation, and underwent electrocardiography to allow assessment of autonomic nerve activities.

RESULTS

After the fatigue-inducing task, the total error counts on the ATMT tended to increase (P = 0.076); the ATMT for total trial counts (P = 0.001), the subjective level of fatigue (P < 0.001), and the % low-frequency power (%LF) (P = 0.035) increased significantly; and the % high-frequency power (%HF) decreased compared with before the fatigue-inducing task although this did not reach the statistical significance (P = 0.170). Although LF measured in absolute units did not change significantly before and after the fatigue-inducing task (P = 0.771), and HF measured in absolute units decreased after the task (P = 0.020). The %LF and LF/HF ratio were positively associated with the daily level of fatigue evaluated using Chalder's fatigue scale. In addition, %HF was negatively associated with the fatigue score.

CONCLUSIONS

Increased sympathetic activity and decreased parasympathetic activity may be characteristic features of both acute and daily levels of fatigue. Our findings provide new perspectives on the mechanisms underlying fatigue.

Autonomic dysfunction in chronic liver disease

It is becoming increasingly clear that quality of life (QOL) is impaired in those with chronic liver disease (CLD). One of the most important contributors to impaired QOL is the symptomatic burden which can range from slight to debilitating. Autonomic dysfunction accounts for a significant proportion of these symptoms, which can be common, non-specific and challenging to treat. Investigating the autonomic nervous system can be straight forward and can assist the clinician to diagnose and treat specific symptoms. Evidence-based treatment options for autonomic symptoms, specifically in CLD, can be lacking and must be extrapolated from other studies and expert opinion. For those with severely impaired quality of life, liver transplantation may offer an improvement; however, more research is needed to confirm this.

Mental fatigue caused by prolonged cognitive load associated with sympathetic hyperactivity

Background

It is known that chronic fatigue is associated with sympathetic hyperactivity. However, the relationship between autonomic function and mental fatigue caused by a prolonged mental load in healthy humans is still unclear. Thus, in order to clarify the mechanisms underlying mental fatigue, we examined the association between mental fatigue and autonomic functions.

Methods

The study group comprised 10 healthy participants. To induce mental fatigue, participants performed mental tasks, which consisted of the advanced trail making test, kana pick-out test and mirror drawing test, for 8 hr, corresponding to a normal work day. Autonomic functions were measured by accelerated plethysmography before and after the fatigue-inducing mental tasks. As a control, the same participants completed an 8-hr relaxation session 4 weeks before the fatigue session.

Results

After the 8-hr relaxation session, low-frequency component power (LF), high-frequency component power (HF) and low-frequency component power/high-frequency component power ratio (LF/HF ratio) were not changed from baseline. In contrast, after the fatigue session, the HF and LF/HF ratio were significantly changed from baseline; specifically, the HF was lower and LF/HF ratio was higher as compared to those after the relaxation session.

Conclusions

Sympathetic hyperactivity based on decreased parasympathetic activity is associated with mental fatigue induced by prolonged cognitive load.

Reduction in functional ability is significant postliver transplantation compared with matched liver disease and community dwelling controls

We compared functional ability and symptom severity in liver transplant recipients and matched chronic liver disease (CLD) and community controls. A total of 103/140 consecutive liver transplant recipients from a single centre (73%) and matched controls completed the patient-reported functional outcome measure: Patient-Reported Outcomes Measurement Information System, Health Assessment Questionnaire (PROMIS HAQ). Symptoms frequently seen in CLD were quantified by (i) Fatigue Impact Scale (FIS), (ii) Orthostatic Grading Scale (OGS: autonomic dysfunction), (iii) Cognitive Failures Questionnaire (CFQ) and (iv) Epworth Sleepiness Scale (ESS: Daytime somnolence). Liver transplant recipients exhibited significant reduction in function (P<0.0001) across all domains of the PROMIS HAQ suggesting that functional impairment is broad-based. Seventy-seven per cent of all postliver transplants identified some difficulty with activities of daily living. There was no relationship between PROMIS HAQ and liver biochemistry (r²=0.04, P=NS) or time since transplant (r² =0.1, P=NS). Elevation in PROMIS HAQ (and therefore functional impairment) strongly associated with symptoms, particularly fatigue, cognitive impairment and daytime somnolence. Fatigue severity was independently associated with functional impairment (FIS) (Beta 0.727, P < 0.0001). Symptoms or functional ability was not different between liver transplant recipients and matched chronic liver disease controls. Although survival postliver transplantation is improving, our cross-sectional study suggests that functional ability may not improve postliver transplantation. Further study is warranted to address the mechanisms responsible for post-transplant functional impairment and to develop effective rehabilitation regimes to maximize function following liver transplantation.

Critical flicker frequency fails to disclose brain dysfunction in patients with primary biliary cirrhosis

BACKGROUND

Recent studies suggest that stage-independent symptoms of primary biliary cirrhosis (PBC) such as chronic fatigue are a consequence of structural and functional abnormalities of the brain. Critical flicker frequency (CFF) is a psychophysiological modality analysing function of cerebral cortex.

AIM

To analyse the usefulness of CFF in detection of brain dysfunction in patients with PBC.

METHODS

Fifty-one (37 non-cirrhotic/14 cirrhotic) patients with PBC were included. Control group consisted of 31 matched healthy individuals. Fatigue and health-related quality of life (HRQoL) were assessed using Fatigue Impact Scale (FIS) and questionnaire PBC-40. CFF was analysed with HEPAtonorm Analyzer(®).

RESULTS

When compared to healthy controls all patients with PBC showed significantly impaired HRQoL in majority of PBC-40 domains and increased fatigue level in physical domain of FIS. No differences in HRQoL and PBC-40 domains were seen, when patients with and without cirrhosis where compared. CFF analysis showed no difference between healthy controls and patients with PBC. CFF did not correlate with PBC-40 and FIS domains.

CONCLUSION

CFF fails to determine brain dysfunction in non-encephalopatic patients with PBC, suggesting that functional efficiency of their cerebral cortex remains unaffected and other central mechanisms are responsible for chronic fatigue in these patients.

The specificity of fatigue in primary biliary cirrhosis: evaluation of a large clinic practice

Quality of life is an important concern for patients with chronic liver disease. We sought to describe the frequency, severity, and associations of fatigue, in patients with primary biliary cirrhosis (PBC). We performed association testing between PBC-40 multidomain disease-specific quality of life responses and clinical findings. Three hundred twenty-seven patients from a single clinic with PBC (94% female, 92% AMA-positive) were evaluated. The average age was 57 years and average disease duration 7.2 years. Verbally reported fatigue was noted in 48% but present in the overwhelming majority on PBC-40 completion, with 44% having moderate or severe symptoms. Of those not complaining of fatigue clinically, 25% documented moderate or severe fatigue by questionnaire. Age had an inverse relationship with fatigue (P < 0.01), whereas body mass index (BMI) was positively associated (P < 0.01), as was the presence of pruritus (P < 0.001), sicca symptoms (P < 0.001), depression (P < 0.001), fibromyalgia (P < 0.004), and scleroderma (P < 0.05). For those with varices (P < 0.05) or cirrhosis clinically (P < 0.05), higher fatigue scores were noted, although those who initially presented with noncirrhotic disease had higher scores at the time of testing (P < 0.005). Fatigue was associated with greater use of prescription medication (P < 0.01), in particular for antipruritics (cholestyramine: P < 0.001; rifampin: P < 0.001), proton pump inhibitors (P < 0.002), beta-blockers (P < 0.02), and antidepressants (P < 0.001), whereas those taking calcium and vitamin D appeared less fatigued (P < 0.05). In a multivariate model, calcium and vitamin D use, BMI, stage of disease at diagnosis, as well as symptomatic fatigue or pruritus, were significant. Biochemical response to UDCA was not associated with lower fatigue scores.

CONCLUSION

Attempts at defining the biological basis of fatigue in patients with PBC, and improving its treatment, must account for its multifactoral causes.

Impaired cerebral autoregulation in primary biliary cirrhosis: implications for the pathogenesis of cognitive decline

BACKGROUND

Cognitive impairment is recognised in the early stages of primary biliary cirrhosis (PBC).

AIMS

To determine the mechanisms that underlie the cognitive dysfunction that can occur in early-stage PBC, with a particular focus on the role of autonomic dysfunction and altered cerebral autoregulation.

PATIENTS

Early-stage PBC patients, and age- and sex-matched controls.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Brain magnetic resonance imaging to determine the relationship between structural brain abnormalities (T(2)) and cerebral vasculature responsiveness assessed using the Valsalva manoeuvre. Dynamic assessment of cerebral vascular flow using transcranial Doppler was also performed in PBC subjects to derive the pulsatility index (a marker of cerebral resistance) and the autoregulatory slope index [ASI; ratio between the cerebral blood flow velocity and blood pressure (BP)].

RESULTS

Cerebral resistance was increased (P=0.04), and cerebral autoregulation in response to the Valsalva was significantly impaired in the PBC group with markedly lower mean ASI values compared with the controls (7.8+/-7.0 vs -8.5+/-8.4; P=0.002). All controls had normal cerebral autoregulation compared with only 20% of the PBC group. Indicators of sympathetic failure (BP change between Valsalva phases III-IV and low-frequency heart rate variability) correlated with increasing globus pallidus (GP) T(2) values (P<0.05), beyond the effect of age.

CONCLUSION

This study demonstrates the presence of increased cerebral vascular resistance and abnormal cerebral autoregulation in PBC patients, and identifies a potentially important association between the degree of abnormality in structural changes in the GP. These findings suggest that organic brain injury in PBC is directly related to autonomic dysfunction.

Fatigue in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic, autoimmune, cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis of the liver and may need liver transplantation in the late stage of disease. Fatigue and pruritus are the most common symptoms of PBC, but the majority of patients are asymptomatic at first presentation. There is no specific treatment for fatigue in PBC, but modafinil has shown some potential beneficial effects, such as increased energy levels and decreased total sleep time. This Review article discusses the natural history and the measurement of fatigue in patients with PBC. The central and the peripheral mechanisms that have been suggested for the pathogenesis of fatigue in PBC are also discussed and treatment options are reviewed.

Impaired cardiovascular function in primary biliary cirrhosis

Cardiovascular system dysregulation in the form of autonomic dysfunction is common at all stages of the disease process in the autoimmune liver disease primary biliary cirrhosis (PBC) and associates with the symptom of fatigue. The mechanisms underpinning autonomic dysfunction in PBC are, however, at present unclear. In this study we set out to explore, for the first time, cardiac structure and function in PBC using impedance cardiography (ICG) and magnetic resonance methodologies. ICG was assessed beat to beat in response to orthostasis (by head-up tilt) in age and sex case-matched high-fatigue and low-fatigue PBC groups (assessed by Fatigue Impact Scale), normal control subjects (n = 15 each group) and a liver disease control cohort (primary sclerosing cholangitis). Cardiac structure and bioenergetics were examined in 15 of the PBC subjects and 8 of the normal control subjects by magnetic resonance spectroscopy and cine imaging. Capacity of the left ventricle to respond to orthostasis [left ventricular ejection time (LVET)] was impaired in PBC compared with matched normal control subjects (P = 0.05). This was a PBC-specific phenomenon unrelated to fatigue status. PBC patients exhibited significantly lower cardiac muscle phosphocreatine-to-ATP ratio (PCr/ATP ratio; measure of cardiac bioenergetic integrity) compared with control subjects (P < 0.01). PCr/ATP <1.6 (indicative of increased risk of death in cardiomyopathy) was present in 6/15 (40%) PBC patients (0/8 control subjects; P < 0.05). Cardiac structure and function were similar in all measures of left ventricular morphology between control subjects and PBC. The close relationship between PCr/ATP and LVET seen in normal subjects (r(2) = 0.6; P < 0.05) was lost in PBC patients, a finding compatible with myocardial dysfunction. Significant correlation was seen between fatigue severity in PBC and fall in cardiac output on orthostasis (r(2) = 0.25; P = 0.005). Our findings suggest the presence of altered myocardial function in PBC. Autonomic "dysfunction" may, rather than being an abnormal process, represent a compensatory mechanism to increase cardiac return to mitigate these effects.

Fatigue and autonomic dysfunction in non-alcoholic fatty liver disease

BACKGROUND

Fatigue is a significant symptom in nonalcoholic fatty liver disease (NAFLD) that impacts upon quality of life and is unrelated to liver disease severity. We examined the relationship between parameters of blood pressure regulation with perception of fatigue in NAFLD.

METHODS

Thirty-four non-diabetic subjects with histologically proven, non-cirrhotic NAFLD (26 [77%] males and 8 [23%] females) (mean +/- SD age 54 +/- 11) and 34 age, sex and BMI matched non-diabetic controls underwent subjective and objective evaluation of cardiovascular autonomic function (24 h blood pressure and head up tilt testing). All subjects completed the fatigue impact scale.

RESULTS

The NAFLD group had significantly higher autonomic symptom burden assessed using the orthostatic grading scale (OGS) compared to controls (4 +/- 4 vs. 1 +/- 2; p = 0.0003). Increasing orthostatic symptoms correlated with increasing fatigue (p = 0.006; r(2) = 0.3). Fatigue in NAFLD correlated inversely with 24 h measurement of systolic, diastolic and mean blood pressures (all p < 0.03; r(2) = 0.2). This relationship was predominantly related to lower blood pressure at night (p < 0.003; r(2) = 0.3). On head up tilt testing 57% of the NAFLD group had neurally-mediated hypotension (vasovagal syncope and/or orthostatic hypotension) (p = 0.006 compared to controls). The degree of blood pressure drop in response to standing correlated with fatigue severity (p = 0.008; r(2) = 0.3) and the autonomic symptom burden (OGS) (p = 0.03; r(2) = 0.2).

CONCLUSION

Autonomic symptoms are prevalent in NAFLD and associate with objective measures of autonomic dysfunction. Fatigue in NAFLD is associated with lower blood pressure and autonomic dysfunction. Studies are needed to determine whether this is a potential therapeutic target for fatigue in NAFLD.

Microvascular optical assessment confirms the presence of peripheral autonomic dysfunction in primary biliary cirrhosis

BACKGROUND

Autonomic dysfunction (AD) is a significant problem in primary biliary cirrhosis (PBC) and is equally present in early disease stages. Currently, AD in PBC is considered to be central in origin. The aim of this study was to examine peripheral mechanisms in the pathogenesis of AD in PBC using novel microvascular optical assessments for this patient group.

METHODS

Twenty-four early stage PBC patients and 24 age-matched controls attended for two microvascular optical-based measurement techniques. Firstly, the regulation of microvascular blood volume to the periphery was assessed using multisite photoplethysmography (PPG) by examining the degree of correlation between the right and left sides of the body, with reduced correlation consistent with peripheral AD. Secondly, the peripheral vasomotor reflex response to standing was dynamically tested using laser Doppler flowmetry to quantify the degree of autonomic tone in peripheral vasoconstriction.

RESULTS

PBC patients had a significantly reduced right to left side blood volume multisite PPG correlation compared with controls when corrected for age, body mass index, heart rate and systolic blood pressure [impaired synchronization between pulse wave amplitude between right and left fingers and right and left ears (both P<0.05)]. The veno-arteriolar reflex on standing in PBC patients was significantly lower than for the controls, consistent with poorer autonomic tone for vasoconstriction in PBC (P<0.01).

CONCLUSIONS

This study provides evidence for the presence of peripheral autonomic nervous system involvement in PBC. Prospective studies are now warranted to determine the full clinical potential of microvascular optical assessment in PBC.

Autonomic dysfunction in chronic liver disease

Autonomic dysfunction (AD) is common in chronic liver disease (CLD) of all aetiologies and even more so in those awaiting transplantation. As yet, the pathophysiology is not completely understood but the clinical effects are dramatic for the patient, who has a heavy symptomatic burden. There are several considerations, specific to liver disease, which complicate AD. Outlined here is a practical guide for clinicians detailing the common presentations and consequences of AD, investigation techniques and treatment options. As morbidity and mortality is increased in CLD patients with AD its recognition, investigation and management is important to all who encounter such patients.

Lower ambulatory blood pressure in chronic fatigue syndrome

OBJECTIVE

To examine blood pressure circadian rhythm in subjects with chronic fatigue syndrome (CFS) and appropriate normal and fatigued controls to correlate parameters of blood pressure regulation with perception of fatigue in an observational cohort study. The cause of CFS remains unknown and there are no effective treatments.

METHODS

To address whether inactivity was a confounder, we performed a 24-hour ambulatory blood pressure monitoring in the following three subject groups: 1) CFS patients (Fukuda Diagnostic criteria) (n = 38); 2) normal controls (n = 120); and 3) a fatigue comparison group (n = 47) with the autoimmune liver disease primary biliary cirrhosis (PBC). All patients completed a measure of fatigue severity (Fatigue Impact Scale). In view of the different demographics between the patient groups, patients were age- and sex-matched on a case-by-case basis to normal controls and blood pressure parameters were compared.

RESULTS

Compared with the control population, the CFS group had significantly lower systolic blood pressure (p < .0001) and mean arterial blood pressure (p = .0002) and exaggerated diurnal variation (p = .009). There was a significant inverse relationship between increasing fatigue and diurnal variation of blood pressure in both the CFS and PBC groups (p < .05).

CONCLUSION

Lower blood pressure and abnormal diurnal blood pressure regulation occur in patients with CFS. We would suggest the need for a randomized, placebo-controlled trial of agents to increase blood pressure such as midodrine in CFS patients with an autonomic phenotype.

Central nervous system fatigue alters autonomic nerve activity

AIMS

Fatigue is a common symptom in modern society. In order to clarify the mechanisms underlying fatigue, we examined the association between central nervous system fatigue and autonomic nerve activity.

MAIN METHODS

The study group consisted of 20 healthy subjects. They performed the 2-back test for 30 min to induce fatigue. Just before and after the fatigue-inducing session, they completed the advanced trail making test (ATMT) for 30 min as a fatigue-evaluating task session. In order to measure autonomic nerve activity, electrocardiograms were monitored continuously throughout the experiment.

KEY FINDINGS

After the fatigue-inducing task session, impaired task performance was demonstrated based on the total trial number and error counts of the ATMT. During the task session, although task performance as measured using the accuracy and the mean reaction time of the 2-back test was almost unchanged, electrocardiographic R-R wave interval analyses showed a decreased high-frequency component power and an increasing trend in the low-frequency component power/high-frequency component power ratio.

SIGNIFICANCE

Decreased vagal nerve activity and increased sympathetic nerve activity are associated with central nervous system fatigue.

Pilot study of peripheral muscle function in primary biliary cirrhosis: potential implications for fatigue pathogenesis

BACKGROUND & AIMS

Primary biliary cirrhosis (PBC) is characterized in 95% of patients by autoantibody responses directed against the mitochondrial antigen pyruvate dehydrogenase complex (PDC). Although anti-PDC inhibits PDC function in vitro, mitochondrial function in vivo in PBC has not been examined.

METHODS

(31)P magnetic resonance spectroscopy was performed in PBC patients (n = 15) and fatigued (chronic fatigue syndrome/myalgic encephalomyelitis, n = 8), cholestatic (primary sclerosing cholangitis [PSC], n = 4), and normal (n = 8) controls to define mitochondrial function and pH regulation in peripheral muscle during exercise at 25% and 35% of maximum voluntary contraction.

RESULTS

Normal, chronic fatigue syndrome/myalgic encephalomyelitis, and PSC subjects all showed close correlation between kinetics of adenosine diphosphate (ADP) and phosphocreatine (PCr) recovery after low-impact exercise, reflecting the normal tight regulation of PCr "response" by mitochondria to ADP "drive." This relationship was lost in PBC patients, indicating mitochondrial dysfunction (normal r(2) = 0.78, P < .005; PBC r(2) = 0.007, P = ns). Ratio between PCr and ADP recovery half-times (constant in controls, indicating normal mitochondrial responsivity) was significantly elevated in PBC patients (but not PSC) and was associated with anti-PDC levels. At higher levels of exercise PBC (but not PSC) patients showed excess muscle acidosis, with pH correlating with elevation of PCr/ADP recovery ratio, indicating a link to mitochondrial dysfunction. PBC patients alone also showed significant prolongation of muscle pH recovery time after exercise (unrelated to mitochondrial function), which correlated with clinical fatigue.

CONCLUSIONS

PBC patients exhibit a variable degree of muscle mitochondrial dysfunction that manifests as excess acidosis after exercise. The extent to which patients can recover rapidly from acidosis appears to determine whether they are clinically fatigued.

Cognitive impairment in primary biliary cirrhosis: symptom impact and potential etiology

Qualitative studies suggest that patients with primary biliary cirrhosis (PBC) experience significant problems with memory and concentration. Studies of nonhepatic disease have linked hypotension and cognitive impairment. In this study, we determined the prevalence of cognitive symptoms in PBC, examined the relationship between symptoms and overt cognitive impairment and structural brain lesions, and explored the role of autonomic dysfunction. The prevalence of cognitive symptoms was determined in 198 patients with PBC. Twenty-eight representative early-stage female patients with PBC and 11 matched controls underwent formal cognitive testing at baseline and after 2 years of follow-up. Autonomic nervous system function was assessed according to heart rate variability and baroreflex sensitivity. Eleven subjects with PBC had structural brain lesions quantified via magnetic resonance imaging. Cognitive symptoms were frequent in our PBC population, with 53% of patients experiencing moderate or severe problems with concentration and/or memory, which were unrelated in their severity to biochemical and histological makers of liver disease severity, suggesting that this symptom burden is largely or entirely unrelated to hepatic encephalopathy. Perceived cognitive symptoms correlated with objectively assessed cognitive impairment (r(2) = 0.2, P < 0.05). Cognitive deficits were seen in the PBC cohort compared with controls, with significant decline detected over 2 years of follow-up. Correlations were seen between cognitive performance (full-scale intelligence quotient) and systolic blood pressure (P = 0.01, r(2) = 0.2) with decline in cognitive function associated with autonomic abnormalities. Structural brain lesions were found in PBC, the density of which correlated with degree of cognitive impairment (P = 0.01, r(2) = 0.5) and autonomic function (P = 0.03, r(2) = 0.2).

CONCLUSION

Cognitive symptoms are prevalent in PBC independent of liver disease severity and are associated with poorer performance on objective cognitive testing. Cognitive impairment is, in turn, associated with structural brain lesions and autonomic dysfunction, which may predict risk of cognitive decline.

An integrated care pathway improves quality of life in Primary Biliary Cirrhosis

BACKGROUND

Clinical management of the chronic autoimmune liver disease, Primary Biliary Cirrhosis (PBC) involves addressing the underlying liver disease and a range of symptoms independent of liver disease severity. We have formally explored how these two perspectives of chronic disease management can be combined into a clinic consultation and impact upon quality of life (QOL) in PBC.

AIMS

To develop and implement the first Integrated Care Pathway (ICP) for the management of liver disease progression and symptom management in PBC.

METHODS

Process mapping of current practice by a multidisciplinary group developed a flowchart of care from which the clinical record evolved. Symptom assessment is incorporated into the PBC ICP (QOL; PBC-40, autonomic symptoms; Orthostatic Grading Scale, daytime sleepiness; Epworth Sleepiness Scale). All patients were considered who attended clinic between July 2005 and June 2006. Symptom assessment was repeated after 1 year in those participating in the initial clinic cohort.

RESULTS

The PBC ICP was successfully introduced into our clinical environment with high levels of patient satisfaction. A total of 225 PBC patients attended over 12 months. Initial QOL assessments were in 195 (87%). Five patients died (3%). Repeat assessment 1 year later occurred in 149 subjects (149/190; 78%). All symptom domains improved after ICP implementation with significant improvements in those with moderate and severe symptoms in all PBC-40 symptom domains (P < 0.02). In those with severe fatigue (n = 38) symptom improvement was even more dramatic (P = 0.002).

CONCLUSION

ICP implementation delivers evidence-based care, leads to improvements in QOL coupled with high levels of patient satisfaction.