Acetyl-L-carnitine improves cognitive functions in severe hepatic encephalopathy: a randomized and controlled clinical trial

L-Carnitine in the Treatment of Psychiatric and Neurological Manifestations: A Systematic Review

OBJECTIVE

L-carnitine (LC), a vital nutritional supplement, plays a crucial role in myocardial health and exhibits significant cardioprotective effects. LC, being the principal constituent of clinical-grade supplements, finds extensive application in the recovery and treatment of diverse cardiovascular and cerebrovascular disorders. However, controversies persist regarding the utilization of LC in nervous system diseases, with varying effects observed across numerous mental and neurological disorders. This article primarily aims to gather and analyze database information to comprehensively summarize the therapeutic potential of LC in patients suffering from nervous system diseases while providing valuable references for further research.

METHODS

A comprehensive search was conducted in PubMed, Web Of Science, Embase, Ovid Medline, Cochrane Library and Clinicaltrials.gov databases. The literature pertaining to the impact of LC supplementation on neurological or psychiatric disorders in patients was reviewed up until November 2023. No language or temporal restrictions were imposed on the search.

RESULTS

A total of 1479 articles were retrieved, and after the removal of duplicates through both automated and manual exclusion processes, 962 articles remained. Subsequently, a meticulous re-screening led to the identification of 60 relevant articles. Among these, there were 12 publications focusing on hepatic encephalopathy (HE), while neurodegenerative diseases (NDs) and peripheral nervous system diseases (PNSDs) were represented by 9 and 6 articles, respectively. Additionally, stroke was addressed in five publications, whereas Raynaud's syndrome (RS) and cognitive disorder (CD) each had three dedicated studies. Furthermore, migraine, depression, and amyotrophic lateral sclerosis (ALS) each accounted for two publications. Lastly, one article was found for other symptoms under investigation.

CONCLUSION

In summary, LC has demonstrated favorable therapeutic effects in the management of HE, Alzheimer's disease (AD), carpal tunnel syndrome (CTS), CD, migraine, neurofibromatosis (NF), PNSDs, RS, and stroke. However, its efficacy appears to be relatively limited in conditions such as ALS, ataxia, attention deficit hyperactivity disorder (ADHD), depression, chronic fatigue syndrome (CFS), Down syndrome (DS), and sciatica.

Pathophysiological-Based Nutritional Interventions in Cirrhotic Patients with Sarcopenic Obesity: A State-of-the-Art Narrative Review

In recent decades, following the spread of obesity, metabolic dysfunction has come to represent the leading cause of liver disease. The classical clinical presentation of the cirrhotic patient has, therefore, greatly changed, with a dramatic increase in subjects who appear overweight or obese. Due to an obesogenic lifestyle (lack of physical activity and overall malnutrition, with an excess of caloric intake together with a deficit of proteins and micronutrients), these patients frequently develop a complex clinical condition defined as sarcopenic obesity (SO). The interplay between cirrhosis and SO lies in the sharing of multiple pathogenetic mechanisms, including malnutrition/malabsorption, chronic inflammation, hyperammonemia and insulin resistance. The presence of SO worsens the outcome of cirrhotic patients, affecting overall morbidity and mortality. International nutrition and liver diseases societies strongly agree on recommending the use of food as an integral part of the healing process in the comprehensive management of these patients, including a reduction in caloric intake, protein and micronutrient supplementation and sodium restriction. Based on the pathophysiological paths shared by cirrhosis and SO, this narrative review aims to highlight the nutritional interventions currently advocated by international guidelines, as well as to provide hints on the possible role of micronutrients and nutraceuticals in the treatment of this multifaceted clinical condition.

Osteosarcopenia in NAFLD/MAFLD: An Underappreciated Clinical Problem in Chronic Liver Disease

Chronic liver disease (CLD), including non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), affects a significant portion of the population worldwide. NAFLD is characterised by fat accumulation in the liver, while NASH is associated with inflammation and liver damage. Osteosarcopenia, which combines muscle and bone mass loss, is an emerging clinical problem in chronic liver disease that is often underappreciated. The reductions in muscle and bone mass share several common pathophysiological pathways; insulin resistance and chronic systemic inflammation are the most crucial predisposing factors and are related to the presence and gravity of NAFLD and to the worsening of the outcome of liver disease. This article explores the relationship between osteosarcopenia and NAFLD/MAFLD, focusing on the diagnosis, prevention and treatment of this condition in patients with CLD.

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study

BACKGROUND/AIMS

L-carnitine is potentially beneficial in patients with hepatic encephalopathy (HE). We aimed to evaluate the impact of L-carnitine on the quality of life and liver function in patients with liver cirrhosis and covert HE.

METHODS

We conducted an investigator-initiated, prospective, multi-center, double- blind, randomized phase III trial in patients with covert HE. A total of 150 patients were randomized 1:1 to L-carnitine (2 g/day) or placebo for 24 weeks. Changes in quality of life and liver function were assessed at 6 months. The model for end-stage liver disease (MELD), the 36-Item Short Form Survey (SF-36), the psychometric hepatic encephalopathy score (PHES), and the Stroop Test were evaluated in all patients.

RESULTS

The total SF-36 score significantly improved in the L-carnitine group after 24 weeks (difference: median, 2; interquartile range, 0 to 11; p < 0.001); however, these values were comparable between the two groups. Furthermore, there was a significant ordinal improvement in PHES scores among patients with minimal HE who were in the L-carnitine group (p = 0.007). Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (color test, r = 0.3; word test, r = 0.4; inhibition test, r = 0.5; inhibition/switching test, r = 0.3; all p < 0.05). Nevertheless, the MELD scores at week 24 did not differ between the groups.

CONCLUSION

Twenty-four weeks of L-carnitine supplementation was safe but ineffective in improving quality of life and liver function.

Impact of l-Carnitine Supplementation on Liver Enzyme Normalization in Patients with Chronic Liver Disease: A Meta-Analysis of Randomized Trials

The effectiveness of l-carnitine in chronic liver disease remains controversial. We conducted this meta-analysis to assess the efficacy of various forms of l-carnitine in the treatment of chronic liver disease. Methods: We searched the Cochrane Library, EMBASE, KMBASE, and Medline databases for all relevant studies published until April 2022 that examined the ability of l-carnitine or its derivatives to normalize liver enzymes in patients with chronic liver disease. We performed meta-analyses of the proportion of patients with alanine aminotransferase (ALT) normalization and post-treatment serum aspartate aminotransferase (AST) and ALT levels. A random effects model was used for meta-analyses. Results: Fourteen randomized controlled trials (1217 patients) were included in this meta-analysis. The proportion of patients in whom ALT normalized was higher in the carnitine-orotate treatment group than in the control group (pooled odds ratio (OR), 95% confidence interval (CI) = 4.61 (1.48–14.39)). The proportion of patients in whom ALT normalized was also higher among those who received the carnitine-orotate complex, a combination of carnitine-orotate, biphenyl dimethyl dicarboxylate, and other minor supplementary compounds than in those who did not without significant heterogeneity (pooled OR (95% CI) = 18.88 (7.70–46.27); df = 1; p = 0.51; I² = 0%). l-carnitine supplementation effectively lowered serum ALT levels compared to controls (pooled mean difference (95% CI) = −11.99 (−22.48 to −1.49)). Conclusions: l-carnitine supplementation significantly lowered ALT and AST levels and normalized ALT levels in patients with chronic liver disease.

Hyperammonemia in Inherited Metabolic Diseases

Ammonia is a neurotoxic compound which is detoxified through liver enzymes from urea cycle. Several inherited or acquired conditions can elevate ammonia concentrations in blood, causing severe damage to the central nervous system due to the toxic effects exerted by ammonia on the astrocytes. Therefore, hyperammonemic patients present potentially life-threatening neuropsychiatric symptoms, whose severity is related with the hyperammonemia magnitude and duration, as well as the brain maturation stage. Inherited metabolic diseases caused by enzymatic defects that compromise directly or indirectly the urea cycle activity are the main cause of hyperammonemia in the neonatal period. These diseases are mainly represented by the congenital defects of urea cycle, classical organic acidurias, and the defects of mitochondrial fatty acids oxidation, with hyperammonemia being more severe and frequent in the first two groups mentioned. An effective and rapid treatment of hyperammonemia is crucial to prevent irreversible neurological damage and it depends on the understanding of the pathophysiology of the diseases, as well as of the available therapeutic approaches. In this review, the mechanisms underlying the hyperammonemia and neurological dysfunction in urea cycle disorders, organic acidurias, and fatty acids oxidation defects, as well as the therapeutic strategies for the ammonia control will be discussed.

Role of Carnitine in Non-alcoholic Fatty Liver Disease and Other Related Diseases: An Update

Carnitine is an amino acid-derived substance that coordinates a wide range of biological processes. Such functions include transport of long-chain fatty acids from the cytoplasm to the mitochondrial matrix, regulation of acetyl-CoA/CoA, control of inter-organellar acyl traffic, and protection against oxidative stress. Recent studies have found that carnitine plays an important role in several diseases, including non-alcoholic fatty liver disease (NAFLD). However, its effect is still controversial, and its mechanism is not clear. Herein, this review provides current knowledge on the biological functions of carnitine, the “multiple hit” impact of carnitine on the NAFLD progression, and the downstream mechanisms. Based on the “multiple hit” hypothesis, carnitine inhibits β-oxidation, improves mitochondrial dysfunction, and reduces insulin resistance to ameliorate NAFLD. L-carnitine may have therapeutic role in liver diseases including non-alcoholic steatohepatitis, cirrhosis, hepatocellular carcinoma, alcoholic fatty liver disease, and viral hepatitis. We also discuss the prospects of L-carnitine supplementation as a therapeutic strategy in NAFLD and related diseases, and the factors limiting its widespread use.

Cognitive Impairment After Resolution of Hepatic Encephalopathy: A Systematic Review and Meta-Analysis

Hepatic encephalopathy (HE) is one of the most disabling metabolic diseases. It consists of a complication of liver disease through the action of neurotoxins, such as excessive production of ammonia from liver, resulting in impaired brain function. Its prevalence and incidence are not well known, although it has been established that up to 40% of cirrhotic patients may develop HE. Patients with HE episodes display a wide range of neurological disturbances, from subclinical alterations to coma. Recent evidence suggests that the resolution of hepatic encephalopathy does not fully restore cognitive functioning in cirrhotic patients. Therefore, the aim of this review was to evaluate the evidence supporting the presence of lingering cognitive deficits in patients with a history of HE compared to patients without HE history and how liver transplant affects such outcome in these patients. We performed two distinct meta-analysis of continuous outcomes. In both cases the results were pooled using random-effects models. Our results indicate that cirrhotic patients with a history of HE show clear cognitive deficits compared to control cirrhotic patients (Std. Mean Difference (in SDs) = −0.72 [CI 95%: −0.94, −0.50]) and that these differences are not fully restored after liver transplant (Std. Mean Difference (in SDs) = −0.48 [CI 95%: −0.77, −0.19]).

Carnitine Serum Levels in Frail Older Subjects

Frailty is an expression that reconciles and condenses loss of autonomy, both physical and cognitive decline and a wide spectrum of adverse outcomes due to aging. The decrease in physical and cognitive activity is associated with altered mitochondrial function, and energy loss and consequently morbidity and mortality. In this cross-sectional study, we evaluated the carnitine levels in frailty status. The mean serum concentrations of total carnitine (TC) were lower in frail elderly subjects than in prefrail ones (p = 0.0006), higher in frail vs. robust subjects (p < 0.0001), and higher in prefrail vs. robust subjects (p < 0.0001). The mean serum concentrations of free carnitine (FC) were lower in frail elderly subjects than in prefrail ones (p < 0.0001), lower in frail vs. robust subjects (p < 0.0001) and lower in prefrail vs. robust subjects (p = 0.0009). The mean serum concentrations of acylcarnitine (AC) were higher in frail elderly subjects than in prefrail ones (p = 0.054) and were higher in pre-frail vs. robust subjects (p = 0.0022). The mean urine concentrations of TC were lower in frail elderly subjects than in prefrail ones (p < 0.05) and lower in frail vs. robust subjects (p < 0.0001). The mean urine concentrations of free carnitine were lower in frail elderly vs. robust subjects (p < 0.05). The mean urine concentrations of acyl carnitines were lower in frail elderly subjects than those in both prefrail (p < 0.0001) and robust subjects (p < 0.0001). Conclusion: high levels of carnitine may have a favorable effect on the functional status and may treat the frailty status in older subjects.

Effect of L-carnitine on health-related quality of life in patients with liver cirrhosis

L-carnitine (4-N-trimethylammonium-3-hydroxybutyric acid) is the physiologically active form of carnitine and is a natural compound that has been shown to exhibit antioxidant activity. L-carnitine is used as a supplementary treatment in patients with cirrhosis with hepatic encephalopathy, hyperammonemia or muscle cramps. In the present study, the effect of L-carnitine supplementation on health-related quality of life in 30 patients with cirrhosis was prospectively examined. L-carnitine (1,800 mg/day) was administered orally for 6 months. To assess the effects of L-carnitine on chronic fatigue, patients filled out a self-report questionnaire regarding their physical and mental health. The levels of total and free carnitine, and acylcarnitine were found to be significantly higher 1, 3 and 6 months after therapy initiation compared with before treatment. Serum albumin levels were significantly increased 3 and 6 months after initiation of therapy. L-carnitine supplementation significantly increased the BAP/d-ROM ratio, a marker of antioxidant status in patients with cirrhosis. Changes in serum carnitine concentrations were positively correlated with changes in serum albumin levels (R²=0.369; P=0.012), but not with changes in serum ammonia levels (R²= 0.005; P=0.78). Total and mental health scores improved significantly, and physical scores improved marginally 3 and 6 months after initiation of L-carnitine. These findings may be attributed to the enhanced serum albumin levels and oxidative stress rather than the reduced serum ammonia levels. Based on these results, it is suggested that L-carnitine can potentially alleviate chronic fatigue, along with the increased BAP/d-ROM ratio, which were involved in increased oxidative stress in patients with cirrhosis. The specific mechanisms by which L-carnitine ameliorates chronic fatigue is not fully understood and requires further investigation.

Usefulness of Carnitine Supplementation for the Complications of Liver Cirrhosis

Carnitine is a vitamin-like substance that regulates lipid metabolism and energy production. Carnitine homeostasis is mainly regulated by dietary intake and biosynthesis in the organs, including the skeletal muscle and the liver. Therefore, liver cirrhotic patients with reduced food intake, malnutrition, biosynthetic disorder, and poor storage capacity of carnitine in the skeletal muscle and liver are more likely to experience carnitine deficiency. In particular, liver cirrhotic patients with sarcopenia are at a high risk for developing carnitine deficiency. Carnitine deficiency impairs the important metabolic processes of the liver, such as gluconeogenesis, fatty acid metabolism, albumin biosynthesis, and ammonia detoxification by the urea cycle, and causes hypoalbuminemia and hyperammonemia. Carnitine deficiency should be suspected in liver cirrhotic patients with severe malaise, hepatic encephalopathy, sarcopenia, muscle cramps, and so on. Importantly, the blood carnitine level does not always decrease in patients with liver cirrhosis, and it sometimes exceeds the normal level. Therefore, patients with liver cirrhosis should be treated as if they are in a state of relative carnitine deficiency at the liver, skeletal muscle, and mitochondrial levels, even if the blood carnitine level is not decreased. Recent clinical trials have revealed the effectiveness of carnitine supplementation for the complications of liver cirrhosis, such as hepatic encephalopathy, sarcopenia, and muscle cramps. In conclusion, carnitine deficiency is not always rare in liver cirrhosis, and it requires constant attention in the daily medical care of this disease. Carnitine supplementation might be an important strategy for improving the quality of life of patients with liver cirrhosis.

Acetyl-L-Carnitine in Dementia and Other Cognitive Disorders: A Critical Update

Several studies explored the effects of acetyl-L-carnitine (ALC) in dementia, suggesting a role in slowing down cognitive decline. Nevertheless, in 2003 a systematic review concluded there was insufficient evidence to recommend a clinical use, although a meta-analysis in the same year showed a significant advantage for ALC for clinical scales and psychometric tests. Since then, other studies have been published; however, a critical review is still lacking. We provide an update of the studies on ALC in primary and secondary dementia, highlighting the current limitations and translational implications. Overall, the role of ALC in dementia is still under debate. The underlying mechanisms may include restoring of cell membranes and synaptic functioning, enhancing cholinergic activity, promoting mitochondrial energy metabolism, protecting against toxins, and exerting neurotrophic effects. The effects of ALC on the gut-liver-brain axis seem to identify the category of patients in which the new insights contribute most to the mechanisms of action of ALC, likely being the liver metabolism and the improvement of hepatic detoxifying mechanisms the primary targets. In this framework, our research group has dealt with this topic, focusing on the ALC-related cross-talk mechanisms. Further studies with homogeneous sample and longitudinal assessment are needed before a systematic clinical application.

Acetyl-L-Carnitine in Dementia and Other Cognitive Disorders: A Critical Update

Several studies explored the effects of acetyl-L-carnitine (ALC) in dementia, suggesting a role in slowing down cognitive decline. Nevertheless, in 2003 a systematic review concluded there was insufficient evidence to recommend a clinical use, although a meta-analysis in the same year showed a significant advantage for ALC for clinical scales and psychometric tests. Since then, other studies have been published; however, a critical review is still lacking. We provide an update of the studies on ALC in primary and secondary dementia, highlighting the current limitations and translational implications. Overall, the role of ALC in dementia is still under debate. The underlying mechanisms may include restoring of cell membranes and synaptic functioning, enhancing cholinergic activity, promoting mitochondrial energy metabolism, protecting against toxins, and exerting neurotrophic effects. The effects of ALC on the gut-liver-brain axis seem to identify the category of patients in which the new insights contribute most to the mechanisms of action of ALC, likely being the liver metabolism and the improvement of hepatic detoxifying mechanisms the primary targets. In this framework, our research group has dealt with this topic, focusing on the ALC-related cross-talk mechanisms. Further studies with homogeneous sample and longitudinal assessment are needed before a systematic clinical application.

Novel Therapies in Hepatic Encephalopathy

Despite widespread use of lactulose and rifaximin for the treatment of hepatic encephalopathy, this complication of advanced liver disease remains a major burden on the health care system in the United States and continues to predispose to high morbidity and mortality. Several agents have surfaced over recent years with promise to treat hepatic encephalopathy and mitigate the cognitive impairment associated with this disease process. The purpose of this article is to highlight the leading emerging therapies in hepatic encephalopathy as well as their therapeutic targets.

Effect of L-carnitine on liver enzymes and biochemical factors in hepatic encephalopathy: A systematic review and meta-analysis

BACKGROUND AND AIMS

We aimed to investigate the effect of L-carnitine on biochemical factors including ammonia, bilirubin, albumin, alanine aminotransferase, aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine (Cr) in patients with hepatic encephalopathy (HE).

METHODS

A systematic search was carried out in Web of Science, PubMed, Scopus, and Cochrane Library databases to find articles related to the effect of L-carnitine supplementation in patients with HE, up to 7 February 2019. There was no language and time limitation. Meta-analyses were carried out using both the random and fixed effects models where appropriate, and I² index was used to evaluate the heterogeneity.

RESULTS

Search yielded 3462 publications. Nine randomized clinical trials with 779 patients were eligible. L-carnitine supplementation significantly reduced blood levels of ammonia. Furthermore, our results indicated that L-carnitine supplementation significantly reduced blood levels of bilirubin, AST, BUN, and Cr in patients with HE. Subgroup analysis demonstrated that L-carnitine significantly reduced ammonia in patients with all the ages, long and short duration of the supplementation, doses less or higher than 4000 mg/day, any route of treatment (intravenous or oral), and in patients with any grade of the symptoms of HE. Moreover, we found that L-carnitine significantly increased circulating levels of albumin in HE patients.

CONCLUSIONS

Present systematic review and meta-analysis revealed that L-carnitine supplementation significantly reduced blood levels of ammonia, bilirubin, AST, BUN, and Cr in HE patients. Moreover, we found that L-carnitine significantly increased circulating levels of albumin. However, further large-scale randomized clinical trials are needed.

Effects of carnitine supplementation on liver aminotransferase enzymes: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND AND AIMS

This meta-analysis of the randomized controlled trials was performed to assess effects of carnitine supplementation on serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

METHODS

A comprehensive literature search of PubMed, Cochrane's library, Web of Science, Scopus, and Embase was performed up to May 2018. From a total of 2012 articles identified initially, only 17 articles were included in the final meta-analysis to evaluate the effects of carnitine supplementation on serum levels of ALT and AST enzymes.

RESULTS

Random effects model meta-analysis showed that carnitine supplementation led to reduction in serum ALT (weighted mean difference [WMD] - 10.25 IU/L; 95% CI = - 15.73, - 4.77; p < 0.001) and AST levels (WMD - 7.85 IU/L; 95% CI = - 11.85, - 3.86; p < 0.001). The results of subgroup analysis showed that carnitine could reduce serum AST levels at dosages equal to 2000 mg/day (p = 0.014) or more than 2000 mg/day (p < 0.001). However, carnitine supplementation at dosages of ≤ 1000 mg/day (p = 0.035) or equal to 2000 mg/day (p = 0.013) resulted in significant reduction in ALT level, while doses more than 2000 mg/day did not change ALT significantly. Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months.

CONCLUSION

Results of the current meta-analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly, especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels.

Does L-carnitine supplementation affect serum levels of enzymes mainly produced by liver? A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND AND AIMS

L-carnitine supplementation is proposed to reduce liver enzymes levels; however, previous findings were equivocal. The current systematic review and meta-analysis of randomized controlled clinical trials (RCTs) were performed to assess the effect of L-carnitine supplementation on serum levels of enzymes mainly produced by liver [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGTP)].

METHODS

Online databases as well as the reference lists of relevant studies were searched from inception up to June 2019. The risk of bias in individual studies was assessed using Cochrane Collaboration's tool. Data were pooled using the random-effects model and expressed as mean differences (MDs) with 95% confidence intervals (CIs).

RESULTS

In total, 18 RCTs (1161 participants) met the eligibility criteria. L-carnitine supplementation dose ranged from 500 to 4000 mg/day. L-carnitine supplementation significantly reduced serum ALT (MD = - 8.65 IU/L, 95% CI - 13.40, - 3.90), AST (MD = - 8.52 IU/L, 95% CI - 12.16, - 4.89), and GGTP (MD = - 8.80 IU/L, 95% CI - 13.67, - 3.92) levels. The subgroup analysis showed that L-carnitine might be more effective in reducing the enzymes when supplemented in higher doses (≥ 2000 mg/day), for longer durations (> 12 weeks), and among patients with liver diseases. The meta-evidence was graded as "moderate" for ALT and AST, and "low" for GGTP according to NutriGrade scoring system.

CONCLUSION

L-carnitine supplementation significantly improves circulating ALT, AST and GGTP levels; therefore, it might positively affect liver function, especially among patients with liver diseases. Further high-quality RCTs are recommended to confirm our results.

Nutrition in Cirrhosis

PURPOSE OF REVIEW

This review discusses the prevalence of malnutrition in cirrhosis, metabolic functions of the liver and alterations in cirrhosis, malnutrition screening tools, and common macronutrient and micronutrient deficiencies encountered in individuals with chronic liver disease and their impact on morbidity and mortality.

RECENT FINDINGS

Several meta-analyses and international society guidelines recommend malnutrition screening and nutrition interventions to improve outcomes in all patients with chronic liver disease given their high risk of malnutrition which is often under recognized. Malnutrition is common in individuals with chronic liver disease and has a significant impact on patient outcomes. Thus, it is critical that validated malnutrition screening tools are used routinely in this patient population in order to identify high-risk patients and implement nutrition and exercise interventions early.

Effect of Acetyl-L-carnitine Used for Protection of Neonatal Hypoxic-Ischemic Brain Injury on Acute Kidney Changes in Male and Female Rats

Neonatal hypoxia-ischemia (HI) is a common cause of brain injury in infants. Acute kidney injury frequently occurs after birth asphyxia and is associated with adverse outcome. Treatment with acetyl-L-carnitine (ALCAR) after HI protects brain and improves outcome. Rat pups underwent carotid ligation and 75 min hypoxia on postnatal day 7 to determine effects of HI on kidney which is understudied in this model. HI + ALCAR pups were treated at 0, 4 and 24 h after HI. The organic cation/carnitine transporter 2 (OCTN2), transports ALCAR and functions to reabsorb carnitine and acylcarnitines from urine. At 24 h after injury OCTN2 levels were significantly decreased in kidney from HI pups, 0.80 ± 0.04 (mean ± SEM, p < 0.01), compared to sham controls 1.03 ± 0.04, and HI + ALCAR pups 1.11 ± 0.06. The effect of HI on the level of pyruvate dehydrogenase (PDH) was determined since kidney has high energy requirements. At 24 h after HI, kidney PDH/β-actin ratios were significantly lower in HI pups, 0.98 ± 0.05 (mean ± SEM, p < 0.05), compared to sham controls 1.16 ± 0.06, and HI + ALCAR pups 1.24 ± 0.03, p < 0.01. Treatment of pups with ALCAR after HI prevented the decrease in renal OCTN2 and PDH levels at 24 h after injury. Protection of PDH and OCTN2 after HI would improve energy metabolism in kidney, maintain tissue carnitine levels and overall carnitine homeostasis which is essential for neonatal health.

Pathophysiology of hepatic encephalopathy and future treatment options

Understanding of the pathophysiology of hepatic encephalopathy has conditioned new treatment options. Ammonia detoxification in hepatic encephalopathy is regulated by two enzymes: glutaminase or glutamine synthetase. The first produces ammonia and the second detoxifies the ammonia, which is why treatments are aimed at glutaminase inhibition or glutamine synthetase activation. At present, we know that both enzymes are found not only in the liver, but also in the muscle, intestine, kidney, and brain. Therefore, current treatments can be directed at each enzyme at different sites. Awareness of those potential treatment sites makes different options of approach possible in the patient with hepatic encephalopathy, and each approach should be personalized.

Levocarnitine Use Is Associated With Improvement in Sarcopenia in Patients With Liver Cirrhosis

Although the effect of levocarnitine (L-carnitine) on hyperammonemia has been reported in patients with liver cirrhosis (LC), its effect on sarcopenia remains to be elucidated. We assessed the effects of L-carnitine on sarcopenia in patients with LC. We retrospectively evaluated 52 patients with LC who were treated with L-carnitine for more than 3 months between February 2013 and June 2017. Computed tomography was used to measure the cross-sectional area of the skeletal muscles at the level of the third lumbar vertebra. The relative change in skeletal muscle index (SMI) per year (ΔSMI/year) was computed in each patient. We evaluated the relationship between ΔSMI/year and various parameters, such as age, sex, liver functional reserve, and dose of L-carnitine. The median ΔSMI/year for all patients was -0.22%. The ΔSMI/year values in Child-Pugh classes A, B, and C were not significantly different among the three groups. There was no significant relationship between ΔSMI/year and sex, age, body mass index, and sarcopenia. Multivariate analysis showed that only a high dose of L-carnitine (odds ratio [OR], 4.812; 95% confidence interval [CI], 1.233-18.784; P = 0.024) was associated with increased muscle mass. The L-carnitine high-dose group included a significantly larger number of patients with increased muscle mass compared with the low-dose group (OR, 3.568; 95% CI, 1.138-11.185; P = 0.027). Administration of L-carnitine led to a significant and gradual reduction in serum ammonia levels. Conclusion: L-carnitine seems to suppress the progression of sarcopenia dose dependently, and this was noted to be associated with the improvement of hyperammonemia in patients with LC.

Acetyl-L-carnitine for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a common and devastating neuropsychiatric complication of acute liver failure or chronic liver disease. Ammonia content in the blood seems to play a role in the development of hepatic encephalopathy. Treatment for hepatic encephalopathy is complex. Acetyl-L-carnitine is a substance that may reduce ammonia toxicity. This review assessed the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

OBJECTIVES

To assess the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, and Science Citation Index Expanded for randomised clinical trials. We sought additional randomised clinical trials from the World Health Organization Clinical Trials Search Portal and ClinicalTrials.gov. We performed all electronic searches until 10 September 2018. We looked through the reference lists of retrieved publications and review articles, and we searched the FDA and EMA websites.

SELECTION CRITERIA

We searched for randomised clinical trials in any setting, recruiting people with hepatic encephalopathy. Trials were eligible for inclusion if they compared acetyl-L-carnitine plus standard care (e.g. antibiotics, lactulose) versus placebo or no acetyl-L-carnitine plus standard care. We are well aware that by selecting randomised clinical trials, we placed greater focus on potential benefits than on potential harms.

DATA COLLECTION AND ANALYSIS

We selected randomised clinical trials, assessed risk of bias in eight domains, and extracted data in a duplicate and independent fashion. We estimated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. We measured statistical heterogeneity using I² and D² statistics. We subjected our analyses to fixed-effect and random-effects model meta-analyses. We assessed bias risk domains to control systematic errors. We assessed overall quality of the data for each individual outcome by using the GRADE approach.

MAIN RESULTS

We identified five randomised clinical trials involving 398 participants. All trials included only participants with cirrhosis as the underlying cause of hepatic encephalopathy. Trials included participants with covert or overt hepatic encephalopathy. All trials were conducted in Italy by a single team and assessed acetyl-L-carnitine compared with placebo. Oral intervention was the most frequent route of administration. All trials were at high risk of bias and were underpowered. None of the trials were sponsored by the pharmaceutical industry.None of the identified trials reported information on all-cause mortality, serious adverse events, or days of hospitalisation. Only one trial assessed quality of life using the Short Form (SF)-36 scale (67 participants; very low-quality evidence). The effects of acetyl-L-carnitine compared with placebo on general health at 90 days are uncertain (MD -6.20 points, 95% confidence interval (CI) -9.51 to -2.89). Results for additional domains of the SF-36 are also uncertain. One trial assessed fatigue using the Wessely and Powell test (121 participants; very low-quality evidence). The effects are uncertain in people with moderate-grade hepatic encephalopathy (mental fatigue: MD 0.40 points, 95% CI -0.21 to 1.01; physical fatigue: MD -0.20 points, 95% CI -0.92 to 0.52) and mild-grade hepatic encephalopathy (mental fatigue: -0.80 points, 95% CI -1.48 to -0.12; physical fatigue: 0.20 points, 95% CI -0.72 to 1.12). Meta-analysis showed a reduction in blood ammonium levels favouring acetyl-L-carnitine versus placebo (MD -13.06 mg/dL, 95% CI -17.24 to -8.99; 387 participants; 5 trials; very low-quality evidence). It is unclear whether acetyl-L-carnitine versus placebo increases the risk of non-serious adverse events (8/126 (6.34%) vs 3/120 (2.50%); RR 2.51, 95% CI 0.68 to 9.22; 2 trials; very low-quality evidence). Overall, adverse events data were poorly reported and harms may have been underestimated.

AUTHORS' CONCLUSIONS

This Cochrane systematic review analysed a heterogeneous group of five trials at high risk of bias and with high risk of random errors conducted by only one research team. We assessed acetyl-L-carnitine versus placebo in participants with cirrhosis with covert or overt hepatic encephalopathy. Hence, we have no data on the drug for hepatic encephalopathy in acute liver failure. We found no information about all-cause mortality, serious adverse events, or days of hospitalisation. We found no clear differences in effect between acetyl-L-carnitine and placebo regarding quality of life, fatigue, and non-serious adverse events. Acetyl-L-carnitine reduces blood ammonium levels compared with placebo. We rated all evidence as of very low quality due to pitfalls in design and execution, inconsistency, small sample sizes, and very few events. The harms profile for acetyl-L-carnitine is presently unclear. Accordingly, we need further randomised clinical trials to assess acetyl-L-carnitine versus placebo conducted according to the SPIRIT statements and reported according to the CONSORT statements.

Recent advances in drug delivery via the organic cation/carnitine transporter 2 (OCTN2/SLC22A5)

INTRODUCTION

Transporters in the plasma membrane have been exploited successfully for the delivery of drugs in the form of prodrugs and nanoparticles. Organic cation/carnitine transporter 2 (OCTN2, SLC22A5) has emerged as a viable target for drug delivery. OCTN2 is a Na⁺-dependent high-affinity transporter for L-carnitine and a Na⁺-independent transporter for organic cations. OCTN2 is expressed in the blood-brain barrier, heart, liver, kidney, intestinal tract and placenta and plays an essential role in L-carnitine homeostasis in the body. Areas covered: In recent years, several studies have been reported in the literature describing the utility of OCTN2 to enhance the delivery of drugs, prodrugs and nanoparticles. Here we summarize the salient features of OCTN2 in terms of its role in the cellular uptake of its physiological substrate L-carnitine in physiological and pathological context; the structural requirements for recognition and the recent advances in OCTN2-targeted drug delivery systems, including prodrugs and nanoparticles, are discussed. Expert opinion: This transporter has great potential to be utilized as a target for drug delivery to improve oral absorption of drugs in the intestinal tract. It also has potential to facilitate the transfer of drugs across the biological barriers such as the blood-brain barrier, blood-retinal barrier, and maternal-fetal barrier.

Unusual Signs and Symptoms in HIV-Positive Patients Coinfected with Leishmania spp: The Importance of Neglected Tropical Disease in Differential Diagnosis

BACKGROUND:

Leishmaniasis is a parasitic disease affecting both animals and humans, acquired with the bite of sand flies or, in Injection Drug Users (IDUs), with contaminated needles, still hypoendemic in Sicily and the Mediterranean basin. Even though it is responsible for 20,000 to 40,000 deaths per year, this parasitic infection is still considered a neglected tropical disease. People Living with HIV (PLWH) are considered at high-risk of developing Leishmaniasis and, despite the introduction of Highly Active Anti-Retroviral Therapy (HAART), mortality rate and relapses prevalence are still high in coinfected people.

CASE REPORT:

We present a case of HIV-Leishmania coinfection, posing the attention on the atypical signs and symptoms and the importance of thinking about other causes than the HIV infection progression when the patient presents with a worsening of his immune status during HAART.

CONCLUSION:

This parasitic disease has a high mortality rate, so it is mandatory to think about it in all the patients having a low CD4+ T-cell count and an inverted CD4/CD8 ratio under HAART.

L-Carnitine for the Treatment of Overt Hepatic Encephalopathy in Patients with Advanced Liver Cirrhosis

Hepatic encephalopathy is a major complication in patients with advanced cirrhosis and is associated with poor prognosis. To evaluate the effectiveness of L-carnitine supplementation in patients with overt hepatic encephalopathy (OHE), outcomes were retrospectively analyzed in patients with OHE who were treated with intravenous branched-chain amino acids (BCAA), with or without intravenous L-carnitine. Twenty-six patients were treated with intravenous BCAA in addition to conventional agents such as lactulose and non-absorbable antibiotics (Group A), and 19 patients were treated with these agents plus intravenous L-carnitine (Group L). Changes in blood ammonia concentrations, hepatic coma grade and the Glasgow Coma Scale (GCS) were compared in the two groups. Recurrence-free survival (RFS) was evaluated in the two groups and in patients who were and were not administered oral L-carnitine supplementation. At baseline, GCS scores were significantly lower and deterioration in liver function greater in Group L. After 3 d of intravenous L-carnitine, however, GCS showed a significantly greater improvement in Group L than in Group A. Blood ammonia levels improved stably over time in Group L. Overall survival and RFS were similar in Group L and Group A, but median RFS was significantly longer in patients who did than did not receive oral L-carnitine supplementation (735 versus 497 d, p=0.03). Although these findings are preliminary, L-carnitine supplementation may be a therapeutic option for patients with OHE and disturbed consciousness.

Oral carnitine supplementation influences mental health parameters and biomarkers of oxidative stress in women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Limited data are available assessing the effects of oral carnitine supplementation on mental health parameters and biomarkers of oxidative stress of women with polycystic ovary syndrome (PCOS).This study was designed to determine the effects of oral carnitine supplementation on mental health parameters and biomarkers of oxidative stress in women with PCOS.

METHODS

In the current randomized, double-blind, placebo-controlled trial, 60 patients diagnosed with PCOS were randomized to take either 250 mg carnitine supplements (n = 30) or placebo (n = 30) for 12 weeks.

RESULTS

After 12 weeks' intervention, compared with the placebo, carnitine supplementation resulted in a significant improvement in Beck Depression Inventory total score (-2.7 ± 2.3 versus -0.2 ± 0.7, p < 0.001), General Health Questionnaire scores (-6.9 ± 4.9 versus -0.9 ± 1.5, p < 0.001) and Depression Anxiety and Stress Scale scores (-8.7 ± 5.9 versus -1.2 ± 2.9, p = 0.001). In addition, changes in plasma total antioxidant capacity (TAC) (+84.1 ± 151.8 versus +4.6 ± 64.5 mmol/L, p = 0.01), malondialdehyde (MDA) (-0.4 ± 1.0 versus  +0.5 ± 1.5 μmol/L, p = 0.01) and MDA/TAC ratio (-0.0005 ± 0.0010 versus +0.0006 ± 0.0019, p = 0.003) in the supplemented group were significantly different from the changes in these indicators in the placebo group.

CONCLUSIONS

Overall, our study demonstrated that carnitine supplementation for 12 weeks among patients with PCOS had favorable effects on parameters of mental health and biomarkers of oxidative stress.

Carnitine dynamics and their effects on hyperammonemia in cirrhotic Japanese patients

AIM

Supplementation with levocarnitine preparations has been reported to improve hepatic encephalopathy, but no detailed investigations have addressed the dynamics of carnitine or its supplementation indication in cirrhosis patients. We studied carnitine dynamics in cirrhotic patients by measuring serum and liver tissue carnitine levels and tested the effects of levocarnitine supplementation on concurrent hyperammonemia.

METHODS

In a pilot cohort of seven patients with liver cirrhosis and five patients without cirrhosis, the serum and liver carnitine concentrations were measured. Then the serum carnitine fractions were analyzed in 70 liver cirrhosis patients. Among them, a levocarnitine preparation (1800 mg/day) was supplemented orally for 3 months in 27 patients with refractory hyperammonemia, and the effects were evaluated.

RESULTS

A significant correlation was observed between serum and liver tissue carnitine concentrations (r = 0.69, P < 0.05). The serum total carnitine concentration was 68.4 ± 4.7 μmol/L, the free carnitine concentration was 53.2 ± 2.6 μmol/L, and the acylcarnitine concentration was 13.2 ± 1.1 μmol/L in 70 cirrhotic patients (reference values are 45-91, 36-74, 6-23 μmol/L, respectively). There was no correlation between blood ammonia and serum carnitine concentrations. The serum carnitine concentration rose with levocarnitine supplementation, reaching steady state after 1 month and, in parallel, refractory hyperammonemia was significantly improved. The cut-off level for a 20% decrease in blood ammonia was identified as 62.0 μmol/L total carnitine concentration by receiver-operating characteristic curve analysis, with an area under the curve of 0.69.

CONCLUSION

Serum carnitine concentrations were within standard levels in the majority of liver cirrhosis patients. In patients with concurrent hyperammonemia, the levocarnitine supplementation reduced blood ammonia levels.

Management of Neurologic Manifestations in Patients with Liver Disease

OPINION STATEMENT

Liver disease, both in its acute and chronic forms, can be associated with a wide spectrum of neurologic manifestations, both central and peripheral, ranging in severity from subclinical changes to neurocritical conditions. Neurologists are frequently consulted to participate in their management. In this review, we present an overview of management strategies for patients with hepatic disease whose clinical course is complicated by neurologic manifestations. Type A hepatic encephalopathy (HE), which occurs in acute liver failure, is a neurologic emergency, and multiple measures should be taken to prevent and treat cerebral edema. In Type C HE, which occurs in chronic liver disease, management should be aimed at correcting precipitant factors and hyperammonemia. There is an increasing spectrum of drug treatments available to minimize ammonia toxicity. Acquired hepatocerebral degeneration is a rare complication of the chronic form of HE, with typical clinical and brain MRI findings, whose most effective treatment is liver transplantation. Epilepsy is frequent and of multifactorial cause in patients with hepatic disease, and careful considerations should be made regarding choice of the appropriate anti-epileptic drugs. Several mechanisms increase the risk of stroke in hepatic disease, but many of the drugs used to treat and prevent stroke are contraindicated in severe hepatic failure. Hepatitis C infection increases the risk of ischemic stroke. Hemorrhagic stroke is more frequent in patients with liver disease of alcoholic etiology. Viral hepatitis is associated with a wide range of immune-mediated complications, mostly in the peripheral nervous system, which respond to different types of immunomodulatory treatment. Several drugs used to treat hepatic disease, such as the classical and the new direct-acting antivirals, may have neurologic complications which in some cases preclude its continued use.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND

Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD.

DISCUSSION

Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.

Investigation of inflammatory profile in MSUD patients: benefit of L-carnitine supplementation

Maple Syrup Urine Disease (MSUD) is a metabolic disorder caused by a severe deficiency of the branched-chain α-keto acid dehydrogenase complex activity which leads to the accumulation of branched-chain amino acids (BCAA) leucine (Leu), isoleucine and valine and their respective α-keto-acids in body fluids. The main symptomatology presented by MSUD patients includes ketoacidosis, failure to thrive, poor feeding, apnea, ataxia, seizures, coma, psychomotor delay and mental retardation, but, the neurological pathophysiologic mechanisms are poorly understood. The treatment consists of a low protein diet and a semi-synthetic formula restricted in BCAA and supplemented with essential amino acids. It was verified that MSUD patients present L-carnitine (L-car) deficiency and this compound has demonstrated an antioxidant and anti-inflammatory role in metabolic diseases. Since there are no studies in the literature reporting the inflammatory profile of MSUD patients and the L-car role on the inflammatory response in this disorder, the present study evaluates the effect of L-car supplementation on plasma inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), interferon-gamma (INF-ɣ), and a correlation with malondialdehyde (MDA), as a marker of oxidative damage, and with free L-car plasma levels in treated MSUD patients. Significant increases of IL-1β, IL-6, and INF-ɣ were observed before the treatment with L-car. Moreover, there is a negative correlation between all cytokines tested and L-car concentrations and a positive correlation among the MDA content and IL-1β and IL-6 values. Our data show that L-car supplementation can improve cellular defense against inflammation and oxidative stress in MSUD patients and may represent an additional therapeutic approach to the patients affected by this disease.

Management of hepatic encephalopathy

OPINION STATEMENT

Hepatic encephalopathy management varies depending on the acuity of liver failure. However, in patients with either acute or chronic liver failure five basic steps in management are critical: stabilization, addressing modifiable precipitating factors, lowering blood ammonia, managing elevated intracranial pressure (ICP) (if present), and managing complications of liver failure that can contribute to encephalopathy, particularly hyponatremia. Because liver failure patients are prone to a variety of other medical problems that can lead to encephalopathy (such as coagulopathy associated intracranial hemorrhage, electrolyte disarray, renal failure, hypotension, hypoglycemia, and infection), a thorough history, physical and neurologic examination is mandated in all encephalopathic liver failure patients. There should be a low threshold for brain imaging in patients with focal neurological deficits given the propensity for spontaneous intracranial hemorrhage. In patients with acute liver failure and high grade encephalopathy, identification of the etiology of acute liver failure is essential to guide treatment and antidote administration, particularly in the case of acetaminophen poisoning. Equally critical is management of elevated ICP in acute liver failure. Intracranial hypertension can be treated with hypertonic saline and/or adjustment of the dialysis bath. Placement of an intracranial monitor to guide ICP therapy is risky because of concomitant coagulopathy and remains controversial. Continuous renal replacement therapy may help lower serum ammonia, treat coexisting uremia, and improve symptoms. Liver transplantation is the definitive treatment for patients with acute liver failure and hepatic encephalopathy. In patients with chronic hepatic encephalopathy, lactulose and rifaxamin remain a mainstay of therapy. In these patients, it is essential to identify reversible causes of hepatic encephalopathy such as increased ammonia production and/or decreased clearance (eg, infection, GI bleed, constipation, hypokalemia, dehydration). Chronic hyponatremia should be managed by gradual sodium correction of no more than 8‒12 meq/L per day to avoid central myelinolysis syndrome. Free water restriction and increased dietary sodium are reasonable, cost effective treatment options. Many emerging therapies, both pharmacologic and interventional, are currently being studied to improve management of hepatic encephalopathy.

Recent insights into the pathogenesis of hepatic encephalopathy and treatments

Hepatic encephalopathy (HE) encompasses a spectrum of neuropsychiatric disorders related to liver failure. The development of HE can have a profound impact on mortality as well as quality of life for patients and carers. Ammonia is central in the disease process contributing to alteration in neurotransmission, oxidative stress, and cerebral edema and astrocyte swelling in acute liver failure. Inflammation in the presence of ammonia coactively worsens HE. Inflammation can result from hyperammonemic responses, endotoxemia, innate immune dysfunction or concurrent infection. This review summarizes the current processes implicated in the pathogenesis of HE, as well as current and potential treatments. Treatments currently focus on reducing inflammation and/or blood ammonia levels and provide varying degrees of success. Optimization of current treatments and initial testing of novel therapies will provide the basis of improvement of care in the near future.

L-carnitine supplementation as a potential antioxidant therapy for inherited neurometabolic disorders

In recent years increasing evidence has emerged suggesting that oxidative stress is involved in the pathophysiology of a number of inherited metabolic disorders. However the clinical use of classical antioxidants in these diseases has been poorly evaluated and so far no benefit has been demonstrated. l-Carnitine is an endogenous substance that acts as a carrier for fatty acids across the inner mitochondrial membrane necessary for subsequent beta-oxidation and ATP production. Besides its important role in the metabolism of lipids, l-carnitine is also a potent antioxidant (free radical scavenger) and thus may protect tissues from oxidative damage. This review addresses recent findings obtained from patients with some inherited neurometabolic diseases showing that l-carnitine may be involved in the reduction of oxidative damage observed in these disorders. For some of these diseases, reduced concentrations of l-carnitine may occur due to the combination of this compound to the accumulating toxic metabolites, especially organic acids, or as a result of protein restricted diets. Thus, l-carnitine supplementation may be useful not only to prevent tissue deficiency of this element, but also to avoid oxidative damage secondary to increased production of reactive species in these diseases. Considering the ability of l-carnitine to easily cross the blood-brain barrier, l-carnitine supplementation may also be beneficial in preventing neurological damage derived from oxidative injury. However further studies are required to better explore this potential.

Mini-Mental State Examination in patients with hepatic encephalopathy and liver cirrhosis: a prospective, quantified electroencephalography study

Background

Mini-Mental State Examination (MMSE) is one of the most commonly used methods in the assessment of cognitive mental status. MMSE has been used in hepatology but its usefulness in the evaluation of hepatic encephalopathy (HE) has never been properly assessed. The aim of the study was to investigate the value of MMSE in detection of HE in patients with cirrhosis.

Methods

One hundred and one consecutive patients with liver cirrhosis underwent neurological examination, MMSE and electroencephalography (EEG). Spectral analysis of EEG was done with calculation of mean dominant frequency (MDF) and relative power of delta, theta, alpha and beta rhythms. Minimal HE was diagnosed in patients with normal neurological status and alterations in spectral EEG. Statistical analysis included Fisher’s exact and Anova analysis. Categorical data were compared using Levene’s test for equality of variances. Correlation-coefficient analysis was performed by the Pearson’s r or Z-test, as needed. Tests performance was assessed by the calculating the area under the ROC curve (AUC) and evaluating its difference from reference area (AUC=0.5). A p value <0.05 was considered statistically significant.

Results

Overt HE was identified in 49 (48.5%) and minimal HE in 22 (21.8%) patients. Although there were significant correlations between both severity of liver disease (Child-Pugh classification), overt HE (West-Haven criteria) and various MMSE items, MDF showed no correlation with any of MMSE items as well as MMSE summary score. MMSE (score and items) did not discriminate patients without HE and minimal HE. The only significant differences between patients without HE and with overt HE were seen in respect of MMSE score (p<0.02), orientation to place (p<0.003), repetition (p<0.01) and complex commands-understanding (p<0.02). Test performance analysis has shown that MMSE has no value as a prediction method in determining minimal HE and in respect of overt HE has a sensitivity of 63% and specificity of 52% by a cut-off level at 27.5 points to diagnose overt HE.

Conclusions

In conclusion, although MMSE score and single items are altered in patients with overt HE, MMSE has no value in the assessment of minimal HE. Because MMSE could be impaired in several cognitive dysfunctions, more specific test should be used for measuring HE.

Serum carnitine levels and levocarnitine supplementation in institutionalized Huntington's disease patients

Along with antioxidant properties, carnitine is an important regulator of lipid metabolism in humans. While beneficial effects of carnitine have been demonstrated in animal models of Huntington's disease (HD), metabolism of carnitine has not been studied in humans with this illness. In this retrospective database review from 23 patients admitted to a HD-specialized nursing home unit, we found a relatively high prevalence of hypocarnitinemia (6 cases, 26%). Our review suggests that catabolism and chronic valproate use predisposed our patients to develop hypocarnitinemia. The patients with low serum carnitine levels who received levocarnitine supplementation, during a mean period of 7.3 months, showed improvement in motor, cognitive and behavioral measures. We hypothesize that observed improvement related to the resolution of reversible metabolic encephalopathy and myopathy associated with secondary carnitine deficiency. In conclusion, notwithstanding its limitations, this is the first study to report measurements of carnitine levels in HD patients, revealing relatively high prevalence of hypocarnitinemia in our population. Our findings suggest that HD patients with hypocarnitinemia may benefit from low-dose levocarnitine supplementation. Further studies of carnitine metabolism and supplementation in HD patients are warranted.

Acetyl-L-carnitine in hepatic encephalopathy

Hepatic encephalopathy is a common complication of hepatic cirrhosis. The clinical diagnosis is based on two concurrent types of symptoms: impaired mental status and impaired neuromotor function. Impaired mental status is characterized by deterioration in mental status with psychomotor dysfunction, impaired memory, and increased reaction time, sensory abnormalities, poor concentration, disorientation and coma. Impaired neuromotor function include hyperreflexia, rigidity, myoclonus and asterixis. The pathogenesis of hepatic encephalopathy has not been clearly defined. The general consensus is that elevated levels of ammonia and an inflammatory response work in synergy to cause astrocyte to swell and fluid to accumulate in the brain which is thought to explain the symptoms of hepatic encephalopathy. Acetyl-L-carnitine, the short-chain ester of carnitine is endogenously produced within mitochondria and peroxisomes and is involved in the transport of acetyl-moieties across the membranes of these organelles. Acetyl-L-carnitine administration has shown the recovery of neuropsychological activities related to attention/concentration, visual scanning and tracking, psychomotor speed and mental flexibility, language short-term memory, attention, and computing ability. In fact, Acetyl-L-carnitine induces ureagenesis leading to decreased blood and brain ammonia levels. Acetyl-L-carnitine treatment decreases the severity of mental and physical fatigue, depression cognitive impairment and improves health-related quality of life. The aim of this review was to provide an explanation on the possible toxic effects of ammonia in HE and evaluate the potential clinical benefits of ALC.

Hepatic encephalopathy

Hepatic encephalopathy (HE) represents a continuum of transient and reversible neurologic and psychiatric dysfunction. It is a reversible state of impaired cognitive function or altered consciousness in patients with liver disease or portosystemic shunting. Over the last several years, high-quality studies have been conducted on various pharmacologic therapies for HE; as more data emerge, it is hoped that HE will become a more easily treated complication of decompensated liver disease. In the interim, it is important that physicians continue to screen for minimal HE and treat patients early in addition to continuing to provide current treatments of overt HE.

Carnitine derivatives: clinical usefulness

PURPOSE OF REVIEW

Carnitine and its derivatives are natural substances involved in both carbohydrate and lipid metabolism. This review summarizes the recent progress in the field in relation to the molecular mechanisms.

RECENT FINDINGS

The pool of different carnitine derivatives is formed by acetyl-L-carnitine (ALC), propionyl-L-carnitine (PLC), and isovaleryl-carnitine. ALC may have a preferential effect on the brain tissue. ALC represents a compound of great interest for its wide clinical application in various neurological disorders: it may be of benefit in treating Alzheimer's dementia, depression in the elderly, HIV infection, chronic fatigue syndrome, peripheral neuropathies, ischemia and reperfusion of the brain, and cognitive impairment associated with various conditions. PLC has been demonstrated to replenish the intermediates of the tricarboxylic acid cycle by the propionyl-CoA moiety, a greater affinity for the sarcolemmal carrier, peripheral vasodilator activity, a greater positive inotropism, and more rapid entry into myocytes. Most studies of the therapeutic use of PLC are focused on the prevention and treatment of ischemic heart disease, congestive heart failure, hypertrophic heart disease, and peripheral arterial disease. ALC and PLC are considered well tolerated without significant side-effects.

SUMMARY

A number of therapeutic effects possibly come from the interaction of carnitine and its derivatives with the elements of cellular membranes.

Management of overt hepatic encephalopathy

Hepatic encephalopathy (HE) is a potentially reversible state of impaired cognitive function or altered consciousness in patients with liver disease or portosystemic shunting. Overt HE is a particularly pressing problem. Given the many targets of treatment and lack of a clear singular cause of overt HE, there is no consensus on a single best treatment. Over the past several years, high-quality studies have been conducted on the various pharmacologic therapies for HE and, as more data emerge, hopefully HE will become a much more easily treated complication of decompensated liver disease.