Usefulness of Carnitine Supplementation for the Complications of Liver Cirrhosis

Metabolic predictors of COVID-19 mortality and severity: a survival analysis

Introduction

The global healthcare burden of COVID-19 pandemic has been unprecedented with a high mortality. Metabolomics, a powerful technique, has been increasingly utilized to study the host response to infections and to understand the progression of multi-system disorders such as COVID-19. Analysis of the host metabolites in response to SARS-CoV-2 infection can provide a snapshot of the endogenous metabolic landscape of the host and its role in shaping the interaction with SARS-CoV-2. Disease severity and consequently the clinical outcomes may be associated with a metabolic imbalance related to amino acids, lipids, and energy-generating pathways. Hence, the host metabolome can help predict potential clinical risks and outcomes.

Methods

In this prospective study, using a targeted metabolomics approach, we studied the metabolic signature in 154 COVID-19 patients (males=138, age range 48-69 yrs) and related it to disease severity and mortality. Blood plasma concentrations of metabolites were quantified through LC-MS using MxP Quant 500 kit, which has a coverage of 630 metabolites from 26 biochemical classes including distinct classes of lipids and small organic molecules. We then employed Kaplan-Meier survival analysis to investigate the correlation between various metabolic markers, disease severity and patient outcomes.

Results

A comparison of survival outcomes between individuals with high levels of various metabolites (amino acids, tryptophan, kynurenine, serotonin, creatine, SDMA, ADMA, 1-MH and carnitine palmitoyltransferase 1 and 2 enzymes) and those with low levels revealed statistically significant differences in survival outcomes. We further used four key metabolic markers (tryptophan, kynurenine, asymmetric dimethylarginine, and 1-Methylhistidine) to develop a COVID-19 mortality risk model through the application of multiple machine-learning methods.

Conclusions

Metabolomics analysis revealed distinct metabolic signatures among different severity groups, reflecting discernible alterations in amino acid levels and perturbations in tryptophan metabolism. Notably, critical patients exhibited higher levels of short chain acylcarnitines, concomitant with higher concentrations of SDMA, ADMA, and 1-MH in severe cases and non-survivors. Conversely, levels of 3-methylhistidine were lower in this context.

Time-Course Metabolomic Analysis: Production of Betaine Structural Analogs by Fungal Fermentation of Seaweed

Betaine structural analogs are compounds characterized by the presence of positive and negative charges in a single molecule and have been reported to have physiological properties, such as anti-inflammatory activities. In this study, we performed a metabolomic analysis of metabolite composition changes during the fermentation of Neopyropia yezoensis, an edible red alga, with Aspergillus oryzae for 72 h. The results indicated that three specific betaine structural analogs (betaine, stachydrine, and carnitine) exhibited significant changes in production by the end of the 72 h fermentation period. Time-course analysis suggested that betaine was generated from the precursor choline at 12-24 h during the late stage of fungal growth, while stachydrine was generated from the precursor-related compound glutamic acid at 48-72 h during the sporulation stage. However, the contribution of the precursor lysine to the increased production of carnitine during the 12-72 h period was unclear. This study provides useful information on the efficient production of betaine structural analogs by the fungal fermentation of seaweed as well as various other food materials.

Possible pathogenetic role of ammonia in liver cirrhosis without hyperammonemia of venous blood: The so-called latency period of abnormal ammonia metabolism

Ammonia plays a crucial role in the pathogenesis of hepatic encephalopathy. Ammonia is also involved in many other pathological conditions seen in cirrhosis, such as sarcopenia, liver fibrosis, hepatocellular injury, immune dysfunction, and hyperammonemia. Furthermore, the ammonia level of the veins is a useful prognostic factor for cirrhosis. In cirrhosis without hyperammonemia of the vein, however, covert hepatic encephalopathy has been reported. This discrepancy is because of the anatomical features of ammonia metabolism. There are two systems in the body for detoxifying ammonia: one is the urea cycle in the liver, and the other is the glutamine synthesis pathway in skeletal muscle and other tissues. The blood processed in the liver's urea cycle is then transported via arteries to various organs. Further processing occurs in the brain and skeletal muscle's glutamine synthesis pathway before entering the veins. When the urea cycle function decreases in cirrhosis, the ammonia levels in the artery increase. In response, the glutamine synthesis pathway compensates by increasing the capacity to process ammonia. Therefore, the ammonia concentration in the veins downstream of skeletal muscles does not increase immediately. However, the brain and skeletal muscles, which receive arterial blood, might be exposed to high ammonia concentrations. In addition, branched-chain amino acids in venous blood decrease. This period is the transition phase from early- to late-phase cirrhosis, and understanding the pathophysiology during this stage is extremely important for preventing the progression of cirrhosis.

Modification of Preservative Fluids with Antioxidants in Terms of Their Efficacy in Liver Protection before Transplantation

Transplantation is currently the only effective treatment for patients with end-stage liver failure. In recent years, many advanced studies have been conducted to improve the efficiency of organ preservation techniques. Modifying the composition of the preservation fluids currently used may improve graft function and increase the likelihood of transplantation success. The modified fluid is expected to extend the period of safe liver storage in the peri-transplantation period and to increase the pool of organs for transplantation with livers from marginal donors. This paper provides a literature review of the effects of antioxidants on the efficacy of liver preservation fluids. Medline (PubMed), Scopus, and Cochrane Library databases were searched using a combination of MeSH terms: "liver preservation", "transplantation", "preservation solution", "antioxidant", "cold storage", "mechanical perfusion", "oxidative stress", "ischemia-reperfusion injury". Studies published up to December 2023 were included in the analysis, with a focus on publications from the last 30 years. A total of 45 studies met the inclusion criteria. The chemical compounds analyzed showed mostly bioprotective effects on hepatocytes, including but not limited to multifactorial antioxidant and free radical protective effects. It should be noted that most of the information cited is from reports of studies conducted in animal models, most of them in rodents.

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.

The influence of a maternal vegan diet on carnitine and vitamin B2 concentrations in human milk

Background

The maternal diet greatly influences the nutritional composition of human milk. With the rise of vegan diets by lactating mothers, there are concerns about the nutritional adequacy of their milk. Two important nutrients, vitamin B2 and carnitine, are mostly ingested via animal products.

Objective

We investigated the influence of a vegan diet on the vitamin B2 and carnitine concentrations in milk and serum of lactating women.

Methods

In this case-control study, 25 lactating mothers following an exclusive vegan diet were comparted to 25 healthy lactating mothers with an omnivorous diet without use of supplements. High-performance liquid chromatography and liquid chromatography-tandem mass spectrometry were used to measure vitamin B2 and carnitine concentrations, respectively. A linear regression model was used to determine differences in human milk and serum concentrations between study groups.

Results

Vitamin B2 concentrations in human milk and serum did not differ between study groups. While the human milk free carnitine (C0) and acetyl carnitine (C2) concentrations did not differ between study groups, serum carnitine concentrations were lower in participants following a vegan diet than in omnivorous women (p < 0.0001).

Conclusion

A maternal vegan diet did not affect human milk concentration of vitamin B2 and carnitine. Breastfed infants of mothers following an exclusive vegan diet therefore are likely not at increased risk of developing a vitamin B2 or carnitine deficiency.

L-carnitine promotes liver regeneration after hepatectomy by enhancing lipid metabolism

BACKGROUND

Lipid metabolism plays an important role in liver regeneration, but its regulation still requires further research. In this study, lipid metabolites involved in mouse liver regeneration at different time points were sequenced and analyzed to study their influence on liver regeneration and its mechanism.

METHODS

Our experiment was divided into two parts. The first part examined lipid metabolites during liver regeneration in mice. In this part, lipid metabolites were sequentially analyzed in the livers of 70% mouse hepatectomy models at 0, 1, 3and 7 days after operation to find the changes of lipid metabolites in the process of liver regeneration. We screened L-carnitine as our research object through metabolite detection. Therefore, in the second part, we analyzed the effects of carnitine on mouse liver regeneration and lipid metabolism during liver regeneration. We divided the mouse into four groups: control group (70% hepatectomy group); L-carnitine group (before operation) (L-carnitine were given before operation); L-carnitine group (after operation)(L-carnitine were given after operation) and L-carnitine + perhexiline maleate (before operation) group. Weighing was performed at 24 h, 36 and 48 h in each group, and oil red staining, HE staining and MPO staining were performed. Tunnel fluorescence staining, Ki67 staining and serological examination.

RESULTS

Sequencing analysis of lipid metabolites in 70% of mouse livers at different time points after hepatectomy showed significant changes in carnitine metabolites. The results showed that, compared with the control group the mouse in L-carnitine group (before operation) at 3 time points, the number of fat drops in oil red staining was decreased, the number of Ki67 positive cells was increased, the number of MPO positive cells was decreased, the number of Tunnel fluorescence positive cells was decreased, and the liver weight was increased. Serum enzymes were decreased. Compared with control group, L-carnitine group (after operation) showed similar trends in all indexes at 36 and 48 h as L-carnitine group (before operation). L-carnitine + perhexiline maleate (before operation) group compared with control group, the number of fat drops increased, the number of Ki67 positive cells decreased, and the number of MPO positive cells increased at 3 time points. The number of Tunnel fluorescent positive cells increased and serum enzyme increased. However, both liver weights increased.

CONCLUSION

L-carnitine can promote liver cell regeneration by promoting lipid metabolism and reduce aseptic inflammation caused by excessive lipid accumulation.

From Listing to Recovery: A Review of Nutritional Status Assessment and Management in Liver Transplant Patients

Liver transplantation (LT) is a complex surgical procedure requiring thorough pre- and post-operative planning and care. The nutritional status of the patient before, during, and after LT is crucial to surgical success and long-term prognosis. This review aims to assess nutritional status assessment and management before, during, and after LT, with a focus on patients who have undergone bariatric surgery. We performed a comprehensive topic search on MEDLINE, Ovid, In-Process, Cochrane Library, EMBASE, and PubMed up to March 2023. It identifies key factors influencing the nutritional status of liver transplant patients, such as pre-existing malnutrition, the type and severity of liver disease, comorbidities, and immunosuppressive medications. The review highlights the importance of pre-operative nutritional assessment and intervention, close nutritional status monitoring, individualised nutrition care plans, and ongoing nutritional support and monitoring after LT. The review concludes by examining the effect of bariatric surgery on the nutritional status of liver transplant recipients. The review offers valuable insights into the challenges and opportunities for optimising nutritional status before, during, and after LT.

Add-on Therapeutic Effects of Rifaximin on Treatment-resistant Hepatic Encephalopathy

Objective Rifaximin is used to treat hepatic encephalopathy. However, whether or not rifaximin and lactulose combination therapy can enhance the treatment outcomes and reduce the hospitalization rate of patients with hepatic encephalopathy that are resistant to lactulose has yet to be determined. The present study investigated the hospitalization rate before and after rifaximin add-on therapy in patients resistant to lactulose. Methods A total of 36 patients who were resistant to lactulose with add-on rifaximin therapy were enrolled. Patients who were hospitalized and/or did not achieve normalization of ammonia levels under lactulose administration were defined as treatment-resistant. The primary outcome was the change in hospitalization rate due to hepatic encephalopathy at 24 weeks before and after rifaximin administration. Results Before rifaximin administration, 15 (41.6%) patients were hospitalized due to hepatic encephalopathy. After rifaximin administration, 8 (22.2%) patients were hospitalized due to hepatic encephalopathy. The hospitalization rates were significantly reduced after rifaximin administration (p=0.02). The median (interquartile range) ammonia levels upon rifaximin administration (baseline) and 8, 12, and 24 weeks after rifaximin administration were 124 (24-310) μg/dL, 78 (15-192) μg/dL, 67 (21-233) μg/dL, and 77 (28-200) μg/dL, respectively. Furthermore, the ammonia levels were significantly reduced by rifaximin add-on therapy (p=0.005, p=0.01, and p=0.01). Conclusion The addition of rifaximin to lactulose treatment in treatment-resistant patients decreases the hospitalization rate among patients with hepatic encephalopathy and may be used as an add-on treatment.

Detection and alterations of acetylcarnitine (AC) in human liver by 1 H MRS at 3T after supplementation with l-carnitine

PURPOSE

Acetylcarnitine can be assessed in vivo using proton MRS (1 H-MRS) with long TEs and this has been previously applied successfully in muscle. The aim of this study was to evaluate a 1 H-MRS technique for liver acetylcarnitine quantification in healthy humans before and after l-carnitine supplementation.

METHOD

Baseline acetylcarnitine levels were quantified using a STEAM sequence with prolonged TE in 15 healthy adults. Using STEAM with four different TEs was evaluated in phantoms. To assess reproducibility of the measurements, five of the participants had repeated 1 H-MRS without receiving l-carnitine supplementation. To determine if liver acetylcarnitine could be changed after l-carnitine supplementation, acetylcarnitine was quantified 2 h after intravenous l-carnitine supplementation (50 mg/kg body weight) in the other 10 participants. Hepatic lipids were also quantified from the 1 H-MRS spectra.

RESULTS

There was good separation between the acetylcarnitine and fat in the phantoms using TE = 100 ms. Hepatic acetylcarnitine levels were reproducible (coefficient of reproducibility = 0.049%) and there was a significant (p < 0.001) increase in the relative abundance after a single supplementation of l-carnitine. Hepatic allylic, methyl, and methylene peaks were not altered by l-carnitine supplementation in healthy volunteers.

CONCLUSION

Our results demonstrate that our 1 H-MRS technique could be used to measure acetylcarnitine in the liver and detect changes following intravenous supplementation in healthy adults despite the presence of lipids. Our techniques should be explored further in the study of fatty liver disease, where acetylcarnitine is suggested to be altered due to hepatic inflexibilities.

Effects of L-carnitine supplementation on glucolipid metabolism: a systematic review and meta-analysis

Background: L-carnitine supplementation has been utilized against glucolipid metabolism disruption. However, to the best of our knowledge, no meta-analysis process has analyzed the effects of L-carnitine supplementation on insulin resistance, fasting blood glucose, lipid metabolism, and liver enzyme levels in adults. Methods: Through the analysis and screening of 12 221 studies, 15 studies were selected from eligible trials for meta-analysis. Meta-analysis was performed in a random effect model with heterogeneity determined by I², and subgroup analyses were used to further identify the source of heterogeneity. Result: The results showed significant effects of L-carnitine on FBG (MD = -4.94 mg dL^-1, 95% CI: -7.07 to -2.82), insulin (MD = -0.99 μU mL^-1, 95% CI: -1.41 to -0.56), HOMA-IR (MD = -0.58, 95% CI: -0.77 to -0.38), TG (MD = -11.22 mg dL^-1, 95% CI: -19.21 to -3.22), TC (MD = -6.45 mg dL^-1, 95% CI: -9.95 to -2.95, LDLc (MD = -8.28 mg dL^-1, 95% CI: -11.08 to -5.47), and ALT (MD = -19.71 IU L^-1, 95% CI: -36.45 to -2.96). However, no significant effect of L-carnitine supplementation was observed in HDLc (MD = -0.77 mg dL^-1, 95% CI: -0.10 to -1.63) or AST (MD = -11.05 IU L^-1, 95% CI: -23.08 to 0.99). The duration of carnitine supplementation was negatively associated with mean differences in FBG, as assessed by meta-regression. Conclusion: The current meta-analysis revealed that L-carnitine may have favorable effects on glucolipid profile, especially insulin, FBG, HOMA-IR, TG, TC, LDLc, and ALT levels.

Carnitine derivatives beyond fatigue: an update

PURPOSE OF REVIEW

Carnitine is an essential micronutrient that transfer long-chain fatty acids from the cytoplasm into the mitochondrial matrix for the β-oxidation. Carnitine is also needed for the mitochondrial efflux of acyl groups in the cases wherein substrate oxidation exceeds energy demands.

RECENT FINDINGS

Carnitine deficiency can affect the oxidation of free fatty acids in the mitochondria resulting in the aggregation of lipids in the cytoplasm instead of entering the citric acid cycle. The aggregation leads a lack of energy, acetyl coenzyme A accumulation in the mitochondria and cytotoxic production.

SUMMARY

Carnitine and its derivatives show great clinical therapeutic effect without significant side effects.

Sarcopenia and Frailty in Cirrhosis

Sarcopenia and frailty are frequent in cirrhosis, and both contribute to increased morbidity and mortality. The complex pathogenesis of sarcopenia in cirrhosis is mainly determined by hyperammonemia and malnutrition. Sarcopenia/frailty screening and reevaluation should be undertaken in all cirrhotic patients. Frailty tests are useful in the ambulatory setting, whereas the computed tomography scan is the diagnostic gold standard for sarcopenia. To manage sarcopenia/frailty, a multidisciplinary team should develop a personalized comprehensive care plan that includes patient education, protein/calorie intake goals, late evening meals, exercise programs, and micronutrient replenishment. In selected patients, branched-chain amino acid and testosterone supplements may also be beneficial.

Silica nanoparticles aggravated the metabolic associated fatty liver disease through disturbed amino acid and lipid metabolisms-mediated oxidative stress

The metabolic associated fatty liver disease (MAFLD) is a public health challenge, leading to a global increase in chronic liver disease. The respiratory exposure of silica nanoparticles (SiNPs) has revealed to induce hepatotoxicity. However, its role in the pathogenesis and progression of MAFLD was severely under-studied. In this context, the hepatic impacts of SiNPs were investigated in vivo and in vitro through using ApoE^-/- mice and free fatty acid (FFA)-treated L02 hepatocytes. Histopathological examinations and biochemical analysis showed SiNPs exposure via intratracheal instillation aggravated hepatic steatosis, lipid vacuolation, inflammatory infiltration and even collagen deposition in ApoE^-/- mice, companied with increased hepatic ALT, AST and LDH levels. The enhanced fatty acid synthesis and inhibited fatty acid β-oxidation and lipid efflux may account for the increased hepatic TC/TG by SiNPs. Consistently, SiNPs induced lipid deposition and elevated TC in FFA-treated L02 cells. Further, the activation of hepatic oxidative stress was detected in vivo and in vitro, as evidenced by ROS accumulation, elevated MDA, declined GSH/GSSG and down-regulated Nrf2 signaling. Endoplasmic reticulum (ER) stress was also triggered in response to SiNPs-induced lipid accumulation, as reflecting by the remarkable ER expansion and increased BIP expression. More importantly, an UPLC-MS-based metabolomics analysis revealed that SiNPs disturbed the hepatic metabolic profile in ApoE^-/- mice, prominently on amino acids and lipid metabolisms. In particular, the identified differential metabolites were strongly correlated to the activation of oxidative stress and ensuing hepatic TC/TG accumulation and liver injuries, contributing to the progression of liver diseases. Taken together, our study showed SiNPs promoted hepatic steatosis and liver damage, resulting in the aggravation of MAFLD progression. More importantly, the disturbed amino acids and lipid metabolisms-mediated oxidative stress was a key contributor to this phenomenon from a metabolic perspective.

Mac-2-binding protein glycosylation isomer is useful to predict muscle cramps in patients with chronic liver disease

Muscle cramps are frequently overlooked and worsen the quality of life in patients with chronic liver disease (CLD). Therefore, a valuable biomarker for predicting muscle cramps is required in the clinical setting. This study aimed to investigate whether the serum Mac-2-binding protein glycosylation isomer (M2BPGi) levels, a reliable liver fibrosis marker, could predict muscle cramps in patients with CLD. This retrospective study included 80 patients with CLD. Muscle cramps were assessed using a questionnaire regarding their presence, frequency, pain severity, and duration. The associated predictors were analyzed using logistic regression analysis. The diagnostic accuracy and optimal cutoff values were evaluated using receiver operating characteristic curves. Of the 80 patients, 55% had muscle cramps and showed significantly higher serum M2BPGi levels than those without them (4.54 cutoff index [COI] vs 2.20; P = .001). Multivariate analysis revealed that M2BPGi (odds ratio [ORs], 1.19; 95% confidence interval, 1.003-1.42; P = .046) was independently associated with the presence of muscle cramps. The optimal COI value for predicting muscle cramps was 3.95, and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 61.4%, 80.6%, 79.4%, 63.0%, and 70.0%, respectively. Patients with a COI value ≥3.95 had a 2-fold higher incidence of muscle cramps than patients with a COI value <3.95 (79% vs 37%; P < .001). M2BPGi levels were also associated with the duration of muscle cramps. Serum M2BPGi appears useful as a biomarker for predicting muscle cramps in patients with CLD.

A machine-learning approach for predicting the effect of carnitine supplementation on body weight in patients with polycystic ovary syndrome

The present study aimed to explore the effect of carnitine supplementation on body weight in patients with polycystic ovary syndrome (PCOS) and predict an appropriate dosage schedule using a machine-learning approach. Data were obtained from literature mining and the rates of body weight change from the initial values were selected as the therapeutic index. The maximal effect (E_max) model was built up as the machine-learning model. A total of 242 patients with PCOS were included for analysis. In the machine-learning model, the E_max of carnitine supplementation on body weight was -3.92%, the ET₅₀ was 3.6 weeks, and the treatment times to realize 25%, 50%, 75%, and 80% (plateau) E_max of carnitine supplementation on body weight were 1.2, 3.6, 10.8, and 14.4 weeks, respectively. In addition, no significant relationship of dose-response was found in the dosage range of carnitine supplementation used in the present study, indicating the lower limit of carnitine supplementation dosage, 250 mg/day, could be used as a suitable dosage. The present study first explored the effect of carnitine supplementation on body weight in patients with PCOS, and in order to realize the optimal therapeutic effect, carnitine supplementation needs 250 mg/day for at least 14.4 weeks.

Rifaximin enhances the L‑carnitine‑mediated preventive effects on skeletal muscle atrophy in cirrhotic rats by modulating the gut‑liver‑muscle axis

The gut‑liver‑muscle axis is associated with the development of sarcopenia in liver cirrhosis. The present study aimed to illustrate the combined effects of rifaximin and L‑carnitine on skeletal muscle atrophy in cirrhotic rats with steatohepatitis. For this purpose, a total of 344 Fischer rats were fed a choline‑deficient L‑amino acid‑defined (CDAA) diet with the daily oral administration of rifaximin (100 mg/kg) and/or L‑carnitine (200 mg/kg), and measurements of psoas muscle mass index and forelimb grip strength were performed. After feeding for 12 weeks, blood samples, and liver, ileum and gastrocnemius muscle tissues were harvested. The effects of L‑carnitine on rat myocytes were assessed using in vitro assays. Treatment with rifaximin attenuated hyperammonemia and liver fibrosis in the CDAA‑fed rats. Moreover, it improved intestinal permeability with the restoration of tight junction proteins and suppressed the lipopolysaccharide (LPS)‑mediated hepatic macrophage activation and pro‑inflammatory response. In addition, rifaximin prevented skeletal muscle mass atrophy and weakness by decreasing intramuscular myostatin and pro‑inflammatory cytokine levels. Moreover, rifaximin synergistically enhanced the L‑carnitine‑mediated improvement of skeletal muscle wasting by promoting the production of insulin‑like growth factor‑1 and mitochondrial biogenesis, resulting in the inhibition of the ubiquitin‑proteasome system (UPS). The in vitro assays revealed that L‑carnitine directly attenuated the impairment of mitochondrial biogenesis, thereby inhibiting the UPS in rat myocytes that were stimulated with LPS or tumor necrosis factor‑α. On the whole, the present study demonstrates that the combination of rifaximin with L‑carnitine may provide a clinical benefit for liver cirrhosis‑related sarcopenia.

Metabolite profile of COVID-19 revealed by UPLC-MS/MS-based widely targeted metabolomics

The metabolic characteristics of COVID-19 disease are still largely unknown. Here, 44 patients with COVID-19 (31 mild COVID-19 patients and 13 severe COVID-19 patients), 42 healthy controls (HC), and 42 patients with community-acquired pneumonia (CAP), were involved in the study to assess their serum metabolomic profiles. We used widely targeted metabolomics based on an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The differentially expressed metabolites in the plasma of mild and severe COVID-19 patients, CAP patients, and HC subjects were screened, and the main metabolic pathways involved were analyzed. Multiple mature machine learning algorithms confirmed that the metabolites performed excellently in discriminating COVID-19 groups from CAP and HC subjects, with an area under the curve (AUC) of 1. The specific dysregulation of AMP, dGMP, sn-glycero-3-phosphocholine, and carnitine was observed in the severe COVID-19 group. Moreover, random forest analysis suggested that these metabolites could discriminate between severe COVID-19 patients and mild COVID-19 patients, with an AUC of 0.921. This study may broaden our understanding of pathophysiological mechanisms of COVID-19 and may offer an experimental basis for developing novel treatment strategies against it.

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.

Survival benefit of L-carnitine supplementation in patients with cirrhosis

BACKGROUND

L-carnitine supplementation is effective in improving muscle cramps, hyperammonemia, and hepatic encephalopathy in patients with cirrhosis. However, limited evidence is available on the effect of L-carnitine supplementation on the survival of patients with cirrhosis.

METHODS

In this retrospective study, 674 patients with cirrhosis admitted to Gifu University Hospital or Chuno Kosei Hospital between October 2011 and December 2018 were enrolled. L-carnitine supplementation was defined as the use of L-carnitine for more than 30 consecutive days during the follow-up period. Propensity score matching was applied to create comparable groups between L-carnitine-treated and untreated patients. Mortality was evaluated using the Cox proportional hazards model.

RESULTS

Among the patients, 93 were excluded. Of the remaining 581 patients, 71 (12%) received L-carnitine supplementation. Propensity matching identified 189 patients (63 L-carnitine-treated and 126 untreated patients) with comparable baseline characteristics in both groups. Of the matched patients, 33 (52%) L-carnitine-treated and 74 (59%) untreated patients died during the median follow-up period of 36.3 months. Overall survival was significantly higher in L-carnitine-treated patients than in untreated patients (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.43-0.99). A subgroup analysis showed that the survival benefit of L-carnitine supplementation was prominent in patients with Child-Pugh class B or C (HR, 0.39; 95% CI, 0.23-0.68), albumin levels ≤3.5 g/dL (HR, 0.59; 95% CI, 0.37-0.95), and ammonia levels ≥90 μg/dL (HR, 0.50; 95% CI, 0.26-0.97) and those without sarcopenia (HR, 0.56; 95% CI, 0.35-0.90).

CONCLUSION

L-carnitine supplementation may improve survival in patients with cirrhosis.

CLINICAL RELEVANCY STATEMENT

Carnitine is a vitamin-like compound that regulates lipid and energy metabolism. Although it has been recognized that L-carnitine supplementation improves hyperammonemia, hepatic encephalopathy, sarcopenia, and frailty in patients with cirrhosis, the relationship between L-carnitine supplementation mortality remains unknown. The results of our study provide the first evidence that L-carnitine supplementation may improve survival in patients with cirrhosis. L-carnitine supplementation may shed a new light on the nutritional intervention for patients with cirrhosis. This article is protected by copyright. All rights reserved.

Grip Strength in Patients with Gastrointestinal Diseases

We sought to elucidate factors contributing to the grip strength (GS) decline in patients with gastrointestinal diseases (Ga-Ds, n = 602, 379 males, median age = 72 years). The GS decline in males and females was defined as <28 kg and <18 kg, respectively, following the current Asian guidelines. The median GS (male) was 28.8 kg, and GS decline (male) was found in 169 patients (44.6%). The median GS (female) was 17.5 kg, and GS decline (female) was found in 122 patients (54.7%). Advanced cancer was identified in 145 patients (24.1%). In terms of the univariate analysis of parameters of the GS decline, age (p < 0.0001), gender (p = 0.0181), body mass index (BMI, p = 0.0002), ECOG-PS (p < 0.0001), SARC-F score (p < 0.0001), hemoglobin value (p < 0.0001), total lymphocyte count (p < 0.0001), serum albumin value (p < 0.0001), C reactive protein (CRP) value (p < 0.0001), and estimated glomerular filtration rate were statistically significant. In terms of the multivariate analysis, age (p < 0.0001), BMI (p = 0.0223), hemoglobin value (p = 0.0186), serum albumin value (p = 0.0284), the SARC-F score (p = 0.0003), and CRP value (p < 0.0001) were independent parameters. In conclusion, the GS decline in patients with Ga-Ds is closely associated with not only the primary factor (i.e., aging) but also secondary factors such as inflammatory factors and nutritional factors.

Study of dose-dependent actoprotective effect of ATACL on physical performancend psychoemotional status of animals under exhausting exercise

Introduction: The aim of the study was to investigate the dose-dependent actoprotective effect of ATACL on physical performance and psychoemotional status of animals under conditions of exhausting exercise.

Materials and methods: Outbred male mice (23–25 g) were used in the experiment. The test compound in various dosages, as well as the reference drug, were administered intragastrically 60 minutes before the forced swimming test for 10 days of the experiment. At the end of the physical activity, the psychoemotional status of the animals was assessed in the Open Field (OF) and Elevated plus maze (EPM) tests.

Results and discussion: In the course of the experiment, it was found that under conditions of exhausting physical execise, a smooth increase in performance was observed in the group that had received the test compound 4-hydroxy-3,5-di-tert butyl cinnamic acid (ATACL) at a dosage of 100 mg/kg for 10 days. The peak of performance was recorded on the 8th day, which was 47.3% (p&lt;0.05) higher than the physical activity of the mice treated with the reference drug ethylthiobenzimidazole hydrobromide (EBH). When assessing changes in the Open Field test, it was found that the test compound ATACL at a dosage of 100 mg/kg is also a leader in stabilizing the psychoemotional status of the animals, which is reflected in the improvement of the motor activity (the number of sectors crossed by 4.7 times (p&lt; 0.05)), exploratory activity (an increase in the number of «peeps» and rearings by 8.5 times (p&lt;0.05) and 12.7 times (p&lt;0.05), respectively) and changes in the level of anxiety (a 2.5-time decrease in the number of short-term grooming acts (p&lt;0.05)) in comparison with the negative control (NC) group. The results obtained in the EPM test are completely consistent with the results of the OF test; the most pronounced activity was observed for the ATACL compound at a dosage of 100 mg/kg.

Conclusion: Based on the combination of reproducible methods, it can be concluded that the most pronounced actоprotective effect is exerted by the compound at a dosage of 100 mg/kg, not inferior, at the same time, to the reference drug EBН.

Graphical abstract:

The Role of l-Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation

Mitochondria control cellular fate by various mechanisms and are key drivers of cellular metabolism. Although the main function of mitochondria is energy production, they are also involved in cellular detoxification, cellular stabilization, as well as control of ketogenesis and glucogenesis. Conditions like neurodegenerative disease, insulin resistance, endocrine imbalances, liver and kidney disease are intimately linked to metabolic disorders or inflexibility and to mitochondrial dysfunction. Mitochondrial dysfunction due to a relative lack of micronutrients and substrates is implicated in the development of many chronic diseases. l-carnitine is one of the key nutrients for proper mitochondrial function and is notable for its role in fatty acid oxidation. l-carnitine also plays a major part in protecting cellular membranes, preventing fatty acid accumulation, modulating ketogenesis and glucogenesis and in the elimination of toxic metabolites. l-carnitine deficiency has been observed in many diseases including organic acidurias, inborn errors of metabolism, endocrine imbalances, liver and kidney disease. The protective effects of micronutrients targeting mitochondria hold considerable promise for the management of age and metabolic related diseases. Preventing nutrient deficiencies like l-carnitine can be beneficial in maintaining metabolic flexibility via the optimization of mitochondrial function. This paper reviews the critical role of l-carnitine in mitochondrial function, metabolic flexibility and in other pathophysiological cellular mechanisms.

Treatment of Muscle Cramps in Patients With Cirrhosis of Liver: A Systematic Review

BACKGROUND

Muscle cramps are witnessed in 22-88% of patients with cirrhosis of liver and frequently lead to sleep disturbance with an appalling impact on quality of life. Despite such a high prevalence, there is lack of evidence-based management protocol due to scarcity of trials on treatment options in the literature. This study aimed to review systematically the available therapeutic options for muscle cramps in patients with cirrhosis of liver.

METHODS

A systematic review of the relevant databases (PubMed, Scopus, Embase, and Web of Science) to identify treatments for muscle cramps in patients with hepatic cirrhosis was performed. Studies meeting the selection criteria were reviewed and assessed for risk of bias and analyzed.

RESULTS

Twenty-four publications were identified as eligible for inclusion in this systematic review. Seven randomized controlled trials (RCTs) and 17 prospective studies were included. Taurine, methocarbamol, baclofen, and orphenadrine are relatively safer and effective treatment option for muscle cramps in cirrhosis on the basis of recently conducted RCTs. Moreover, l-carnitine, branched-chain amino acids (BCAAs), pregabalin, zinc, and vitamin D are also safe and showed beneficial effects on muscle cramps. However, studies on vitamin E revealed contradictory results.

CONCLUSION

Taurine, BCAAs, orphenadrine, and baclofen are safe and well-tolerated treatment options for muscle cramps in cirrhosis. However, well-designed randomized controlled clinical trials are the need of the hour to determine the most suitable treatment options for skeletal muscle cramps in patients with cirrhosis of liver.

Effect of l-carnitine supplementation on lead acetate-induced liver cell apoptosis and inflammation: role of caspase-3 and glycogen synthase kinase-3β enzymes

AIM

The study aimed at studying the hepatoprotective effect of l-carnitine against lead (Pb) acetate-induced hepatocellular injury, emphasizing the role of caspase-3 and glycogen synthase kinase-3β in hepatocellular apoptosis and inflammation.

MATERIALS AND METHODS

Male Wistar rats were used. The experimental approach involved estimation of the liver enzymes' serum levels. Oxidative and inflammatory biomarkers were measured in hepatic tissue homogenates. Paraffin-embedded hepatic sections were prepared for histopathology and immunohistochemistry. Quantitative determination of the phosphorylated glycogen synthase kinase-3 beta was performed.

KEY FINDINGS

The serum showed a significant elevation in ALT, AST, and LDH; tissue homogenates showed significant elevation in lipid peroxide and inflammatory biomarkers with significant reduction in reduced glutathione in the Pb acetate-treated group. Co-administration of l-carnitine with Pb acetate produced significant reduction in liver enzymes with significant improvement in oxidant, antioxidant and inflammatory markers. Lead acetate treatment significantly reduced the phosphorylated glycogen synthase kinase-3 beta, while l-carnitine enhanced its phosphorylation. Histopathological examination showed inflammatory reaction around blood vessels with fatty degeneration in hepatocytes of the Pb acetate intoxicated group. l-Carnitine caused a decrease in hepatic damage with minimal vascular alterations in central vein. Caspase-3 expression in hepatocytes was decreased in Pb-treated group supplemented with l-carnitine.

SIGNIFICANCE

Our study reveals that oxidative stress and inflammation participate in Pb acetate-induced hepatocellular injury. Glycogen synthase kinase-3β and caspase-3 play role in Pb acetate-induced hepatic damage. l-Carnitine shows significant protective effects against hepatocellular apoptosis and inflammation induced by Pb acetate through antioxidant, anti-inflammatory and anti-apoptotic pathways in part mediated by GSK-3β inhibition.

Levocarnitine Supplementation Suppresses Lenvatinib-Related Sarcopenia in Hepatocellular Carcinoma Patients: Results of a Propensity Score Analysis

This study investigated the inhibitory effect of levocarnitine supplementation on sarcopenia progression in hepatocellular carcinoma (HCC) patients treated with lenvatinib. We evaluated the skeletal muscle index (SMI). After propensity score matching for age, sex, modified albumin-bilirubin grade, baseline presence of sarcopenia, and branched-chain amino acid administration, we selected 17 patients who received levocarnitine supplementation after starting lenvatinib therapy and 17 propensity-score-matched patients who did not receive levocarnitine. Sarcopenia was present in 76% of the patients at baseline. Changes in baseline SMI at 6 and 12 weeks of treatment were significantly suppressed in the group with levocarnitine supplementation compared with those without (p = 0.009 and p = 0.018, respectively). While there were no significant differences in serum free carnitine levels in cases without levocarnitine supplementation between baseline and after 6 weeks of treatment (p = 0.193), free carnitine levels were significantly higher after 6 weeks of treatment compared with baseline in cases with levocarnitine supplementation (p < 0.001). Baseline SMI and changes in baseline SMI after 6 weeks of treatment were significantly correlated with free carnitine levels (r = 0.359, p = 0.037; and r = 0.345, p = 0.045, respectively). Levocarnitine supplementation can suppress sarcopenia progression during lenvatinib therapy.

Change in Anemia by Carnitine Supplementation in Patients Undergoing Peritoneal Dialysis: A Retrospective Observational Study

Background: Carnitine supplementation improves various dialysis-related symptoms including erythropoietin-resistant anemia in patients who are undergoing hemodialysis. However, the utility of carnitine supplementation in patients who are undergoing peritoneal dialysis (PD) is not fully understood.

Methods: Thirteen patients undergoing PD [mean age: 54.2 ± 14.8 years, males: 9/13 (69%)] administered oral carnitine supplementation (mean dose: 9.1 ± 3.3 mg/kg/day) for 4–6 months were retrospectively investigated. Changes in serum carnitine levels and other clinical variables including the erythropoietin resistance index (ERI) were analyzed after carnitine supplementation.

Results: Carnitine supplementation increased serum total carnitine (48.5 ± 10.2 vs. 130.1 ± 37.2 μmol/L, P < 0.01), free carnitine (31.1 ± 8.3 vs. 83.1 ± 24.6 μmol/L, P < 0.01), and acyl carnitine (17.4 ± 2.8 vs. 46.9 ± 13.8, P < 0.01) levels. The acyl carnitine/free carnitine ratio was not affected (0.6 ± 0.1 vs. 0.6 ± 0.1, P = 0.75). Although the mean ERI was not affected by carnitine supplementation [13.7 ± 4.7 vs. 11.6 ± 3.4 IU/kg/(g/dL)/week, P = 0.28], the ERI change rate was significantly decreased (1.00 ± 0.00 vs. 0.87 ± 0.11, P < 0.01).

Conclusion: Carnitine supplementation may improve erythropoietin resistance in patients who are undergoing PD.

Influencing Factors and Molecular Pathogenesis of Sarcopenia and Osteosarcopenia in Chronic Liver Disease

The liver plays a pivotal role in nutrient/energy metabolism and storage, anabolic hormone regulation, ammonia detoxification, and cytokine production. Impaired liver function can cause malnutrition, hyperammonemia, and chronic inflammation, leading to an imbalance between muscle protein synthesis and proteolysis. Patients with chronic liver disease (CLD) have a high prevalence of sarcopenia, characterized by progressive loss of muscle mass and function, affecting health-related quality of life and prognosis. Recent reports have revealed that osteosarcopenia, defined as the concomitant occurrence of sarcopenia and osteoporosis, is also highly prevalent in patients with CLD. Since the differentiation and growth of muscles and bones are closely interrelated through mechanical and biochemical communication, sarcopenia and osteoporosis often progress concurrently and affect each other. Osteosarcopenia further exacerbates unfavorable health outcomes, such as vertebral fracture and frailty. Therefore, a comprehensive assessment of sarcopenia, osteoporosis, and osteosarcopenia, and an understanding of the pathogenic mechanisms involving the liver, bones, and muscles, are important for prevention and treatment. This review summarizes the molecular mechanisms of sarcopenia and osteosarcopenia elucidated to data in hopes of promoting advances in treating these musculoskeletal disorders in patients with CLD.

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.

Additional L-Carnitine Reduced the Risk of Hospitalization in Patients with Overt Hepatic Encephalopathy on Rifaximin

BACKGROUND

Data regarding the additional effect on the recurrence of hepatic encephalopathy (HE) after oral L-carnitine administration are scarce.

OBJECTIVE

This study aimed to assess the additional effects of L-carnitine in patients who were receiving rifaximin for HE.

METHODS

This randomized study comprised a screening visit and a 12-week treatment period. Patients who fulfilled the eligibility criteria were randomized to either group A (additional rifaximin) or group B (additional L-carnitine and rifaximin). Group A received 1,200 mg/day of rifaximin. Group B received 1,500 mg/day of L-carnitine and rifaximin at 1,200 mg/day. The endpoints were the changes in the portal systemic encephalopathy (PSE) index and the admission rate from the baseline for the duration of the study in both groups.

RESULTS

Eighty-three patients were randomized to either group A (n = 42) or group B (n = 41). In group A, the PSE index decreased from 0.35 ± 0.09 at baseline to 0.27 ± 0.11 on the final evaluation day (p = 0.001). In group B, the PSE index decreased from 0.37 ± 0.09 at baseline to 0.24 ± 0.11 on the final evaluation day (p = 0.001). Although there was not a significant reduction in the PSE index in group A compared to that in group B (p = 0.202), the admission rates were 30.9% and 9.8% in groups A and B, respectively. Additional L-carnitine significantly reduced the admission rate (p = 0.028).

CONCLUSION

L-Carnitine addition reduced the risk of hospitalization for patients who received rifaximin for HE.

Impact of Liver and Pancreas Diseases on Nutritional Status

Liver and pancreatic diseases have significant consequences on nutritional status, with direct effects on clinical outcomes, survival, and quality of life. Maintaining and preserving an adequate nutritional status is crucial and should be one of the goals of patients with liver or pancreatic disease. Thus, the nutritional status of such patients should be systematically assessed at follow-up. Recently, great progress has been made in this direction, and the relevant pathophysiological mechanisms have been better established. While the spectrum of these diseases is wide, and the mechanisms of the onset of malnutrition are numerous and interrelated, clinical and nutritional manifestations are common. The main consequences include an impaired dietary intake, altered macro and micronutrient metabolism, energy metabolism disturbances, an increase in energy expenditure, nutrient malabsorption, sarcopenia, and osteopathy. In this review, we summarize the factors contributing to malnutrition, and the effects on nutritional status and clinical outcomes of liver and pancreatic diseases. We explain the current knowledge on how to assess malnutrition and the efficacy of nutritional interventions in these settings.