Improvement of Nonalcoholic Fatty Liver Disease With Carnitine-Orotate Complex in Type 2 Diabetes (CORONA): A Randomized Controlled Trial

Intestinal-Failure-Associated Liver Disease: Beyond Parenteral Nutrition

Short bowel syndrome (SBS), usually resulting from massive small bowel resections or congenital defects, may lead to intestinal failure (IF), requiring intravenous fluids and parenteral nutrition to preserve patients' nutritional status. Approximately 15% to 40% of subjects with SBS and IF develop chronic hepatic damage during their life, a condition referred to as intestinal-failure-associated liver disease (IFALD), which ranges from steatosis to fibrosis or end-stage liver disease. Parenteral nutrition has been largely pointed out as the main pathogenetic factor for IFALD. However, other elements, such as inflammation, bile acid metabolism, bacterial overgrowth and gut dysbiosis also contribute to the development of liver damage and may deserve specific treatment strategies. Indeed, in our review, we aim to explore IFALD pathogenesis beyond parenteral nutrition. By critically analyzing recent literature, we seek to delve with molecular mechanisms and metabolic pathways underlying liver damage in such a complex set of patients.

Dual-layer spectral-detector CT for detecting liver steatosis by using proton density fat fraction as reference

OBJECTIVES

To evaluate the diagnostic accuracy of liver dual-layer spectral-detector CT (SDCT) derived parameters of liver parenchyma for grading steatosis with reference to magnetic resonance imaging-based proton density fat fraction (MRI-PDFF).

METHODS

Altogether, 320 consecutive subjects who underwent MRI-PDFF and liver SDCT examinations were recruited and prospectively enrolled from four Chinese hospital centers. Participants were classified into normal (n = 152), mild steatosis (n = 110), and moderate/severe(mod/sev) steatosis (n = 58) groups based on MRI-PDFF. SDCT liver parameters were evaluated using conventional polychromatic CT images (CTpoly), virtual mono-energetic images at 40 keV (CT40kev), the slope of the spectral attenuation curve (λ), the effective atomic number (Zeff), and liver to spleen attenuation ratio (L/S ratio). Linearity between SDCT liver parameters and MRI-PDFF was examined using Spearman correlation. Cutoff values for SDCT liver parameters in determining steatosis grades were identified using the area under the receiver-operating characteristic curve analyses.

RESULTS

SDCT liver parameters demonstrated a strong correlation with PDFF, particularly Zeff (rs = -0.856; p < 0.001). Zeff achieved an area under the curve (AUC) of 0.930 for detecting the presence of steatosis with a sensitivity of 89.4%, a specificity of 82.4%, and an AUC of 0.983 for detecting mod/sev steatosis with a sensitivity of 93.1%, a specificity of 93.5%, the corresponding cutoff values were 7.12 and 6.94, respectively. Zeff also exhibited good diagnostic performance for liver steatosis grading in subgroups, independent of body mass index.

CONCLUSION

SDCT liver parameters, particularly Zeff, exhibit excellent diagnostic accuracy for grading steatosis.

CRITICAL RELEVANCE STATEMENT

Dual-layer SDCT parameter, Zeff, as a more convenient and accurate imaging biomarker may serve as an alternative indicator for MRI-based proton density fat fraction, exploring the stage and prognosis of liver steatosis, and even metabolic risk assessment.

KEY POINTS

Liver biopsy is the standard for grading liver steatosis, but is limited by its invasive nature. The diagnostic performance of liver steatosis using SDCT-Zeff outperforms conventional CT parameters. SDCT-Zeff accurately and noninvasively assessed the grade of liver steatosis.

The Effects of L-Carnitine Supplementation on Weight Loss, Glycemic Control, and Cardiovascular Risk Factors in Patients With Type 2 Diabetes: A Systematic Review and Dose-response Meta-Analysis of Randomized Controlled Trials

PURPOSE

L-carnitine supplementation has been recommended to improve cardiometabolic health markers in diabetic patients. Our purpose was to assess the dose-dependent effects of l-carnitine supplementation on cardiometabolic risk factors in patients with type 2 diabetes.

METHODS

PubMed/Medline, Scopus, and Web of Science were searched until May 2022 for randomized controlled trials that examined the impact of l-carnitine supplementation on cardiometabolic risk factors in adults with type 2 diabetes. The mean difference (MD) and its 95% confidence interval (CI) were estimated utilizing a random-effects model. Nonlinear dose-response associations were modeled with restricted cubic splines. The certainty of evidence was rated using the GRADE approach.

FINDINGS

Twenty-one randomized trials with 2041 patients with type 2 diabetes were included. We found that every 1 g/d supplementation with l-carnitine significantly reduced body mass index (MD: -0.37 kg/m2, 95% CI: -0.59, -0.15; I2 =93%, n=13, GRADE=low), HbA1c (MD: -0.16%, 95% CI: -0.32, -0.01; I2 = 94%, n = 18, GRADE = moderate), and low-density lipoprotein cholesterol (MD: -0.11 mmol/L, 95% CI: -0.16, -0.05; I2 = 91%, n = 11, GRADE = high). There were also reductions in serum triglycerides (MD: 0.07 mmol/L), total cholesterol (MD: -0.13 mmol/L), and fasting plasma glucose (MD: -0.17 mmol/L). A U-shaped effect was demonstrated for body mass index, with the largest reduction at 2 g/d. A linear reduction was seen for serum triglycerides, total cholesterol, and fasting plasma glucose up to l-carnitine supplementation of 4 g/d.

IMPLICATIONS

L-carnitine supplementation resulted in a small reduction in serum lipids and plasma glucose in patients with type 2 diabetes. However, due to high statistical heterogeneity, the results should be interpreted very cautiously.

Insulin Resistance, Non-Alcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus: Clinical and Experimental Perspective

It has been generally accepted that insulin resistance (IR) and reduced insulin secretory capacity are the basic pathogenesis of type 2 diabetes mellitus (T2DM). In addition to genetic factors, the persistence of systemic inflammation caused by obesity and the associated threat of lipotoxicity increase the risk of T2DM. In particular, the main cause of IR is obesity and subjects with T2DM have a higher body mass index (BMI) than normal subjects according to recent studies. The prevalence of T2DM with IR has increased with increasing BMI during the past three decades. According to recent studies, homeostatic model assessment of IR was increased compared to that of the 1990s. Rising prevalence of obesity in Korea have contributed to the development of IR, non-alcoholic fatty liver disease and T2DM and cutting this vicious cycle is important. My colleagues and I have investigated this pathogenic mechanism on this theme through clinical and experimental studies over 20 years and herein, I would like to summarize some of our studies with deep gratitude for receiving the prestigious 2023 Sulwon Award.

The Effects of L-Carnitine Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-response Meta-analysis

PURPOSE

Hypertension stands as a prominent risk factor for cardiovascular disease, making it of utmost importance to address. Studies have shown that L-carnitine supplementation may lower blood pressure (BP) parameters in different populations. Therefore, we have conducted a systematic review and dose-response meta-analysis of published Randomized Controlled Trials (RCTs), including the most recent articles on the effect of L-carnitine supplementation on BP.

METHODS

PubMed, ISI Web of Science, Cochrane databases, and Scopus were used to collect RCT studies published up to October 2022 without limitations in language. Inclusion criteria were adult participants and recipients of L-carnitine in oral supplemental forms. The funnel plot test, Begg's test, and Egger's test were used to examine publication bias.

FINDINGS

After the search strategy, 22 RCTs (n = 1412) with 24 effect sizes fulfilled the criteria. It was found L-Carnitine supplementation did not have a significant effect on systolic blood pressure (SBP) (mm Hg) (weighted mean difference [WMD] = -1.22 mm Hg, 95% CI: -3.79, 1.35; P = 0.352; I2 = 85.0%, P < 0.001), and diastolic blood pressure (mm Hg) (WMD = -0.50 mm Hg, 95% CI: -1.49, 0.48; P = 0.318; I2 = 43.4%, P = 0.021) in the pooled analysis. Subgroup analyses have shown that L-carnitine supplementation had no lowering effect on SBP in any subgroup. However, there was a significant reduction in diastolic blood pressure in participants with a baseline body mass index >30 kg/m2 (WMD = -1.59 mm Hg; 95% CI: -3.11, -0.06; P = 0.041; I2 = 41.3%, P = 0.164). There was a significant nonlinear relationship between the duration of L-carnitine intervention and changes in SBP (coefficients = -6.83, P = 0.045).

IMPLICATIONS

L-carnitine supplementation in adults did not significantly affect BP. But anyway, more studies should be done in this field on different individuals.

Comparative effectiveness of multiple different treatment regimens for nonalcoholic fatty liver disease with type 2 diabetes mellitus: a systematic review and Bayesian network meta-analysis of randomised controlled trials

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are closely related and mutually contribute to the disease's development. There are many treatment options available to patients. We provide a comprehensive overview of the evidence on the treatment effects of several potential interventions for NAFLD with T2DM.

METHODS

This systematic review and network meta-analysis included searches of PubMed, Embase, Cochrane Library, and Web of Science from inception to June 30, 2023, for randomised controlled trials of treatment of NAFLD with T2DM. We performed Bayesian network meta-analyses to summarise effect estimates of comparisons between interventions. We applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) frameworks to rate all comparative outcomes' certainty in effect estimates, categorise interventions, and present the findings. This study was registered with PROSPERO, CRD42022342373.

RESULTS

Four thousand three hundred and sixty-nine records were retrieved from the database and other methods, of which 24 records were eligible for studies enrolling 1589 participants. Eight clinical indicators and 14 interventions were finally in focus. Referring to the lower surface under the cumulative ranking curves (SUCRA) and the league matrix table, exenatide and liraglutide, which are also glucagon-like peptide-1 receptor agonists (GLP-1RAs), showed excellent potential to reduce liver fat content, control glycemia, reduce body weight, and improve liver function and insulin resistance. Exenatide was more effective in reducing glycated haemoglobin (HbA1c) (mean difference (MD) 0.32, 95%CI 0.12 to 0.52), lowering BMI (MD 0.81, 95%CI 0.18 to 1.45), and lowering alanine transaminase (ALT) (MD 10.96, 95%CI 5.27 to 16.66) compared to liraglutide. However, this evidence was assessed as low certainty. Omega-3 was the only intervention that did not have a tendency to lower HbA1c, with standard-treatment (STA-TRE) as reference (MD - 0.17, 95%CI - 0.42 to 0.07). Glimepiride is the only intervention that causes an increase in ALT levels, with standard-treatment (STA-TRE) as reference (MD - 11.72, 95%CI - 17.82 to - 5.57). Based on the available evidence, the treatment effects of pioglitazone, dapagliflozin, and liraglutide have a high degree of confidence.

CONCLUSIONS

The high confidence mandates the confident application of these findings as guides for clinical practice. Dapagliflozin and pioglitazone are used for glycaemic control in patients with NAFLD combined with T2DM, and liraglutide is used for weight loss therapy in patients with abdominal obesity. The available evidence does not demonstrate the credibility of the effectiveness of other interventions in reducing liver fat content, visceral fat area, ALT, and insulin resistance. Future studies should focus on the clinical application of GLP-1Ras and the long-term prognosis of patients.

The effects of L-carnitine supplementation on inflammatory and anti-inflammatory markers in adults: a systematic review and dose-response meta-analysis

L-carnitine supplementation may be beneficial in improving inflammatory conditions and reducing the level of inflammatory cytokines. Therefore, according to the finding of randomized controlled trials (RCTs), the systematic review and meta-analysis aimed to investigate the effect of L-carnitine supplementation on inflammation in adults. To obtain acceptable articles up to October 2022, a thorough search was conducted in databases including PubMed, ISI Web of Science, the Cochrane Library, and Scopus. A random-effects model was used to estimate the weighted mean difference (WMD). We included the 48 RCTs (n = 3255) with 51 effect sizes in this study. L-carnitine supplementation had a significant effect on C-reactive protein (CRP) (p < 0.001), interleukin-6 (IL-6) (p = 0.001), tumor necrosis factor-α (TNF-α) (p = 0.002), malondialdehyde (MDA) (p = 0.001), total antioxidant capacity (TAC) (p = 0.029), alanine transaminase (ALT) (p < 0.001), and aspartate transaminase (AST) (p < 0.001) in intervention, compared to the placebo group. Subgroup analyses showed that L-carnitine supplementation had a lowering effect on CRP and TNF-α in trial duration ≥ 12 weeks in type 2 diabetes and BMI ≥ 25 kg/m2. L-carnitine supplementation reduced ALT levels in overweight and normal BMI subjects at any trial dose and trial duration ≥ 12 weeks and reduced AST levels in overweight subjects and trial dose ≥ 2 g/day. This meta-analysis revealed that L-carnitine supplementation effectively reduces the inflammatory state by increasing the level of TAC and decreasing the levels of CRP, IL-6, TNF-α and MDA in the serum.

The efficacy of L-carnitine in patients with nonalcoholic steatohepatitis and concomitant obesity

BACKGROUND

In light of the high prevalence of nonalcoholic fatty liver disease and obesity, treatment options for nonalcoholic steatohepatitis are of particular interest. The purpose of the study is to assess the efficacy of L-carnitine and its effects on the functional state of the liver, as well as on lipid and carbohydrate metabolism in patients with nonalcoholic steatohepatitis and concomitant obesity.

METHODS

People in the control group followed a hypocaloric diet and received 1 tablet of simvastatin 20 mg once a day and 2 capsules of essential phospholipids 600 mg three times a day for 90 days. People in the experimental group followed a hypocaloric diet and received 1 tablet of simvastatin 20 mg once a day and L-carnitine 10 mL orally two times a day for 90 days.

RESULTS

L-carnitine normalized the blood lipid profile of subjects, as demonstrated by a significant decrease in the blood levels of total cholesterol, triglycerides, low-density lipoproteins, atherogenic index, and insulin resistance. The use of L-carnitine in patients with nonalcoholic steatohepatitis and concomitant obesity contributes to the steady reduction of the main clinical and biochemical symptoms of nonalcoholic steatohepatitis.

CONCLUSIONS

L-carnitine produces positive effects on the blood lipid profile and carbohydrate metabolism.

Efficacy and safety of carnitine supplementation on NAFLD: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The efficacy and safety of L-carnitine supplementation on non-alcoholic fatty liver disease (NAFLD) are unclear. This systematic review and meta-analysis aimed to assess the efficacy and safety of L-carnitine supplementation on NAFLD.

METHODS

We searched in four databases (PubMed, Embase, Cochrane Library, and Web of Science) from inception to 1 November 2022 (updated on March 20, 2023) for potentially relevant records without language restrictions. We collected information on the first author, publication year, country, setting, study design, population characteristics, duration of follow-up, outcome variables of interest, and sources of funding. We used a modified Cochrane risk of bias tool to assess the risk of bias, used GRADE to assess the certainty of evidence, and used the Credibility of Effect Modification Analyses (ICEMAN) tool to assess the credibility of any apparent subgroup effect.

RESULTS

This systematic review and meta-analysis included eight eligible randomized controlled trials (RCTs). Compared to placebo, low certainty evidence show that L-carnitine supplementation significantly changes (reduced) more in AST levels and ALT levels (MD: - 26.38, 95%CI: - 45.46 to - 7.30), and moderate certainty evidence show that L-carnitine supplementation significantly changes (reduced) more in HDL cholesterol levels (MD: 1.14, 95%CI: 0.21 to 2.07) and triglyceride levels (MD: - 6.92, 95%CI: - 13.82 to - 0.03). Moderate credibility of ICEMAN results shows that L-carnitine supplementation has no difference in changes of AST and ALT levels in younger ones (MD: 0.5, 95%CI: - 0.70 to 1.70) but has significant changes (reduced) in adults (MD: - 20.3, 95%CI: - 28.62 to - 12.28) compared to placebo.

CONCLUSION

L-carnitine supplementation may improve liver function and regulate triglyceride metabolism in patients with NAFLD, and with no significant adverse effects.

Selective Hepatic Cbs Knockout Aggravates Liver Damage, Endothelial Dysfunction and ROS Stress in Mice Fed a Western Diet

Cystathionine-β-synthase (CBS) is highly expressed in the liver, and deficiencies in Cbs lead to hyperhomocysteinemia (HHCy) and disturbed production of antioxidants such as hydrogen sulfide. We therefore hypothesized that liver-specific Cbs deficient (LiCKO) mice would be particularly susceptible to the development of non-alcoholic fatty liver disease (NAFLD). NAFLD was induced by a high-fat high-cholesterol (HFC) diet; LiCKO and controls were split into eight groups based on genotype (con, LiCKO), diet (normal diet, HFC), and diet duration (12 weeks, 20 weeks). LiCKO mice displayed intermediate to severe HHCy. Plasma H₂O₂ was increased by HFC, and further aggravated in LiCKO. LiCKO mice fed an HFC diet had heavier livers, increased lipid peroxidation, elevated ALAT, aggravated hepatic steatosis, and inflammation. LiCKO mice showed decreased L-carnitine in the liver, but this did not result in impaired fatty acid oxidation. Moreover, HFC-fed LiCKO mice demonstrated vascular and renal endothelial dysfunction. Liver and endothelial damage correlated significantly with systemic ROS status. In conclusion, this study demonstrates an important role for CBS in the liver in the development of NAFLD, which is most probably mediated through impaired defense against oxidative stress.

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.

Functional foods and dietary supplements in the management of non-alcoholic fatty liver disease: A systematic review and meta-analysis

Objective

In this systematic review and meta-analysis, we aimed to clarify the overall effects of functional foods and dietary supplements in non-alcoholic fatty liver disease (NAFLD) patients.

Methods

Randomized controlled trials (RCTs) published in PubMed, ISI Web of Science, Cochrane library, and Embase from January 1, 2000 to January 31, 2022 were systematically searched to assess the effects of functional foods and dietary supplements in patients with NAFLD. The primary outcomes were liver-related measures, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatic fibrosis and steatosis, while the secondary outcomes included body mass index (BMI), waist circumference (WC), triacylglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). These indexes were all continuous variables, so the mean difference (MD) was used for calculating the effect size. Random-effects or fixed-effects models were used to estimate the mean difference (MD). The risk of bias in all studies was assessed with guidance provided in the Cochrane Handbook for Systematic Reviews of Interventions.

Results

Twenty-nine articles investigating functional foods and dietary supplements [antioxidants (phytonutrients and coenzyme Q10) = 18, probiotics/symbiotic/prebiotic = 6, fatty acids = 3, vitamin D = 1, and whole grain = 1] met the eligibility criteria. Our results showed that antioxidants could significantly reduce WC (MD: -1.28 cm; 95% CI: -1.58, -0.99, P < 0.05), ALT (MD: -7.65 IU/L; 95% CI: -11.14, -4.16, P < 0.001), AST (MD: -4.26 IU/L; 95% CI: -5.76, -2.76, P < 0.001), and LDL-C (MD: -0.24 mg/dL; 95% CI: -0.46, -0.02, P < 0.05) increased in patients with NAFLD but had no effect on BMI, TG, and TC. Probiotic/symbiotic/prebiotic supplementation could decrease BMI (MD: -0.57 kg/m2; 95% CI: -0.72, -0.42, P < 0.05), ALT (MD: -3.96 IU/L; 95% CI: -5.24, -2.69, P < 0.001), and AST (MD: -2.76; 95% CI: -3.97, -1.56, P < 0.0001) levels but did not have beneficial effects on serum lipid levels compared to the control group. Moreover, the efficacy of fatty acids for treating NAFLD was full of discrepancies. Additionally, vitamin D had no significant effect on BMI, liver transaminase, and serum lipids, while whole grain could reduce ALT and AST but did not affect serum lipid levels.

Conclusion

The current study suggests that antioxidant and probiotic/symbiotic/prebiotic supplements may be a promising regimen for NAFLD patients. However, the usage of fatty acids, vitamin D, and whole grain in clinical treatment is uncertain. Further exploration of the efficacy ranks of functional foods and dietary supplements is needed to provide a reliable basis for clinical application.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier: CRD42022351763.

The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis

Background and aims

Hyperglycemia and insulin resistance are concerns today worldwide. Recently, L-carnitine supplementation has been suggested as an effective adjunctive therapy in glycemic control. Therefore, it seems important to investigate its effect on glycemic markers.

Methods

PubMed, Scopus, Web of Science, and the Cochrane databases were searched in October 2022 for prospective studies on the effects of L-carnitine supplementation on glycemic markers. Inclusion criteria included adult participants and taking oral L-carnitine supplements for at least seven days. The pooled weighted mean difference (WMD) was calculated using a random-effects model.

Results

We included the 41 randomized controlled trials (RCTs) (n = 2900) with 44 effect sizes in this study. In the pooled analysis; L-carnitine supplementation had a significant effect on fasting blood glucose (FBG) (mg/dl) [WMD = -3.22 mg/dl; 95% CI, -5.21 to -1.23; p = 0.002; I ² = 88.6%, p < 0.001], hemoglobin A1c (HbA1c) (%) [WMD = -0.27%; 95% CI, -0.47 to -0.07; p = 0.007; I ² = 90.1%, p < 0.001] and homeostasis model assessment-estimate insulin resistance (HOMA-IR) [WMD = -0.73; 95% CI, -1.21 to -0.25; p = 0.003; I ² = 98.2%, p < 0.001] in the intervention compared to the control group. L-carnitine supplementation had a reducing effect on baseline FBG ≥100 mg/dl, trial duration ≥12 weeks, intervention dose ≥2 g/day, participants with overweight and obesity (baseline BMI 25-29.9 and >30 kg/m²), and diabetic patients. Also, L-carnitine significantly affected insulin (pmol/l), HOMA-IR (%), and HbA1c (%) in trial duration ≥12 weeks, intervention dose ≥2 g/day, and participants with obesity (baseline BMI >30 kg/m²). It also had a reducing effect on HOMA-IR in diabetic patients, non-diabetic patients, and just diabetic patients for insulin, and HbA1c. There was a significant nonlinear relationship between the duration of intervention and changes in FBG, HbA1c, and HOMA-IR. In addition, there was a significant nonlinear relationship between dose (≥2 g/day) and changes in insulin, as well as a significant linear relationship between the duration (weeks) (coefficients = -16.45, p = 0.004) of intervention and changes in HbA1C.

Conclusions

L-carnitine could reduce the levels of FBG, HbA1c, and HOMA-IR.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022358692.

Prolonged Use of Carnitine-Orotate Complex (Godex®) Is Associated with Improved Mortality: A Nationwide Cohort Study

Despite its hepatoprotective effects and favorable metabolic effects, the association between carnitine-orotate complex (Godex®) intake and mortality has never been investigated. We enrolled 13,413 adults who underwent national health examination and were prescribed the carnitine-orotate complex. Subjects were classified into three groups based on duration of using carnitine-orotate complex: <30, 30−180, and ≥180 days and were followed-up until 2019. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality were estimated using Cox proportional hazards regression. During the follow-up period, 708 deaths were documented. Adjusted HR of mortality was 0.69 (95% CI 0.51−0.92) in those who used carnitine-orotate complex for ≥180 days compared to those who used it for <30 days. Use of carnitine-orotate complex for ≥180 days was associated with significantly reduced mortality in individuals with metabolic risk factors such as obesity, metabolic syndrome, dyslipidemia, and fatty liver than the shorter period of use. A significant interaction was observed in individuals with type 2 diabetes (HR 0.43, 95% CI 0.29−0.63, p-value 0.001). In this nationwide study, longer use of carnitine-orotate complex was associated with improved mortality compared to a shorter period of use, and the risk reductions were prominent in individuals with metabolic risk factors.

Luteolin alleviates methionine-choline-deficient diet-induced non-alcoholic steatohepatitis by modulating host serum metabolome and gut microbiome

Background and purpose

Previous studies have indicated the protective effects of luteolin against non-alcoholic steatohepatitis (NASH), but the definite underlying mechanism still remains unclear. This study aimed to explore the metabolomic and metagenomic signatures of NASH with luteolin supplementation.

Experimental approach

Mice were fed with a methionine–choline-deficient (MCD) diet containing 0.05% luteolin for 6 weeks. NASH severity was determined based on the liver histological observations, serum and hepatic biochemical measurements. Targeted metabolomics was conducted to identify differential metabolites in mice serum. 16S rRNA sequencing was conducted to assess the gut microbiota composition and function in mice colon.

Results

In detail, luteolin treatment significantly alleviated MCD diet-induced hepatic lipid deposition, liver function damage, and oxidative stress. Targeted plasma metabolomics revealed that 5-hydroxyindole, LPE (0:0/22:5), indole 3-phosphate, and N-phenylacetylphenylalanine were remarkably elevated, and homogentisic acid, thiamine, KN-93, PC (16:1e/8, 9-EpETE), carnitine C9:1-OH, FFA (18:4) and carnitine C8:1 were significantly decreased in NASH group as compared to normal group, which could be profoundly reversed after luteolin treatment. 16S rRNA sequencing indicated that luteolin supplementation significantly increased Erysipelatoclostridium and Pseudomonas as well as decreased Faecalibaculum at genus level. Most importantly, a negative association between thiamine and Faecalibaculum was observed based on Spearman's correlation analysis, which may play an important role in the preventive effects of luteolin against NASH.

Conclusion

Collectively, luteolin may alleviate the NASH by modulating serum metabolome and gut microbiome, which supports its use as a dietary supplement for NASH prevention.

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.

Therapeutic mechanisms and beneficial effects of non-antidiabetic drugs in chronic liver diseases

The global burden of chronic liver disease (CLD) is substantial. Due to the limited indication of and accessibility to antiviral therapy in viral hepatitis and lack of effective pharmacological treatment in nonalcoholic fatty liver disease, the beneficial effects of antidiabetics and non-antidiabetics in clinical practice have been continuously investigated in patients with CLD. In this narrative review, we focused on non-antidiabetic drugs, including ursodeoxycholic acid, silymarin, dimethyl4,4'-dimethoxy-5,6,5',6'-dimethylenedixoybiphenyl-2,2'-dicarboxylate, L-ornithine L-aspartate, branched chain amino acids, statin, probiotics, vitamin E, and aspirin, and summarized their beneficial effects in CLD. Based on the antioxidant, anti-inflammatory properties, and regulatory functions in glucose or lipid metabolism, several non-antidiabetic drugs have shown beneficial effects in improving liver histology, aminotransferase level, and metabolic parameters and reducing risks of hepatocellular carcinoma and mortality, without significant safety concerns, in patients with CLD. Although the effect as the centerpiece management in patients with CLD is not robust, the use of these non-antidiabetic drugs might be potentially beneficial as an adjuvant or combined treatment strategy.

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.

Antioxidant for treatment of diabetic complications: A meta-analysis and systematic review

Antioxidants may provide a complementary treatment for patients with chronic diseases. Nevertheless, studies that have measured the effects of antioxidant on diabetes complications have provided conflicting results. This study aimed to elucidate the association between antioxidant and diabetic complications and to develop robust evidence for clinical decisions by systematic reviews and meta-analysis. PubMed, Embase, The Cochrane Library, Web of Science, Scopus databases were searched to collect clinical studies related to the efficacy of antioxidants in the treatment of diabetes complications from inception to May 5, 2021. Statistical meta-analyses were performed using the RevMan 5.4 software. Stata16 software was used to detect publication bias. The data of diabetic nephropathy (DN), diabetic nonalcoholic fatty liver disease (NAFLD), and diabetic periodontitis were collected to analyze the effect of antioxidant on diabetes and the above three complications. The meta-analysis results showed that antioxidant treatment was associated with significantly changes in the fasting plasma glucose (FPG) (standardized mean difference [SMD]: - 0.21 [95% confidence interval [CI]: - 0.33, -0.10], p < 0.001), hemoglobin A1c (HbA1c) (MD: - 0.41 [95% CI: - 0.63, -0.18], p < 0.001), total antioxidant capacity (TAC) (SMD: 0.44 [95% CI: 0.24, 0.63], p < 0.001) and malondialdehyde (MDA) (SMD: - 0.82 [95% CI: - 1.24, -0.41], p < 0.001) than the control group. Antioxidant supplements have the potential to treat three complications of diabetes. In conclusion, the meta-analysis results indicate that antioxidant treatment is effective clinically for diabetes mellitus and its complications.

Magnesium intake is inversely associated with risk of non-alcoholic fatty liver disease among American adults

PURPOSE

Human data are limited linking magnesium (Mg) intake to the risk of non-alcoholic fatty liver disease (NAFLD). We aimed to examine the association between Mg intake and the risk of NAFLD among young adults in the US with a 25-year follow-up.

METHODS

This study included 2685 participants from the Coronary Artery Risk Development in Young Adult (CARDIA) study. Diet and dietary supplements were assessed at baseline (1985-1986) and exam years 7 and 20 using an interview-based dietary history. NAFLD, defined as liver attenuation ≤ 51 Hounsfield Units excluding secondary causes of liver fat accumulation, was identified by non-contrast-computed tomography scanning at exam year 25. Multivariable-adjusted logistic regression model was used to examine the associations between cumulative average total intake of Mg (dietary plus supplemental) and NAFLD odds.

RESULTS

A total of 629 NAFLD cases were documented. After adjustment for potential confounders, an inverse association between total Mg intake and NAFLD odds was observed. Compared to participants in the lowest quintile of total Mg intake, the odds of NAFLD was 55% lower among individuals in the highest quintile [multivariable-adjusted odds ratio (OR) = 0.45, 95% confidence interval (CI) (0.23, 0.85), p for trend = 0.03]. Consistently, whole-grain consumption, a major dietary source of Mg, was inversely associated with NAFLD odds (p for trend = 0.02).

CONCLUSIONS

This study suggests that higher cumulative intake of Mg throughout adulthood is associated with lower odds of NAFLD in midlife. Future studies are needed to establish a possible causal relationship.

Carnitine Orotate Complex Ameliorates Insulin Resistance and Hepatic Steatosis Through Carnitine Acetyltransferase Pathway

BACKGROUND

Carnitine orotate complex (Godex) has been shown to decrease glycated hemoglobin levels and improve steatosis in patients with type 2 diabetes mellitus with non-alcoholic fatty liver disease. However, the mechanisms of Godex in glucose metabolism remain unclear.

METHODS

Male C57BL/6J mice were divided into four groups: normal-fat diet, high-fat diet, a high-fat diet supplemented with intraperitoneal injection of (500 mg or 2,000 mg/kg/day) Godex for 8 weeks. Computed tomography, indirect calorimetry, and histological analyses including electron microscopy of the liver were performed, and biochemical profiles and oral glucose tolerance test and insulin tolerance test were undertaken. Expressions of genes in the lipid and glucose metabolism, activities of oxidative phosphorylation enzymes, carnitine acetyltransferase, pyruvate dehydrogenase, and acetyl-coenzyme A (CoA)/CoA ratio were evaluated.

RESULTS

Godex improved insulin sensitivity and significantly decreased fasting plasma glucose, homeostatic model assessment for insulin resistance, steatosis, and gluconeogenesis, with a marked increase in fatty acid oxidation as well as better use of glucose in high-fat diet-fed mice. It preserved mitochondrial function and ultrastructure, restored oxidative phosphorylation enzyme activities, decreased acetyl-CoA/CoA ratio, and increased carnitine acetyltransferase content and pyruvate dehydrogenase activity. Carnitine acetyltransferase knockdown partially reversed the effects of Godex in liver and in vitro.

CONCLUSION

Godex improved insulin resistance and steatosis by regulating carnitine acetyltransferase in liver in high-fat diet-fed mice.

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.

Besifovir dipivoxil maleate: a novel antiviral agent with low toxicity and high genetic barriers for chronic hepatitis B

INTRODUCTION

Chronic hepatitis B is an important public health concern. Introduction of oral nucleos(t)ide analogs (NAs), inhibitors of hepatitis B virus (HBV) polymerase, was a milestone that lowered the high viral loads associated with an increased risk of liver-related complications.

AREAS COVERED

Although the currently available NAs are effective in suppressing viral replication, anti-HBV treatment in principle requires lifelong drug administration, and some patients have limitations such as the incidence of liver cancer and the likelihood of toxicities following long-term treatment despite viral suppression. Besifovir dipivoxil maleate (BSV), an oral nucleotide analog, is a prodrug that is metabolized to its active form. It has consistent and well-characterized pharmacokinetics in animals and human. In clinical studies, BSV exhibits significant and potent viral suppression of HBV replication with maintenance of antiviral efficacy for over 192 weeks without resistance, or renal and bone toxicities. Herein, the authors discuss the data of BSV and provide the reader with their expert opinion.

EXPERT OPINION

BSV is a newly developed antiviral agent against HBV. This new agent has strong antiviral activity with low toxicity and a high barrier to resistance. Because there is concern that patients treated with a high dose of BSV require carnitine supplementation, BSV with carnitine supplementation is recommended during antiviral therapy.

Nutritional supplementation for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of non-alcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases risks of liver cirrhosis, hepatocellular carcinoma, and the requirement for liver transplantation. Uncertainty surrounds relative benefits and harms of various nutritional supplements in NAFLD. Currently no nutritional supplement is recommended for people with NAFLD.

OBJECTIVES

• To assess the benefits and harms of different nutritional supplements for treatment of NAFLD through a network meta-analysis • To generate rankings of different nutritional supplements according to their safety and efficacy SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, the World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) for people with NAFLD, irrespective of method of diagnosis, age and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods whenever possible and calculated differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios with 95% credible intervals (CrIs) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included in the review a total of 202 randomised clinical trials (14,200 participants). Nineteen trials were at low risk of bias. A total of 32 different interventions were compared in these trials. A total of 115 trials (7732 participants) were included in one or more comparisons. The remaining trials did not report any of the outcomes of interest for this review. Follow-up ranged from 1 month to 28 months. The follow-up period in trials that reported clinical outcomes was 2 months to 28 months. During this follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. We did not calculate effect estimates for mortality because of sparse data (zero events for at least one of the groups in the trial). None of the trials reported that they measured overall health-related quality of life using a validated scale. The evidence is very uncertain about effects of interventions on serious adverse events (number of people or number of events). We are very uncertain about effects on adverse events of most of the supplements that we investigated, as the evidence is of very low certainty. However, people taking PUFA (polyunsaturated fatty acid) may be more likely to experience an adverse event than those not receiving an active intervention (network meta-analysis results: OR 4.44, 95% CrI 2.40 to 8.48; low-certainty evidence; 4 trials, 203 participants; direct evidence: OR 4.43, 95% CrI 2.43 to 8.42). People who take other supplements (a category that includes nutritional supplements other than vitamins, fatty acids, phospholipids, and antioxidants) had higher numbers of adverse events than those not receiving an active intervention (network meta-analysis: rate ratio 1.73, 95% CrI 1.26 to 2.41; 6 trials, 291 participants; direct evidence: rate ratio 1.72, 95% CrI 1.25 to 2.40; low-certainty evidence). Data were sparse (zero events in all groups in the trial) for liver transplantation, liver decompensation, and hepatocellular carcinoma. So, we did not perform formal analysis for these outcomes. The evidence is very uncertain about effects of other antioxidants (antioxidants other than vitamins) compared to no active intervention on liver cirrhosis (HR 1.68, 95% CrI 0.23 to 15.10; 1 trial, 99 participants; very low-certainty evidence). The evidence is very uncertain about effects of interventions in any of the remaining comparisons, or data were sparse (with zero events in at least one of the groups), precluding formal calculations of effect estimates. Data were probably because of the very short follow-up period (2 months to 28 months). It takes follow-up of 8 to 28 years to detect differences in mortality between people with NAFLD and the general population. Therefore, it is unlikely that differences in clinical outcomes are noted in trials providing less than 5 to 10 years of follow-up.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about effects of nutritional supplementation compared to no additional intervention on all clinical outcomes for people with non-alcohol-related fatty liver disease. Accordingly, high-quality randomised comparative clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (study design in which multiple interventions are trialed within large longitudinal cohorts of patients to gain efficiencies and align trials more closely to standard clinical practice) comparing interventions such as vitamin E, prebiotics/probiotics/synbiotics, PUFAs, and no nutritional supplementation. The reason for the choice of interventions is the impact of these interventions on indirect outcomes, which may translate to clinical benefit. Outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource utilisation measures including costs of intervention and decreased healthcare utilisation after minimum follow-up of 8 years (to find meaningful differences in clinically important outcomes).

Pharmacotherapy for Weight Loss in Cirrhosis and Liver Transplantation: Translating the Data and Underused Potential

BACKGROUND AND AIMS

Thirty percent of patients with cirrhosis are obese and the prevalence of obesity increases after transplant to >40% post-transplant. There are currently four weight loss medications approved by the FDA for treatment of obesity (orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide). The aim of this review was to investigate the data on the use of these weight loss medications and alternative medicines in patients with cirrhosis and in liver transplant recipients (LTRs).

APPROACH AND RESULTS

While there is paucity of data for these medications in patients with cirrhosis and LTRs, Liraglutide appears to be generally safe in view of its pharmacokinetic properties. Phentermine-topiramate seems to have the highest weight loss potential but special consideration should be given to neuropsychiatric disorders, cardiovascular comorbidities, and drug interactions. There are emerging data on use of alternative medicines for weight loss but more data are needed.

CONCLUSIONS

The use of weight loss medications is feasible in this patient population but the decision of which medication to prescribe should be individualized based on the degree of renal and hepatic impairment, other co-morbidities, and concomitant medications.

Efficacy and Safety of Biphenyl Dimethyl Dicarboxylate and Ursodeoxycholic Acid Combination in Chronic Hepatitis Related to Metabolic Syndrome Components

Backgrounds/Aims

Steatohepatitis related to metabolic syndrome is a chronic liver disease prevalent in patients not only with non-alcoholic steatohepatitis but also with alcoholic liver disease and chronic viral hepatitis. On the other hand, there is limited data on the effects of hepatotonic agents in these patients. Therefore, this study evaluated the efficacy of a combined hepatotonic agent in this population.

Methods

Thirty-three adults with chronic hepatitis and one or more components of metabolic syndrome were assigned randomly to receive biphenyl dimethyl dicarboxylate/ursodeoxycholic acid or a placebo for 24 weeks. The primary outcome was the normalization of ALT (≤40 U/L). The secondary outcomes were the change in controlled attenuation parameter, transient elastography, and Chronic Liver Disease Questionnaire score.

Results

The 33 patients were assigned randomly to two groups. Eight (50%) of 16 patients who received the intervention drug showed the normalization of ALT, whereas only one (6%) of 17 patients in the placebo group did so. In contrast, the change in controlled attenuation, transient elastography, and Chronic Liver Disease Questionnaire were similar in the two groups. ALT was changed significantly during the four assessment periods, and this change was affected by the group. The interaction between the group and time was also significant. AST was changed significantly during the same period. This change was not affected by the group.

Conclusions

Biphenyl dimethyl dicarboxylate/ursodeoxycholic acid combination reduced ALT in chronic liver disease related to metabolic syndrome. On the other hand, there is no evidence that this leads to improved hepatic steatosis and fibrosis within 6 months.

L-carnitine treatment attenuates renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction

BACKGROUND/AIMS

Accumulating evidence indicates that L-carnitine (LC) protects against multiorgan damage through its antioxidant properties and preservation of the mitochondria. Little information is available about the effects of LC on renal fibrosis. This study examined whether LC treatment would provide renoprotection in a rat model of unilateral ureteral obstruction (UUO) and in vitro.

METHODS

Sprague-Dawley rats that underwent UUO were treated daily with LC for 7 or 14 days. The influence of LC on renal injury caused by UUO was evaluated by histopathology, and analysis of gene expression, oxidative stress, mitochondrial function, programmed cell death, and phosphatidylinositol 3-kinase (PI3K)/ AKT/forkhead box protein O 1a (FoxO1a) signaling. In addition, H2O2-exposed human kidney cells (HK-2) were treated with LC.

RESULTS

LC treatment inhibited expression of proinflammatory and profibrotic cytokines, and was followed by a significant attenuation of tubulointerstitial inflammation and fibrosis. The increased oxidative stress caused by UUO was associated with mitochondrial dysfunction and excessive apoptosis and autophagy via PI3K/AKT/FoxO1a-dependent signaling, and this was abrogated by administration of LC. In H2O2-exposed HK-2 cells, LC decreased intracellular production of reactive oxygen species, and suppressed expression of profibrotic cytokines and reduced the number of apoptotic cells.

CONCLUSION

LC protects against the progression of tubulointerstitial fibrosis in an obstructed kidney.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

The effects of L-carnitine supplementation on lipid concentrations inpatients with type 2 diabetes: A systematic review and meta-analysis of randomized clinical trials

This meta-analysis was performed to assess the effect of L-carnitine supplementation on lipid profile. A systematic search were conducted in PubMed and Scopus to identify randomized clinical trials (RCTs) which evaluated the effects of L-carnitine on lipid profile. Pooled effect sizes were measured using random-effect model (Dersimonian-Laird). Meta-analysis showed that L-carnitine supplementation significantly reduced total cholesterol (TC) (weighted mean difference [WMD]: -8.17 mg/dL; 95% CI,-14.68 to -1.65, I²=52.2%, P = 0.041). Baseline level of TC was a source of heterogeneity, with a greater effect in studies with a baseline level of more than 200 mg/d (WMD: -11.93 mg/dL; 95% CI, -20.80 to-3.05). L-carnitine also significantly decreased low-density lipoprotein-cholesterol (LDL-C) (WMD:-5.22 mg/dL; 95% CI, -9.54 to -0.91, I²=66.7%, P = 0.010), and LDL-C level <100 mg/dL), trial duration,and L-carnitine dosage were potential sources of heterogeneity. L-carnitine supplementation appeared to have no significant effect on high-density lipoprotein-cholesterol (HDL-C) (WMD: -0.51 mg/dL;95% CI, -2.45 to 1.44) and triglyceride (TG) (WMD: 2.80 mg/dL; 95% CI, -8.09 to 13.69). This meta-analysisrevealed that L-carnitine may have favorable effects on lipid profile, especially LDL-C and TC. However, further RCTs are needed to confirm the veracity of these results, particularly among hyperlipidemic patients.

ESPEN practical guideline: Clinical nutrition in liver disease

BACKGROUND

The Practical guideline is based on the current scientific ESPEN guideline on Clinical Nutrition in Liver Disease.

METHODS

It has been shortened and transformed into flow charts for easier use in clinical practice. The guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with chronic liver disease.

RESULTS

A total of 103 statements and recommendations are presented with short commentaries for the nutritional and metabolic management of patients with (i) acute liver failure, (ii) alcoholic steatohepatitis, (iii) non-alcoholic fatty liver disease, (iv) liver cirrhosis, and (v) liver surgery/transplantation. The disease-related recommendations are preceded by general recommendations on the diagnostics of nutritional status in liver patients and on liver complications associated with medical nutrition.

CONCLUSION

This practical guideline gives guidance to health care providers involved in the management of liver disease to offer optimal nutritional care.

Development and Validation of a Simple Index Based on Non-Enhanced CT and Clinical Factors for Prediction of Non-Alcoholic Fatty Liver Disease

OBJECTIVE

A widely applicable, non-invasive screening method for non-alcoholic fatty liver disease (NAFLD) is needed. We aimed to develop and validate an index combining computed tomography (CT) and routine clinical data for screening for NAFLD in a large cohort of adults with pathologically proven NAFLD.

MATERIALS AND METHODS

This retrospective study included 2218 living liver donors who had undergone liver biopsy and CT within a span of 3 days. Donors were randomized 2:1 into development and test cohorts. CTL-S was measured by subtracting splenic attenuation from hepatic attenuation on non-enhanced CT. Multivariable logistic regression analysis of the development cohort was utilized to develop a clinical-CT index predicting pathologically proven NAFLD. The diagnostic performance was evaluated by analyzing the areas under the receiver operating characteristic curve (AUC). The cutoffs for the clinical-CT index were determined for 90% sensitivity and 90% specificity in the development cohort, and their diagnostic performance was evaluated in the test cohort.

RESULTS

The clinical-CT index included CT_L-S, body mass index, and aspartate transaminase and triglyceride concentrations. In the test cohort, the clinical-CT index (AUC, 0.81) outperformed CTL-S (0.74; p < 0.001) and clinical indices (0.73-0.75; p < 0.001) in diagnosing NAFLD. A cutoff of ≥ 46 had a sensitivity of 89% and a specificity of 41%, whereas a cutoff of ≥ 56.5 had a sensitivity of 57% and a specificity of 89%.

CONCLUSION

The clinical-CT index is more accurate than CTL-S and clinical indices alone for the diagnosis of NAFLD and may be clinically useful in screening for NAFLD.

Efficacy of Dietary Supplements to Reduce Liver Fat

Liver fat accumulation is an important pathophysiological feature of non-alcoholic fatty liver disease that may be modulated by dietary supplements (DS). A systematic search of the literature was conducted for randomized controlled trials (RCTs) pertaining to the effect of a DS on liver fat as assessed using quantitative tomographic imaging in human adults. Where feasible, data were pooled, and meta-analyses conducted using random-effect model. Quality assessment was done according the Cochrane Collaboration's tool for assessing risk of bias. Twenty RCTs, involving 1171 overweight and obese adults, of which 36% were females, with or without comorbidities, were included. Only RCTs assessing omega-3 fatty acids (n = 4) and resveratrol (n = 4) qualified for meta-analysis. Results did neither favor omega-3 (effect size -1.17; weighted mean difference (WMD) (95% confidence interval (CI)) -3.62, 1.28; p < 0.001) nor resveratrol supplementation (0.18; 95% CI -1.08, 1.43; p = 0.27). The findings of the qualitatively summarized RCTs suggested that catechins (n = 1), Lactobacillus reuteri (n = 1), and carnitine (n = 1) may reduce liver fat. All other DS did not show any influence. The current evidence is scarce, of limited quality and does not support DS use to reduce liver fat. Further well-designed trials are warranted.

The Importance of the Fatty Acid Transporter L-Carnitine in Non-Alcoholic Fatty Liver Disease (NAFLD)

L-carnitine transports fatty acids into the mitochondria for oxidation and also buffers excess acetyl-CoA away from the mitochondria. Thus, L-carnitine may play a key role in maintaining liver function, by its effect on lipid metabolism. The importance of L-carnitine in liver health is supported by the observation that patients with primary carnitine deficiency (PCD) can present with fatty liver disease, which could be due to low levels of intrahepatic and serum levels of L-carnitine. Furthermore, studies suggest that supplementation with L-carnitine may reduce liver fat and the liver enzymes alanine aminotransferase (ALT) and aspartate transaminase (AST) in patients with Non-Alcoholic Fatty Liver Disease (NAFLD). L-carnitine has also been shown to improve insulin sensitivity and elevate pyruvate dehydrogenase (PDH) flux. Studies that show reduced intrahepatic fat and reduced liver enzymes after L-carnitine supplementation suggest that L-carnitine might be a promising supplement to improve or delay the progression of NAFLD.

Effect of L-Carnitine Supplementation on Lipid Profiles of Patients with Liver Disease: A Systematic Review and Meta-Analysis

Results of previous studies regarding the effect of L-carnitine on lipid profiles in the patients with liver diseases are contradictory. This meta-analysis was performed to assess the effect of L-carnitine on serum levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and total cholesterol (TC) in overweight patients with liver diseases. A systematic search was carried out using the Web of Science, PubMed, Scopus, and Cochrane library databases to identify articles published before April 2019 investigating the effects of L-carnitine supplementation on patients with liver disease. There was no language or time limitation for the studies. A meta-analysis was carried out using both the random and fixed effects model where appropriate, and I2 index were used to evaluate heterogeneity. These results indicated that L-carnitine supplementation significantly reduces blood levels of TC and TG in patients with liver disease, whereas carnitine had no effect on the levels of HDL and LDL. The reducing effect of L-carnitine on both TC and TG was found following long-term carnitine supplementation (≥24 weeks), supplementation with doses less than or equal to 2,000 mg/d, and in patients with chronic hepatitis C. This meta-analysis indicates the beneficial effect of L-carnitine on TC and TG in overweight patients with liver disease, particularly patients with chronic hepatitis C, in both long-term and low doses.

Molecular mechanisms of hepatic insulin resistance in nonalcoholic fatty liver disease and potential treatment strategies

The prevalence of nonalcoholic fatty liver disease (NAFLD) in the general population is estimated at 25 %, and there is currently no effective treatment of NAFLD. Although insulin resistance (IR) is not the only factor causing the pathogenesis of NAFLD, hepatic IR has a cause-effective relationship with NAFLD. Improving hepatic IR is a potential therapeutic strategy to treat NAFLD. This review highlights the molecular mechanisms of hepatic IR in the development of NAFLD. Available data on potential drugs including glucagon-like peptide 1 receptor (GLP-1) agonists, peroxisome proliferator-activated receptor (PPAR-γ/α/δ) agonists, farnesoid X receptor (FXR) agonists, etc. are carefully discussed.

Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus: A Position Statement of the Fatty Liver Research Group of the Korean Diabetes Association

This clinical practice position statement, a product of the Fatty Liver Research Group of the Korean Diabetes Association, proposes recommendations for the diagnosis, progression and/or severity assessment, management, and follow-up of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). Patients with both T2DM and NAFLD have an increased risk of non-alcoholic steatohepatitis (NASH) and fibrosis and a higher risk of cardiovascular diseases and diabetic complications compared to those without NAFLD. With regards to the evaluation of patients with T2DM and NAFLD, ultrasonography-based stepwise approaches using noninvasive biomarker models such as fibrosis-4 or the NAFLD fibrosis score as well as imaging studies such as vibration-controlled transient elastography with controlled attenuation parameter or magnetic resonance imaging-proton density fat fraction are recommended. After the diagnosis of NAFLD, the stage of fibrosis needs to be assessed appropriately. For management, weight reduction achieved by lifestyle modification has proven beneficial and is recommended in combination with antidiabetic agent(s). Evidence that some antidiabetic agents improve NAFLD/NASH with fibrosis in patients with T2DM is emerging. However, there are currently no definite pharmacologic treatments for NAFLD in patients with T2DM. For specific cases, bariatric surgery may be an option if indicated.

TMAVA, a Metabolite of Intestinal Microbes, Is Increased in Plasma From Patients With Liver Steatosis, Inhibits γ-Butyrobetaine Hydroxylase, and Exacerbates Fatty Liver in Mice

BACKGROUND & AIMS

Nonalcoholic fatty liver disease is characterized by excessive hepatic accumulation of triglycerides. We aimed to identify metabolites that differ in plasma of patients with liver steatosis vs healthy individuals (controls) and investigate the mechanisms by which these might contribute to fatty liver in mice.

METHODS

We obtained blood samples from 15 patients with liver steatosis and 15 controls from a single center in China (discovery cohort). We performed untargeted liquid chromatography with mass spectrometry analysis of plasma to identify analytes associated with liver steatosis. We then performed targeted metabolomic analysis of blood samples from 2 independent cohorts of individuals who underwent annual health examinations in China (1157 subjects with or without diabetes and 767 subjects with or without liver steatosis; replication cohorts). We performed mass spectrometry analysis of plasma from C57BL/6J mice, germ-free, and mice given antibiotics. C57BL/6J mice were given 0.325% (m/v) N,N,N-trimethyl-5-aminovaleric acid (TMAVA) in their drinking water and placed on a 45% high-fat diet (HFD) for 2 months. Plasma, liver tissues, and fecal samples were collected; fecal samples were analyzed by 16S ribosomal RNA gene sequencing. C57BL/6J mice with CRISPR-mediated disruption of the gene encoding γ-butyrobetaine hydroxylase (BBOX-knockout mice) were also placed on a 45% HFD for 2 months. Hepatic fatty acid oxidation (FAO) in liver tissues was determined by measuring liberation of ³H₂O from [³H] palmitic acid. Liver tissues were analyzed by electron microscopy, to view mitochondria, and proteomic analyses. We used surface plasmon resonance analysis to quantify the affinity of TMAVA for BBOX.

RESULTS

Levels of TMAVA, believed to be a metabolite of intestinal microbes, were increased in plasma from subjects with liver steatosis compared with controls, in the discovery and replication cohorts. In 1 replication cohort, the odds ratio for fatty liver in subjects with increased liver plasma levels of TMAVA was 1.82 (95% confidence interval [CI], 1.14-2.90; P = .012). Plasma from mice given antibiotics or germ-free mice had significant reductions in TMAVA compared with control mice. We found the intestinal bacteria Enterococcus faecalis and Pseudomonas aeruginosa to metabolize trimethyllysine to TMAVA; levels of trimethyllysine were significantly higher in plasma from patients with steatosis than controls. We found TMAVA to bind and inhibit BBOX, reducing synthesis of carnitine. Mice given TMAVA had alterations in their fecal microbiomes and reduced cold tolerance; their plasma and liver tissue had significant reductions in levels of carnitine and acyl-carnitine and their hepatocytes had reduced mitochondrial FAO compared with mice given only an HFD. Mice given TMAVA on an HFD developed liver steatosis, which was reduced by carnitine supplementation. BBOX-knockout mice had carnitine deficiency and decreased FAO, increasing uptake and liver accumulation of free fatty acids and exacerbating HFD-induced fatty liver.

CONCLUSIONS

Levels of TMAVA are increased in plasma from subjects with liver steatosis. In mice, intestinal microbes metabolize trimethyllysine to TMAVA, which reduces carnitine synthesis and FAO to promote steatosis.

L-carnitine supplementation in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) dominates the landscape of modern hepatology. Affecting 25% of the general population, there is critical unmet need to identify broadly available, safe and cost-effective treatments. Cumulative evidence in animal and human models suggests that intrahepatic and skeletal muscle fatty acid oxidation is impaired in NAFLD, such that lipid accretion is not matched by efficient utilisation. L-carnitine is a crucial mediator of fatty acid metabolism in vivo, promoting mitochondrial lipid β-oxidation and enhancing tissue metabolic flexibility. These physiological properties have generated research interest in L-carnitine as a potentially effective adjunctive therapy in NAFLD.

AIM

To systematically review randomised trials reporting effects of dietary L-carnitine supplementation on liver biochemistry, liver fat and insulin sensitivity in NAFLD.

METHODS

Search strategies, eligibility criteria and analytic methods were specified a priori (PROSPERO reference: CRD42018107063). Ovid MEDLINE, Ovid EMBASE, PubMed, Web of Science and the Cochrane Library were searched from their inception until April 2019. Outcome measures included serum concentrations of alanine and aspartate aminotransferase (ALT and AST), liver fat and insulin sensitivity assessed by the homeostasis model of insulin resistance (HOMA-IR). A random effects meta-analysis was performed for, ALT, AST and HOMA-IR measures separately. Between-study heterogeneity was measured using I² statistics.

RESULTS

Five eligible randomised trials were included in the qualitative and quantitative synthesis (n = 338). All of the 5 included trials assessed the effect of L-carnitine on serum ALT, identified from Italy, South Korea and Iran. Weighted mean difference (WMD) for ALT between L-carnitine and control groups after intervention was -25.34 IU/L [95%CI: -41.74-(-8.94); P = 0.002]. WMD for AST between L-carnitine and control groups was -13.68 IU/L (95%CI: -28.26-0.89; P = 0.066). In three studies (n = 204), HOMA-IR was evaluated. WMD for HOMA-IR between L-carnitine and control groups was -0.74 units [95%CI: -1.02-(-0.46); P < 0.001]. Two studies using validated outcome measures reported a significant reduction in liver fat in L-carnitine vs control groups post-intervention (P < 0.001).

CONCLUSION

Pooled results indicate that L-carnitine supplementation attenuates ALT, liver fat and insulin resistance in NAFLD cohorts, confirming a beneficial effect of L-carnitine for a highly prevalent condition with a growing economic burden.

The effects of carnitine supplementation on clinical characteristics of patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The beneficial effects of carnitine supplementation on nonalcoholic fatty liver disease are unclear. We conducted a systematic review and meta-analysis to evaluate the effects of carnitine supplementation on liver function, lipid profile, body mass index, body weight, and homeostasis model assessment of insulin resistance in patients with nonalcoholic fatty liver disease.

METHODS

A comprehensive search of PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar databases were performed. Only randomized placebo-controlled human studies that examined the effects of carnitine supplementation on liver function, lipid profile, body mass index, body weight, and homeostasis model assessment of insulin resistance up to September 2019 were included. Fixed effects or random-effects models were applied to compute the pooled effect size. Heterogeneity assessments were performed using Cochran's Q test and I-squared statistics. The quality of the studies was assessed using the Jaded scale.

RESULTS

A total of 5 articles were selected, including 334 individuals (167 in control and 167 in intervention groups). The results demonstrated that carnitine supplementation significantly reduced homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.91; 95 % CI: -1.11, -0.72; p < 0.001, I² = 0.0 %) and the levels of aspartate aminotransferase (AST) (WMD: -16.62; 95 % CI: -28.11, -5.14; IU/l; p = 0.005, I² = 93.5 %), alanine aminotransferase (ALT) (WMD: -33.39; 95 % CI: -45.13, -21.66; IU/l; p < 0.001, I² = 93.4 %), and triglycerides (TG) (WMD: -22.13; 95 % CI: -38.91, -5.34; mg/dl; p = 0.01; I² = 0.0 %). However, the results of the pooled effect size did not show any significant effect of carnitine supplementation on body mass index (BMI) (WMD: 0.07; 95 % CI: -0.15, 0.29; p = 0.55; I² = 0.0 %), body weight (WMD: -0.28; 95 % CI: -2.23, 1.68; p = 0.78; I² = 45.7 %), the levels of gamma-glutamyl transferase (γGT) (WMD: -11.31; 95 % CI: -24.35, 1.73; IU/l; p = 0.09, I² = 61.1 %), cholesterol (WMD: -13.58; 95 % CI: -46.77, 19.60; mg/dl; p = 0.42; I² = 94.9 %), high-density lipoprotein-cholesterol (HDL-C) (WMD: 1.36; 95 % CI: -0.96, 3.68; mg/dl; p = 0.25; I² = 64.7 %), and low density lipoprotein-cholesterol (LDL-C) (WMD: -14.85; 95 % CI: -45.43, 15.73; mg/dl; p = 0.34; I² = 96.4 %).

CONCLUSIONS

This analysis shows that carnitine supplementation for patients with nonalcoholic fatty liver disease demonstrates a reduction in AST, ALT, TG levels and HOMA-IR. However, no significant effect of carnitine supplementation was observed on BMI, body weight, the levels of γGT, TC, HDL-cholesterol and LDL-cholesterol.

The Effects of L-Carnitine Supplementation on Serum Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background:

The findings of trials investigating the effects of L-carnitine administration on serum lipids are inconsistent. This meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effects of L-carnitine intake on serum lipids in patients and healthy individuals.

Methods:

Two authors independently searched electronic databases including MEDLINE, EMBASE, Cochrane Library, Web of Science, PubMed and Google Scholar from 1990 until August 1, 2019, in order to find relevant RCTs. The quality of selected RCTs was evaluated using the Cochrane Collaboration risk of bias tool. Cochrane’s Q test and I-square (I2) statistic were used to determine the heterogeneity across included trials. Weight mean difference (SMD) and 95% CI between the two intervention groups were used to determine pooled effect sizes. Subgroup analyses were performed to evaluate the source of heterogeneity based on suspected variables such as, participant’s health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location between primary RCTs.

Results:

Out of 3460 potential papers selected based on keywords search, 67 studies met the inclusion criteria and were eligible for the meta-analysis. The pooled results indicated that L-carnitine administration led to a significant decrease in triglycerides (WMD: -10.35; 95% CI: -16.43, -4.27), total cholesterol (WMD: -9.47; 95% CI: - 13.23, -5.70) and LDL-cholesterol (LDL-C) concentrations (WMD: -6.25; 95% CI: -9.30, -3.21), and a significant increase in HDL-cholesterol (HDL-C) levels (WMD: 1.39; 95% CI: 0.21, 2.57). L-carnitine supplementation did not influence VLDL-cholesterol concentrations. When we stratified studies for the predefined factors such as dosage, and age, no significant effects of the intervention on triglycerides, LDL-C, and HDL-C levels were found.

Conclusion:

This meta-analysis demonstrated that L-carnitine administration significantly reduced triglycerides, total cholesterol and LDL-cholesterol levels, and significantly increased HDL-cholesterol levels in the pooled analyses, but did not affect VLDL-cholesterol levels; however, these findings were not confirmed in our subgroup analyses by participant’s health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location.

Differing Associations between Fatty Liver and Dyslipidemia According to the Degree of Hepatic Steatosis in Korea

Objective

Fatty liver is associated with insulin resistance-related diseases, such as dyslipidemia, obesity, and type 2 diabetes. The aim of this study was to evaluate the association of dyslipidemia with fatty liver and assess the differences in these associations according to the degree of hepatic steatosis.

Methods

A total of 2,462 subjects (1,679 men and 783 women) who underwent a comprehensive health check-up (including abdominal computed tomography) from January 2010 to December 2013 were enrolled at Samsung Changwon Hospital Healthcare Center. The liver attenuation index (LAI), defined as the difference between mean hepatic and splenic attenuation, was used to assess the degree of hepatic steatosis. An LAI below 5 Hounsfield units was defined as fatty liver.

Results

We found that 32.2% of the study subjects had fatty liver. Serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG), and fasting blood glucose concentrations and glycated hemoglobin (HbA1c percentage) were significant greater in the fatty liver group compared with the non-fatty liver group, while serum high-density lipoprotein cholesterol (HDL-C) was significantly lower in the fatty liver group. Subjects with fatty liver had 1.7-fold greater risk of dyslipidemia than those without fatty liver after adjusting for age, sex, body mass index (BMI), and HbA1c. When individuals with fatty liver were analyzed by tertiles of LAI values, LDL-C, TG, fasting glucose, BMI, and HbA1c concentrations increased while HDL-C decreased with decreasing LAI tertiles. Compared with LAI tertile 3, the risk for dyslipidemia significantly increased with adjusted odds ratios of 1.42, and 1.81 in tertiles 2 and 1, respectively.

Conclusion

Fatty liver was significantly associated with dyslipidemia and this association varied according to the degree of hepatic steatosis.

The effects of L-carnitine supplementation on glycemic control: a systematic review and meta-analysis of randomized controlled trials

The findings of trials investigating the effect of L-carnitine administration on glycemic control are controversial. This meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of L-carnitine intake on glycemic control. Two authors independently searched electronic databases including MEDLINE, EMBASE, Cochrane Library, Web of Science, PubMed and Google scholar from 1990 until February 2019, in order to find relevant RCTs. 37 studies with 44 effect sizes met the inclusion criteria and were eligible for the meta-analysis. L-carnitine supplementation resulted in a significant reduction in fasting plasma glucose (FPG) (WMD: -4.57; 95 % CI: -6.88, -2.25), insulin (WMD: -1.21; 95 % CI: -1.85, -0.57), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: -0.67; 95 % CI: -0.90, -0.44) and HbA1C concentrations (WMD: -0.30; 95 % CI: -0.47, -0.13). L-Carnitine supplementation significantly reduced FPG, insulin, HOMA-IR, and HbA1c 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.

Feasibility of non-enhanced CT for assessing longitudinal changes in hepatic steatosis

To evaluate the feasibility of computed tomography (CT) in the assessment of the change in hepatic steatosis (HS) in longitudinal follow-up by employing pathological HS as the reference standard.We retrospectively evaluated 38 living liver donor candidates (27 men and 11 women; mean age, 29.5 years) who underwent liver biopsy twice and had liver CT scans within 1 week of each biopsy. Four readers independently calculated CTL-S index by subtracting spleen attenuation from liver attenuation on non-enhanced CT images. The changes in pathological HS (ΔHS) and CTL-S (ΔCTL-S) between the 1st and 2nd examinations were assessed. The correlation between ΔHS and ΔCTL-S was assessed using the linear regression analysis. Inter-observer measurement error for ΔCTL-S among the 4 readers was assessed using the repeatability coefficient.ΔCTL-S showed a significant correlation with ΔHS in all readers (r = 0.571-0.65, P < .001). The inter-observer measurement error for ΔCTL-S was ±8.9. The ΔCTL-S values beyond the measurement error were associated with a consistent change in HS in 83.3% (13/15) to 100% (15/15), with sensitivities of 47.8 to 79.9% and specificities of 86.7 to 100% for detecting an absolute change of ≥10% in HS among the 4 readers. However, ΔCTL-S values within the measurement error were associated with a consistent change in HS in 43.5% (8/19) to 61.5% (16/26).The change in CTL-S roughly reflects the change in HS during longitudinal follow-up. A small change in CTL-S should not be considered meaningful, while a larger change in CTL-S beyond the measurement error strongly indicates a true change in HS.

Nonalcoholic Fatty Liver Disease and Diabetes: Part II: Treatment

Nonalcoholic fatty liver disease (NAFLD) and diabetes are common metabolic disorders that are often comorbid conditions. Among many proposed treatments, weight reduction is the only approved option for NAFLD to date. However, it is not easy to maintain weight loss by lifestyle modification alone; pharmacological treatments are helpful in this regard. Although many drugs have been investigated, pioglitazone could be a first-line therapy in patients with NAFLD and diabetes. Many more drugs are currently being developed and investigated, and it is likely that combination strategies will be used for future treatment of NAFLD and diabetes. Attention should be paid to the management of NAFLD and diabetes and efforts should be made to intervene early and individualize treatment of NAFLD in patients with diabetes.

The effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND & AIMS

Several randomized clinical trials (RCTs) have investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors; however, the results were conflicting. Therefore, a meta-analysis was performed to assess the effect of l-carnitine on lipid profile and glycaemic control in adults with cardiovascular risk factors.

METHODS

We searched PubMed, Scopus, Cochrane Databases, Google Scholar, ProQuest, Web of Science and Embase for randomized, placebo-controlled human trials that investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control up to April 2017. From the eligible trials, 24 articles were selected for the meta-analysis. The meta-analysis was performed in a random-effects model. Heterogeneity was determined by I² statistics and Cochrane Q test.

RESULTS

The result showed significant effect of l-carnitine on TC (WMD: -13.73 [95% CI: -22.28, -5.17] mg/dL; P < 0.001), LDL-C (WMD = - 7.70 [95% CI: - 11.80, -3.61]mg/dL; p < 0.001), HDL-C (WMD = 0.82 [95% CI: 0.44, 1.21] mg/dL; P > 0.001), Lp(a) (WMD = - 7.13 [95% CI: -9.82,- 4.43]mg/dL; P < 0.001), FPG (WMD = -6.25 [95% CI: -10.35, -2.16] mg/dL; P < 0.001), HbA1C (WMD (%) = - 0.35 [95% CI: -0.65,- 0.05]; p = 0.02) and HOMA-IR (WMD (%) = - 0.94 [95% CI: -1.89, -0.00]; P = 0.05). No effect of l-carnitine was detected in TG, Apo A-I and Apo B 100 on pooled effect size. Additionally, sensitivity analysis showed l-carnitine supplementation could improve glycaemic control, particularly along with hypocaloric diet.

CONCLUSION

This meta-analysis showed that l-carnitine supplementation could improve lipid profile levels, particularly in doses more than 1500 mg/day. More RCTs with large sample sizes, focusing on gut microbiome profiles and dietary patterns are needed to better understand the effect of l-carnitine on patients with cardiovascular risk factors.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.