D-livering the message: the importance of vitamin D status in chronic liver disease

Vitamin D Supplementation Is Associated with Inflammation Amelioration and Cognitive Improvement in Decompensated Patients with Cirrhosis

Background/Objectives: Decompensated cirrhosis is characterized by systemic inflammation and innate and adaptive immune dysfunction. Hepatic encephalopathy (HE) is a prevalent and debilitating condition characterized by cognitive disturbances in which ammonia and inflammation play a synergistic pathogenic role. Extraskeletal functions of vitamin D include immunomodulation, and its deficiency has been implicated in immune dysfunction and different forms of cognitive impairment. The aim was to assess changes in cognitive function and inflammation in decompensated patients with cirrhosis receiving vitamin D supplementation. Methods: Patients with cirrhosis discharged from decompensation in two tertiary hospitals in Spain (from September 2017 to January 2020) were assessed before, at 6 and 12 months after vitamin D supplementation. A comprehensive neuropsychological battery and neuroinflammatory markers were examined. In a subgroup of patients, peripheral immune blood cells were analyzed. Results: Thirty-nine patients were recruited. Of those, 27 completed the 6 months evaluation and were analyzed [age 62.4 ± 11.3 years; 22 men; Model for End-Stage Liver Disease (MELD) 11.7 ± 4.0; prior overt HE 33%; median 25-hydroxyvitamin D (25OHD) plasma level 12.7 µgr/L] and 22 achieved 12 months assessment. At baseline, learning and memory (R = 0.382; p = 0.049) and working memory (R = 0.503; p = 0.047) subtests correlated with plasma 25OHD levels. In addition, processing speed (R = -0.42; p = 0.04), attention (R = -0.48; p = 0.04), Tinnetti balance (R = -0.656; p < 0.001) and Tinnetti score (R = -0.659; p < 0.001) were linked to neuroinflammation marker IL-1β. Patients with lower 25OHD had a greater proportion of TH1cells at baseline and a larger amelioration of IL-1β and IL-6 following supplementation. An improvement in working memory was found after 25OHD replacement (46.7 ± 13 to 50 ± 11; p = 0.047). Conclusions: This study supports that vitamin D supplementation modulates low-grade inflammation in decompensated cirrhosis providing cognitive benefits, particularly in working memory.

Bioactive metabolites: A clue to the link between MASLD and CKD?

Metabolites produced as intermediaries or end-products of microbial metabolism provide crucial signals for health and diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD). These metabolites include products of the bacterial metabolism of dietary substrates, modification of host molecules (such as bile acids [BAs], trimethylamine-N-oxide, and short-chain fatty acids), or products directly derived from bacteria. Recent studies have provided new insights into the association between MASLD and the risk of developing chronic kidney disease (CKD). Furthermore, alterations in microbiota composition and metabolite profiles, notably altered BAs, have been described in studies investigating the association between MASLD and the risk of CKD. This narrative review discusses alterations of specific classes of metabolites, BAs, fructose, vitamin D, and microbiota composition that may be implicated in the link between MASLD and CKD.

Double Trouble: Metabolic Dysfunction-Associated Fatty Liver Disease in Fraternal Twins

Pediatric cases of metabolic dysfunction-associated fatty liver disease (MASLD, formerly termed non-alcoholic fatty liver disease (NAFLD) are a troubling new outcome of the pediatric obesity epidemic. Advising patients and families with this condition is challenging considering the nutrition needed to sustain developmentally appropriate growth in youth. Describing risk factors, comorbidities, management, and referrals for MASLD could improve surveillance and outcomes for this condition. MASLD is commonly seen with other comorbidities such as dyslipidemia, obstructive sleep apnea, type 2 diabetes, hypothyroidism, anxiety, and depression. Considerations of epigenetics, diabetes, and adverse childhood experiences will be explored as additional underlying contributors to MASLD. Screening patients for this condition in conjunction with other comorbidities is essential to preventing the progression to non-alcoholic steatohepatitis (NASH) and cirrhosis, as well as lowering the risk for hepatocellular carcinoma. This fraternal twin case report describes pertinent diagnostics, recommendations for referrals, follow-up consultations, and red flags for more advanced liver disease.

Effects of vitamin D deficiency on chronic alcoholic liver injury

Vitamin D deficiency (VDD) has been found among alcoholics. However, little is known about the effect of VDD on alcoholic liver disease and the molecular mechanisms remain unclear. The aim of the current study was to evaluate whether vitamin D was deficient among patients with alcoholic fatty liver disease (AFLD) and the effect of VDD on chronic alcoholic liver injury and possible molecular mechanisms in mice. Our results found that lower 25-hydroxyvitamin D [25(OH)D] concentrations in patients with AFLD. And further analysis found that 25(OH)D is a protective factor in patients with AFLD. Mice experiments indicated that VDD can alter the composition of gut microbiota, down-regulate the protein levels of intestinal tight junction protein Occludin and E-cadherin, up-regulate the expression of inflammatory cytokines (tnf-α, il-1β, il-6, il-8, ccl2, il-10) in liver and colon tissue. And further exacerbated the protein levels of p65,P-IκB,P-p65 in alcoholic liver injury mice. In conclusion, VDD aggravates chronic alcoholic liver injury by activating NF-κB signaling pathway.

No causal relationship between serum vitamin D levels and alcoholic liver disease: a two-sample bidirectional Mendelian randomization study

BACKGROUND

Numerous observational studies have presented an association between Vitamin D (VD) and Alcoholic Liver Disease (ALD). However, sufficient evidence from Randomized Controlled Trials (RCTs) substantiating this correlation is scarce, thus leaving the causality of this relationship ambiguous. To overcome the shortcomings of traditional observational studies, we performed a two-sample bidirectional Mendelian randomization (MR) analysis to ascertain the causal relationship between VD and ALD.

METHODS

We utilized summary statistics datasets from Genome-Wide Association Studies (GWAS) for VD and ALD. We selected genetic instruments that measure circulating VD levels (n = 64,979), and retrieved ALD statistics from GWASs, inclusive of 1,416 cases and 217,376 healthy controls, while excluding chronic liver diseases such as nonalcoholic fatty liver disease, toxic liver disease, and viral hepatitis. Subsequent, MR analyses were performed to obtain effect estimates using inverse variance weighted (IVW) random effect models. Cochran's Q statistic and MR-Egger regression intercept analyses were used to assess pleiotropy. Sensitivity analyses using the MR Egger, weighted median, simple mode, and weighted mode methods were also performed. Leave-one-out analysis was used to identify SNPs with potential effect. Reverse MR analysis was also performed.

RESULTS

In IVW, our MR analysis incorporated 21 independent SNPs, circulating VD levels had no causal effect on ALD [OR = 0.624 (0.336-1.160), p = 0.136] and ALD had no causal effect on circulating VD [OR = 0.997 (0.986-1.008), p = 0.555]. No heterogeneity or pleiotropy was observed (p > 0.05). Other MR methods also agreed with IVW results.

CONCLUSION

This study provides the causal relationship between genetically predicted circulating Vitamin D levels and ALD and provides new insights into the genetics of ALD.

Vitamin D Receptor Regulates Liver Regeneration After Partial Hepatectomy in Male Mice

Vitamin D signals through the vitamin D receptor (VDR) to induce its end-organ effects. Hepatic stellate cells control development of liver fibrosis in response to stressors and vitamin D signaling decreases fibrogenesis. VDR expression in hepatocytes is low in healthy liver, and the role of VDR in hepatocyte proliferation is unclear. Hepatocyte-VDR null mice (hVDR) were used to assess the role of VDR and vitamin D signaling in hepatic regeneration. hVDR mice have impaired liver regeneration and impaired hepatocyte proliferation associated with significant differential changes in bile salts. Notably, mice lacking hepatocyte VDR had significant increases in expression of conjugated bile acids after partial hepatectomy, consistent with failure to normalize hepatic function by the 14-day time point tested. Real-time PCR of hVDR and control livers showed significant changes in expression of cell-cycle genes including cyclins D1 and E1 and cyclin-dependent kinase 2. Gene expression profiling of hepatocytes treated with vitamin D or control showed regulation of groups of genes involved in liver proliferation, hepatitis, liver hyperplasia/hyperproliferation, and liver necrosis/cell death. Together, these studies demonstrate an important functional role for VDR in hepatocytes during liver regeneration. Combined with the known profibrotic effects of impaired VDR signaling in stellate cells, the studies provide a mechanism whereby vitamin D deficiency would both reduce hepatocyte proliferation and permit fibrosis, leading to significant liver compromise.

The contribution of vitamin D insufficiency to the onset of steatotic liver disease among individuals with metabolic dysfunction

The interplay between fatty liver disease (FLD) and metabolic dysfunction has given rise to the concept of metabolic associated fatty liver disease (MAFLD). With vitamin D insufficiency frequently co-occurring with FLD and linked to metabolic abnormalities, this study investigates the potential role of vitamin D in the development of MAFLD. In this cross-sectional analysis, 22,476 participants with baseline metabolic dysfunction and known serum 25-OH-vitamin D3 levels were examined. The fatty liver index (FLI) was utilized to predict FLD, dividing subjects into MAFLD and non-MAFLD groups. Further stratification by vitamin D levels (sufficient vs. insufficient) and gender provided a detailed assessment through binary logistic regression to determine the association of vitamin D status with MAFLD incidence. Vitamin D insufficiency correlated with a higher MAFLD incidence in metabolically impaired individuals. Post-adjustment, the correlation was stronger (men: aOR = 1.32, 95% CI = 1.22-1.43, P < 0.001; women: aOR = 1.53, 95% CI = 1.18-1.98, P = 0.001). Lower serum 25-OH-vitamin D3 levels were found in MAFLD patients across genders (men: P = 0.003; women: P = 0.014), with a higher prevalence of insufficiency in MAFLD cases (men: P = 0.007; women: P = 0.003). The vitamin D-MAFLD link was stable across subgroups and using varying FLI criteria. Our findings indicate a clear association between vitamin D insufficiency and increased MAFLD incidence, underscoring the potential of vitamin D as an anti-lipogenic and anti-fibrotic agent.

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.

Vitamin D Binding Protein and Postsurgical Outcomes and Tissue Injury Markers After Hip Fracture: A Prospective Study

CONTEXT

Hip fracture is a serious injury that can lead to increased morbidity and mortality. Vitamin D binding protein (DBP) is a potential prognostic indicator of outcomes since it is important for actin scavenging and inflammation after tissue injury.

OBJECTIVE

To determine whether circulating DBP is associated with mobility or mortality after hip fracture and its association with acute tissue injury markers.

METHODS

Post hoc analysis of a multisite North American prospective study of 260 patients with hip fracture; mobility assessed at 30 and 60 days and mortality at 60 days after repair surgery. Biochemical markers were measured before, and 2 to 4 days after surgery. Tissue injury markers were measured in 100 randomly selected patients and controls. The primary outcome was mobility and mortality by DBP tertiles. Secondary outcomes were assessment of pre- and postoperative biomarkers.

RESULTS

Among all patients (81 ± 9 years, BMI 25 ± 4 kg/m2; 72% female), the highest DBP tertile had greater mobility at 30 (OR: 2.66; 95% CI: 1.43, 4.92; P = .002) and 60 days (OR: 2.31; 95% CI: 1.17, 4.54; P = .014) and reduced mortality (OR: 0.18; 95% CI: 0.04, 0.86; P = .032) compared with the lowest DBP tertile (<28.0 mg/dL). Total 25-hydroxyvitamin-D did not differ between tertiles (22.0 ± 9.5 ng/mL). Circulating DBP and gelsolin were lower and interleukin-6, C-reactive protein, and F-actin were higher (P < .01) in patients vs controls, and worsened (P < .01) after surgery.

CONCLUSION

High circulating DBP concentrations are associated with better mobility and reduced mortality after hip fracture surgery. The role of DBP as an acute phase reactant to tissue injury and clinical outcomes should be addressed in future study.

Association of Serum Irisin Levels with Body Composition, Metabolic Profile, Leptin, and Adiponectin Levels in Lean and Obese Children

Background and Objectives: Irisin is an adipo-myokine with potential metabolic effects in the body, and its association with childhood obesity is still controversial. This study aimed to investigate the relationship between serum irisin levels and anthropometric parameters, body composition, metabolic profiles, leptin, and adiponectin in obese and normal-weight children. Methods: The study sample consisted of a total of 80 children aged 6-10, including 44 obese children (BMI ≥ 97th percentile) and 36 normal-weight children. Anthropometric parameters were measured. Body composition was determined with the use of the Bioelectrical Impedance Analysis (BIA) method. Metabolic profiles, as well as irisin, leptin, and adiponectin levels, were analyzed. Results: Anthropometric parameters and body composition were found to be significantly different between the obese and normal-weight groups (p < 0.05). Fasting blood glucose, insulin, HOMA-IR, and leptin levels were found to be significantly higher in the obese group, while the normal-weight group had significantly higher HDL cholesterol and adiponectin levels (p < 0.05). Serum irisin levels did not differ between the obese and normal-weight groups, or based on sex, vitamin D levels, and insulin resistance status. There was also no statistically significant correlation between serum irisin levels and anthropometric parameters, metabolic profile, leptin, and adiponectin. Conclusions: The study concluded that the obese children who participated in this study had high leptin levels and low adiponectin levels, with no significant difference in the irisin levels between the groups. More comprehensive clinical studies are needed to investigate the relationship between irisin and adipokines in children.

Insights into the role of vitamin D in targeting the culprits of non-alcoholic fatty liver disease

Vitamin D (VD) is a secosteroid hormone that is renowned for its crucial role in phospho-calcium homeostasis upon binding to the nuclear vitamin D receptor (VDR). Over and above, the pleiotropic immunomodulatory, anti-inflammatory, and metabolic roles VD plays in different disease settings started to surface in the past few decades. On the other hand, a growing body of evidence suggests a correlation between non-alcoholic fatty liver disease (NAFLD) and its progressive inflammatory form non-alcoholic steatohepatitis (NASH) with vitamin D deficiency (VDD) owing to the former's ingrained link with obesity and metabolic syndrome. Accordingly, a better understanding of the contribution of disrupted VDR signalling to NAFLD incidence and progression would provide further insights into its diagnosis, treatment modalities, and prognosis. This is especially significant as, hitherto, no drug for NAFLD has been approved. This review, therefore, sought to set forth the likely contribution of VDR signalling in NAFLD and how it might influence its multiple drivers.

The Triglyceride-Glucose Index is Associated with Vitamin D Status in Metabolic-Associated Fatty Liver Disease

Purpose

Vitamin D deficiency was thought to be associated with insulin resistance and metabolic-associated fatty liver disease (MAFLD). The aim of this study was to investigate the relationship between the triglyceride-glucose (TyG) index, a useful surrogate biomarker of insulin resistance, and vitamin D status in patients with MAFLD.

Patients and Methods

A total of 566 patients with MAFLD were included in this retrospective cross-sectional study. Clinical characteristics were compared between participants with and without vitamin D deficiency. The association between the TyG index and serum 25-hydroxyvitamin D [25(OH)D] levels was determined by Spearman correlation analysis and logistic regression analysis. The receiver operating characteristic curve (ROC) was used to assess the diagnostic efficacy of TyG index for vitamin D deficiency in MAFLD patients.

Results

The TyG index levels were higher in the vitamin D deficient group than in the non-vitamin D deficient group, and serum 25(OH)D was negatively correlated with the TyG index. The TyG index was an independent risk factor for vitamin D deficiency in patients with MAFLD. The area under the curve (AUC) of the TyG index for the identification of vitamin D deficiency in MAFLD patients was 0.744 (95% CI: 0.701-0.787, p<0.001).

Conclusion

The TyG index is negatively associated with vitamin D status in patients with MAFLD. In patients with MAFLD, a higher TyG index may be an indication of a higher prevalence of vitamin D deficiency.

The Role of Vitamin D in Obese Children with Non-Alcoholic Fatty Liver Disease and Associated Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) represents a complex chronic condition, which in the absence of screening-monitoring markers and effective standardized treatment is one of the most important issues in pediatric pathology. In this study, we analyzed the role of vitamin D supplementation in obese children with/without NAFLD and the impact on the components of the associated metabolic syndrome (MS). The study included 22 children with simple obesity (SO) and 50 with NAFLD, aged between 6 and 14 years, who received regimen-based therapy or vitamin D supplementation in case of deficiency. Anthropometric and paraclinical data associated with MS were statistically compared before and after treatment. It was observed that there was a statistical association of NAFLD with MS components, which were present both in SO and in the 6-9 years group. Vitamin D deficiency was associated with the presence of obesity, NAFLD and MS components, and correction of the deficiency induced a tendency to normalize the associated parameters. In the case of a treatment strictly based on the regimen, we found decreases in vitamin D values and additional alteration of some parameters. Supplementation with vitamin D potentiates the effects of the specific regimen, and the effects seem to be dependent on the MS components.

The stop-feed effect of cholecalciferol (vitamin D3) and the efficacy of brodifacoum combined with cholecalciferol in Y139C-resistant Norway rats (Rattus norvegicus)

Second-generation anticoagulant rodenticides potentially build persistent residues in animals and accordingly pose a risk of secondary poisoning. We examined the effect of a low concentration of cholecalciferol in brodifacoum bait on bait consumption by Norway rats (Rattus norvegicus Berkenhout 1769) and on the control success in a laboratory study and in field trials. Additionally, the efficacy of both baits was determined against resistant Y139C rats. Cholecalciferol caused a strong stop-feed effect after two days in the laboratory study. On two field study sites each, bait containing either 25 mg kg-1 brodifacoum or 25 mg kg-1 brodifacoum and 100 mg kg-1 cholecalciferol was applied to treat infestations of Norway rats. Infestations were assessed pre- and post-treatment. Rats were radio-tagged, and carcasses were searched for during the treatment period. DNA of each rat was genotyped to determine the resistance status conferred by the VKORC1 gene. On all farms, control success exceeded 90%. On farms treated with brodifacoum only, the ratio of total bait consumption to pre-treatment census was significantly higher (6.6 and 4.8 times) than on farms treated with the combination (2.7 and 2.9 times). 78.8% of 183 rats were confirmed Y139C resistant. Bait ingestion was reduced by almost fifty per-cent when cholecalciferol was added to the bait with no impact on control success. All treatments resulted in control levels exceeding 90%, despite a high proportion of anticoagulant-resistant rats. When the use of highly toxic compounds is required in resistance management, addition of cholecalciferol to these baits may reduce the transfer of residues to the environment.

Severe acute respiratory syndrome coronavirus 2 may cause liver injury via Na+/H+ exchanger

The liver has many significant functions, such as detoxification, the urea cycle, gluconeogenesis, and protein synthesis. Systemic diseases, hypoxia, infections, drugs, and toxins can easily affect the liver, which is extremely sensitive to injury. Systemic infection of severe acute respiratory syndrome coronavirus 2 can cause liver damage. The primary regulator of intracellular pH in the liver is the Na⁺/H⁺ exchanger (NHE). Physiologically, NHE protects hepatocytes from apoptosis by making the intracellular pH alkaline. Severe acute respiratory syndrome coronavirus 2 increases local angiotensin II levels by binding to angiotensin-converting enzyme 2. In severe cases of coronavirus disease 2019, high angi-otensin II levels may cause NHE overstimulation and lipid accumulation in the liver. NHE overstimulation can lead to hepatocyte death. NHE overstimulation may trigger a cytokine storm by increasing proinflammatory cytokines in the liver. Since the release of proinflammatory cytokines such as interleukin-6 increases with NHE activation, the virus may indirectly cause an increase in fibrinogen and D-dimer levels. NHE overstimulation may cause thrombotic events and systemic damage by increasing fibrinogen levels and cytokine release. Also, NHE overstimulation causes an increase in the urea cycle while inhibiting vitamin D synthesis and gluconeogenesis in the liver. Increasing NHE3 activity leads to Na⁺ loading, which impairs the containment and fluidity of bile acid. NHE overstimulation can change the gut microbiota composition by disrupting the structure and fluidity of bile acid, thus triggering systemic damage. Unlike other tissues, tumor necrosis factor-alpha and angiotensin II decrease NHE3 activity in the intestine. Thus, increased luminal Na⁺ leads to diarrhea and cytokine release. Severe acute respiratory syndrome coronavirus 2-induced local and systemic damage can be improved by preventing virus-induced NHE overstimulation in the liver.

Prognostic Significance of Severe Vitamin D Deficiency in Patients with Primary Sclerosing Cholangitis

Vitamin D deficiency has been linked with adverse events in various liver diseases. The present study aimed to recognize the association between severe vitamin D deficiency and disease progression, hepatobiliary malignancies, liver-related mortality, and the need for liver transplantation in primary sclerosing cholangitis (PSC). Patients with a diagnosis of PSC (n = 354), followed by the autoimmune liver disease clinic at the University of Alberta, were included. Patients with vitamin D levels < 25 nmol/L were defined as severely deficient. Univariate and multivariate analyses were conducted using the Cox proportional hazards regression models. The mean vitamin D level was 59 ± 2 nmol/L, and 63 patients (18%) had a severe vitamin D deficiency. Patients with a severe vitamin D deficiency were 2.5 times more likely to experience hepatobiliary malignancies (HR 2.55, 95% CI, 1.02-6.40, p = 0.046). A severe vitamin D deficiency at diagnosis (HR 1.82, 95% CI, 1.05-3.15, p = 0.03) and persistent deficiencies over time (HR 2.26, 95% CI, 1.17-4.37, p = 0.02) were independently associated with a higher risk of poor clinical liver outcomes. A severe vitamin D deficiency at diagnosis and persistent deficiency at longitudinal assessments were associated with liver-related mortality or the need for liver transplantation.

Vitamin D ameliorates diethylnitrosamine-induced liver preneoplasia: A pivotal role of CYP3A4/CYP2E1 via DPP-4 enzyme inhibition

Growing evidence has indicated that vitamin D (Vit D) regulates cell proliferation and differentiation in cancer cells. Accordingly, the present study was conducted to investigate the possible beneficial effects of Vit D on diethylnitrosamine (DEN)-induced liver preneoplasia. The effect of Vit D on HepG2 cells was investigated using MTT assay. Additionally, liver preneoplasia was induced in Swiss male albino mice by giving overnight fasted animals 5 consecutive doses of DEN (75 mg/kg/week). Oral treatment with Vit D (200 IU/kg/day) was initiated either 2 weeks before DEN (first protocol) or 1 week after the first dose of DEN injection (second protocol). At the end of the experiment, tissue levels of GGT, DPP-4, TNF-α, IL-6, CYP2E1, and CYP3A4 were also estimated. Moreover, the histopathological study of liver tissue and immunohistochemical detection of GST-P, PCNA, and NF-κB were performed. Vit D exerted a significant cytotoxic effect on HepG2 cells via significantly increasing BAX, p53, and BAX/Bcl2 ratio, and significantly decreasing Bcl2 mRNA expression. In both in vivo protocols, Vit D was capable of normalizing relative liver weight, PCNA, altered hepatocellular foci, and ductular proliferation. Moreover, Vit D significantly reduced the DEN-induced elevation of AST, ALT, ALP, GGT, DDP-4, TNF-α, IL-6, CYP2E1, liver DNA damage, GST-P, NF-κB, nuclear hyperchromasia/pleomorphism, cholestasis, and inflammatory cell aggregates, but significantly increased CYP3A4 content. In conculsion, current results reflect the potential impact of Vit D in the management of early stages of liver cancer.

Role of Vitamin D in Liver Disease and Complications of Advanced Chronic Liver Disease

Vitamin D is a crucial nutrient with many pleiotropic effects on health and various chronic diseases. The purpose of this review is to provide a detailed report on the pathophysiological mechanisms underlying vitamin D deficiency in patients with chronic liver disease, addressing the different liver etiologies and the condition of advanced chronic liver disease (cirrhosis) with related complications. To date, patients with liver disease, regardless of underlying etiology, have been shown to have reduced levels of vitamin D. There is also evidence of the predictive role of vitamin D values in complications and progression of advanced disease. However, specific indications of vitamin D supplementation are not conclusive concerning what is already recommended in the general population. Future studies should make an effort to unify and validate the role of vitamin D supplementation in chronic liver disease.

Vitamin D-VDR Novel Anti-Inflammatory Molecules-New Insights into Their Effects on Liver Diseases

There is consistent evidence that vitamin D deficiency is strongly associated with liver dysfunction, disease severity, and poor prognosis in patients with liver disease. Vitamin D and its receptor (VDR) contribute to the regulation of innate and adaptive immune responses. The presence of genetic variants of vitamin D- and VDR-associated genes has been associated with liver disease progression. In our recent work, we summarized the progress in understanding the molecular mechanisms involved in vitamin D-VDR signaling and discussed the functional significance of VDR signaling in specific cell populations in liver disease. The current review focuses on the complex interaction between immune and liver cells in the maintenance of liver homeostasis and the development of liver injury, the interplay of vitamin D and VDR in the development and outcome of liver disease, the role of vitamin D- and VDR-associated genetic variants in modulating the occurrence and severity of liver disease, and the therapeutic value of vitamin D supplementation in various liver diseases. The association of the vitamin D-VDR complex with liver dysfunction shows great potential for clinical application and supports its use as a prognostic index and diagnostic tool.

Resolution of, and Risk of Incident Non-alcoholic Fatty Liver Disease With Changes in Serum 25-hydroxy Vitamin D Status

CONTEXT

A protective or causative role of vitamin D status on the risk of nonalcoholic fatty liver disease (NAFLD) remains inconclusive.

OBJECTIVE

To evaluate the association between changes in serum 25-hydroxyvitamin D [25(OH)D] status during follow-up and the risk of incident NAFLD and resolution of preexisting NAFLD.

DESIGN

A retrospective cohort study.

SETTING

Kangbuk Samsung Health Study based on routine health screening examinations.

PARTICIPANTS

Korean adults (mean age, 36.8 years; range, 18-96 years) who underwent comprehensive health examinations including assessment of serum 25(OH)D levels.

MAIN OUTCOME MEASURES

The main outcomes were (1) incidence and (2) resolution of NAFLD assessed by liver ultrasound. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% CIs for outcomes according to serum 25(OH)D levels.

RESULTS

Among 139 599 participants without NAFLD at baseline, 27 531 developed NAFLD during follow-up. Serum 25(OH)D levels were significantly and inversely associated with NAFLD development. Among 48 702 participants with NAFLD at baseline, 13 449 showed NAFLD resolution. Multivariable-adjusted HR (95% CI) for NAFLD resolution comparing 25(OH)D 10 to <20, 20 to <30, and ≥30 ng/mL to <10 ng/mL were 1.09 (1.03-1.15), 1.13 (1.06-1.21), and 1.21 (1.09-1.35), respectively. Additionally, an increase in 25(OH)D levels between baseline and the subsequent visit (median, 1.8 years) was associated with decreased NAFLD incidence, while persistently adequate 25(OH)D levels over time was associated with decreased incidence and increased resolution of NAFLD.

CONCLUSIONS

Maintaining adequate serum 25(OH)D concentrations may be beneficial for both prevention as well as resolution of NAFLD.

Diosgenin Ameliorates Non-alcoholic Fatty Liver Disease by Modulating the Gut Microbiota and Related Lipid/Amino Acid Metabolism in High Fat Diet-Fed Rats

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease closely associated with dietary habits. Diosgenin is abundant in yam, a common food and traditional Chinese medicine. The molecular mechanism of diosgenin on NAFLD has been preliminarily explored. However, the effect of diosgenin on metabolism and gut microbiota in NAFLD has not been reported. This study confirmed that diosgenin could suppress excessive weight gain, reduce serum levels of total cholesterol and triglycerides, and decrease liver fat accumulation in high-fat diet-induced NAFLD rats. Moreover, fecal metabolomics analysis suggested diosgenin improved abnormal lipid and amino acid metabolism. Bile acids, including lithocholic acid and ursodeoxycholic acid 3-sulfate that function as excretion, absorption, and transport of fats, were remarkably regulated by diosgenin. Aromatic amino acid and lysine metabolism was regulated by diosgenin as well. 16S rRNA gene sequencing analysis demonstrated that diosgenin restored gut microbiota disorder, especially Globicatella, Phascolarctobacterium, Pseudochrobactrum, and uncultured_bacterium_f_Prevotellaceae at the genus level. Additionally, these regulated bacterial genera showed significant correlations with lipid and amino acid metabolism-related biomarkers. This study further confirmed the significant effect of diosgenin on NAFLD, and provided a new perspective for the mechanism.

NAFLD and Vitamin D: Evidence for Intersection of MicroRNA Regulated Pathways

Non-alcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease, worldwide. The molecular pathogenesis of NAFLD is complex, involving numerous signalling molecules including microRNAs (miRNAs). Dysregulation of miRNA expression is associated with hepatic inflammation, fibrosis and hepatocellular carcinoma. Although miRNAs are also critical to the cellular response to vitamin D, mediating regulation of the vitamin D receptor (VDR) and vitamin D’s anticancer effects, a role for vitamin D regulated miRNAs in NAFLD pathogenesis has been relatively unexplored. Therefore, this review aimed to critically assess the evidence for a potential subset of miRNAs that are both dysregulated in NAFLD and modulated by vitamin D. Comprehensive review of 89 human studies identified 25 miRNAs found dysregulated in more than one NAFLD study. In contrast, only 17 studies, including a protocol for a trial in NAFLD, had examined miRNAs in relation to vitamin D status, response to supplementation, or vitamin D in the context of the liver. This paper summarises these data and reviews the biological roles of six miRNAs (miR-21, miR-30, miR-34, miR-122, miR-146, miR-200) found dysregulated in multiple independent NAFLD studies. While modulation of miRNAs by vitamin D has been understudied, integrating the data suggests seven vitamin D modulated miRNAs (miR-27, miR-125, miR-155, miR-192, miR-223, miR-375, miR-378) potentially relevant to NAFLD pathogenesis. Our summary tables provide a significant resource to underpin future hypothesis-driven research, and we conclude that the measurement of serum and hepatic miRNAs in response to vitamin D supplementation in larger trials is warranted.

The Interplay of Vitamin D Deficiency and Cellular Senescence in The Pathogenesis of Obesity-Related Co-Morbidities

This scoping review aims to clarify the interplay between obesity, vitamin D deficiency, cellular senescence, and obesity-related metabolic consequences, mainly subclinical atherosclerosis, and non-alcoholic fatty liver disease (NAFLD). Obesity is a significant global health problem that involves cellular, environmental, behavioral, and genetic elements. The fundamental cause of obesity throughout all life stages is an energy imbalance, and its consequences are countless and, foremost, very common. Obesity has been comprehensively studied in the literature given its association with low serum vitamin D, with many proposed mechanisms linking the two conditions. Moreover, markers of exaggerated cellular senescence have been proven to accumulate in obese individuals. Subclinical atherosclerosis initiates an early stage that ends in serious cardiac events, and obesity, low vitamin D, and senescent cells largely contribute to its associated chronic low-grade inflammation. Furthermore, NAFLD signifies the hepatic manifestation of metabolic syndrome, and studies have highlighted the important role of obesity, vitamin D deficiency, and cellular senescence in its development. Therefore, we outlined the most important mechanisms tying these conditions to one another.

The Effects of Vitamin D Supplementation on Anthropometric and Biochemical Indices in Patients With Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Background: Vitamin D was reported to be associated with non-alcoholic fatty liver disease (NAFLD). This systematic review and meta-analysis aimed to investigate the effects of the vitamin D supplementation on anthropometric and biochemical indices in patient with NAFLD. Methods: PubMed, Web of science, Scopus, and Embase databases were explored to identify all randomized controlled trial (RCT) investigating the effects of vitamin D supplementation on anthropometric and biochemical indices in patients with NAFLD. A random-effects model was used to pool weighted mean difference (WMD) and corresponding 95% confidence intervals (CIs). The statistical heterogeneity among the studies was assessed using I2 statistic (high ≥ 50%, low < 50%) and Cochran's Q-test. Results: Sixteen RCTs were included in this meta-analysis. The results identified that high-density lipoprotein-cholesterol (HDL-C) level significantly increased following vitamin D supplementation (P = 0.008). Vitamin D reduced body weight (P = 0.007), body mass index (P = 0.002), waist circumstance (WC) (P = 0.02), serum alanine transaminase (ALT) (P = 0.01), fasting blood sugar (FBS) (P = 0.01), homeostatic model assessment for insulin resistance (HOMA-IR) (P = 0.004), and calcium (P = 0.01). No significant changes were found on body fat, triglyceride (TG), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), aspartate transaminase, alkaline phosphatase, gamma-glutamyl transferase, and adiponectin following vitamin D supplementation. Conclusion: Vitamin D had significant effects on anthropometric and biochemical indices including HDL-C, body weight, BMI, WC, serum ALT, serum FBS, HOMA-IR, and calcium. Vitamin D supplementation can be considered as an effective strategy in management of patients with NAFLD. Systematic Review Registration: [website], identifier [registration number].

Role of Serum Vitamin D, Interleukin 13, and microRNA-135a in Hepatocellular Carcinoma and Treatment Failure in Egyptian HCV-Infected Patients Receiving Direct Antiviral Agents

Direct-acting antivirals (DAAs) are used for hepatitis C virus (HCV) treatment. However, treatment failure and hepatocellular carcinoma (HCC) development following treatment was reported. In this study, we assessed the role of serum vitamin D, interleukin 13 (IL-13), and microRNA-135a in the prediction of treatment failure with DAA and HCC development among Egyptian HCV-infected patients. A total of 950 patients with HCV-related chronic liver disease underwent DAA treatment. Before DAAs, serum vitamin D and IL-13 were determined by ELISA, and gene expression of miRNA-135a was assessed in serum by real-time PCR. The predictive abilities of these markers were determined using the receiver operating characteristic (ROC) curve. Sustained virological response (SVR) was achieved in 92.6% of HCV-infected patients (responders). High viral load, IL-13, miRNA-135a, and low vitamin D levels were associated with treatment failure and HCC development. HCC development was recorded in non-responders, but not in the responders (35.7% vs. 0% p < 0.001). In conclusion: serum IL-13, Vitamin D, and miRNA-135a could be potential biomarkers in monitoring DAA treatment and HCC prediction. DAAs-induced SVR may decrease the incidence of HCC.

Vitamin D supplementation for chronic liver diseases in adults

BACKGROUND

Vitamin D deficiency is often reported in people with chronic liver diseases. Improving vitamin D status could therefore be beneficial for people with chronic liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation in adults with chronic liver diseases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index-Science. We also searched ClinicalTrials.gov  and the World Health Organization International Clinical Trials Registry Platform. We scanned bibliographies of relevant publications and enquired experts and pharmaceutical companies as to additional trials. All searches were up to November 2020.

SELECTION CRITERIA

Randomised clinical trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults with chronic liver diseases. Vitamin D could have been administered as supplemental vitamin D (vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), 25-hydroxyvitamin D (calcidiol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 27 randomised clinical trials with 1979 adult participants. This review update added 12 trials with 945 participants. We assessed all trials as at high risk of bias. All trials had a parallel-group design. Eleven trials were conducted in high-income countries and 16 trials in middle-income countries. Ten trials included participants with chronic hepatitis C, five trials participants with liver cirrhosis, 11 trials participants with non-alcoholic fatty liver disease, and one trial liver transplant recipients. All of the included trials reported the baseline vitamin D status of participants. Participants in nine trials had baseline serum 25-hydroxyvitamin D levels at or above vitamin D adequacy (20 ng/mL), whilst participants in the remaining 18 trials were vitamin D insufficient (less than 20 ng/mL). Twenty-four trials administered vitamin D orally, two trials intramuscularly, and one trial intramuscularly and orally. In all 27 trials, the mean duration of vitamin D supplementation was 6 months, and the mean follow-up of participants from randomisation was 7 months. Twenty trials (1592 participants; 44% women; mean age 48 years) tested vitamin D₃ (cholecalciferol); three trials (156 participants; 28% women; mean age 54 years) tested vitamin D₂; four trials (291 participants; 60% women; mean age 52 years) tested 1,25-dihydroxyvitamin D; and one trial (18 participants; 0% women; mean age 52 years) tested 25-hydroxyvitamin D. One trial did not report the form of vitamin D. Twelve trials used a placebo, whilst the other 15 trials used no intervention in the control group. Fourteen trials appeared to be free of vested interest. Eleven trials did not provide any information on clinical trial support or sponsorship. Two trials were funded by industry. We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on all-cause mortality (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.51 to 1.45; 27 trials; 1979 participants). The mean follow-up was 7 months (range 1 to 18 months). We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on liver-related mortality (RR 1.62, 95% CI 0.08 to 34.66; 1 trial; 18 participants) (follow-up: 12 months); serious adverse events such as hypercalcaemia (RR 5.00, 95% CI 0.25 to 100.8; 1 trial; 76 participants); myocardial infarction (RR 0.75, 95% CI 0.08 to 6.81; 2 trials; 86 participants); thyroiditis (RR 0.33, 95% CI 0.01 to 7.91; 1 trial; 68 participants); circular haemorrhoidal prolapse (RR 3.00, 95% CI 0.14 to 65.9; 1 trial; 20 participants); bronchopneumonia (RR 0.33, 95% CI 0.02 to 7.32; 1 trial 20 participants); and non-serious adverse events. The certainty of evidence for all outcomes is very low. We found no data on liver-related morbidity such as gastrointestinal bleeding, hepatic encephalopathy, hepatorenal syndrome, ascites, or liver cancer. There were also no data on health-related quality of life. The evidence is also very uncertain regarding the effect of vitamin D versus placebo or no intervention on rapid, early, and sustained virological response in people with chronic hepatitis C.

AUTHORS' CONCLUSIONS

Given the high risk of bias and insufficient power of the included trials and the very low certainty of the available evidence, vitamin D supplementation versus placebo or no intervention may increase or reduce all-cause mortality, liver-related mortality, serious adverse events, or non-serious adverse events in adults with chronic liver diseases. There is a lack of data on liver-related morbidity and health-related quality of life. Further evidence on clinically important outcomes analysed in this review is needed.

Changes in the estimated renal function after hepatitis C virus eradication with direct-acting antiviral agents: Impact of changes in skeletal muscle mass

Hepatitis C virus (HCV) infection can cause renal dysfunction, expected to improve upon HCV eradication. However, adverse effects of HCV eradication using direct-acting antiviral agents (DAAs) on renal function have been recently reported. This retrospective study aimed to evaluate renal function with glomerular filtration rate (eGFR) estimated using creatinine (eGFRcre) and cystatin C (eGFRcys). Complete clinical information and preserved serum samples were collected from 207 patients with HCV infection treated with interferon-free DAA at baseline and SVR48 (SVR48). Patients who underwent paired computed tomography (CT) at baseline and ≥12 months after DAA were evaluated for changes in skeletal muscle mass using the psoas muscle mass index (PMI). eGFRcre significantly worsened at SVR48, while eGFRcys was similar at baseline and SVR48. At baseline, eGFRcre was significantly higher than eGFRcys; eGFRcre and eGFRcys were similar at SVR48. Multivariate analysis revealed that the presence of liver cirrhosis and low-albumin level, as well as cirrhosis and age, was significantly associated with the overestimation of renal function by eGFRcre at baseline and SVR48, respectively. In the 57 patients who underwent paired CT at baseline and ≥12 months after DAA, relative values of PMI significantly increased after DAA. After DAA, in patients with increased PMI (65% 37/57), eGFRcre significantly worsened but did not change in patients without increased PMI. eGFRcre significantly worsened after DAAs; however, this might not reflect accurate changes in renal function, partially because of changes in skeletal muscle mass. eGFRcys did not change after DAAs, and it is a potential alternative to eGFRcre.

Nutritional Evaluation and Treatment of the Cirrhotic Patient

Malnutrition and sarcopenia that lead to functional deterioration, frailty, and increased risk for complications and mortality are common in cirrhosis. Sarcopenic obesity, which is associated with worse outcomes than either condition alone, may be overlooked. Lifestyle intervention aiming for moderate weight reduction can be offered to obese compensated cirrhotic patients, with diet consisting of reduced caloric intake, achieved by reduction of carbohydrate and fat intake, while maintaining high protein intake. Dietary and moderate exercise interventions in patients with cirrhosis are beneficial. Cirrhotic patients with malnutrition should have nutritional counseling, and all patients should be encouraged to avoid a sedentary lifestyle.

Response of Helicobacter Pylori Eradication Treatment in Patients With Normal and Below-Normal Serum Vitamin D Levels

Introduction

 The infection of Helicobacter pylori (H. pylori) is affected by the host immune system and the genetic makeup. It is postulated that deficiency of vitamin D may interfere in normal immunological response to infectious agents, including H. pylori, and increase the risk of infection. This study aims to find the relationship between vitamin D status in the body and patient’s response to H. pylori eradication treatment.

Methods

 One hundred and fifty patients (n = 150) between the ages of 18 and 60 years of either gender, diagnosed with H. pylori, were included in the study. After enrollment, patients were started on first-line eradication therapy, which included omeprazole, amoxicillin, and clarithromycin for 14 days. Patient’s vitamin D levels were tested via laboratory. After 14 days, patients' stools were tested for presence of H. pylori antigen. 

Results

 A total of 128 participants completed the study, out of which 92 (71.8%) participants showed no H. pylori antigen in stool after 14 days and 36 (28.1%) participants still showed H. pylori in their stool. The mean serum vitamin D level was significantly higher in participants who had successful treatment compared to those who had unsuccessful treatment (31.01 ± 7.8 ng/mL vs. 18.9 ± 5.6 ng/mL; p-value < 0.0001).

Conclusion

 Vitamin D levels may affect the response of H. pylori eradication therapy. Further large-scale studies are needed in which vitamin D is given as an intervention to further study the association between vitamin D levels and H. pylori treatment response. 

Handgrip Strength and Vitamin D as Predictors of Liver Fibrosis and Malnutrition in Chronic Hepatitis C Patients

Background

In patients with chronic hepatitis C (CHC), a negative impact of associated malnutrition on both morbidity and mortality was reported. We aimed to elucidate the efficacy of serum liver fibrosis markers (fibronectin (FN), hydroxyproline (Hyp), and hyaluronic acid (HA)) and their respective indices (HA index, Hyp index, and FN index) and vitamin D status in predicting malnutrition associated with liver fibrosis in CHC patients and to investigate their association with the value of current clinical malnutrition assessment tools subjective global assessment (SGA), handgrip strength (HGS), and muscle mass scores (SGA, BMI, MAMC, and HGS).

Materials and Methods

A cross-sectional study was conducted on 80 patients aged 40-60 years with proven viremia, HCV antibodies, HCV-RNA positivity, genotype determinations, and established chronic hepatitis C virus for more than 6 years and 80 control subjects. SGA, HGS, and muscle mass score (MAMC) were estimated in both patients and control subjects. Based on SGA scores, CHC patients were classified into three groups: well nourished (n = 12; SGA-A); mild or moderately malnourished (n = 25; SGA-B); and severely malnourished (n = 43; SGA-C). Liver fibrosis markers, inflammatory indicator α-Fetoprotein (AFP), tumor necrosis factor-alpha (TNF-α), 25-hydroxyvitamin D, and PTH were estimated using immunoassay techniques.

Results

CHC patients with moderate and severe malnutrition SGA scores showed a significant decline in the levels of vitamin D, increased PTH, and lower values of HGS and muscle mass indices compared to well-nourished patients and control subjects. In addition, malnutrition, vitamin D deficiency, and lower values of HGS, MAC, TSF, and MAMC showed significant correlation with liver severity among CHC patients. Liver fibrosis markers Hyp, HA, FN, APRI, HypI, HAI, and FNI as noninvasive biomarkers showed significant correlation with both severity of liver diseases and associated malnutrition, especially in cirrhotic HCV patients (F4) compared to those with significant fibrosis (F2-F3).

Conclusion

The results showed that deficiency in vitamin D levels, HGS, SGA, and muscle mass scores (MAC, MAMC, or TSF) could be used as markers of liver pathogenicity in patients with CHC. In addition, the study concluded that noninvasive biomarkers Hyp, HA, FN, APRI, HypI, HAI, and FNI separately or in association with vitamin D status, HGS, SGA, and muscle mass scores (MAC, MAMC, or TSF) were significantly associated with an incidence of malnutrition between ~70.5% and 89.6% of CHC patients with significant fibrosis and cirrhosis.

The association between gastric bacterial infection and low level of vitamin D among patients with type 2 diabetes mellitus

Objectives: The present research aimed to find an association between infection by Helicobacter pylori and vitamin D deficiency in type 2 diabetic Iraqis attending Al-Yarmouk Teaching Hospital. Methods: According to fasting blood glucose, the samples were divided into a non-diabetic group with ten diabetic individuals and a diabetic group with thirty individuals. Results: The anti-H. pylori (IgG) levels were 86.77±58.62 NTU/μL in diabetic patients compared with 10.12_7.40 NTU/μL in non-diabetic group. Vitamin D levels were decreased significantly in infected patients compared to non-infected subjects. Conclusion: The H. pylori-infected patients have recorded the lowest level of vitamin D than non-infected individuals.

Recommendations on the measurement and the clinical use of vitamin D metabolites and vitamin D binding protein - A position paper from the IFCC Committee on bone metabolism

Vitamin D, an important hormone with a central role in calcium and phosphate homeostasis, is required for bone and muscle development as well as preservation of musculoskeletal function. The most abundant vitamin D metabolite is 25-hydroxyvitamin D [25(OH)D], which is currently considered the best marker to evaluate overall vitamin D status. 25(OH)D is therefore the most commonly measured metabolite in clinical practice. However, several other metabolites, although not broadly measured, are useful in certain clinical situations. Vitamin D and all its metabolites are circulating in blood bound to vitamin D binding protein, (VDBP). This highly polymorphic protein is not only the major transport protein which, along with albumin, binds over 99% of the circulating vitamin D metabolites, but also participates in the transport of the 25(OH)D into the cell via a megalin/cubilin complex. The accurate measurement of 25(OH)D has proved a difficult task. Although a reference method and standardization program are available for 25(OH)D, the other vitamin D metabolites still lack this. Interpretation of results, creation of clinical supplementation, and generation of therapeutic guidelines require not only accurate measurements of vitamin D metabolites, but also the accurate measurements of several other "molecules" related with bone metabolism. IFCC understood this priority and a committee has been established with the task to support and continue the standardization processes of vitamin D metabolites along with other bone-related biomarkers. In this review, we present the position of this IFCC Committee on Bone Metabolism on the latest developments concerning the measurement and standardization of vitamin D metabolites and its binding protein, as well as clinical indications for their measurement and interpretation of the results.

The Impact of Dietary Patterns and Nutrition in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common causes of chronic liver disease worldwide. The prevalence of NAFLD has grown proportionally with the rise in obesity, sedentary lifestyle, unhealthy dietary patterns, and metabolic syndrome. Currently, in the absence of approved pharmacologic treatment, the keystone of treatment is lifestyle modification focused on achieving a weight loss of 7%-10%, cardiovascular exercise, and improving insulin sensitivity. The primary aim of this review is to outline the effect of different dietetic approaches against NAFLD and highlight the important micronutrient components in the management of NAFLD.

Oxidative Stress in Non-alcoholic Fatty Liver Disease. An Updated Mini Review

Non-alcoholic fatty liver disease (NAFLD) is a challenging disease caused by multiple factors, which may partly explain why it remains still orphan of an adequate therapeutic strategy. Herein we focus on the interplay between oxidative stress (OS) and the other causal pathogenetic factors. Different reactive oxygen species (ROS) generators contribute to NAFLD inflammatory and fibrotic progression, which is quite strictly linked to the lipotoxic liver injury from fatty acids and/or a wide variety of their biologically active metabolites in the context of either a two-hit or a (more recent) multiple parallel hits theory. An antioxidant defense system is usually able to protect hepatic cells from damaging effects caused by ROS, including those produced into the gastrointestinal tract, i.e., by-products generated by usual cellular metabolic processes, normal or dysbiotic microbiota, and/or diet through an enhanced gut–liver axis. Oxidative stress originating from the imbalance between ROS generation and antioxidant defenses is under the influence of individual genetic and epigenetic factors as well. Healthy diet and physical activity have been shown to be effective on NAFLD also with antioxidant mechanisms, but compliance to these lifestyles is very low. Among several considered antioxidants, vitamin E has been particularly studied; however, data are still contradictory. Some studies with natural polyphenols proposed for NAFLD prevention and treatment are encouraging. Probiotics, prebiotics, diet, or fecal microbiota transplantation represent new therapeutic approaches targeting the gut microbiota dysbiosis. In the near future, precision medicine taking into consideration genetic or environmental epigenetic risk factors will likely assist in further selecting the treatment that could work best for a specific patient.

Nutraceuticals for the treatment of sarcopenia in chronic liver disease

BACKGROUND AND AIMS

Sarcopenia, defined as loss of muscle mass, strength and function, is associated with adverse clinical outcomes in patients with cirrhosis. Despite improved understanding of the multifaceted pathogenesis, there are few established therapies to treat or prevent muscle loss in this population. This narrative review examines the available literature investigating the role of nutraceuticals for the prevention or treatment of muscle wasting in chronic liver disease.

METHODS

A comprehensive search or Medline and PubMED databases was conducted. Reference lists were screened to identify additional articles.

RESULTS

A number of nutritional supplements and vitamins target the specific metabolic derangements that contribute to sarcopenia in cirrhosis including altered amino acid metabolism, hyperammonaemia and inflammation. Branched chain amino acid (BCAA) supplementation has proposed anabolic effects through dual pathways of enhanced ammonia clearance and stimulation of muscle protein synthesis. l-carnitine also has multimodal effects on muscle and shows promise as a therapy for muscle loss through anti-inflammatory, antioxidant and ammonia lowering properties. Other nutraceuticals including l-ornithine l-aspartate, omega-3 polyunsaturated fatty acids and zinc and vitamin D supplementation, may similarly have positive effects on muscle homeostasis, however further evidence to support their use in cirrhotic populations is required.

CONCLUSION

Nutraceuticals offer a promising and likely safe adjunct to standard care for sarcopenia in cirrhosis. While there is most evidence to support the use of BCAA and l-carnitine supplementation, further well-designed clinical trials are needed to elucidate their efficacy as a therapy for muscle loss in this population.

Active Vitamin D3 Treatment Attenuated Bacterial Translocation via Improving Intestinal Barriers in Cirrhotic Rats

SCOPE

Pathological bacterial translocation from the disrupted intestinal barrier leads to substantial complications and mortality in liver cirrhosis. Vitamin D is reported as beneficial to gut barriers in some animal models. However, its effect on cirrhotic bacterial translocation is unknown. The authors aim to investigate the effects of calcitriol on bacterial translocation in cirrhotic rats.

METHODS AND RESULTS

Cirrhotic rats are administrated with a 2-week course of active vitamin D3 (calcitriol, 0.1 μg kg-1  per day) or vehicle by oral gavage after thioacetamide (TAA) injection for 16 weeks. Bacterial translocation, gut permeability, gut microbiota, and associated mechanisms are investigated. Calcitriol treatment significantly attenuates bacterial translocation and reduces intestinal permeability in TAA-induced cirrhotic rats. It upregulates the expressions of occludin in the small intestine and claudin-1 in the colon of cirrhotic rats directly independent of intrahepatic status. Even when a short period of calcitriol treatment do not reduce intestinal bacterial overgrowth, it induces a remarkable change of bacterial diversities and enrichment of Muribaculaceae, Bacteroidales, Allobaculum, Anaerovorax, and Ruminococcaceae.

CONCLUSION

Calcitriol treatment attenuates intestinal permeability, reduces bacterial translocation, and enriches potentially beneficial gut microbiota in cirrhotic rats that may enable it as a potential therapeutic agent to prevent cirrhotic complications.

The association between vitamin D status and non-alcoholic fatty liver disease in adults: a hospital-based study

Background

The association between vitamin D levels and non-alcoholic fatty liver disease (NAFLD) has been increasingly determined in recent researches. The aim of this study was to determine the association between vitamin D levels, measured as serum 25-hydroxy vitamin D (25(OH)D) and NAFLD. Serum 25(OH)D was prospectively determined in 80 patients. Of them, 40 subjects had NAFLD, whereas 40 subjects served as healthy control. Vitamin D deficiency was defined as serum 25(OH)D level < 20 ng/ml. Receiver operating characteristic (ROC) and regression analysis methods were used in our analysis.

Results

About 70% of patients with NAFLD had vitamin D deficiency, but only 35% in the control group had. The mean serum 25 (OH)D was significantly lower in patients with NAFLD than the healthy control group (16.13 ± 10.23 versus 27.35 ± 10.58 ng/mL; P < 0.001). ROC curve analysis revealed that serum 25(OH)D level of less than 11.2 ng/ml increases the risk of NAFLD with 45% sensitivity and 97.5% specificity (Serum 25(OH)D level ≤ 18.1 ng/ml in males and ≤ 9.4 ng/ml in females increase the risk of NAFLD). Multivariate regression analysis showed that vitamin D deficiency, high age, and high BMI were associated with a significant high risk of NAFLD.

Conclusion

NAFLD patients have low serum vitamin D concentrations, suggesting that vitamin D may have a role in the development of NAFLD. Future studies are recommended to determine the important therapeutic implications of vitamin D for the prophylaxis or the treatment of NAFLD.

Calcitriol alleviates ethanol-induced hepatotoxicity via AMPK/mTOR-mediated autophagy

Excessive ethanol consumption causes cellular damage, leading to fetal alcohol syndrome and alcohol liver diseases, which are frequently seen with vitamin D (VD) deficiency. A great deal of progress has been achieved in the mechanisms of ethanol-induced hepatocyte damage. However, there are limited intervention means to reduce or rescue hepatocytes damage caused by ethanol. On the basis of our preliminary limited screen process, calcitriol showed a positive effect on protecting hepatocyte viability. Therefore, the molecular basis is worth elucidating. We found that calcitriol pretreatment markedly improved the cell viability, decreased cell apoptosis and oxidative stress and alleviated the abnormal mitochondrial morphology and membrane potential of hepatocytes induced by ethanol. Notably, autophagy was significantly enhanced by calcitriol, as evident by the increasing number of autophagosomes and autolysosomes, upregulated LC3B-Ⅱ and ATG5 levels, and promotion of p62 degradation. Furthermore, calcitriol pretreatment increased the colocalization of GFP-LC3-labeled autophagosomes with mitochondria, suggesting that calcitriol effectively promoted ethanol-induced mitophagy in hepatocytes. In addition, the inhibition of autophagy attenuated the protective and preventive effect of calcitriol. Furthermore, the effect of calcitriol on autophagy was regulated by AMPK/mTOR signaling, and signaling transduction was dependent on the Vitamin D receptor (VDR). In conclusion, calcitriol ameliorates ethanol-induced hepatocyte damage by enhancing autophagy. It may offer a convenient preventive and hepatoprotective mean for people on occasional social drink.

Vitamin D receptor gene polymorphism and hepatocellular carcinoma in chronic hepatitis C patients

Background

Hepatocellular carcinoma (HCC) is a prevalent malignancy worldwide. Vitamin D receptor (VDR) gene polymorphisms were linked to different cancers. This study was carried out to assess the possible relation between VDR gene polymorphism and the occurrence of HCC in chronic hepatitis C patients. This study included 102 subjects classified into three groups. Group A included 34 healthy subjects as control. Group B included 34 chronic hepatitis C patients with HCC. Group C included 34 chronic hepatitis C patients without HCC. Estimation of Apa-1 VDR gene polymorphism was performed by restriction fragment length polymorphism-Polymerase chain reaction (RFLP-PCR).

Results

In HCC group, C allele was more frequent than A allele (80.88% and 19.12%), respectively. In chronic hepatitis group, C allele was more frequent than A allele (64.71% and 35.29%), respectively. In control group, A allele was more frequent than C allele (73.53% and 26.47%), respectively. Genotype CC + CA was dominant in HCC group (91.18%) and chronic hepatitis group (79.41%). In the control group, the dominant genotype was AA (58.82%). Moreover, there was a significant relation between Apa-1 VDR genotype CC and tumor size.

Conclusions

There is an association between VDR Apa-1 polymorphism and the occurrence of HCC in chronic hepatitis C patients.

Serum vitamin D level is related to disease progression in primary biliary cholangitis

BACKGROUND AND AIM

A nonskeletal role of vitamin D in primary biliary cholangitis (PBC) patients is not yet clear. The purpose of this study is to investigate the serum vitamin D level in patients with PBC and to explore whether serum vitamin D level is related to disease progression.

METHODS

The serum levels of 25(OH)D₃ were measured in 185 PBC patients and 141 healthy controls. The association with vitamin D levels and disease progression, particularly natural course, was assessed.

RESULTS

Serum vitamin D levels were measured in 185 patients with PBC. The mean level of vitamin D in advanced stage patients was lower than that in early stage patients (9.15 ± 5.33 ng/ml vs. 13.68 ± 6.33 ng/ml, p = .000). In the follow-up patients, the vitamin D level in the taken calcitriol patients showed an upward trend, while the un-taken calcitriol patients was opposite. Besides, vitamin D levels were correlated with the changes of bilirubin, albumin (ALB) and APRI (p<.05). PBC patients with vitamin D deficiency had higher bilirubin levels and lower ALB levels (p<.05). Moreover, there were differences in serum vitamin D levels between taken calcitriol patients and un-taken calcitriol patients (p = .027).

CONCLUSIONS

Vitamin D deficiency is highly prevalent in PBC patients. The decrease of vitamin D levels may indicate disease progression in PBC. PBC patients need to be regularly measured for serum vitamin D level and take appropriate vitamin D supplementation.

Changes in hepatic fibrosis and vitamin D levels after viral hepatitis C eradication using direct-acting antiviral therapy

BACKGROUND

Vitamin D (VD) is important in hepatic fibrogenesis in animal models and human studies. VD deficiency is associated with liver fibrosis progression. Metabolic dysfunction of the liver, as an intermediate organ for VD metabolism, contributes partly to this deficiency. We hypothesized that improving hepatic fibrosis and inflammation in chronic hepatitis C (CHC) patients after eradication with direct-acting antivirals (DAA) would increase 25-hydroxyVD [25(OH)VD] levels.

METHODS

Eighty CHC patients (17 chronic hepatitis, and 63 cirrhosis) were enrolled. Baseline characteristics, hepatitis C viral load (VL), genotypes, liver enzymes and liver stiffness measurements (LSM) were assessed at baseline. Blood samples for 25(OH)VD and the procollagen type III N-terminal peptide (P3NP) were collected at baseline, 24 and 48 weeks. LSMs were re-evaluated at 48 weeks. Serum 25(OH)VD levels < 30 ng/mL were defined as VD insufficiency/deficiency. Paired t-tests were used for statistical analyses.

RESULTS

Among 80 patients, the mean age was 57.7 ± 10.5 years, and 52.5% were men. The mean VL was 6.1 ± 0.7 logIU/mL with genotype 1 predominance (55%). All patients achieved sustained virological response. The alanine aminotransferase levels decreased from 79.9 ± 53.3 U/L at baseline to 25.7 ± 17.2 and 22.3 ± 11.0 U/L at 24 and 48 weeks, respectively (p < 0.001). The mean LSM decreased from 19.2 ± 15.3 to 11.7 ± 8.0 kPa at 48 weeks (p < 0.001). The P3NP levels decreased from 43.6 ± 22.0 ng/mL before treatment to 35.7 ± 21.1 and 29.4 ± 15.0 ng/mL at 24 and 48 weeks, respectively (p < 0.001). The proportions of VD insufficiency/deficiency were 72.5%, 91.3%, and 86.5% at baseline, 24 and 48 weeks, respectively. The 25(OH)VD levels decreased from 26.3 ± 10.7 ng/mL at baseline to 20.8 ± 8.1 and 20.8 ± 8.5 ng/mL at 24 and 48 weeks, respectively (p < 0.001).

CONCLUSIONS

Curative treatment with DAA attenuated the liver stiffness and inflammation but did not improve VD levels. Over 80% of patients remained VD insufficient/deficient. Whether VD replacement during and after DAA therapy can improve hepatic fibrosis remains unclear. Trial registration The Thai Clinical Trial Registry as TCTR20161025001 (31 October 2016). http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=2136 .

Relationship between hepatic and systemic angiopoietin-like 3, hepatic Vitamin D receptor expression and NAFLD in obesity

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and an independent risk factor for cardiovascular mortality. Angiopoietin-like proteins (ANGPTLs) are targets for vitamin D receptor (VDR)-mediated gene transcription and this axis may promote NAFLD. ANGPTL3 is a hepatokine which inhibits lipoprotein lipase and its experimentally induced inactivation reduces hepatosteatosis. Little is known on ANGPTL3 in human NAFLD and no data exist on its relationship with hepatic VDR/VD-related genes. The aim of this research was to investigate hepatic ANGPTLs and VDR/VD-related gene expression in human obesity in relation to NAFLD.

METHODS

We conducted a cross-sectional investigation on forty obese subjects with/without NAFLD. We evaluated hepatic ANGPTL3, ANGPTL4, ANGPTL8, LPL, VDR, CYP27A1 and CYP2R1 mRNA expression in liver biopsies by RT-PCR; VDR expression was further investigated by immunohistochemistry; circulating ANGPTL3 was measured by Milliplex assay.

RESULTS

Compared to non-NAFLD, NAFLD individuals had significantly higher hepatic VDR, ANGPTL3 and LPL expression. ANGPTL3 correlated with steatosis grade, LPL, VDR, CYP27A1 and CYP2R1 expression. Plasma ANGPTL3 concentrations were positively associated with clinical/histological markers of NAFLD/NASH and with hepatic ANGPTL3 expression. Greater hepatic VDR expression was the main determinant of hepatic ANGPTL3 after adjusting for multiple confounders.

CONCLUSIONS

Hepatic ANGPTL3 expression correlates with greater VDR expression, presence and severity of NAFLD and translates in increased circulating ANGPTL3, likely as a result of its modulation by up-regulated hepatic VDR in NAFLD. This study provides novel insights to potential mechanisms underlying ANGPTLs-mediated ectopic fat accumulation and NAFLD development in obesity.

The relation of 25-hydroxy vitamin D concentrations to liver histopathology, seasonality and baseline characteristics in chronic hepatitis C virus genotype 2 or 3 infection

Background and objectives

The hydroxylation to 25-hydroxy vitamin D (25(OH)D) occurs in the liver and the impact of liver disease on vitamin D is unclear. This study evaluated the relationship between vitamin D concentrations and hepatic histopathology, seasonality and patient characteristics in well-characterized patients having undergone a liver biopsy.

Method

25(OH)D was measured post-hoc in pre-treatment serum from 331 North European patients with chronic HCV genotype 2 or 3 infection (NORDynamIC study). Liver biopsies were scored for fibrosis and inflammation according to the Ishak protocol, and graded for steatosis. Non-invasive markers of hepatic fibrosis as well as baseline viral and host characteristics, including genetic polymorphisms rs2228570, rs7975232, and rs10877012 were also evaluated.

Results

Mean 25(OH)D concentration was 59 ±23 nmol/L, with 41% having values <50 nmol/L and 6% were <30 nmol/L. 25(OH)D correlated with fibrosis (r = -0.10, p ≤0.05) in univariate but not in multivariate analyses. No association was observed between 25(OH)D and hepatic inflammation, but with steatosis in HCV genotype 2 infected patients. None of the genetic polymorphisms impacted on 25(OH)D levels or fibrosis. 25(OH)D levels were significantly inversely correlated to BMI (r = -0.19, p = 0.001), and was also associated with season and non-Caucasian ethnicity.

Conclusion

Fibrosis was not independently associated with 25(OH)D concentration and no association was seen with hepatic inflammation, but HCV genotype 2 infected patients with moderate-to-severe steatosis had lower 25(OH)D levels compared to those without steatosis. A high percentage had potential risk of 25(OH)D deficiency, and BMI, seasonality and ethnicity were independently associated with 25(OH)D as previously reported.

Low serum vitamin D is independently associated with unexplained elevated ALT only among non-obese men in the general population

INTRODUCTION AND OBJECTIVES

There are inconsistent findings on the association between human non-alcoholic fatty liver disease (NAFLD) and vitamin D, perhaps due to insufficient specificity for gender and obesity status. We aimed to assess whether serum levels of 25-hydroxyvitamin D are associated with unexplained elevated alanine aminotransferase (ALT) in general population across gender and body mass index (BMI) levels.

MATERIALS AND METHODS

A cross-sectional analysis of a population-based cohort with a nationwide-distribution using electronic medical database. The population consisted of individuals aged 20-60 years who underwent blood tests for ALT and vitamin D.

RESULTS

A total of 82,553 subjects were included (32.5% men, mean age 43.91±10.15 years). The prevalence of elevated ALT was higher among men and women with vitamin D insufficiency or deficiency, but in multivariate analysis, adjusting for: age, BMI, serum levels of glucose, total cholesterol, triglycerides, statin use and season, only the association among men remained significant for the vitamin D deficiency category (OR=1.16, 95%CI 1.04-1.29, P=0.010). Stratification by BMI revealed that only among normal weight and overweight men vitamin D deficiency was associated with elevated ALT (OR=1.27, 95%CI 1.01-1.59, P=0.041 and OR=1.27, 95%CI 1.08-1.50, P=0.003, respectively). No independent association was shown among women at all BMI categories.

CONCLUSIONS

In a "real-life" general population, the association between vitamin D deficiency and unexplained elevated ALT is specific for non-obese men. The clinical significance of vitamin D for human NAFLD should be further elucidated with attention for a modifying effect of gender and adiposity.

Vitamin D levels are not associated with non-alcoholic fatty liver disease severity in a Brazilian population

Some epidemiological evidence suggests an inverse correlation between non-alcoholic fatty liver disease (NAFLD) frequency and vitamin D levels. Likewise, a beneficial effect of vitamin D on diabetes mellitus (DM) and insulin resistance has been observed, but this is an unsolved issue. Thus, we aimed to investigate the prevalence of hypovitaminosis D in a NAFLD Brazilian population and its association with disease severity and presence of comorbidities. In a cross-sectional study, the clinical, biochemical and histological parameters of 139 NAFLD patients were evaluated according to two different cut-off points of serum 25-hydroxyvitamin D levels (20 ng/mL and 30 ng/mL). The mean age of the population was 56 ± 16 years, most patients were female (83%), 72% had hypertension, 88% dyslipidemia, 46% DM, 98% central obesity, and 82% metabolic syndrome. Serum vitamin D levels were < 30 ng/mL in 78% of the patients, and < 20 ng/mL in 35%. The mean vitamin D level was 24.3 ± 6.8 ng/mL. The comparison between the clinical, biochemical and histological characteristics of the patients according to the levels of vitamin D showed no significant difference. Most patients with NAFLD had hypovitaminosis D, but low vitamin D levels were not related to disease severity and the presence of comorbidities.

Decreased circulating vitamin D reflects adverse outcomes of hepatitis C virus infection: A systematic review and meta-analysis

OBJECTIVES

This study aimed to clarify associations of circulating vitamin D and its status with severity of HCV infection.

METHODS

We performed systemic literature search in PubMed, Scopus, and Cochrane library databases from inception until the end of December 2019 with terms related to vitamin D and hepatitis C.

RESULTS

A total of 28 studies consisting of 7736 HCV-infected patients and 14061 control subjects without liver diseases were included. Compared to controls, circulating vitamin D levels were significantly lessened in HCV-infected patients (mean difference, MD=-14.15, 95% CI: -20.51 to -7.80). Remarkably decreased circulating vitamin D was found in the patients with severe fibrosis (MD=-3.38, 95% CI: -4.51 to -2.25), non-achieving SVR (MD=-2.99, 95%CI: -5.55 to -0.42), and advanced inflammation (MD=-4.68, 95% CI: -8.50 to -0.86). Low vitamin D status (<20 ng/mL) was significantly associated with increased odds of HCV infection (pooled OR=2.41, 95% CI: 1.48 to 3.95). Besides, HCV-infected patients with low vitamin D status showed significantly escalated odds of severe fibrosis and non-achieving SVR (pooled OR=1.70, 95% CI: 1.27 to 2.26; pooled OR=2.04, 95% CI: 1.62 to 2.57, respectively).

CONCLUSION

HCV-infected patients with declined circulating vitamin D levels were associated with severe fibrosis, non-achieving SVR, and advanced inflammation.