Severity of Nonalcoholic Fatty Liver Disease in Type 2 Diabetes Mellitus: Relationship between Nongenetic Factors and PNPLA3/HSD17B13 Polymorphisms

PNPLA3 as a driver of steatotic liver disease: navigating from pathobiology to the clinics via epidemiology

Steatotic liver disease (SLD), particularly metabolic dysfunction-associated SLD, represents a significant public health concern worldwide. Among the various factors implicated in the development and progression of this condition, the patatin-like phospholipase domain-containing protein 3 (PNPLA3 ) gene has emerged as a critical player. Variants of PNPLA3 are associated with altered lipid metabolism, leading to increased hepatic fat accumulation and subsequent inflammation and fibrosis. Understanding the role of PNPLA3 not only enhances our comprehension of the pathomechanisms driving SLD but also informs potential therapeutic strategies. The molecular mechanisms through which PNPLA3 variants contribute to lipid dysregulation and hepatocyte injury in SLD are critically discussed in the present review article. We extensively analyze clinical cohorts and population-based studies underpinning the association between PNPLA3 polymorphisms and the risk of developing SLD, and its liver-related and protean extrahepatic outcomes, in concert with other risk modifiers, notably including age, sex, and ethnicity in adults and children. We also discuss the increasingly recognized role played by the PNPLA3 gene in liver transplantation, autoimmune hepatitis, and acquired immunodeficiency syndrome. Finally, we examine the clinical implications of PNPLA3 diagnostics regarding risk stratification and targeted therapies for patients affected by SLD in the context of precision medicine approaches.

The interplay between Helicobacter pylori infection and rs738409 PNPLA3 in metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Recent studies have suggested an association between H. pylori and metabolic-disfunction associated fatty liver disease (MASLD). However, epidemiologic studies have yielded inconsistent results. We aim to evaluate the association of H. pylori and G-allele PNPLA3 in MASLD diagnosis, and markers of severity.

METHODS

A multi-center cross-sectional study was conducted. A total 224 functional dyspepsia (FD) patients cohort who underwent gastroscopy was selected. Biochemical, clinical parameters, ultrasound, FIB-4 score, LSM by VCTE, gastric biopsies, H. pylori status, and rs738409 PNPLA3 were evaluated. A second retrospective cohort of 86 patients with biopsy-proven MASLD who underwent gastroscopy with gastric biopsies was analyzed.

RESULTS

In the FD cohort MASLD was observed in 52%, and H. pylori-positive in 51%. H. pylori infection was associated with MASLD prevalence, but in multivariate analyses adjusted for G-allele PNPLA3, it became not significant. Then in MASLD-only dyspeptic cohort, H. pylori infection was significantly linked to elevated serum AST levels and increased liver stiffness measurements, suggesting a potential role in liver injury and fibrosis. Histopathological analysis in biopsy-proven MASLD patients further supported these findings, showing a significant association between H. pylori infection and increased NAS score, fibrosis stage, and prevalence of MASH. Notably, the combination of H. pylori infection and G-allele PNPLA3 appeared to exacerbate MASLD severity beyond individual effects.

CONCLUSIONS

Our results suggest that H. pylori infection may play a role in the progression of liver injury and fibrosis in patients with MASLD, especially in those with specific genetic predispositions.

17-Beta-Hydroxysteroid Dehydrogenase 13 Loss of Function Does Not Confer Protection to Nonalcoholic Fatty Liver Disease in Indian Population

Background

A splice variant in HSD17B13 gene is demonstrated to protect against nonalcoholic fatty liver disease (NAFLD), and mitigate the effect of Patatin-like phospholipase domain-containing 3 (PNPLA3-I148M). It is being explored as a putative drug target and in polygenic risk scores. Based on whole exome sequencing (WES) in our cohort of biopsy proven NAFLD and limited data on the variant in our ethnicity, we sought to explore its role.

Methods

This is a cross-sectional study that recruited 1,020 individuals with ultrasound/biopsy-confirmed NAFLD and matched controls. Liver enzymes and lipid profiles were estimated (Beckman coulter LX750/DXH800); WES was performed in NAFLD patients and controls (Illumina; HiSeqX); HSD17B13-A-INS/I148M-PNPLA3 variants were genotyped (sequencing/qR T-PCR); HSD17B13 protein expression was estimated (immunohistochemistry); the Student's t-test/Mann-Whitney U/Chi-square test and odds ratio (95% confidence interval) were used.

Results

There was no significant difference (Odds ratio = 0.76; 95% CI -0.57 to 1.03; P = 0.76) in the frequency of the rs72613567-A-INS between controls and patients (17.8% vs. 14.4%). No difference in the ALT (Alanine transaminase; 72.24 ± 65.13 vs. 73.70 ± 60.06; P = 0.51) and AST levels (Aspartate aminotransferase; 60.72 ± 55.59 vs. 61.63 ± 60.33; P = 0.91) between HSD17B13-wild and variant carriers were noted. Significantly elevated liver enzymes were seen in PNPLA3-148-variant/HSD17B13-wild compared with PNPLA3-148-variant/HSD17B13-variant (90.44 ± 59.0 vs. 112.32 ± 61.78; P = 0.02). No difference in steatosis (P = 0.51) between HSD17B13-wild and variant carriers was noted. No other variants in the intron-exon boundaries were identified. Although, protein expression differences were noted between wild and variant carriers, no difference in the extent of steatosis was seen.

Conclusion

Our study reports lack of association of the splice variant with reduced risk of NAFLD, and mitigating the effect of PNPLA3 variant. Ethnicity-based validation must be carried out before including it in assessing protection against NAFLD.

miRNA and lncRNA as potential tissue biomarkers in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is primary liver cancer, frequently diagnosed at advanced stages with limited therapeutic options. MicroRNAs (miRNAs) regulate target gene expression and through inhibitory competitive binding of miRNA influence cellular processes including carcinogenesis. Extensive evidence proved that certain miRNA's are specifically expressed in neoplastic tissues of HCC patients and are confirmed as important factors that can participate in the regulation of key signalling pathways in cancer cells. As such, miRNAs have a great potential in the clinical diagnosis and treatment of HCC and can improve the limitations of standard diagnosis and treatment. Long non-coding RNAs (lncRNAs) have a critical role in the development and progression of HCC. HCC-related lncRNAs have been demonstrated to exhibit abnormal expression and contribute to transformation process (such as proliferation, apoptosis, accelerated vascular formation, and gain of invasive potential) through their interaction with DNA, RNA, or proteins. LncRNAs can bind mRNAs to release their target mRNA and enable its translation. These lncRNA-miRNA networks regulate cancer cell expression and so its proliferation, apoptosis, invasion, metastasis, angiogenesis, epithelial-mesenchymal transition (EMT), drug resistance, and autophagy. In this narrative review, we focus on miRNA and lncRNA in HCC tumor tissue and their interaction as current tools, and biomarkers and therapeutic targets unravelled in recent years.

Global prevalence of non-alcoholic fatty liver disease in type 2 diabetes mellitus: an updated systematic review and meta-analysis

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, with type 2 diabetes mellitus (T2DM) as a major predictor. Insulin resistance and chronic inflammation are key pathways in the pathogenesis of T2DM leading to NAFLD and vice versa, with the synergistic effect of NAFLD and T2DM increasing morbidity and mortality risks. This meta-analysis aims to quantify the prevalence of NAFLD and the prevalence of clinically significant and advanced fibrosis in people with T2DM.

METHODS

MEDLINE and Embase databases were searched from inception until 13 February 2023. The primary outcomes were the prevalence of NAFLD, non-alcoholic steatohepatitis (NASH) and fibrosis in people with T2DM. A generalised linear mixed model with Clopper-Pearson intervals was used for the analysis of proportions with sensitivity analysis conducted to explore heterogeneity between studies.

RESULTS

156 studies met the inclusion criteria, and a pooled analysis of 1 832 125 patients determined that the prevalence rates of NAFLD and NASH in T2DM were 65.04% (95% CI 61.79% to 68.15%, I2=99.90%) and 31.55% (95% CI 17.12% to 50.70%, I2=97.70%), respectively. 35.54% (95% CI 19.56% to 55.56%, I2=100.00%) of individuals with T2DM with NAFLD had clinically significant fibrosis (F2-F4), while 14.95% (95% CI 11.03% to 19.95%, I2=99.00%) had advanced fibrosis (F3-F4).

CONCLUSION

This study determined a high prevalence of NAFLD, NASH and fibrosis in people with T2DM. Increased efforts are required to prevent T2DM to combat the rising burden of NAFLD.

PROSPERO REGISTRATION NUMBER

CRD42022360251.

Identification of shared genetic architecture between non-alcoholic fatty liver disease and type 2 diabetes: A genome-wide analysis

BACKGROUND

The incidence of complications of non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) has been increasing.

METHOD

In order to identify the shared genetic architecture of the two disease phenotypes of NAFLD and T2D, a European population-based GWAS summary and a cross-trait meta-analysis was used to identify significant shared genes for NAFLD and T2D. The enrichment of shared genes was then determined through the use of functional enrichment analysis to investigate the relationship between genes and phenotypes. Additionally, differential gene expression analysis was performed, significant differentially expressed genes in NAFLD and T2D were identified, genes that overlapped between those that were differentially expressed and cross-trait results were reported, and enrichment analysis was performed on the core genes that had been obtained in this way. Finally, the application of a bidirectional Mendelian randomization (MR) approach determined the causal link between NAFLD and T2D.

RESULT

A total of 115 genes were discovered to be shared between NAFLD and T2D in the GWAS analysis. The enrichment analysis of these genes showed that some were involved in the processes such as the decomposition and metabolism of lipids, phospholipids, and glycerophospholipids. Additionally, through the use of differential gene expression analysis, 15 core genes were confirmed to be linked to both T2D and NAFLD. They were correlated with carcinoma cells and inflammation. Furthermore, the bidirectional MR identified a positive causal relationship between NAFLD and T2D.

CONCLUSION

Our study determined the genetic structure shared between NAFLD and T2D, offering a new reference for the genetic pathogenesis and mechanism of NAFLD and T2D comorbidities.

Review article: the role of HSD17B13 on global epidemiology, natural history, pathogenesis and treatment of NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) occurs in around a quarter of the global population and is one of the leading causes of chronic liver disease. The phenotypic manifestation and the severity of NAFLD are influenced by an interplay of environmental and genetic factors. Recently, several inactivating variants in the novel 17-Beta hydroxysteroid dehydrogenase 13 (HSD17B13) gene have been found to be associated with a reduced risk of chronic liver diseases, including NAFLD.

AIMS

To review the existing literature on the epidemiology of HSD17B13 and discuss its role in the natural history, disease pathogenesis and treatment of NAFLD.

METHODS

We extensively searched relevant literature in PubMed, Google Scholar, clinicaltrials.gov and the reference list of articles included in the review.

RESULTS

HSD17B13 is a liver-specific, lipid droplet (LD)-associated protein that has enzymatic pathways involving steroids, pro-inflammatory lipid mediators and retinol. The estimated prevalence of the best characterised HSD17B13 variant (rs72613567) ranges from 5% in Africa to 34% in East Asia. Loss-of-function variants in HSD17B13 are protective against the progression of NAFLD from simple steatosis to non-alcoholic steatohepatitis (NASH), liver fibrosis, cirrhosis and hepatocellular carcinoma. Emerging data from mechanistic and preclinical studies with RNA interference (RNAi) and small molecule agents indicate that inhibiting HSD17B13 activity may prevent NAFLD progression.

CONCLUSIONS

The loss-of-function polymorphisms of the newly identified HSD17B13 gene mitigate the progression of NAFLD. It is important to understand the exact mechanism by which these variants exert a protective effect and implement the gathered knowledge in the treatment of NAFLD.

Prevalence of elevated liver stiffness in patients with type 1 and type 2 diabetes: A systematic review and meta-analysis

BACKGROUND & AIMS

Liver stiffness is an indirect marker of liver fibrosis, which predicts clinical outcomes in patients with nonalcoholic fatty liver disease (NAFLD). The aim of the present systematic review and meta-analysis is to summarize evidence on the prevalence of elevated liver stiffness in patients with diabetes.

METHODS

We systematically searched PubMed-MEDLINE and Scopus from inception to May 2022 for observational studies reporting the prevalence of elevated liver stiffness diagnosed by vibration controlled transient elastography (VCTE) in adult patients with either type 1 (T1D) or type 2 diabetes (T2D). Prevalence values from individual studies were meta-analyzed using random effects models. Subgroup and sensitivity analyses were performed to identify potential sources of heterogeneity.

RESULTS

Of the 428 titles initially scrutinized, 29 studies fulfilled the criteria and were included, providing data on 390 patients with T1D and 10,487 patients with T2D. Prevalence rates of elevated liver stiffness were 5.2% (95% CI 1.1-9.2) in patients with T1D and 19.8% (95% CI 16.8-22.8) in patients with T2D. In studies performed in patients with T2D, multivariate meta-regression analysis showed that higher body mass index, higher age, a higher proportion of males, lower VCTE cut-off and Asian ethnicity were associated with increased prevalence rates. This model explained 32.7% of the observed heterogeneity. No signs of publication bias were identified by visual inspection of the funnel plot or by Egger's test.

CONCLUSIONS

This meta-analysis indicates that 1 in 20 patients with T1D and 1 in 5 patients with T2D has elevated liver stiffness, indicative of potential significant or advanced liver fibrosis.

Triglyceride and glucose index is a simple and easy-to-calculate marker associated with nonalcoholic fatty liver disease

OBJECTIVE

The aim of this study was to evaluate the relationship between the triglyceride and glucose (TyG) index and nonalcoholic fatty liver disease (NAFLD) using a large, population-based cohort study database.

METHODS

A total of 52,575 participants were enrolled from 2007 to 2013 in the Kangbuk Samsung Health Study cohort. The presence of NAFLD was ascertained by ultrasonography in the absence of other known liver diseases.

RESULTS

Over a median 5.1 years of follow-up, 7,292 participants (13.87%) were diagnosed with NAFLD. In a multivariate-adjusted model, the hazard ratio for NAFLD of the TyG index was 1.413 (95% CI: 1.349-1.480) in the first 6 months, 1.480 (95% CI: 1.408-1.556) in months 6 to 12, 1.427 (95% CI: 1.370-1.485) in months 12 to 18, and 1.246 (95% CI: 1.159-1.339) in months >18. The hazard ratios of triglycerides, glucose, fatty liver index, and homeostatic model assessment of insulin resistance for NAFLD in months >18 were 1.124 (95% CI: 1.061-1.190), 1.037 (95% CI: 0.970-1.109), 1.508 (95% CI: 1.417-1.605), and 1.177 (95% CI: 1.116-1.242), respectively. The NAFLD-free rate decreased with increasing TyG index quartile (p < 0.001). The TyG index level from which the risk of NAFLD increased appeared to be 8.24.

CONCLUSIONS

This study found that the TyG index is a simple and easy-to-calculate marker associated with NAFLD.

Influence of Type 2 Diabetes in the Association of PNPLA3 rs738409 and TM6SF2 rs58542926 Polymorphisms in NASH Advanced Liver Fibrosis

Nonalcoholic steatohepatitis (NASH) is a leading cause of cirrhosis in western countries. Insulin resistance (IR), type 2 diabetes (T2D), and the polymorphisms patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 and transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 are independent risk factors of NASH. Nevertheless, little is known about the interaction between IR and T2D with these polymorphisms in the pathogenesis of NASH and the development of advanced fibrosis. Thus, our study aimed to investigate this relationship. This is a cross-sectional study including NASH patients diagnosed by liver biopsy, at the Vall d’Hebron University Hospital. A total of 140 patients were included (93 T2D, 47 non-T2D). T2D (OR = 4.67; 95%CI 2.13−10.20; p < 0.001), PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphisms (OR = 3.94; 95%CI 1.63−9.54; p = 0.002) were independently related with advanced liver fibrosis. T2D increased the risk of advance fibrosis on top of the two polymorphisms (OR = 14.69; 95%CI 3.03−77.35; p = 0.001 for PNPLA3 rs738409 and OR = 11.45; 95%CI 3.16−41.55; p < 0.001 for TM6SF2 rs58542926). In non-T2D patients, the IR (HOMA-IR ≥ 5.2, OR = 14.33; 95%CI 2.14−18.66; p = 0.014) increased the risk of advanced fibrosis when the polymorphisms were present (OR = 19.04; 95%CI 1.71−650.84; p = 0.042). The T2D and IR status increase the risk of advanced fibrosis in patients with NASH carrying the PNPLA3 rs738409 and/or TM6SF2 rs58542926 polymorphisms, respectively.

HSD17B13 and other liver fat-modulating genes predict development of hepatocellular carcinoma among HCV-positive cirrhotics with and without viral clearance after DAA treatment

BACKGROUND

Genetic predisposition to accumulate liver fat (expressed by a polygenic risk score, GRS, based on the number of at-risk alleles of PNPLA3, TM6SF2, MBOAT7 and GCKR) may influence the probability of developing hepatocellular carcinoma (HCC) after hepatitis C treatment. Whether this holds true taking into account carriage of the HSD17B13:TA splice variant, also affecting lipogenesis, and achievement of viral clearance (SVR), is unknown.

METHODS

PNPLA3, TM6SF2, MBOAT7, GCKR and HSD17B13 variants were determined in a cohort of 328 cirrhotic patients free of HCC before starting treatment with direct acting antivirals (DAA).

RESULTS

SVR in the study cohort was 96%. At the end of follow-up, N = 21 patients had been diagnosed an HCC; none of the genes included in the GRS was individually associated with HCC development. However, in a Cox proportional hazards model, a GRS > 0.457 predicted HCC independently of sex, diabetes, albumin, INR and FIB4. The fit of the model improved adding treatment outcome and carriage of the HSD17B13:TA splice variant, with sex, GRS > 0.457, HSD17B13:TA splice variant and failure to achieve an SVR (hazard ratio = 6.75, 4.24, 0.24 and 7.7, respectively) being independent predictors of HCC.

CONCLUSION

Our findings confirm that genes modulating liver fat and lipogenesis are important risk factors for HCC development among cirrhotics C treated with DAA.

Genetic Polymorphisms and Clinical Features in Diabetic Patients With Fatty Liver: Results From a Single-Center Experience in Southern Italy

Genetic background may be involved in the promotion and progression of non-alcoholic fatty liver disease (NAFLD). Previous studies have suggested that the single nucleotide polymorphisms (SNPs) may be associated with the specific clinical features in the patients with hepatic steatosis; however, data on the patients with diabetes from Southern Italy are lacking. We enrolled 454 patients and 260 of them had type 2 diabetes. We studied the PNPLA3 rs738409, LPIN1 rs13412852, KLF6 rs3750861, SOD2 rs4880, TM6SF2 rs58542926, and ZNF624 rs12603226 SNPs and their distribution in the study population. Lipid profile, liver stiffness, and kidney function were also studied to understand the potential role of the SNPs in the development of clinical phenotypes. No differences were observed in the distribution of polymorphisms between the diabetic and non-diabetic subjects. Carriers of risk allele G for PNPLA3 rs738409 SNP showed a lower mean value of serum triglycerides and a higher liver stiffness. Risk allele for KLF6 rs3750861 and SOD2 rs4880 polymorphism had a lower estimated glomerular filtration rate (eGFR) value, whereas no differences in the glucose and glycated hemoglobin level were observed in the subgroups by the different genotypes. Genetic polymorphisms are useful to identify the patients at higher risk of development of liver fibrosis and lower eGFR values in the patients with diabetes and NAFLD. Their use in clinical practice may help the clinicians to identify the patients who require a more strict follow-up program.

Research progress, challenges and perspectives on PNPLA3 and its variants in Liver Diseases

The human patatin-like phospholipase domain-containing 3 gene (PNPLA3) is highly expressed in liver and adipose tissue and encodes a transmembrane polypeptide chain containing 481 amino acids. The I148M variant of PNPLA3 is a single nucleotide polymorphism, which is related to a variety of liver and cardiovascular diseases and their complications (such as non-alcoholic fatty liver disease, liver fibrosis, coronary artery disease). This review mainly describes the pathophysiological effects of PNPLA3 and its variants, and their roles in the progression of liver disease and its complications.

Albuminuria Is Associated with Steatosis Burden in Patients with Type 2 Diabetes Mellitus and Nonalcoholic Fatty Liver Disease

BACKGROUND

This study aimed to investigate the association between hepatic steatosis burden and albuminuria in Korean patients with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD).

METHODS

We recruited 100 patients with both T2DM and NAFLD, but without chronic kidney disease. Albuminuria was defined as a spot urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. Transient elastography was performed, and the steatosis burden was quantified by controlled attenuation parameter (CAP) with significant steatosis defined as CAP >302 dB/m.

RESULTS

The prevalence of significant steatosis and albuminuria was 56.0% and 21.0%, respectively. Subjects with significant steatosis were significantly younger and had a significantly shorter duration of T2DM, greater waist circumference, and higher body mass index, total cholesterol, triglyceride, and low density lipoprotein cholesterol levels, than subjects without severe NAFLD (all P<0.05). Albuminuria was higher in patients with significant steatosis than in patients without significant steatosis (32.1% vs. 6.8%, P=0.002). Urinary ACR showed a correlation with CAP (r=0.331, P=0.001), and multiple linear regression analysis revealed a significant association between a high degree of albuminuria and high CAP value (r=0.321, P=0.001). Additionally, multivariate logistic regression analysis demonstrated the independent association between urinary ACR and significant steatosis after adjustment for confounding factors including age, body mass index, duration of T2DM, low density lipoprotein level, and renin-angiotensin system blocker use (odds ratio, 1.88; 95% confidence interval, 1.31 to 2.71; P=0.001).

CONCLUSION

T2DM patients with NAFLD had a higher prevalence of albuminuria, which correlated with their steatosis burden.

Associations of Hydroxysteroid 17-beta Dehydrogenase 13 Variants with Liver Histology in Chinese Patients with Metabolic-associated Fatty Liver Disease

BACKGROUND AND AIMS

In Europeans, variants in the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) gene impact liver histology in metabolic-associated fatty liver disease (MAFLD). The impact of these variants in ethnic Chinese is unknown. The aim of this study was to investigate the potential associations in Chinese patients.

METHODS

In total, 427 Han Chinese with biopsy-confirmed MAFLD were enrolled. Two single nucleotide polymorphisms in HSD17B13 were genotyped: rs72613567 and rs6531975. Logistic regression was used to test the association between the single nucleotide polymorphisms and liver histology.

RESULTS

In our cohort, the minor allele TA of the rs72613567 variant was related to an increased risk of fibrosis [odds ratio (OR): 2.93 (1.20-7.17), p=0.019 for the additive model; OR: 3.32 (1.39-7.91), p=0.007 for the recessive model], representing an inverse association as compared to the results from European cohorts. In contrast, we observed a protective effect on fibrosis for the minor A allele carriers of the HSD17B13 rs6531975 variant [OR: 0.48 (0.24-0.98), p=0.043 for the additive model; OR: 0.62 (0.40-0.94), p=0.025 for the dominant model]. HSD17B13 variants were only associated with fibrosis but no other histological features. Furthermore, HSD17B13 rs6531975 modulated the effect of PNPLA3 rs738409 on hepatic steatosis.

CONCLUSIONS

HSD17B13 rs72613567 is a risk variant for fibrosis in a Han Chinese MAFLD population but with a different direction for allelic association to that seen in Europeans. These data exemplify the need for studying diverse populations in genetic studies in order to fine map genome-wide association studies signals.

Lifestyle and silymarin: a fight against liver damage in NAFLD associated - prediabetic disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is common in both prediabetic patients and healthy overweight individuals, yet it remains understudied. This study investigates the effects of hepatic steatosis on fibrosis and evaluates the major predictors of liver injury in prediabetes and whether this damage is reversible with Mediterranean diet and administration of the nutraceutical silymarin.

METHODS

First, a case-control study was conducted in which 212 patients with prediabetes, not known to have NAFLD, and 126 healthy controls underwent clinical evaluation, transient elastography with measurement of liver stiffness (LS) and controlled attenuation parameter (CAP). Subsequently, the 212 prediabetic patients were enrolled into a prospective randomized interventional study: 104 were allocated to Mediterranean diet alone while 108 followed Mediterranean diet plus supplementation with silymarin (a flavonolignan complex isolated from Silybum marianum and Morus alba). The administered silymarin dose was 210 mg twice daily for 6 months. Clinical and instrumental evaluations were repeated at the end of the 6 month-study period. Prediabetics were genotyped for patatin like phospholipase domain containing 3 (PNPLA3).

RESULTS

In the case-control study, 29% of prediabetic patients have significant fibrosis defined as LS ≥ 7.9 kPa vs only 3% of controls (p < 0.001). PNPLA3 genotype CG/GG are significantly associated with significant fibrosis LS ≥ 7.9 relative to CC genotype χ2(1) = 76.466, p < 0.001. Binomial regression analysis shows that increase in BMI, ALT and AST are significantly associated with increased likelihood of significant fibrosis (χ2(7) = 191.9, p < .001) prior to intervention. In the randomized interventional study, prediabetics following Mediterranean diet alone (group 1) experienced a significant regression of fibrosis and decrease in ALT, HbA1c, FBS after 6 months (p < 0.001); similar findings were observed in patients following Mediterranean diet plus silymarin regimen (group 2); group 2 had a significant decrease in HbA1c relative to group 1 (95% CI: 37.8-38.6 vs 39.5-40.3, p < 0.001).

CONCLUSION

PNPLA3 genotype CG/GG and elevated BMI are the major predictors of significant fibrosis in prediabetic patients prior to intervention in this study. Mediterranean diet either alone or with silymarin treatment for 6 months leads to significant regression of liver damage and improvement of the glycemic profile in prediabetic patients. Yet, as combination treatment of silymarin with Mediterranean diet shows significant reduction of HbA1c when compared to diet alone, this suggests that silymarin may exert an independent anti-glycemic action.

The effect of liraglutide on nonalcoholic fatty liver disease in type 2 diabetes mellitus

Aims

The objective is to investigate the effects of liraglutide on nonalcoholic fatty liver disease in type 2 diabetes mellitus.

Materials and methods

Thirty-two patients with T2DM and NAFLD admitted to the Third Affiliated Hospital of Dalian Medical University from December 2014 to December 2016 were selected, including 11 females and 21 males, aged 39.34 ± 8.54 years old. The patients were given liraglutide on the basis of their original hypoglycemic regimen.

Results

After 3 months treatment of liraglutide, FPG was reduced from 8.54 ± 2.21 mmol/L to 6.90 ± 1.73 mmol/L. HbA1c was reduced from 9.72 ± 1.95 to 7.78 ± 1.99. WC was reduced from 103.27 ± 9.92 kg to 93.97 ± 8.35 kg. BMI was reduced from 30.56 ± 4.06 kg/m2 to 28.01 ± 3.12 kg/m2. FLI was reduced from 79.23 ± 16.56 to 58.83 ± 19.75. The differences were statistically significant (p < 0.001). TG was reduced from 2.95 ± 2.13 mmol/L to 2.27 ± 1.31 mmol/L. The difference was significant (p < 0.01). Meanwhile, HOMA-IR was reduced from 1.504 ± 0.002 to 1.503 ± 0.002. GGT was reduced from 62.63 ± 71.61 U/L to 38.13 ± 30.13 U/L. AST was reduced from 27.25 ± 13.74 U/L to 25.44 ± 16.69 U/L. The differences were statistically significant (p < 0.05). After treatment, FCP, TC, HDL-C, LDL-C, ALT, and HOMA-β were also improved compared with before treatment, but the difference was not statistically significant (p > 0.05).

Conclusion

In addition to effectively lowering glucose and improving islet resistance, liraglutide could also improve obesity and adjust blood lipids. However, the improvement of islet function might not be significant after 3 months of treatment. Liraglutide could reduce liver fat accumulation in patients with T2DM and NAFLD.

Toward Genetic Prediction of Nonalcoholic Fatty Liver Disease Trajectories: PNPLA3 and Beyond

Nonalcoholic fatty liver disease (NAFLD) is on the verge of becoming the leading cause of liver disease. NAFLD develops at the interface between environmental factors and inherited predisposition. Genome-wide association studies, followed by exome-wide analyses, led to identification of genetic risk variants (eg, PNPLA3, TM6SF2, and SERPINA1) and key pathways involved in fatty liver disease pathobiology. Functional studies improved our understanding of these genetic factors and the molecular mechanisms underlying the trajectories from fat accumulation to fibrosis, cirrhosis, and cancer over time. Here, we summarize key NAFLD risk genes and illustrate their interactions in a 3-dimensional "risk space." Although NAFLD genomics sometimes appears to be "lost in translation," we envision clinical utility in trial design, outcome prediction, and NAFLD surveillance.

Interplay of PNPLA3 and HSD17B13 Variants in Modulating the Risk of Hepatocellular Carcinoma among Hepatitis C Patients

A single-nucleotide polymorphism causing a C to G change in the PNPLA3 gene (rs738409) is associated with disease severity and development of hepatocellular carcinoma (HCC) in nonalcoholic fatty liver disease; the insertion variant rs72613567:TA of the 17β-hydroxysteroid dehydrogenase type 13 (HSD17B13) mitigates this detrimental effect. Our aim was to evaluate if the same holds true in chronic hepatitis C virus infection (HCV). With a case control retrospective study design, we selected 110 patients who developed HCC on a background of HCV infection, matching each patient for sex and age (±30 months) to three HCV-infected, non-HCC patients. All participants underwent genotyping for PNPLA3 and HSD17B13 gene variants. Both univariate and multivariate analyses of risk factors for advanced disease and HCC were performed. Carriage of PNPLA3 G∗ allele was associated with a trend of progressively more severe liver disease, from mild fibrosis to significant fibrosis, cirrhosis, and HCC (p = 0.007). When the HSD17B13:TA status of these patients was taken into account, the abovementioned trend was strengthened among HSD17B13 major allele homozygotes and completely blunted among carriers of the minor allele (p = 0.0003 and 0.953, respectively). In a conditional logistic regression model including diabetes and AST to platelet ratio index among predictor variables, the unfavourable genetic profile characterized by the coexistence of the PNPLA3 minor allele and HSD17B13 major allele (vs. all other possible combinations) was an independent risk factor for HCC (OR = 2.00, 95% CI: 1.23-3.26) together with a history of alcohol abuse. In conclusion, carriage of the combination PNPLA3 minor allele and HSD17B13 major allele may represent a risk factor for HCC among HCV-infected patients. The interplay between the two genes may explain some of the controversy on this topic and may be exploited to stratify HCC risk in hepatitis C.

[Expression of high mobility group protein B1 in periodontal tissues and its association with hepatic lipid metabolism in diabetic rats with periodontitis]

OBJECTIVE

To investigate the expression of high mobility group box-1 protein (HMGB1) and its downstream products, receptor for advanced glycation end-products (RAGE) and tumor necrosis factor-α (TNF-α), in periodontal tissues of diabetic rats with periodontitis, and explore the association of HMGB1 with hepatic lipid metabolism.

METHODS

Immunohistochemical staining was used to detect the expression of HMGB1, RAGE and TNF-α in the periodontal tissues in rat models of diabetes mellitus (DM), periodontitis (CP), and diabetic periodontitis (DM + CP). The serum levels of the indicators of lipid metabolism and biochemical indexes of liver damage were detected by spectroscopy.

RESULTS

The expressions of HMGB1 and RAGE in the periodontal tissues were significantly higher in DM group than in the control group, but the expression of TNF-α showed no significant difference among the groups. In CP group, the expressions of HMGB1 and TNF-α were significantly higher than those in the control group, and the expression of RAGE was comparable with that in the control group but significantly lower than that in DM and DM+CP group. The expressions of HMGB1, RAGE and TNF-α were all significantly higher in DM+CP group than in the control group. Compared with the control rats, the rats in DM, CP, DM+CP group all showed abnormal hepatic lipid metabolism with significantly elevated serum ALT levels.

CONCLUSIONS

HMGB1 and RAGE participate in the inflammation of the periodontal tissues in diabetic rats. Diabetes leads to elevated expression of HMGB1 in the periodontal tissues. Both periodontitis and hyperglycemia contribute to liver metabolic dysfunction. HMGB1- RAGE provides clues in the study of signaling pathways underlying the mutual susceptibility of diabetes and periodontitis.