Validation of PNPLA3 polymorphisms as risk factor for NAFLD and liver fibrosis in an admixed population

Relevance of PNPLA3, TM6SF2, HSD17B13, and GCKR Variants to MASLD Severity in an Egyptian Population

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a frequent clinical condition globally. Single nucleotide polymorphisms (SNPs) associated with NAFLD have been proposed in the literature and based on bioinformatic screening. The association between NAFLD and genetic variants in Egyptians is still unclear. Hence, we sought to investigate the association of some genetic variants with NAFLD in Egyptians. Egyptians have been categorized into either the MASLD group (n = 205) or the healthy control group (n = 187). The severity of hepatic steatosis and liver fibrosis was assessed by a Fibroscan device. TaqMan-based genotyping assays were employed to explore the association of selected SNPs with MASLD. PNPLA3 rs738409 C>G variant is associated with the presence of MASLD with liver fibrosis, the severity of both hepatic steatosis and liver fibrosis, increased systolic and diastolic blood pressure and increased alanine aminotransferase (all p < 0.05), while the TM6SF2 rs58542926 C>T, HSD17B13 rs9992651 G>A, and GCKR rs1260326 T>C variants were not (all p > 0.05). The TM6SF2 rs58542926 T allele is associated with increased fasting blood glucose and a decreased waist circumference. The GCKR rs1260326 C allele is associated with decreased aspartate transaminase and diastolic blood pressure (all p < 0.05). Only after adjusting for the risk factors (age, sex, BMI, WC, HDL, TG, diabetes mellitus, and hypertension) F2 liver fibrosis score is negatively correlated with the HSD17B13 rs9992651 GA genotype. This study offers evidence for the association of the PNPLA3 rs738409 C>G variant with MASLD among Egyptians and for the association of the PNPLA3 rs738409 G allele, the TM6SF2 rs58542926 T allele, and the GCKR rs1260326 C allele with some parameters of cardiometabolic criteria.

Exploring the role of genetic variations in NAFLD: implications for disease pathogenesis and precision medicine approaches

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases, affecting more than one-quarter of people worldwide. Hepatic steatosis can progress to more severe forms of NAFLD, including NASH and cirrhosis. It also may develop secondary diseases such as diabetes and cardiovascular disease. Genetic and environmental factors regulate NAFLD incidence and progression, making it a complex disease. The contribution of various environmental risk factors, such as type 2 diabetes, obesity, hyperlipidemia, diet, and sedentary lifestyle, to the exacerbation of liver injury is highly understood. Nevertheless, the underlying mechanisms of genetic variations in the NAFLD occurrence or its deterioration still need to be clarified. Hence, understanding the genetic susceptibility to NAFLD is essential for controlling the course of the disease. The current review discusses genetics' role in the pathological pathways of NAFLD, including lipid and glucose metabolism, insulin resistance, cellular stresses, and immune responses. Additionally, it explains the role of the genetic components in the induction and progression of NAFLD in lean individuals. Finally, it highlights the utility of genetic knowledge in precision medicine for the early diagnosis and treatment of NAFLD patients.

Psoriasis and steatotic liver disease: Are PNPLA3 and TM6SF2 polymorphisms suitable for the hepato-dermal axis hypothesis?

INTRODUCTION AND OBJECTIVES

A high prevalence of steatotic liver disease has been described in psoriasis. However, the influence of genetic polymorphisms has yet to be investigated in this scenario. This study aims to determine the frequency of steatosis, advanced liver fibrosis and PNPLA3/TM6SF2 genotypes in individuals with psoriasis and to evaluate the impact of genetic polymorphisms, metabolic parameters and cumulative methotrexate dose on steatosis and fibrosis.

MATERIALS AND METHODS

Cross-sectional study that prospectively included psoriasis outpatients, submitted to clinical and laboratory analysis, transient elastography (FibroScan®, Fr) and PNPLA3/TM6SF2 genotyping. Steatosis was defined by CAP ≥275 dB/m and advanced liver fibrosis as transient elastography ≥10 kPa. Logistic regression analysis evaluated the independent variables related to steatosis and fibrosis; p-value< 0.05 was considered significant.

RESULTS

One hundred and ninety-nine patients were enrolled (age 54.6 ± 12.6 years, 57.3% female). Metabolic syndrome (MetS), steatosis and advanced liver fibrosis prevalence were 55.8%, 54.8% and 9%, respectively. PNPLA3 and TM6SF2 genotypes frequencies were CC 42.3%/CG 49.5%/GG 8.2% and CC 88.7%/ CT 11.3%/ TT 0%. MetS (OR3.01 95%CI 1.51-5.98; p = 0.002) and body mass index (OR1.17 95%CI 1.08-1.26; p < 0.01) were independently associated with steatosis. Diabetes Mellitus (T2DM) (OR10.76 95%CI 2.42-47.87; p = 0.002) and harboring at least one PNPLA3 G allele (OR5.66 95%CI 1.08-29.52; p = 0.039) were associated with advanced fibrosis, but not TM6SF2 polymorphism or cumulative MTX dose.

CONCLUSIONS

MetS and T2DM confer higher odds for steatosis and advanced fibrosis in individuals with psoriasis. PNPLA3 G allele, but not TM6SF2 polymorphism, impacts a 5-fold odds of advanced liver fibrosis.

Parental History of Type 2 Diabetes Mellitus and PNPLA3 Polymorphism Increase the Risk of Severe Stages of Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

In non-alcoholic fatty liver disease (NAFLD), the influence of parental history of type 2 diabetes (T2D) allied to single nucleotide polymorphisms (SNPs) in the offspring is not known. We aimed to investigate the impact of the parental history of T2D, PNPLA3 and TM6SF2 polymorphisms in liver steatosis and fibrosis.

METHODS

This was a case-control study involving the offspring of T2D patients and controls without a parental history of T2D. Participants underwent clinical and laboratory evaluation, transient elastography (TE) by Fibroscan® (Echosens, Fr) and genotyping for PNPLA3 and TM6SF2. Multivariate logistic regression evaluated the influence of parental history of T2D on liver steatosis and fibrosis, controlled for age, gender, metabolic traits and SNPs.

RESULTS

161 T2D offspring and 78 controls, 10-46 years old, were included. The offspring of T2D had higher prevalences of obesity, T2D, arterial hypertension and sedentarism. Parental history of T2D was associated with fibrosis ≥ F2 (OR 8.89, CI 95% 1.09-72.01, p = 0.041) after adjustment for age, gender, metabolic traits and SNPs. PNPLA3 GG genotype was independently associated with steatosis ≥ S1 (OR 8.15, CI 95% 1.93-34.38, p = 0.004) and fibrosis ≥ F2 (OR 4.31, CI 95% 1.11-16.61, p = 0.034).

CONCLUSIONS

The offspring of T2D patients present a worse metabolic profile and the parental history of T2D confers an increased likelihood of hepatic fibrosis, independent of metabolic factors. PNPLA3 homozygous GG, but not TM6SF2 genotypes, also impacts on this phenotype.

Prevalence of non-alcoholic fatty liver in the general Dutch population and in groups at increased risk

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is defined as a liver fat content ≥5.56%. It is of clinical interest to know the prevalence of NAFLD in people with a combination of metabolic risk factors. We aimed to examine the prevalence of NAFLD, including groups with metabolic risk factors.

METHODS AND RESULTS

In this cross-sectional analysis of the Netherlands Epidemiology of Obesity (NEO) study, liver fat content was assessed using proton magnetic resonance spectroscopy (H-MRS). Participants with excessive alcohol consumption or missing values were excluded, leaving a total of 1570 participants for the analyses. Mean (SD) age of the population was 55 years, BMI 25.9 (4.0) kg/m2 and 46% were men. The prevalence of NAFLD was 27% (95% CI 24-30). The prevalence of NAFLD was increased in participants with hypertriglyceridemia (57%, 52-63), obesity (62%, 58-66) and diabetes (69%, 61-77). The prevalence of NAFLD was highest in those with diabetes and obesity (79%, 71-87), obesity and hypertriglyceridemia (81%, 76-86) and with diabetes and hypertriglyceridemia (86%, 77-95). NAFLD was also present in 12% (8-16) of participants without overweight.

CONCLUSIONS

The prevalence of NAFLD in a middle-aged population in the Netherlands in 2010 was 27%. The prevalence of NAFLD is particularly increased in individuals with diabetes, obesity, and hypertriglyceridemia. This information may help clinicians and general practitioners in the risk stratification of their patients in daily practice.

Genetic Predictors of Comorbid Course of COVID-19 and MAFLD: A Comprehensive Analysis

Metabolic-associated fatty liver disease (MAFLD) and its potential impact on the severity of COVID-19 have gained significant attention during the pandemic. This review aimed to explore the genetic determinants associated with MAFLD, previously recognized as non-alcoholic fatty liver disease (NAFLD), and their potential influence on COVID-19 outcomes. Various genetic polymorphisms, including PNPLA3 (rs738409), GCKR (rs780094), TM6SF2 (rs58542926), and LYPLAL1 (rs12137855), have been investigated in relation to MAFLD susceptibility and progression. Genome-wide association studies and meta-analyses have revealed associations between these genetic variants and MAFLD risk, as well as their effects on lipid metabolism, glucose regulation, and liver function. Furthermore, emerging evidence suggests a possible connection between these MAFLD-associated polymorphisms and the severity of COVID-19. Studies exploring the association between indicated genetic variants and COVID-19 outcomes have shown conflicting results. Some studies observed a potential protective effect of certain variants against severe COVID-19, while others reported no significant associations. This review highlights the importance of understanding the genetic determinants of MAFLD and its potential implications for COVID-19 outcomes. Further research is needed to elucidate the precise mechanisms linking these genetic variants to disease severity and to develop gene profiling tools for the early prediction of COVID-19 outcomes. If confirmed as determinants of disease severity, these genetic polymorphisms could aid in the identification of high-risk individuals and in improving the management of COVID-19.

Patatin-like phospholipase domain-containing 3 gene (PNPLA3) polymorphic (rs738409) single nucleotide polymorphisms and susceptibility to nonalcoholic fatty liver disease: A meta-analysis of twenty studies

BACKGROUND

To investigate the correlation between rs738409 polymorphism of patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene (encoding I148m) and genetic susceptibility to nonalcoholic fatty liver disease (NAFLD).

METHODS

Web of Science, Embase, PubMed, Cochrane Library, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform databases were subjected to study retrieving, from the earliest records to November 2022. International databases were searched using the key words (PNPLA3 gene or PNPLA3 polymorphism or patatin-like phospholipase domain-containing pro-tein3) and (nonalcoholic fatty liver disease or NAFLD or nonalcoholic steatohepatitis) and their possible combination. There was no limitation to language. Ethnicity and country restrictions were not applied. Hardy-Weinberg equilibrium about the genotype frequencies of rs738,409 polymorphism in group of controls was assessed using a chi-square goodness-of-fit test (P > .05). A chi-square-based Q test was applied to assess heterogeneity among studies. The random-effect model (DerSimonian-Laird method) was used when a probability value of P < .10, I2 > 50%. If not, the fixed-effect model (Mantel-Haenszel method) was adopted. The current meta-analysis was done by using STATA 16.0.

RESULTS

Twenty studies are selected for this meta-analysis, which includes totally 3240 patients in the treatment group and 5210 patients in the control group. These studies demonstrated a significant increased association between rs738,409 and NAFLD under 5 models: allelic contrast (odds ratio [OR] = 1.98, 95% confidence interval [CI] = 1.65-2.37, Pheterogeneity = 0.000, Z = 7.346, P = .000), homozygote comparison (OR = 3.59, 95% CI = 2.56-5.04, Pheterogeneity = 0.000, Z = 7.416, P = .000), heterozygote comparison (OR = 1.93, 95% CI = 1.63-2.30, Pheterogeneity = 0.002, Z = 7.507, P = .000), the dominant allele model (OR = 2.33, 95% CI = 1.89-2.88, Pheterogeneity = 0.000, Z = 7.856, P = .000), and the recessive allele model (OR = 2.56, 95% CI = 1.96-3.35, Pheterogeneity = 0.000, Z = 6.850, P = .000). Subgroup analysis shows that the rs738,409 polymorphism of PNPLA3 gene in Caucasians and those with a sample size of < 300 is significantly associated with the susceptibility to nonalcoholic fatty liver. Sensitivity analysis shows that the results of meta-analysis are stable.

CONCLUSION

PNPLA3 rs738,409 may play a significant role in increasing risk of NAFLD.

PNPLA3 GENE POLYMORPHISM AND RED MEAT CONSUMPTION INCREASED FIBROSIS RISK IN NASH BIOPSY-PROVEN PATIENTS UNDER MEDICAL FOLLOW-UP IN A TERTIARY CENTER IN SOUTHWEST BRAZIL

BACKGROUND

Recent studies show an increase in nonalcoholic fatty liver disease (NAFLD) in populations with higher consumption of red meat, processed and cooked at high temperatures. On the other hand, the single nucleotide polymorphism rs738409 in the Patatin-like phospholipase domain containing 3 (PNPLA3) gene has been implicated in susceptibility to NAFLD and liver fibrosis. However, the synergistic effect between red meat consumption and the PNPLA3 gene polymorphism in NAFLD has not yet been evaluated.

OBJECTIVE

To evaluate the association between the presence of the polymorphism in the PNPLA3 gene and the consumption of macronutrients, including meat consumption and its cooking method among NAFLD patients.

METHODS

This was a cross-sectional study with 91 patients diagnosed with NAFLD by liver biopsy with genotyping for the polymorphism in the PNPLA3 gene were included. The consumption of calories and macronutrients was verified using the semi-quantitative food frequency questionnaire and the specific questionnaire on meat consumption. PNPLA3 gene polymorphism was analyzed by real-time polymerase chain reaction (RT-PCR) and anthropometric evaluation was realized.

RESULTS

The mean BMI was 32.38±4.58 kg/m² and the waist circumference was 107±10 cm. On liver biopsy, 42% of patients had significant fibrosis (F≥2). The odds ratio of F≥2 was 2.12 for the GG group and 1.54 for the CG group, compared to the CC group. The mean caloric intake was 1170±463.20 kcal/d. The odds ratio in the CC group concerning high red meat consumption in comparison to low consumption was 1.33. For white meat, the odds ratio was 0.8 when comparing high and low intake, also in the CC group.

CONCLUSION

High red meat intake and PNPLA3 gene polymorphism seem to synergistically affect NAFLD and liver fibrosis, requiring confirmation in a larger number of patients and in different populations.

Molecular Screening via Sanger Sequencing of the Genetic Variants in Non-Alcoholic Fatty Liver Disease Subjects in the Saudi Population: A Hospital-Based Study

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, along with steatosis and non-alcoholic steatohepatitis (NASH), and is associated with cirrhosis and hepatocellular carcinoma. Candidate gene and genome-wide association studies have validated the relationships between NAFLD, NASH, PNPLA3, TM6SF2, and HFE. The present study utilized five polymorphisms in three genes: PNPLA3 (I148M and K434E) TM6SF2 (E167K), and HFE (H63D and C282Y), based on undocumented case−control studies in the Saudi Arabian population. A total of 95 patients with NAFLD and 78 non-NAFLD subjects were recruited. Genomic DNA was isolated, and polymerase chain reaction and Sanger sequencing were performed using specific primers for the I148M, K434E, E167K, H63D, and C282Y. NAFLD subjects were older when compared to controls and showed the significant association (p = 0.0001). Non-significant association was found between gender (p = 0.26). However, both weight and BMI were found to be associated. Hardy−Weinberg equilibrium analysis confirmed that H63D, I148M, and K434E polymorphisms were associated. Genotype analysis showed only K434E variant was associated with NAFLD and non-NAFLD (OR-2.16; 95% CI: 1.08−4.31; p = 0.02). However, other polymorphisms performed with NAFLD and NASH were not associated (p > 0.05), and similar analysis was found when ANOVA was performed (p > 0.05). In conclusion, we confirmed that K434E polymorphism showed a positive association in the Saudi population.

Contribution of PNPLA3 gene polymorphisms to hepatocellular carcinoma susceptibility in the Chinese Han population

OBJECTIVES

The purpose of this study was to investigate the association of PNPLA3 single nucleotide polymorphisms (SNPs) (rs738409 C > G, rs3747207 G > A, rs4823173 G > A, and rs2896019 T > G) with hepatocellular carcinoma (HCC) susceptibility.

METHODS

This case-control study included 484 HCC patients and 487 controls. Logistic regression analysis was performed to study the associations of PNPLA3 gene polymorphisms with HCC susceptibility, and odds ratios with their corresponding 95% confidence intervals were calculated to evaluate these correlations.

RESULTS

In the overall analysis, we found that the G allele (OR = 1.25, 95% CI = 1.04-1.50, p = 0.018, false discovery rate (FDR)-p = 0.035) and GG genotype (OR = 1.59, 95% CI = 1.06-2.39, p = 0.024, FDR-p = 0.048) of rs2896019 were significantly associated with increased HCC susceptibility. In stratified analysis, we found that all four SNPs were related to increased HCC susceptibility in subjects aged > 55 years. In haplotype analysis, the GAAG haplotype was significantly associated with increased HCC susceptibility (OR = 1.25, 95% CI = 1.03-1.53, p = 0.023, FDR-p = 0.046). Besides, we noticed that rs738409 was significantly correlated with alpha-fetoprotein (AFP) (p = 0.007), and HCC patients with the GG genotype had a higher level of AFP.

CONCLUSIONS

Our study suggested that PNPLA3-rs2896019 was significantly associated with an increased susceptibility to HCC.

African genetic ancestry is associated with lower frequency of PNPLA3 G allele in non-alcoholic fatty liver in an admixed population

INTRODUCTION AND OBJECTIVES

PNPLA3 (rs738409) and TM6SF2 (rs58542926) variants, interindividual and ethnic differences may be risk factors for non-alcoholic fatty liver disease (NAFLD). The PNPLA3 G allele is associated with worse NAFLD evolution in Hispanics and Caucasians. TM6SF2 is associated with hypertriglyceridemia, NAFLD, and cardiovascular disease. We aimed to evaluate the association between genetic ancestry by Ancestry Informative Markers (AIM), PNPLA3 and TM6SF2 polymorphisms in patients with biopsy-proven NAFLD in an admixed population.

METHODS

We included adults with biopsy-proven NAFLD and excluded patients with the presence of other chronic liver disease, alcohol intake &gt;100g/week, HIV, drug-induced fatty liver disease, or liver transplantation. We classified NAFLD using the Non-Alcoholic Steatohepatitis Clinical Research Network (NASH-CRN) histological scoring system. The PNPLA3 (rs738409 c.444C&gt;G) and TM6SF2 (rs58542926 c.449C&gt;T) genotyping were performed by RT-PCR. Genetic ancestry was determined using 46 insertion-deletion AIM; α&lt;0.05 was considered significant.

RESULTS

A total of 248 patients with NAFLD were enrolled [34 with simple steatosis (NAFL); 214 with NASH]. Overall, we detected a greater European ancestry contribution (0.645), followed by African (0.173), Amerindian (0.095), and East Asian (0.087) ancestry contribution, without differences between NAFL and NASH patients. However, we found a higher African genetic ancestry contribution among patients with NAFL who had the PNPLA3 C/C genotype than those with the G allele (0.216 ± 0.205 versus 0.105 ± 0.101, respectively; p=0.047). Ancestry contributions did not differ among TM6SF2 genotypes.

CONCLUSION

Among NAFL patients, greater African genetic ancestry was associated to a lower frequency of the PNPLA3 G allele, demonstrating a possible NASH ancestry-related protective factor.

Genetic variants associated with steatohepatitis and liver fibrosis in HIV-infected patients with NAFLD

Background and aims: Nonalcoholic fatty liver disease (NAFLD) is a common cause of liver damage in people living with HIV (PLWHIV). Several studies have investigated candidate genes for susceptibility to NAFLD and to steatohepatitis. PNPLA3, TM6SF2, and MBOAT7-TMC4 have been reported to be associated with elevated ALT levels and the histologic parameters of nonalcoholic steatohepatitis and severity of fibrosis. Our objective was to analyze the relationship between PNPLA3, TM6SF2, and MBOAT7-TMC4 and steatosis, steatohepatitis, and liver fibrosis in PLWHIV with NAFLD.

Method: A cohort of PLWHIV with persistently elevated aminotransferase levels and suspected NAFLD who underwent liver biopsy and determination of genetic variants was assessed at two large centers in Spain. All participants included in the current study were genotyped for rs738409 (PNPLA3), rs58542926 (TM6SF2), and rs641738 (MBOAT7-TMC4).

Results: The study population comprised PLWHIV who were on stable antiretroviral therapy [7.7% women; median age, 49.3 years (44–53.4)]. The median CD4 count was 829 (650–980), 60% had metabolic syndrome, and 18.5% were diabetic. The median BMI was 28.9 (25.5–30.8). Patients with liver steatosis (any grade) vs. nonsteatosis tended to harbor the PNPLA3 G allele variant [57.6% vs. 16.7% (p = 0.09)], but not TM6SF2 or MBOAT7-TMC4 variants. However, those with steatohepatitis vs. nonsteatohepatitis significantly more frequently had the PNPLA3 G allele variant [69.4% vs. 39.1% (p < 0.05)] and the MBOAT7-TMC4 A allele variant [75% vs. 42% (p < 0.05)]. In our cohort, the TM6SF2 gene variant was not associated with steatosis or steatohepatitis. The PNPLA3 G allele variant was associated with steatohepatitis [OR 4.9 (1.3–18); p 0.02] and liver fibrosis [OR 4.3 (1.1–17.4); p 0.04], and the MBOAT7-TMC4 A allele variant was associated with steatohepatitis [OR 6.6 (1.6–27.6); p 0.01].

Conclusion: The PNPLA3 G allele variant and MBOAT7-TMC4 A allele variant were associated with steatohepatitis and liver fibrosis in PLWHIV with persistently elevated aminotransferases and NAFLD. We recommend routine genotyping for PNPLA3 and MBOAT7-TMC4 in PLWHIV with NAFLD to identify those at higher risk of progression.

Update on Non-Alcoholic Fatty Liver Disease-Associated Single Nucleotide Polymorphisms and Their Involvement in Liver Steatosis, Inflammation, and Fibrosis: A Narrative Review

Genetic factors are involved in the development, progression, and severity of NAFLD. Polymorphisms in genes regulating liver functions may increase liver susceptibility to NAFLD. Therefore, we conducted this literature study to present recent findings on NAFLD-associated polymorphisms from published articles in PubMed from 2016 to 2021. From 69 selected research articles, 20 genes and 34 SNPs were reported to be associated with NAFLD. These mutated genes affect NAFLD by promoting liver steatosis (PNPLA3, MBOAT7, TM2SF6, PTPRD, FNDC5, IL-1B, PPARGC1A, UCP2, TCF7L2, SAMM50, IL-6, AGTR1, and NNMT), inflammation (PNPLA3, TNF-α, AGTR1, IL-17A, IL-1B, PTPRD, and GATAD2A), and fibrosis (IL-1B, PNPLA3, MBOAT7, TCF7L2, GATAD2A, IL-6, NNMT, UCP, AGTR1, and TM2SF6). The identification of these genetic factors helps to better understand the pathogenesis pathways of NAFLD

The association between Dietary Diversity Score and odds of nonalcoholic fatty liver disease: a case-control study

OBJECTIVE

There is no previous study that investigated the association between Dietary Diversity Score (DSS) and odds of nonalcoholic fatty liver disease (NAFLD). The present study aimed to examine the association between DDS and its components and NAFLD among Iranian adults.

METHODS

In the case-control study, we enrolled 121 newly diagnosed cases of NAFLD and 122 with age, BMI and sex-matched controls. All NAFLD patients were diagnosed through ultrasonography methods by gastroenterologists. Anthropometric parameters of participants including weight, height, hip circumference and waist circumference were measured. A validated 147-item semi-quantitative food frequency questionnaire was applied to assess the usual dietary intakes of participants. Binary logistic regression was conducted to estimate the risk of NAFLD in relation to DDS and its components, including refined grains, vegetables, fruits, dairy and meats.

RESULTS

The mean age of study participants was 42.7 years of them 53.1% were male. Higher adherence to DDS [odds ratio (OR) = 0.48; 95% confidence interval (CI), 0.25-0.95] and vegetable group (OR = 0.34; 95% CI, 0.16-0.71) were remarkably associated with lower risk of NAFLD, after adjusting for several confounders including age, BMI, physical activity, energy intake, job, education, and antihypertensive drugs usage. Contrastingly, greater adherence to the refined grain (OR = 3.36; 95% CI, 1.44-7.87) and meat group (OR = 3.27; 95% CI, 1.25-6.90) was significantly associated with increased risk of NAFLD.

CONCLUSION

High DDS is inversely correlated with the risk of NAFLD. Hence, increasing the diversity score of diet by emphasizing the higher diversity scores for vegetables and less for meat and refined grains may be profitable for the management of NAFLD.

Non-Alcoholic Fatty Liver Disease in Long-Term Type 2 Diabetes: Role of rs738409 PNPLA3 and rs499765 FGF21 Polymorphisms and Serum Biomarkers

Fibroblast growth factor 21 (FGF21) signaling and genetic factors are involved in non-alcoholic fatty liver disease (NAFLD) pathogenesis. However, these factors have rarely been studied in type 2 diabetes mellitus (T2D) patients from admixed populations such as in those of Brazil. Therefore, we aimed to evaluate rs738409 patanin-like phospholipase domain-containing protein (PNPLA3) and rs499765 FGF21 polymorphisms in T2D, and their association with NAFLD, liver fibrosis, and serum biomarkers (FGF21 and cytokeratin 18 levels). A total of 158 patients were included, and the frequency of NAFLD was 88.6%, which was independently associated with elevated body mass index. Significant liver fibrosis (≥F2) was detected by transient elastography (TE) in 26.8% of NAFLD patients, and was independently associated with obesity, low density lipoprotein, and gamma-glutamyl transferase (GGT). PNPLA3 GG genotype and GGT were independently associated with cirrhosis. PNPLA3 GG genotype patients had higher GGT and AST levels; PNPLA3 GG carriers had higher TE values than CG patients, and FGF21 CG genotype patients showed lower gamma-GT values than CC patients. No differences were found in serum values of FGF21 and CK18 in relation to the presence of NAFLD or liver fibrosis. The proportion of NAFLD patients with liver fibrosis was relevant in the present admixed T2D population, and was associated with PNPLA3 polymorphisms.

Sociodemographic and genetic determinants of nonalcoholic fatty liver disease in type 2 diabetes mellitus patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) showed significant association with PNPLA3 rs738409 polymorphism in unrelated individuals. However, it is still unknown whether the relationship of NAFLD with PNPLA3 variant exists or not among subjects with type 2 diabetes mellitus (T2DM). Therefore, the study aimed to evaluate sociodemographic and genetic determinants of NAFLD in type 2 diabetics.

METHODS

The cross-sectional analytical study was conducted at the Department of Molecular Biology, Virtual University of Pakistan, Lahore, Pakistan, during 2019-2020. A total of 153 known cases of T2DM were enrolled using convenience sampling. After excluding patients (n = 24) with HCV, alcoholism, or missing information, data from 129 eligible diabetics with and without NAFLD were analyzed using SPSS. Odds ratios using crosstabs and adjusted odds ratios using binary and multinomial logistic regression were calculated to measure the risk of NAFLD.

RESULTS

Adults 18-35 years were 7.0%, 36-55 years were 64.3%, ≥ 56 years were 28.7%, and females were 66.7%. A total of 41.1% of patients had obesity, 52.7% had NAFLD, and 29.05% carried mutant G allele of rs738409 polymorphism. Among overall diabetics, NAFLD showed association with female (OR = 2.998, p = 0.007), illiterate (OR = 3.067, p = 0.005), and obese (OR = 2.211, p = 0.046) but not with PNPLA3 genotype under any model (all p = > 0.05). Among obese diabetics, NAFLD showed association with female (AOR = 4.010, p = 0.029), illiterate (AOR = 3.506, p = 0.037), GG + CG/CC (AOR = 3.303, p = 0.033), and GG/CG + CC (AOR = 4.547, p = 0.034) using binary regression and with female (AOR = 3.411, p = 0.051), illiterate (AOR = 3.323, p = 0.048), GG + CG/CC (AOR = 3.270, p = 0.029), and GG/CG + CC (AOR = 4.534, p = 0.024) using multinomial regression.

CONCLUSIONS

NAFLD and obesity were the most common comorbid diseases of T2DM. Gender female, being illiterate, and PNPLA3 rs738409 polymorphism were significant risk factors of NAFLD among obese diabetic patients.

Clinical and sociodemographic determinants of disease progression in patients with nonalcoholic steatohepatitis in the United States

One fifth of patients with nonalcoholic fatty liver disease (NAFLD) may progress to nonalcoholic steatohepatitis (NASH), which can increase the risk of cirrhosis, cancer, and death. To date, reported predictors of NASH progression have been heterogeneous.We identified determinants of fibrosis progression in patients with NASH in the United States using physician-reported data from the real-world Global Assessment of the Impact of NASH (GAIN) study, including demographics and clinical characteristics, NASH diagnostic information, fibrosis stage, comorbidities, and treatment. We developed a logistic regression model to assess the likelihood of fibrosis progression since diagnosis, controlling for sociodemographic and clinical variables. An iterative nested model selection approach using likelihood ratio test determined the final model.A total of 989 patients from the GAIN US cohort were included; 46% were women, 58% had biopsy-proven NAFLD, and 74% had fibrosis stage F0-F2 at diagnosis. The final multivariable model included age, years since diagnosis, sex, employment status, smoking status, obesity, fibrosis stage, diagnostic biopsy, Vitamin E, and liver transplant proposed at diagnosis. Odds of progression were 17% higher (odds ratio, 1.17 [95% CI: 1.11-1.23]; P < .001) with each year since NASH diagnosis, 41% lower (0.59 [0.38-0.90]; P = .016) for women than men, 131% higher (2.31 [1.30-4.03]; P = .004) for smokers versus non-smokers, and 89% higher (1.89 [1.26-2.86]; P = .002) with obesity. Odds of progression were also higher with part-time, retired, unemployed, and unable to work due to NASH status versus full-time employment, and when a liver transplant was proposed at diagnosis.Disease duration and severity, obesity, smoking, and lack of full-time employment were significant determinants of fibrosis progression. These findings can support clinical and health-policy decisions to improve NASH management in the US.

Ability of a Combined FIB4/miRNA181a Score to Predict Significant Liver Fibrosis in NAFLD Patients

Liver biopsy is the gold standard for assessing fibrosis, but there is a need to seek non-invasive biomarkers for this purpose. The aim of this study was to evaluate the correlation between the serum levels of the microRNAs miR-21, miR-29a, miR-122, miR-155 and miR-181a and the phenotypic expression of NAFLD. A cross-sectional study was carried out on 108 NAFLD patients diagnosed by liver biopsy. FIB-4 and NAFLD fibrosis scores were calculated. The comparison between the distributions of microRNA values according to the presence or absence of histological fibrosis (F2–F4) was performed. A multivariate logistic regression analysis was performed to build a score for predicting fibrosis using FIB-4 and Ln (miR-181a) as independent variables. Only miR-181a showed a statistical difference between patients with significant liver fibrosis (>F2) and those without (F0–F1) (p = 0.017). FIB-4 revealed an AUC on the ROC curve of 0.667 to predict clinically significant fibrosis (F2–F4). When assessed using the score in association with Ln (miR-181a), there was an improvement in the ROC curve, with an AUC of 0.71. miR-181a can be used as a non-invasive method of predicting fibrosis in NAFLD, and an association with FIB-4 has the potential to increase the accuracy of each method alone.

Non-alcoholic fatty liver disease and microRNAs expression, how it affects the development and progression of the disease

The obesity pandemic that affects the global population generates one of the most unfavorable microenvironmental conditions in the hepatocyte, which triggers the metabolic hepatopathy known as non-alcoholic fatty liver; its annual rates increase in its prevalence and does not seem to improve in the future. The international consortia, LITMUS by the European Union and NIMBLE by the United States of America, have started a race for the development of hepatic steatosis and steatohepatitis reliable biomarkers to have an adequate diagnosis. MicroRNAs have been proposed as diagnostic and prognostic biomarkers involved in adaptation to changes in the liver microenvironment, which could improve clinical intervention strategies in patients with hepatic steatosis.

Role of PNPLA3 in the Assessment and Monitoring of Hepatic Steatosis and Fibrosis in Patients with Chronic Hepatitis C Infection Who Achieved a Sustained Virologic Response

Background and Objectives: Hepatic diseases are an important public health problem. All patients with chronic hepatitis C virus (HCV) infection receive treatment, regardless of hepatic fibrosis severity. However, evaluation of hepatic fibrosis and steatosis is still useful in assessing evolution, prognosis and monitoring of hepatic disease, especially after treatment with direct-acting antivirals (DAAs). The aim of this study was to assess the link between patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphism and the degree of hepatic steatosis and fibrosis in patients with chronic HCV infection, as well as changes in steatosis and fibrosis three monthsafter obtaining a sustained viral response (SVR). Materials and Methods:Ourstudy included 100 patients with chronic hepatitis C (CHC) infection and compensated cirrhosis who received DAA treatment and who were evaluated using Fibromax prior to and 3 months after SVR. The influence of PNPLA3 (CC, CG, GG) genotype among these patients on the degree of post-treatment regression of steatosis and fibrosis was assessed. Results: Regression was noticed in the degree of both hepatic steatosis and hepatic fibrosis post-DAA treatment (three months after SVR). Analysis of the correlation between PNPLA3 genotype and fibrosis indicated that the average level of fibrosis (F) before DAA treatment was higher in patients with the GG genotype than in patients with the CC or CG genotype. Three months after SVR, the average level of fibrosis decreased; however, it remained significantly increased in GG subjects compared to that in CC or CG patients. The degree of hepatic steatosis before treatment was not significantly different among patients with different PNPLA3 genotypes, and no significant correlations were observed three months after SVR. Conclusions: The genetic variants of PNPLA3 influence the evolution of hepatic fibrosis. The GG subtype plays an important role in the degree of hepatic fibrosis both before and after treatment (three months after SVR)and could be a prognostic marker for assessment of post-SVR evolution.

Latin American Association for the study of the liver (ALEH) practice guidance for the diagnosis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chronic liver disease, affecting 20-30% of the general population. Furthermore, its prevalence is predicted to increase exponentially in the next decades, concomitantly with the global epidemic of obesity, type 2 diabetes mellitus (T2DM), and sedentary lifestyle. NAFLD is a clinical syndrome that encompasses a wide spectrum of associated diseases and hepatic complications such as hepatocellular carcinoma (HCC). Moreover, this disease is believed to become the main indication for liver transplantation in the near future. Since NAFLD management represents a growing challenge for primary care physicians, the Asociación Latinoamericana para el Estudio del Hígado (ALEH) has decided to organize this Practice Guidance for the Diagnosis and Treatment of Non-Alcoholic Fatty Liver Disease, written by Latin-American specialists in different clinical areas, and destined to general practitioners, internal medicine specialists, endocrinologists, diabetologists, gastroenterologists, and hepatologists. The main purpose of this document is to improve patient care and awareness of NAFLD. The information provided in this guidance may also be useful in assisting stakeholders in the decision-making process related to NAFLD. Since new evidence is constantly emerging on different aspects of the disease, updates to this guideline will be required in future.

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.

Current Options and Future Directions for NAFLD and NASH Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with a broad spectrum ranging from simple steatosis to advanced stage of nonalcoholic steatohepatitis (NASH). Although there are many undergoing clinical trials for NAFLD treatment, there is no currently approved treatment. NAFLD accounts as a major causing factor for the development of hepatocellular carcinoma (HCC), and its incidence rises accompanying the prevalence of obesity and diabetes. Reprogramming of antidiabetic and anti-obesity medicine is a major treatment option for NAFLD and NASH. Liver inflammation and cellular death, with or without fibrosis account for the progression of NAFLD to NASH. Therefore, molecules and signaling pathways involved in hepatic inflammation, fibrosis, and cell death are critically important targets for the therapy of NAFLD and NASH. In addition, the avoidance of aberrant infiltration of inflammatory cytokines by treating with CCR antagonists also provides a therapeutic option. Currently, there is an increasing number of pre-clinical and clinical trials undergoing to evaluate the effects of antidiabetic and anti-obesity drugs, antibiotics, pan-caspase inhibitors, CCR2/5 antagonists, and others on NAFLD, NASH, and liver fibrosis. Non-invasive serum diagnostic markers are developed for fulfilling the need of diagnostic testing in a large amount of NAFLD cases. Overall, a better understanding of the underlying mechanism of the pathogenesis of NAFLD is helpful to choose an optimized treatment.

Plasma and stool metabolomics to identify microbiota derived-biomarkers of metabolic dysfunction-associated fatty liver disease: effect of PNPLA3 genotype

INTRODUCTION

Non-invasive biomarkers are needed for metabolic dysfunction-associated fatty liver disease (MAFLD), especially for patients at risk of disease progression in high-prevalence areas. The microbiota and its metabolites represent a niche for MAFLD biomarker discovery. However, studies are not reproducible as the microbiota is variable.

OBJECTIVES

We aimed to identify microbiota-derived metabolomic biomarkers that may contribute to the higher MAFLD prevalence and different disease severity in Latin America, where data is scarce.

METHODS

We compared the plasma and stool metabolomes, gene patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 single nucleotide polymorphism (SNP), diet, demographic and clinical data of 33 patients (12 simple steatosis and 21 steatohepatitis) and 19 healthy volunteers (HV). The potential predictive utility of the identified biomarkers for MAFLD diagnosis and progression was evaluated by logistic regression modelling and ROC curves.

RESULTS

Twenty-four (22 in plasma and 2 in stool) out of 424 metabolites differed among groups. Plasma triglyceride (TG) levels were higher among MAFLD patients, whereas plasma phosphatidylcholine (PC) and lysoPC levels were lower among HV. The PNPLA3 risk genotype was related to higher plasma levels of eicosenoic acid or fatty acid 20:1 (FA(20:1)). Body mass index and plasma levels of PCaaC24:0, FA(20:1) and TG (16:1_34:1) showed the best AUROC for MAFLD diagnosis, whereas steatosis and steatohepatitis could be discriminated with plasma levels of PCaaC24:0 and PCaeC40:1.

CONCLUSION

This study identified for the first time MAFLD potential non-invasive biomarkers in a Latin American population. The association of PNPLA3 genotype with FA(20:1) suggests a novel metabolic pathway influencing MAFLD pathogenesis.

Mitochondrial Mutations and Genetic Factors Determining NAFLD Risk

NAFLD (non-alcoholic fatty liver disease) is a widespread liver disease that is often linked with other life-threatening ailments (metabolic syndrome, insulin resistance, diabetes, cardiovascular disease, atherosclerosis, obesity, and others) and canprogress to more severe forms, such as NASH (non-alcoholic steatohepatitis), cirrhosis, and HCC (hepatocellular carcinoma). In this review, we summarized and analyzed data about single nucleotide polymorphism sites, identified in genes related to NAFLD development and progression. Additionally, the causative role of mitochondrial mutations and mitophagy malfunctions in NAFLD is discussed. The role of mitochondria-related metabolites of the urea cycle as a new non-invasive NAFLD biomarker is discussed. While mitochondria DNA mutations and SNPs (single nucleotide polymorphisms) canbe used as effective diagnostic markers and target for treatments, age and ethnic specificity should be taken into account.

The role of PNPLA3 and TM6SF2 polymorphisms on liver fibrosis and metabolic abnormalities in Brazilian patients with chronic hepatitis C

Background

Despite the growing body of knowledge about TM6SF2 and PNPLA3 polymorphisms in non-alcoholic fatty liver disease, their influence in the spectrum of HCV liver disease is not yet fully defined. Besides that, admixed populations, such as Brazilians, were not included in most of the studies.

Methods

This cross-sectional study enrolled 365 treatment-naïve patients with HCV and 134 healthy individuals. TM6SF2 (rs58542926 c.499C > T) and PNPLA3 (rs738409 c.444C > G) polymorphisms were evaluated regarding their association with clinical and laboratory data, histological liver steatosis and fibrosis, and with components of the metabolic syndrome.

Results

In HCV subjects, the frequencies of TM6SF2 CC and CT + TT were 89% and 11%, while PNPLA3 frequencies of CC and CG + GG were 51.4% and 48.6%. In the univariate logistic regression analysis, the TM6SF2 CT + TT genotype in HCV was associated with significant liver fibrosis (p = 0.047; OR 1.953; 95% CI 1.009–3.788). In comparison to the CT + TT genotype, the TM6SF2 CC genotype in HCV was associated with older age (p = 0.002), higher frequency of arterial hypertension (p = 0.032), obesity (p = 0.030), metabolic syndrome (p = 0.014) and lower total cholesterol levels (p = 0.036). The PNPLA3 GG subjects had lower body mass index than CG/ CC individuals (p = 0.047). None of the polymorphisms, or their combinations, was independently associated with hepatic steatosis or fibrosis. On the other hand, older age, lower serum levels of total cholesterol, and higher serum levels of alanine aminotransferase and alkaline phosphatase were associated with liver fibrosis in the multivariate logistic regression analysis.

Conclusion

In this evaluation of an admixed HCV population, neither TM6SF2 nor PNPLA3 polymorphisms were independently associated with hepatic steatosis or fibrosis. Other factors seem more influential than these specific polymorphisms in isolation. More studies are warranted to clarify the role of the TM6SF2 and PNPLA3 polymorphisms in Brazilians with HCV.

PNPLA3 and TM6SF2 polymorphisms in Brazilian patients with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease worldwide, with significant morbidity associated with nonalcoholic steatohepatitis (NASH). Genome-wide association studies demonstrated that the variants rs738409 C/G in the PNPLA3 and rs58542926 C/T in the TM6SF2 genes are determinants of inter-individual and ethnicity-related differences in hepatic fat content and NAFLD progression.

AIM

To investigate PNPLA3 and TM6SF2 genotype frequency and their association with NAFLD development and progression in Brazilian patients.

METHODS

This cross-sectional case-control study enrolled 285 individuals from the Gastroenterology and Hepatology clinics at a university hospital in Brazil. The case patients (n = 148) were confirmed to have NAFLD by the identification of hepatic steatosis on ultrasonography and exclusion of other causes of liver disease. According to the clinical protocol, patients underwent liver biopsy when at high risk for NASH and/or advanced fibrosis (n = 65). Steatohepatitis was confirmed in 54 patients. Individuals who did not have biopsy indication or NASH on histology were considered to have simple steatosis (n = 94). The control group (n = 137) was selected among patients that attended the Intestinal Disease clinic and was composed of subjects without abnormalities on abdominal ultrasonography and normal liver biochemical tests. All individuals underwent PNPLA3 and TM6SF2 genotype analysis.

RESULTS

PNPLA3 CC, CG and GG genotype frequencies were 37%, 44% and 19%, respectively, in NAFLD patients and were 58%, 31% and 10% in controls (P < 0.001). In a model adjusted for gender, age, body mass index and type 2 diabetes mellitus, the G allele increased the chance of NAFLD (OR = 1.69, 95%CI: 1.21-2.36, P = 0.002) and NASH (OR = 3.50, 95%CI: 1.84-6.64, P < 0.001). The chance of NASH was even higher with GG homozygosis (OR = 5.53, 95%CI: 2.04-14.92, P = 0.001). No association was found between G allele and the features of metabolic syndrome. In histological assessment, PNPLA3 genotype was not associated with steatosis grade, although GG homozygosis increased the chance of significant NASH activity (OR = 17.11, 95%CI: 1.87-156.25, P = 0.01) and fibrosis (OR = 7.42, 95%CI: 1.55-34.47, P = 0.01) in the same adjusted model. TM6SF2 CC, CT and TT genotype frequencies were 83%, 15% and 0.7%, respectively, in NAFLD patients and were 84%, 16% and 0.7% in controls (P = 0.78). The T allele presence was not associated with NAFLD or NASH, and was not associated with histological features.

CONCLUSION

PNPLA3 may be involved in susceptibility and progression of NAFLD and NASH in the Brazilian population. More advanced histological liver disease was associated with the G allele. The TM6SF2 genetic variants were not associated with NAFLD susceptibility and progressive histological forms in the population studied, but further studies are required to confirm these findings.

Genomics in Personalized Nutrition: Can You "Eat for Your Genes"?

Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations based on an individual's genetic variability at multiple SNPs. However, relatively little is known about most specific gene-diet interactions, and many molecular and clinical phenotypes of interest (e.g., body mass index [BMI]) involve multiple genes. In this review, we discuss direct to consumer genetic testing (DTC-GT) and the current potential for precision nutrition based on an individual's genetic data. We review important issues such as dietary exposure and genetic architecture addressing the concepts of penetrance, pleiotropy, epistasis, polygenicity, and epigenetics. More specifically, we discuss how they complicate using genotypic data to predict phenotypes as well as response to dietary interventions. Then, several examples (including caffeine sensitivity, alcohol dependence, non-alcoholic fatty liver disease, obesity/appetite, cardiovascular, Alzheimer's disease, folate metabolism, long-chain fatty acid biosynthesis, and vitamin D metabolism) are provided illustrating how genotypic information could be used to inform nutritional recommendations. We conclude by examining ethical considerations and practical applications for using genetic information to inform dietary choices and the future role genetics may play in adopting changes beyond population-wide healthy eating guidelines.

Association of PNPLA3 rs738409 G/C gene polymorphism with nonalcoholic fatty liver disease in children: a meta-analysis

Background

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease worldwide. Current studies have shown that PNPLA3 (Patatin-like phospholipase domain containing 3) rs738409 G/C gene polymorphism is associated with adult nonalcoholic fatty liver disease [1, 2].But there is no consensus on the relationship between PNPLA3 rs738409 G/C gene polymorphism and children NAFLD due to differences in population samples. To this end, a meta-analysis of published research is conducted to comprehensively assess the relationship between PNPLA3 gene polymorphism and NAFLD in children.

Methods

We searched MEDLINE, PubMed, EMBASE, and CENTRAL databases from inception to May 2019. Case-control studies assessing the relationship between PNPLA3 rs738409 G/C gene polymorphism with non-alcoholic fatty liver disease in children were selected according to inclusion and exclusion criteria. Random effects model was used to quantify the association between the PNPLA3 rs738409 G/C gene polymorphism and the susceptibility of children’s NAFLD. Fixed effects model was used to quantify the relationship between the PNPLA3 rs738409 G/C gene polymorphism and the severity of NAFLD in children. The Stata 12.0 software was employed for data analysis.

Results

A total of nine case-control studies were included in this meta-analysis containing data of 1173 children with NAFLD and 1792 healthy controls. Five studies compared NAFLD children and non-NAFLD healthy populations. Statistical analysis showed that PNPLA3 gene polymorphism was significantly associated with children’s NAFLD in the allele contrast, dominant, recessive and over dominant models (G vs C,OR = 3.343, 95% CI = 1.524–7.334; GG + GC vs CC,OR = 3.157, 95% CI = 1.446–6.892;GG vs GC + CC,OR = 5.692, 95% CI = 1.941–16.689; GG + CC vs GC,OR = 2.756, 95% CI = 1.729–4.392). Four case-control studies compared Children with nonalcoholic fatty liver (NAFL) and children with nonalcoholic steatohepatitis (NASH). The results showed that the PNPLA3 gene polymorphism was also significantly associated with the severity of NAFLD in children in recessive gene model (GG vs GC + CC,OR = 14.43, 95% CI = 5.985–34.997); The Egger’s test revealed no significant publication bias.

Conclusions

Meta-analysis showed that PNPLA3 gene polymorphism was significantly associated with susceptibility and severity of NAFLD in children.

Genetics and epigenetics purpose in nonalcoholic fatty liver disease

INTRODUCTION

nonalcoholic fatty liver disease (NAFLD) comprises a broad spectrum of diseases, which can progress from benign steatosis to nonalcoholic steatohepatitis, liver cirrhosis and hepatocellular carcinoma. NAFLD is the most common chronic liver disease in developed countries, affecting approximately 25% of the general population. Insulin resistance, adipose tissue dysfunction, mitochondrial and endoplasmic reticulum stress, chronic inflammation, genetic and epigenetic factors are NAFLD triggers that control the disease susceptibility and progression.

AREAS COVERED

In recent years a large number of investigations have been carried out to elucidate genetic and epigenetic factors in the disease pathogenesis, as well as the search for diagnostic markers and therapeutic targets. This paper objective is to report the most studied genetic and epigenetic variants around NAFLD.

EXPERT OPINION

NAFLD lead to various comorbidities, which have a considerable impact on the patient wellness and life quality, as well as on the costs they generate for the country's health services. It is essential to continue with molecular research, since it could be used as a clinical tool for prognosis and disease severity. Specifically, in the field of hepatology, plasma miRNAs could provide a novel tool in liver diseases diagnosis and monitoring, representing an alternative to invasive diagnostic procedures.

Genetic Risk Factors and Disease Modifiers of Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is strongly associated with obesity and the metabolic syndrome, but genetic factors also contribute to disease susceptibility. Human genetic studies have identified several common genetic variants contributing to nonalcoholic fatty liver disease initiation and progression. These findings have provided new insights into the pathogenesis of nonalcoholic fatty liver disease and opened up new avenues for the development of therapeutic interventions. In this review, we summarize the current state of knowledge about the genetic determinants of nonalcoholic fatty liver disease, focusing on the most robustly validated genetic risk factors and on recently discovered modifiers of disease progression.

Paraoxonase-1 Serum Concentration and PON1 Gene Polymorphisms: Relationship with Non-Alcoholic Fatty Liver Disease

Background: Non-alcoholic fatty liver disease (NAFLD) is an important cause of chronic liver diseases around the world. Paraoxonase-1 (PON1) is an enzyme produced by the liver with an important antioxidant role. The aim of this study was to evaluate PON1 serum concentration and PON1 gene polymorphisms in patients with NAFLD. Materials and methods: We studied a group of 81 patients with NAFLD with persistently elevated aminotransferases and a control group of 81 patients without liver diseases. We collected clinical information and performed routine blood tests. We also measured the serum concentration of PON1 and evaluated the PON1 gene polymorphisms L55M, Q192R, and C-108T. Results: There was a significant difference (p < 0.001) in serum PON1 concentrations among the two groups. The heterozygous and the mutated homozygous variants (LM + MM) of the L55M polymorphism were more frequent in the NAFLD group (p < 0.001). These genotypes were found in a multivariate binary logistic regression to be independently linked to NAFLD (Odds ratio = 3.4; p = 0.04). In a multivariate linear regression model, the presence of NAFLD was associated with low PON1 concentration (p < 0.001). Conclusions: PON1 serum concentrations were diminished in patients with NAFLD, and the presence of NAFLD was linked with low PON1 concentration. The LM + MM genotypes of the PON1 L55M polymorphism were an independent predictor for NAFLD with persistently elevated aminotransferases.