Association of single nucleotide polymorphism at PNPLA3 with fatty liver, steatohepatitis, and cirrhosis of liver

Nutritional management and geno-phenotyping of clinical nutrition in patients with glycogen storage diseases type VI and IX

BACKGROUND/OBJECTIVES

Glycogen storage diseases type VI (GSD-VI) and type IX (GSD-IX) are rare inherited metabolic disorders caused by enzyme deficiencies that disrupt glycogen metabolism. The aim of this study was to analyze the clinical features, nutritional management and geno-phenotyping of clinical nutrition in a cohort of patients with GSD-VI and GSD-IX.

SUBJECTS/METHODS

A retrospective cohort study was conducted with 16 patients with GSD-VI and GSD-IX. Demographic characteristics, clinical and laboratory findings, and nutritional treatment outcomes were collected and analyzed.

RESULTS

The mean patient age was 10.57 years (±4.81). The distribution of the diagnoses was as follows: GSD-IXa (3), GSD-IXb (6), GSD-IXc (1), and GSD-VI (6). The average age at diagnosis was 36.5 months (±42.2) (13-114 months) in the GSD-VI group. Among the GSD-IX subgroups, the mean age at diagnosis varied: 23.3months (±4.16) for GSD-IXa, 35.7months (±17.5) for GSD-IXb, and 78months for GSD-IXc. Over the course of the study (4.5 ± 1.77 years), protein intake in GSD VI patients increased by 1.05 g/kg/day (91.3% increase), while in GSD IX patients, it rose by 1.09 g/kg/day (94% rise). Uncooked cornstarch (UCS) started at 1 g/kg/day for GSD-VI and 0.85 g/kg/day for GSD-IX, later reduced to 0.71 g/kg/day (29% decrease) and 0.52 g/kg/day (60% reduction), respectively.

CONCLUSION

Overall, this paper provides valuable insights into managing GSDVI and GSDIX patients, emphasizing the role of a high-protein diet aligned with the disease's pathophysiology and the potential of genotyping to enhance nutritional treatment protocols.

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.

Genetic Polymorphisms and Diversity in Nonalcoholic Fatty Liver Disease (NAFLD): A Mini Review

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease with a wide spectrum of liver conditions ranging from hepatic steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. The prevalence of NAFLD varies across populations, and different ethnicities have specific risks for the disease. NAFLD is a multi-factorial disease where the genetics, metabolic, and environmental factors interplay and modulate the disease's development and progression. Several genetic polymorphisms have been identified and are associated with the disease risk. This mini-review discussed the NAFLD's genetic polymorphisms and focusing on the differences in the findings between the populations (diversity), including of those reports that did not show any significant association. The challenges of genetic diversity are also summarized. Understanding the genetic contribution of NAFLD will allow for better diagnosis and management explicitly tailored for the various populations.

Association of PNPLA3 rs738409 and TM6SF2 rs58542926 Polymorphisms with Non-alcoholic Fatty Liver Disease in the Iranian Population

Background: Non-alcoholic fatty liver disease (NAFLD) is a burgeoning health problem worldwide. Genetic predisposition increases susceptibility to NAFLD. The PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphisms are genetic risk factors for NAFLD. Objectives: This study aimed to investigate the association of rs738409 and rs58542926 polymorphisms with NAFLD among the Iranian population in two groups: (1) Population-based NAFLD (PB-NAFLD), and (2) clinic-based NAFLD (CB-NAFLD). Methods: This case-control study included a group of healthy individuals without NAFLD as the control group and two case groups, PB-NAFLD and CB-NAFLD. All individuals underwent clinical and laboratory assessments and were also diagnosed using ultrasonography. Genotyping for rs738409 and rs58542926 polymorphisms was carried out by the PCR-RFLP method. Results: A total of 110 control, 108 PB-NAFLD, and 73 CB-NAFLD individuals were included in the study. The distribution of rs738409 GG+CG in the PB-NAFLD was 39.8% while it was 52.7% in the control group (P = 0.06, OR = 0.59). The distribution of rs738409 GG in the CB-NAFLD was 19.2%, while it was 8.2% in the control group (P = 0.04, OR = 2.66). The distribution of rs58542926 genotypes was not significantly different between the NAFLD and control groups. In multivariate analysis, metabolic syndrome (OR = 2.85) and BMI > 25 (OR = 3.32) were independent determinants of NAFLD in the PB-NAFLD group, and BMI > 25 (OR = 7.15) was an independent determinant of NAFLD in the CB-NAFLD group. Conclusions: In this study, the PNPLA3 rs738409 polymorphism was associated with NAFLD in the CB-NAFLD cohort; however, the same was not observed for the PB-NAFLD cohort. The TM6SF2 rs58542926 polymorphism was not associated with NAFLD in the Iranian population.

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 non-alcoholic fatty liver disease (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.

Human Genetics to Identify Therapeutic Targets for NAFLD: Challenges and Opportunities

Non-alcoholic fatty liver disease (NAFLD) is a continuous progression of pathophysiologic stages that is challenging to diagnose due to its inherent heterogeneity and poor standardization across a wide variety of diagnostic measures. NAFLD is heritable, and several loci have been robustly associated with various stages of disease. In the past few years, larger genetic association studies using new methodology have identified novel genes associated with NAFLD, some of which have shown therapeutic promise. This mini-review provides an overview of the heterogeneity in NAFLD phenotypes and diagnostic methods, discusses genetic associations in relation to the specific stages for which they were identified, and offers a perspective on the design of future genetic mapping studies to accelerate therapeutic target identification.

Association between PNPLA3 rs738409 polymorphism and nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common disorder that is known to be the leading cause of chronic liver disease worldwide. This study aims to systematically review and meta-analyze the association between PNPLA3 rs738409 polymorphism and non-alcoholic fatty liver.

METHODS

Following a systematic review and meta-analysis method, articles without any time limitation, were extracted from SID, MagIran, IranDoc, Scopus, Embase, Web of Science (WoS), PubMed and ScienceDirect international databases. Random effects model was used for analysis, and heterogeneity of studies was investigated considering the I² index and using Comprehensive Meta-Analysis software.

RESULTS

The odds ratio of CC genotype in patients with non-alcoholic fatty liver demonstrates the protective effect of CC genotype with the ratio of 0.52, whereas CG genotype presents an increasing effect of CG genotype with the ratio of 0.19, and GG genotype also showed an increasing effect of GG genotype with the ratio of 1.05. Moreover, CG + GG genotypes as a single group demostrated an odds rartio of 0.88.

CONCLUSION

This meta-analysis highlights that people with CC genotype has 52% lower chance of developing non-alcoholic fatty liver disease, and those with CG genotype had 19% higher risk of developing non-alcoholic fatty liver. Those with GG genotype were 105% more likely to develop non-alcoholic fatty liver than others. Moreover, those present in a population with CG + GG genotypes were 88% more likely to have non-alcoholic fatty liver disease.

Metabolic syndrome is not uncommon among lean non-alcoholic fatty liver disease patients as compared with those with obesity

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with obesity, which is known to be associated with metabolic syndrome (MS). However, the risk factors for NAFLD in absence of obesity (leanness) is not well-studied. This study aimed to investigate and compare the clinical characteristics, metabolic associations, and cardiovascular risk factors among patients having NAFLD with (body mass index [BMI] ≥ 23 kg/m²) or without obesity (BMI < 23 kg/m²).

METHODS

The cross-sectional study was conducted among the outdoor and indoor patients diagnosed as NAFLD by ultrasonography in a tertiary care teaching hospital in eastern India. Relevant anthropometric measurements, laboratory investigations, and imaging were performed. Metabolic syndrome was classified by the "International Diabetes Federation, 2005" criteria.

RESULTS

Among 120 NAFLD patients, 37 (30.8%) were lean, while 83 (69.2%) were obese. The components of MS such as systolic blood pressure (lean, 138.0 ± 17.6 mmHg; obese, 137.9 ± 15.3 mmHg), diastolic blood pressure (lean, 88.9 ± 6.5 mmHg; obese, 87.3 ± 6.1 mmHg), fasting blood sugar (lean, 127.8 ± 30.8 mg/dL; obese, 135.1 ± 29.5 mg/dL), and serum triglyceride (lean, 170.5 ± 34.2 mg/dL; obese, 186.4 ± 43.8 mg/dL) were comparable among patients with obese and lean NAFLD and were more often abnormal among both the groups of NAFLD as compared with controls.

CONCLUSION

The overall prevalence of MS among NAFLD study population was 64.2%. Lean NAFLD was also associated with the component of MS like obese NAFLD.