Genetic variants in the MTHFR are not associated with fatty liver disease

Factors associated with treatment responses to pioglitazone in patients with steatotic liver disease: A 3-year prospective cohort study

AIM

The response rate to pioglitazone and the predictive factors for its effects on improving liver biochemistry in patients with steatotic liver disease (SLD) remain elusive, so we aimed to investigate these issues.

METHODS

A 3-year prospective cohort study of 126 Taiwanese patients with SLD treated with pioglitazone (15-30 mg/day) was conducted. Phospholipase domain-containing protein 3 I148M rs738409, methylenetetrahydrofolate reductase rs1801133, aldehyde dehydrogenase 2 (ALDH2) rs671 and lipoprotein lipase rs10099160 single nucleotide polymorphisms were assessed in the patients.

RESULTS

Of 126 patients, 78 (61.9%) were men, and the mean and median ages were 54.3 and 56.5 years, respectively. Pioglitazone responders were defined as those with decreased alanine aminotransferase (ALT) levels at 6 months post-treatment, and 105 (83.3%) patients were responders. Compared with non-responders, responders were more frequently women and had higher baseline ALT levels. The proportion of patients with the ALDH2 rs671 GG genotype was lower among responders (38.6% vs. 66.6%, p = .028). Female sex [odds ratio (OR): 4.514, p = .023] and baseline ALT level (OR: 1.015, p = .046; cut-off level: ≥82 U/L) were associated with pioglitazone response. Among responders, the liver biochemistry and homeostasis model assessment of insulin resistance improved from 6 to 24 months post-treatment. The total cholesterol levels decreased within 6 months, while increases in high-density lipoprotein cholesterol levels and decreases in triglyceride levels and fibrosis-4 scores were noted only at 24 months post-treatment. The 2-year cumulative incidences of cardiovascular events, cancers and hepatic events were similar between responders and non-responders.

CONCLUSIONS

Regarding liver biochemistry, over 80% of Taiwanese patients with SLD had a pioglitazone response, which was positively associated with female sex and baseline ALT levels. Insulin resistance improved as early as 6 months post-treatment, while liver fibrosis improvement was not observed until 24 months post-treatment. The link between the pioglitazone response and the ALDH2 genotype warrants further investigation.

Association of liver fibrosis with extrahepatic cancer in steatotic liver disease patients with PNPLA3 I148M GG genotype

The impacts of patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M-rs738409, methylenetetrahydrofolate reductase (MTHFR) Ala222Val-rs1801133, and aldehyde dehydrogenase 2 (ALDH2) Glu504Lys-rs671 on the outcomes of Taiwanese patients with steatotic liver disease (SLD) have remained elusive. An 8-year prospective cohort study of patients with (n = 546) and without (n = 580) SLD (controls) was undertaken in a Taiwanese tertiary care center. The 546 SLD patients comprised 306 (56.0%) men and 240 (44.0%) women with mean ages of 53.3 and 56.4 years, respectively. Compared with the controls, SLD patients had an increased frequency of the PNPLA3 I148M-rs738409 GG genotype (25.5 vs. 5.9%, p = 0.001). Among the SLD patients, 236 (43.1%) suffered cardiovascular events, 52 (9.5%) showed extrahepatic cancers, 13 (2.38%) experienced hepatic events, including hepatocellular carcinoma (n = 3, 0.5%) and liver cirrhosis (n = 8, 1.47%), and none died. The Fibrosis-4 (FIB-4) scores were associated with extrahepatic cancer (hazard ratio [HR] 1.325; 95% confidence interval [CI], 1.038-1.691) and cirrhosis development (HR 1.532; 95% CI, 1.055-2.224), and the PNPLA3 I148M-rs738409 G allele (β = 0.158, 95% CI, 0.054-0.325) was associated with the FIB-4 score. Stratified analyses showed that the impact of the FIB-4 score on extrahepatic cancer development was evident only in SLD patients with the PNPLA3 I148M-rs738409 GG genotype (HR 1.543; 95% CI, 1.195-1.993) and not in patients with the GC or CC genotype. Moreover, the ALDH2 Glu504Lys-rs671 G allele had a dose-dependent effect on alcoholism, and the MTHFR and ALDH2 genotypes were not significantly associated with SLD patient outcomes. In conclusion, special vigilance should be exercised for emerging extrahepatic cancer in SLD patients with the PNPLA3 I148M-rs738409 GG genotype and high FIB-4 scores.

MTHFR epigenetic derepression protects against diabetes cardiac fibrosis

BACKGROUND

Diabetes cardiac fibrosis is associated with altered DNA methylation of fibrogenic genes; however, the underlying mechanisms remain unclear.

OBJECTIVES

In this study, we investigate the critical role of DNA methylation aberration-associated suppression of MTHFR in diabetes cardiac fibrosis, and the protective effects of folate on diabetes cardiac fibrosis, using cultured cells, animal models, and clinical samples.

METHODS AND RESULTS

Herein, we report that DNA methylation repression of MTHFR, critically involved in diabetes cardiac fibrosis, mediates the significant protective effects of folate in a mouse model of diabetes cardiac fibrosis induced by STZ. Heart MTHFR expression was markedly suppressed in diabetes cardiac fibrosis patients and mice, accompanied by increased DNMT3A and MTHFR promoter methylation. Knockdown of DNMT3A demethylated MTHFR promoter, recovered the MTHFR loss, and alleviated the diabetes cardiac fibrosis pathology and cardiac fibroblasts pyroptosis. Mechanistically, DNMT3A epigenetically repressed MTHFR expression via methylation of the promoter. Interestingly, folate supplementation can rescue the effect of MTHFR loss in diabetes cardiac fibrosis, suggesting that inactivation of MTHFR through epigenetics is a critical mediator of diabetes cardiac fibrosis.

CONCLUSIONS

The current study identifies that MTHFR repression due to aberrant DNMT3A elevation and subsequent MTHFR promoter hypermethylation is likely an important epigenetic feature of diabetes cardiac fibrosis, and folate supplementation protects against diabetes cardiac fibrosis.

Metabolic and genetic determinants for progression to severe liver disease in subjects with obesity from the UK Biobank

BACKGROUND

Obesity is among the main determinants of nonalcoholic fatty liver disease progression towards severe liver disease (SLD). However, risk factors for SLD in individuals with obesity have not been examined.

OBJECTIVES

To identify the independent risk factors for SLD among participants with obesity from the UK Biobank.

METHODS

A total of 80,224 UK Biobank participants with obesity (body mass index[BMI] > 30 kg/m²) and 242,822 without obesity, of European descent without clinical history of liver disease and liver cancer were prospectively followed for the onset of SLD, defined as a composite diagnosis of cirrhosis, decompensated liver disease, hepatocellular carcinoma and/or liver transplantation. Risk factors for incident SLD were assessed by Cox proportional hazards models. Different clinical phenotypes were derived by latent class analysis (LCA).

RESULTS

Obesity conferred a 2.6-fold increased risk for SLD that was abolished after the inclusion of waist circumference (WC) in the model. Among individuals with obesity, age (adjusted hazard ratio [aHR] 1.05, 95%CI 1.03-1.07, p = 3.9 * 10^-7), type 2 diabetes (aHR 2.18, 95%CI 1.55-3.05, p = 6.2 * 10^-6), PNPLA3 rs738409 (aHR 1.59, 95%CI 1.33-1.9, p = 3.1 * 10^-7) and WC (aHR 1.04, 95%CI 1.02-1.06, p = 8.5 * 10^-6) were independent predictors of SLD. BMI category-specific WC thresholds allowed a better risk stratification compared to traditional ones. By LCA, the clinical phenotype at highest risk for SLD was that with BMI < 35 kg/m² and WC above BMI-category specific thresholds.

CONCLUSIONS

Age, WC, type 2 diabetes, and the PNPLA3 variant are the main risk factors for SLD in individuals with obesity. WC is the principal mediator of SLD risk conveyed by increased BMI. BMI category-specific WC-thresholds may refine the SLD risk more accurately than traditional thresholds.

Cardiovascular involvement after liver transplantation: role of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

Patients submitted to liver transplantation (LT) are exposed to high risk of cardiovascular (CV) complications which are the main determinants of both short-term and long-term morbidity and mortality in LT. Non-alcoholic fatty liver disease (NAFLD) is a very frequent condition in general population and is associated with a high risk of cardiovascular disease (CVD) which represents the first cause of death of these patients. NAFLD is predicted to become the first indication to LT and nowadays is also frequently detected in patients submitted to LT for other indications. Thus, the risk of CVD in patients submitted to LT is forecasted to increase in the next years. In this review the extent of CV involvement in patients submitted to LT and the role of NAFLD, either recurring after transplantation or as de novo presentation, in increasing CV risk is analysed. The risk of developing metabolic alterations, including diabetes, hypertension, dyslipidemia and weight gain, all manifestations of metabolic syndrome, occurring in the first months after LT, is depicted. The different presentations of cardiac involvement, represented by early atherosclerosis, coronary artery disease, heart failure and arrhythmias in patients with NAFLD submitted to LT is described. In addition, the tools to detect cardiac alterations either before or after LT is reported providing the possibility for an early diagnosis of CVD and an early therapy able to reduce morbidity and mortality for these diseases. The need for long-term concerted multidisciplinary activity with dietary counseling and exercise combined with drug treatment of all manifestations of metabolic syndrome is emphasized.