Liver Fat Content Is Associated with Elevated Serum Uric Acid in the Chinese Middle-Aged and Elderly Populations: Shanghai Changfeng Study

Association between serum uric acid and nonalcoholic fatty liver disease in community patients with type 2 diabetes mellitus

Background

To investigate whether SUA is associated with NAFLD in men and women with T2DM.

Methods

This cross-sectional study enrolled patients with T2DM at Shanxi High-Tech Development Zone Central Hospital (June 2011 to September 2017). Patients were stratified according to gender and presence/absence of NAFLD. Parameters associated with NAFLD were identified using multivariate stepwise linear regression and univariate/multivariate logistic regression.

Results

Among 597 patients (325 males) enrolled, 352 had NAFLD. SUA was higher in the NAFLD group than in the non-NAFLD group for both men and women (P < 0.001). Multiple linear regression showed that body mass index (positively), triglycerides (positively) and estimated glomerular filtration rate (negatively) were independently related to SUA (P < 0.001). Univariate logistic regression revealed increased odds of NAFLD for SUA tertiles 2 (P = 0.022) and 3 (P = 0.001) in women and tertile 3 (P = 0.039) in men. After adjustment for multiple clinical parameters, SUA tertiles were significantly associated with NAFLD for tertile 3 in women (P = 0.014), although there were trends toward associations for tertile 2 in women (P = 0.074) and tertiles 2 and 3 in men (P = 0.085 and 0.054, respectively).

Conclusion

SUA is not independently associated with NAFLD in men or women with T2DM after rigorous adjustment for other metabolic parameters.

The correlation between controlled attenuation parameter and metabolic syndrome and its components in middle-aged and elderly nonalcoholic fatty liver disease patients

This study aims to investigate the correlation between controlled attenuation parameter (CAP) and metabolic syndrome (MetS) and its components in middle-aged and elderly nonalcoholic fatty liver disease (NAFLD) patients.Middle-aged and elderly patients with NAFLD, who visited our hospital from June 2016 to May 2017, were enrolled as study subjects, whereas middle-aged and elderly patients without liver disease were enrolled as controls in the same period. The prevalence of MetS, MetS components, and the different numbers of MetS components were compared among patients with different CAP values.As the CAP value increased, the prevalence of MetS, MetS components, and the different numbers of MetS components significantly increased. The CAP value was positively correlated with the prevalence of MetS, obesity, hypertriglyceridemia, hypertension, hyperglycemia, hyperuricemia, and the number of MetS components, and was negatively correlated with the prevalence of hypo-high-density-lipoprotein cholesterolemia.CAP values are closely correlated to MetS and its components in middle-aged and elder NAFLD patients. CAP may be an indicator of risk of MetS and the severity of metabolic disorders in middle-aged and elderly NAFLD patients.

Metformin attenuates triglyceride accumulation in HepG2 cells through decreasing stearyl-coenzyme A desaturase 1 expression

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased worldwide. Metformin decreases triglyceride (TG) accumulation in hepatocytes in vivo and in vitro. Stearyl-coenzyme A desaturase 1 (SCD1) knockout mice also show decreased liver TG accumulation; however, whether SCD1 plays a role in the effect of metformin on TG accumulation is unknown. Therefore, the aim of this study was to investigate whether SCD1 mediated the effect of metformin on TG accumulation.

METHODS

HepG2 and AML12 cells were exposed to high glucose and high insulin with or without metformin. An adenovirus was used for the SCD1 knockdown and overexpression. The triglyceride level in cells was detected. The expression of related genes was detected by Western blot and quantitative real-time PCR. A dual-luciferase reporter assay was used to determine the effect of metformin on the transcriptional activity of the SCD1 promoter.

RESULTS

Metformin decreased TG accumulation to normal level in HepG2 cells exposed to high glucose and high insulin. The expression of SCD1 and fatty acid synthetase (FAS) was also decreased to normal level by metformin. Knockdown of SCD1 mimicked the effect of metformin on decreasing TG levels in AML12 cells, and the overexpression of SCD1 attenuated the effect of metformin on decreasing TG accumulation in HepG2 cells. The dual-luciferase reporter assay showed that the transcriptional activity of the SCD1 promoter (- 550/+ 199) after metformin treatment was 2-fold lower compared to control group in HepG2 cells. Additionally, the phosphorylation of AMPK after metformin treatment was 2-fold higher, and the expression of sterol regulatory element-binding protein-1c (SREBP-1c) after metformin treatment was about 2-fold lower compared to high glucose and high insulin group in HepG2 cells.

CONCLUSIONS

Together, these results reveal that metformin reduces TG accumulation in HepG2 cells via inhibiting the expression of SCD1.

Role of MicroRNAs in NAFLD/NASH

MicroRNAs (miRNAs) are highly conserved, small, 18-25 nucleotide, non-coding RNAs that regulate gene expression at the post-transcriptional level. Each miRNA can regulate hundreds of target genes, and vice versa each target gene can be regulated by numerous miRNAs, suggesting a very complex network and explaining how miRNAs play pivotal roles in fine-tuning essentially all biological processes in all cell types in the liver. Here, we summarize the current knowledge on the role of miRNAs in the pathogenesis and diagnosis of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) with an outlook to the broader aspects of metabolic syndrome. Furthermore, we discuss the role of miRNAs as potential biomarkers and therapeutic targets in NAFLD/NASH.

Hepatic fat content is a determinant of metabolic phenotypes and increased carotid intima-media thickness in obese adults

Individuals with metabolically healthy obesity (MHO) are at relatively low risk for the development of metabolic abnormalities and subclinical atherosclerosis. This study aims to examine whether hepatic fat accumulation determines metabolic phenotype of obesity and associated with subclinical atherosclerosis. A total of 485 obese adults (aged 40–65 years) who received magnetic resonance spectroscopy were divided into metabolically abnormally obesity (MAO) and MHO groups according to metabolic status. MHO individuals had lower levels of intrahepatic triglyceride (IHTG) content and carotid intima-media thickness (CIMT) than MAO individuals. In multivariable linear regression analyses, IHTG content was independently associated with metabolic syndrome components and CIMT. Based on receiver operating characteristic curve analysis, the IHTG content displayed a higher area under the curve (AUC) for detecting the MAO phenotype (AUC = 0.70, 95%CI = 0.65–0.75) and increased CIMT (AUC = 0.60, 95%CI = 0.54–0.66) than BMI, waist circumference, and body fat percent. MHO individuals were 1.9 times (p < 0.001) more likely to have metabolic syndrome per 1 SD change in IHTG content in multivariable-adjusted models. Likewise, the risk for high CIMT increased 29% per 1 SD change in IHTG content [OR (95% CI):1.29(1.01–1.64)]. These findings suggest that hepatic fat is a potential predictor of metabolically unhealthy obesity phenotype and subclinical atherosclerosis.