Differences in characteristics of glucose intolerance between patients with NAFLD and chronic hepatitis C as determined by CGMS

A genetic mouse model of lean-NAFLD unveils sexual dimorphism in the liver-heart axis

Lean patients with NAFLD may develop cardiac complications independently of pre-existent metabolic disruptions and comorbidities. To address the underlying mechanisms independent of the development of obesity, we used a murine model of hepatic mitochondrial deficiency. The liver-heart axis was studied as these mice develop microvesicular steatosis without obesity. Our results unveil a sex-dependent phenotypic remodeling beyond liver damage. Males, more than females, show fasting hypoglycemia and increased insulin sensitivity. They exhibit diastolic dysfunction, remodeling of the circulating lipoproteins and cardiac lipidome. Conversely, females do not manifest cardiac dysfunction but exhibit cardiometabolic impairments supported by impaired mitochondrial integrity and β-oxidation, remodeling of circulating lipoproteins and intracardiac accumulation of deleterious triglycerides. This study underscores metabolic defects in the liver resulting in significant sex-dependent cardiac abnormalities independent of obesity. This experimental model may prove useful to better understand the sex-related variability, notably in the heart, involved in the progression of lean-NAFLD.

Liver Metabolomics Analysis Revealing Key Metabolites Associated with Different Stages of Nonalcoholic Fatty Liver Disease in Hamsters

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is not only the top cause of liver diseases but also a hepatic-correlated metabolic syndrome. This study performed untargeted metabolomics analysis of NAFLD hamsters to identify the key metabolites to discriminate different stages of NAFLD.

METHODS

Hamsters were fed a high-fat diet (HFD) to establish the NAFLD model with different stages (six weeks named as the NAFLD1 group and twelve weeks as the NAFLD2 group, respectively). Those liver samples were analyzed by untargeted metabolomics (UM) analysis to investigate metabolic changes and metabolites to discriminate different stages of NAFLD.

RESULTS

The significant liver weight gain in NAFLD hamsters was observed, accompanied by significantly increased levels of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Moreover, the levels of TG, LDL-C, ALT, and AST were significantly higher in the NAFLD2 group than in the NAFLD1 group. The UM analysis also revealed the metabolic changes; 27 differently expressed metabolites were detected between the NAFLD2 and NAFLD1 groups. More importantly, the levels of N-methylalanine, allantoin, glucose, and glutamylvaline were found to be significantly different between any two groups (control, NAFLD2 and NAFLD1). Receiver operating characteristic curve (ROC) curve results also showed that these four metabolites are able to distinguish control, NAFLD1 and NAFLD2 groups.

CONCLUSION

This study indicated that the process of NAFLD in hamsters is accompanied by different metabolite changes, and these key differently expressed metabolites may be valuable diagnostic biomarkers and responses to therapeutic interventions.

Cinnabarinic Acid Provides Hepatoprotection Against Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic condition in which excess lipids accumulate in the liver and can lead to a range of progressive liver disorders including non-alcoholic steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. While lifestyle and diet modifications have proven to be effective as NAFLD treatments, they are not sustainable in the long-term, and currently no pharmacological therapies are approved to treat NAFLD. Our previous studies demonstrated that cinnabarinic acid (CA), a novel endogenous Aryl hydrocarbon Receptor (AhR) agonist, activates the AhR target gene, Stanniocalcin 2, and confers cytoprotection against a plethora of ER/oxidative stressors. In this study, the hepatoprotective and anti-steatotic properties of CA were examined against free fatty-acid-induced in vitro and high-fat-diet fed in vivo NAFLD models. The results demonstrated that CA treatment significantly lowered weight gain and attenuated hepatic lipotoxicity both before and after the established fatty liver, thereby protecting against steatosis, inflammation, and liver injury. CA mitigated intracellular free fatty acid uptake concomitant with the downregulation of CD36/fatty acid translocase. Genes involved in fatty acid and triglyceride synthesis were also downregulated in response to CA treatment. Additionally, suppressing AhR and Stc2 expression using RNA interference in vitro verified that the hepatoprotective effects of CA were absolutely dependent on both AhR and its target, Stc2. Collectively, our results demonstrate that the endogenous AhR agonist, CA, confers hepatoprotection against NAFLD by regulating hepatic fatty acid uptake and lipogenesis. SIGNIFICANCE STATEMENT: In this study using in vitro and in vivo models, we demonstrate that cinnabarinic acid (CA), an endogenous AhR agonist, provides protection against non-alcoholic fatty liver disease. CA bestows cytoprotection against steatosis and liver injury by controlling expression of several key genes associated with lipid metabolism pathways, limiting the hepatic lipid uptake, and controlling liver inflammation. Moreover, CA-induced hepatoprotection is absolutely dependent on AhR and Stc2 expression.

Analysis of Severe Hypoglycemia Among Adults With Type 2 Diabetes and Nonalcoholic Fatty Liver Disease

IMPORTANCE

Previous studies have indicated that liver cirrhosis is associated with hypoglycemia, but there have been no studies investigating the association between nonalcoholic fatty liver disease (NAFLD) and hypoglycemia in noncirrhotic populations with type 2 diabetes.

OBJECTIVE

To explore the association of NAFLD with severe hypoglycemia among patients with type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide population-based retrospective cohort study using the National Health Insurance System of South Korea included individuals aged 20 years or older who had undergone a medical health examination between January 1, 2009, and December 31, 2012, and were diagnosed with type 2 diabetes. Participants were followed up until December 31, 2015. Data analyses were performed between January 1, 2019, and February 2, 2021.

EXPOSURES

The baseline fatty liver index (FLI) was used as a surrogate marker for NAFLD.

MAIN OUTCOMES AND MEASURES

The outcome of interest, severe hypoglycemia, was measured using hospital admission and emergency department visit records with a primary diagnosis of hypoglycemia.

RESULTS

Among 1 946 581 individuals with type 2 diabetes, 1 125 187 (57.8%) were male. During a median (IQR) follow-up of 5.2 (4.1-6.1) years, 45 135 (2.3%) experienced 1 or more severe hypoglycemia events. Participants with severe hypoglycemia, vs those without severe hypoglycemia, were older (mean [SD] age, 67.9 [9.9] years vs 57.2 [12.3] years; P < .001) and had lower mean (SD) body mass index (24.2 [3.43] vs 25.1 [3.4]; P < .001). Patients with NAFLD tended to have less severe hypoglycemia without consideration of obesity status. However, after adjustment of multiple clinical covariates, including body mass index, there was a J-shaped association between FLI and severe hypoglycemia (5th decile: adjusted hazard ratio [aHR], 0.86; 95% CI, 0.83-0.90; 9th decile: aHR, 1.02; 95% CI, 0.96-1.08; 10th decile: aHR, 1.29; 95% CI, 1.22-1.37), and the estimated risk of hypoglycemia was higher in participants with NAFLD (aHR, 1.26; 95% CI, 1.22-1.30). The association was more prominent in female participants (aHR, 1.29; 95% CI, 1.23-1.36) and those with underweight (aHR, 1.71; 95% CI, 1.02-2.88).

CONCLUSIONS AND RELEVANCE

In this study, NAFLD was associated with a higher risk of severe hypoglycemia in patients with type 2 diabetes independent of obesity status. Presence of NAFLD should be considered when evaluating vulnerability to hypoglycemia in patients with type 2 diabetes.

Glucose Concentrations from Continuous Glucose Monitoring Devices Compared to Those from Blood Plasma during an Oral Glucose Tolerance Test in Healthy Young Adults

Continuous glucose monitoring devices measure glucose in interstitial fluid. The devices are effective when used by patients with type 1 and 2 diabetes but are increasingly being used by researchers who are interested in the effects of various behaviours of glucose concentrations in healthy participants. Despite their more frequent application in this setting, the devices have not yet been validated for use under such conditions. A total of 124 healthy participants were recruited to a ten-day laboratory study. Each participant underwent four oral glucose tolerance tests, and a total of 3315 out of a possible 4960 paired samples were included in the final analysis. Bland-Altman plots and mean absolute relative differences were used to determine the agreement between the two methods. Bland-Altman analyses revealed that the continuous glucose monitoring devices had proportional bias (R = 0.028, p < 0.001) and a mean bias of -0.048 mmol/L, and device measurements were more variable as glucose concentrations increased. Ninety-nine per cent of paired values were in Zones A and B of the Parkes Error Grid plot, and there was an overall mean absolute relative difference of 16.2% (±15.8%). There was variability in the continuous glucose monitoring devices, and this variability was higher when glucose concentrations were higher. If researchers were to use continuous glucose monitoring devices to measure glucose concentrations during an oral glucose tolerance test in healthy participants, this variability would need to be considered.

Glucose Variability and Risk of Hepatocellular Carcinoma in Patients with Diabetes: A Nationwide Population-Based Study

BACKGROUND

Although diabetes is a well-known risk factor for hepatocellular carcinoma, exactly which metabolic parameters of diabetes are associated with hepatocellular carcinoma remain unexplored. In this study, we investigated the relationship between glucose variability (GV) and hepatocellular carcinoma in patients with diabetes through a nationwide population-based study.

METHODS

A population-based cohort study including 674,178 diabetic subjects participating in more than three health examinations within 5 years from the index year (2009 and 2010) were followed until the end of 2017. The coefficient of variation, SD, variability independent of the mean, and average real variability were calculated as GV indices.

RESULTS

During a median follow-up of 6.7 years, there were 5,494 cases of hepatocellular carcinoma. When groups were classified according to glucose level, the highest risk for hepatocellular carcinoma was observed when the basal blood glucose level was 180 mg/dL or greater [adjusted HR (aHR), 1.19; 95% confidence interval (CI), 1.08-1.31]. We observed increasing trends for the relationship between GV and hepatocellular carcinoma in multivariable Cox proportional analyses. The risk of hepatocellular carcinoma increased by 27% (aHR, 1.27; 95% CI, 1.17-1.38) for the highest quartile of GV relative to the lowest quartile. These findings were consistent regardless of the presence of chronic viral hepatitis or cirrhosis, alcohol consumption, or body mass index.

CONCLUSIONS

GV was an independent predictor of hepatocellular carcinoma, even after adjusting for confounding factors. There was a linear relationship between increase in GV and prevalence of hepatocellular carcinoma.

IMPACT

Visit-to-visit GV might be helpful for identifying patients with diabetes at high risk of hepatocellular carcinoma.

Blood glucose fluctuations detected by continuous glucose monitoring system in gout patients with normal glucose tolerance and the effect of urate-lowering therapy

AIM

The aim of this study was to investigate whether there are blood glucose fluctuations in gout patients with hyperuricemia and normal glucose tolerance, and the effect of urate-lowering therapy on blood glucose fluctuations.

METHODS

Thirty patients with newly diagnosed gout, hyperuricemia and normal glucose tolerance were enrolled in our study. Continuous glucose monitoring system (CGMS) was used to detect the blood glucose fluctuations of these gout patients. Changes in blood glucose fluctuations after allopurinol therapy were also evaluated.

RESULTS

Compared with the reference values of blood glucose fluctuation parameters in China, gout patients had greater glycemic fluctuations including higher mean amplitude of glucose excursions (MAGE) (4.65 vs 1.94 mmol/L, P < .001), higher largest amplitude of blood glucose excursions (LAGE) (4.99 vs 3.72 mmol/L, P < .001) and higher standard deviations of blood glucose (SDBG) (1.36 vs 0.79 mmol/L, P < .001). MAGE was significantly correlated with uric acid (β = .007, P = .024) and HOMA-insulin resistance (IR) (β = .508, P = .03). Allopurinol treatment significantly reduced MAGE (4.16 vs 4.65 mmol/L, P < .001), SDBG (0.99 vs 1.36 mmol/L, P < .001) and HOMA-IR (2.26 vs 3.01, P < .001) in gout patients.

CONCLUSION

Blood glucose fluctuation increased even in the stage of normal glucose tolerance among gout patients. Blood glucose fluctuations in gout patients were associated with the level of serum uric acid and allopurinol could decrease blood glucose fluctuation as well as IR.

Energy metabolism couples hepatocyte integrin-linked kinase to liver glucoregulation and postabsorptive responses of mice in an age-dependent manner

Integrin-linked kinase (ILK) is a critical intracellular signaling node for integrin receptors. Its role in liver development is complex, as ILK deletion at E10.5 (before hepatocyte differentiation) results in biochemical and morphological differences that resolve as mice age. Nevertheless, mice with ILK depleted specifically in hepatocytes are protected from the hepatic insulin resistance during obesity. Despite the potential importance of hepatocyte ILK to metabolic health, it is unknown how ILK controls hepatic metabolism or glucoregulation. The present study tested the role of ILK in hepatic metabolism and glucoregulation by deleting it specifically in hepatocytes, using a cre-lox system that begins expression at E15.5 (after initiation of hepatocyte differentiation). These mice develop the most severe morphological and glucoregulatory abnormalities at 6 wk, but these gradually resolve with age. After identifying when the deletion of ILK caused a severe metabolic phenotype, in depth studies were performed at this time point to define the metabolic programs that coordinate control of glucoregulation that are regulated by ILK. We show that 6-wk-old ILK-deficient mice have higher glucose tolerance and decreased net glycogen synthesis. Additionally, ILK was shown to be necessary for transcription of mitochondrial-related genes, oxidative metabolism, and maintenance of cellular energy status. Thus, ILK is required for maintaining hepatic transcriptional and metabolic programs that sustain oxidative metabolism, which are required for hepatic maintenance of glucose homeostasis.

Hemoglobin A1c Has Suboptimal Performance to Diagnose and Monitor Diabetes Mellitus in Patients with Cirrhosis

BACKGROUND

Glycated hemoglobin A1c (HbA1c) is routinely used to diagnose and monitor type 2 diabetes mellitus (T2DM) in cirrhotic patients. Remarkably, HbA1c may be falsely low in such patients.

AIMS

We assessed the diagnostic and monitoring yield of HbA1c in cirrhotic patients with T2DM (DM-Cirr) and without T2DM (NoDM-Cirr).

METHODS

We conducted a composite study allocating 21 NoDM-Cirr into a cross-sectional module and 16 DM-Cirr plus 13 controls with T2DM only (DM-NoCirr) into a prospective cohort. Oral glucose tolerance test (OGTT) was performed in NoDM-Cirr. DM-Cirr and DM-NoCirr were matched by sex, age, BMI, and T2DM treatment and studied with continuous glucose monitoring (CGM). Percent deviations from target, low/high blood glucose indexes (LBGI/HBGI) were calculated from CGM, as well as the average daily risk range (ADRR) as a marker of glucose variability.

RESULTS

Overall, HbA1c and OGTT diagnostic yield agreed in 12 patients (57%, ρ = 0.45, p < 0.03). CGM captured 3463 glucose determinations in DM-Cirr and 4273 in DM-NoCirr (p = 0.42). Regression analysis showed an inferior association between HbA1c and CGM in DM-Cirr (R² = 0.52), when compared to DM-NoCirr (R² = 0.94), and fructosamine did not improve association for DM-Cirr (R² = 0.31). Interestingly, cirrhosis and Child-Turcotte-Pugh class accounted for HbA1c variance (p < 0.05). Patients in DM-Cirr were less frequently within target glucose (70-180 mg/dL), but at higher risk for hyperglycemia (HBGI > 9) when compared to DM-NoCirr, and they also showed higher glucose variability (ADRR 13.9 ± 2.5 vs. 8.9 ± 1.8, respectively, p = 0.03).

CONCLUSION

HbA1c inaccurately represents chronic glycemia in patients with cirrhosis, likely in relation to increased glucose variability.

Trend over time in hepatic fibrosis score in a cohort of type 2 diabetes patients

AIMS

The prevalence and progression of hepatic fibrosis and its correlated factors in type 2 diabetes (T2DM) are poorly known. We aimed to define the percentage of T2DM patients who progress to fibrosis and the factors associated with disease progression.

METHODS

Data from the electronic health records of 1527 patients with diagnosed T2DM and nonalcoholic fatty liver disease (NAFLD), as diagnosed by the Fatty Liver Index, were extracted from the AMD Annals database, which collects data from the Italian network of diabetes clinics. For the main analysis, we evaluated variables associated with Fibrosis 4 [FIB-4] score at baseline and at 3-year follow-up to determine their role in predicting FIB-4 at 3 years and the risk of hepatic fibrosis in T2DM.

RESULTS

High-risk of advanced fibrosis was detected in 13.1% of patients at baseline and in 18.1% at 3 years, LDL cholesterol, and body-mass index, correlated negatively with baseline FIB-4 scores, whereas gamma glutamil transerasi correlated positively . The FIB-4 score at 3 years was associated with lower values of baseline renal function, LDL, and BMI; however, the baseline FIB-4 score was the strongest predictor for the FIB-4 score at 3 years.

CONCLUSIONS

The prevalence of and progression to hepatic fibrosis within 3 years in patients with T2DM is not negligible. Patients with a higher likelihood of liver scarring differ from those with hepatic steatosis. Differently from NAFLD, the FIB-4 score is inversely correlated with insulin resistance and appears to increase independent of classic metabolic factors.