Loss of SREBP-1c ameliorates iron-induced liver fibrosis by decreasing lipocalin-2.

Sterol regulatory element-binding protein (SREBP)-1c is involved in cellular lipid homeostasis and cholesterol biosynthesis and is highly increased in nonalcoholic steatohepatitis (NASH). However, the molecular mechanism by which SREBP-1c regulates hepatic stellate cells (HSCs) activation in NASH animal models and patients have not been fully elucidated. In this study, we examined the role of SREBP-1c in NASH and the regulation of LCN2 gene expression. Wild-type and SREBP-1c knockout (1cKO) mice were fed a high-fat/high-sucrose diet, treated with carbon tetrachloride (CCl4), and subjected to lipocalin-2 (LCN2) overexpression. The role of LCN2 in NASH progression was assessed using mouse primary hepatocytes, Kupffer cells, and HSCs. LCN2 expression was examined in samples from normal patients and those with NASH. LCN2 gene expression and secretion increased in CCl4-induced liver fibrosis mice model, and SREBP-1c regulated LCN2 gene transcription. Moreover, treatment with holo-LCN2 stimulated intracellular iron accumulation and fibrosis-related gene expression in mouse primary HSCs, but these effects were not observed in 1cKO HSCs, indicating that SREBP-1c-induced LCN2 expression and secretion could stimulate HSCs activation through iron accumulation. Furthermore, LCN2 expression was strongly correlated with inflammation and fibrosis in patients with NASH. Our findings indicate that SREBP-1c regulates Lcn2 gene expression, contributing to diet-induced NASH. Reduced Lcn2 expression in 1cKO mice protects against NASH development. Therefore, the activation of Lcn2 by SREBP-1c establishes a new connection between iron and lipid metabolism, affecting inflammation and HSCs activation. These findings may lead to new therapeutic strategies for NASH.

Mortality in metabolic dysfunction-associated steatotic liver disease: A nationwide population-based cohort study.

BACKGROUND: A new fatty liver disease nomenclature, steatotic liver disease (SLD) has been proposed; however, there are no data on clinical outcomes. We investigated the impact of SLD with metabolic dysfunction (MD; SLD-MD) on all-cause mortality. METHODS: We evaluated nationally representative participants aged ≥19 years using data from the Korea National Health and Nutrition Examination Survey 2007-2015 and their linked death data through 2019. The presence of fatty liver disease was assessed by liver fat score, fatty liver index and significant liver fibrosis was evaluated by the Fibrosis-4 Index, and fibrosis score. SLD-MD was categorized into three groups: metabolic dysfunction-associated steatotic liver disease (MASLD); metabolic alcoholic liver disease (MetALD); and SLD with other combination etiologies. RESULTS: Among 26734 individuals (11561 men and 15173 women, mean age 48.8 years), 1833 (6.9 %) died during a mean follow-up period of 110.6 ± 33.9 months. Mortality risk was significantly higher in individuals with SLD-MD (hazard ratio [HR] = 1.35) than in those without (P < 0.001). Among the three groups, MASLD (HR = 1.32) and SLD with other combination etiologies (HR = 2.06) independently increased mortality risk (all P < 0.001). When individuals with SLD-MD had significant liver fibrosis or diabetes, mortality risk increased further (HR = 1.68 and 1.85, respectively; all P < 0.001). SLD-MD with both significant liver fibrosis and diabetes showed the highest mortality risk (HR = 2.29, P < 0.001). When applied fatty liver index and fibrosis score, similar results were observed. CONCLUSIONS: SLD-MD is associated with a higher mortality risk. When SLD-MD was combined with significant liver fibrosis or diabetes, the mortality risk became much higher. Treatment strategies to reduce fibrotic burden and improve glycemic control in individuals with MASLD are needed.

Appendicular Skeletal Muscle Mass to Visceral Fat Area Ratio Predicts Hepatic Morbidities.

Background/Aims: : Reports on the association between sarcopenic visceral obesity and non-alcoholic fatty liver disease (NAFLD)-associated morbidities remain scarce. We investigated the association between sarcopenia and visceral obesity, and the influence of this association on hepatic and coronary comorbidities. Methods: : The appendicular skeletal muscle mass to visceral fat area ratio (SV ratio) was evaluated using bioelectric impedance analysis. NAFLD and significant liver fibrosis were assessed using transient elastography, and high atherosclerotic cardiovascular disease (ASCVD) risk was defined as a 10-year ASCVD risk score >10%. Sarcopenia was defined as appendicular skeletal muscle mass adjusted by body mass index (<0.789 for men and <0.512 for women). Results: : In total, 82.0% (n=1,205) of the entire study population had NAFLD, and 14.6% of these individuals (n=176) exhibited significant liver fibrosis. Individuals with the lowest SV ratio had a significantly increased risk of NAFLD, significant liver fibrosis, and high ASCVD risk (all p<0.05). Individuals with both the lowest SV ratio and sarcopenia had the highest risk of developing NAFLD (odds ratio [OR]=3.11), significant liver fibrosis (OR=2.03), and high ASCVD risk (OR=4.15), compared with those with a higher SV ratio and without sarcopenia (all p<0.05). Conclusions: : Low SV ratio combined with sarcopenia was significantly associated with an increased risk of NAFLD, significant liver fibrosis, and high ASCVD risk among individuals with a high risk of NAFLD.

2023 Clinical Practice Guidelines for Diabetes Mellitus of the Korean Diabetes Association.

In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.

Lobeglitazone inhibits LPS-induced NLRP3 inflammasome activation and inflammation in the liver.

Liver inflammation is a common feature of chronic liver disease and is often associated with increased exposure of the liver to lipopolysaccharide (LPS). Kupffer cells (KCs) are macrophages in the liver and produce various cytokines. Activation of KCs through the NLRP3 inflammasome pathway leads to release of proinflammatory cytokines and induces hepatocyte injury and hepatic stellate cell (HSC) activation. Lobeglitazone is a peroxisome proliferator-activated receptor gamma ligand and a type of thiazolidinedione that elicits anti-inflammatory effects. However, there is no clear evidence that it has direct anti-inflammatory effects in the liver. This study showed that lobeglitazone reduces LPS-induced NLPR3 inflammasome activation and production of proinflammatory cytokines in primary KCs and hepatocytes. Cytokines secreted by activated KCs increased hepatocyte inflammation and HSC activation, and lobeglitazone inhibited these responses. In addition, lobeglitazone suppressed liver fibrosis by inhibiting LPS-induced transforming growth factor (TGF)-ß secretion and TGF-ß-induced CTGF expression. The inhibitory effect of lobeglitazone on inflammasome activation was associated with suppression of liver fibrosis. These results suggest that lobeglitazone may be a treatment option for inflammation and fibrosis in the liver.

MAFLD might be better in identifying subjects with sarcopenia or cardiovascular risk than NAFLD: A nationwide study.

BACKGROUND AND AIM: Clinical features of non-alcoholic fatty liver disease (NAFLD), but not fulfilling the diagnostic criteria of metabolic dysfunction-associated fatty liver disease (MAFLD), remain unclear. We investigated the risk of sarcopenia and cardiovascular disease (CVD) in MAFLD and non-metabolic risk (MR) NAFLD. METHODS: Subjects were selected from the Korean National Health and Nutrition Examination Surveys 2008-2011. Liver steatosis was assessed using fatty liver index. Significant liver fibrosis was defined using fibrosis-4 index, categorized by age cut-offs. Sarcopenia was defined as the lowest quintile sarcopenia index. Atherosclerotic CVD (ASCVD) risk score > 10% was defined as high probability. RESULTS: A total of 7248 subjects had fatty liver (137 with non-MR NAFLD, 1752 with MAFLD/non-NAFLD, and 5359 with overlapping MAFLD and NAFLD). In non-MR NAFLD group 28 (20.4%) had significant fibrosis. The risk of sarcopenia (adjusted odds ratio [aOR] = 2.71, 95% confidence index [CI] = 1.27-5.78) and high probability of ASCVD (aOR = 2.79, 95% CI = 1.23-6.35) was significantly higher in MAFLD/non-NAFLD group than in non-MR NAFLD group (all P < 0.05). The risk of sarcopenia and high probability of ASCVD was similar between subjects with and without significant fibrosis in non-MR NAFLD group (all P > 0.05). However, the risk was significantly higher in MAFLD group than in non-MR NAFLD group (aOR = 3.38 for sarcopenia and 3.73 for ASCVD; all P < 0.05). CONCLUSIONS: The risks of sarcopenia and CVD were significantly higher in MAFLD group but did not differ according to fibrotic burden in non-MR NAFLD group. The MAFLD criteria might be better for identifying high-risk fatty liver disease than the NAFLD criteria.

Age at Mortality in Patients with Type 2 Diabetes Who Underwent Kidney Transplantation: An Analysis of Data from the Korean National Health Insurance and Statistical Information Service, 2006 to 2018.

BACKGROUND: Although the clinical outcomes of diabetes have improved, diabetes remains the principal cause of end-stage renal disease. The aim of the study is to investigate whether mortality trends in individuals with type 2 diabetes and kidney transplantation (KT) have changed. METHODS: This study analyzed data from the National Health Insurance Service claims database linked to death records from the National Statistical Information Service in Korea. Information from a total of 2521 deaths of KT recipients was collected from 2006 to 2018. RESULTS: The age at death of KT recipients increased from 57.4 years in 2006 to 65.2 years in 2018, with a mean change of +0.65 years/year (p < 0.001). The overall age at death increased by 0.55 and 0.66 years/year in the type 2 diabetes and non-diabetes populations, respectively. The age at death was significantly higher in the type 2 diabetes group, and was maintained during the study period. The proportion of death due to malignancy and cerebrovascular and heart disease was maintained, that due to type 2 diabetes decreased and that due to pneumonia increased. Neither diabetes nor hypertension determined the age at death, and the age at KT was the most prominent factor affecting age at death in KT recipients. CONCLUSIONS: The age at death in KT recipients increased over the 12 years between 2006 and 2018, with similar trends in the type 2 diabetes and non-diabetes groups. The age at KT was higher in patients with type 2 diabetes, and was the main contributor to the age at death in KT recipients.

Fatty Liver & Diabetes Statistics in Korea: Nationwide Data 2009 to 2017.

BACKGROUND: This study investigated the changes of fatty liver disease prevalence in general Korean population. METHODS: This study analyzed data from the Korean National Health Insurance Service from 2009 to 2017 that included individuals aged 20 years or older who had undergone a medical health examination. Fatty liver disease was assessed using the fatty liver index (FLI). The disease severity was defined by FLI cutoff, ≥30 as moderate, and ≥60 as severe fatty liver disease. RESULTS: The prevalence of Korean adults aged 20 years or over with fatty liver disease (FLI ≥60) increased from 13.3% in 2009 to 15.5% in 2017 (P for trend <0.001). The increase in fatty liver disease prevalence was prominent in men (from 20.5% to 24.2%) and the young age (20 to 39 years) group (from 12.8% to 16.4%) (P for interaction <0.001). The prevalence of fatty liver disease was the highest in type 2 diabetes mellitus (T2DM, 29.6%) population compared to that of prediabetes or normoglycemia (10.0% and 21.8%) in 2017. The prevalence of fatty liver disease had statistically increased in individuals with T2DM and prediabetes (P for trend <0.001). Its prevalence increased more steeply in the young-aged population with T2DM, from 42.2% in 2009 to 60.1% in 2017. When applying a lower FLI cutoff (≥30) similar results were observed. CONCLUSION: The prevalence of fatty liver disease in the Korean population has increased. Individuals who are young, male, and have T2DM are vulnerable to fatty liver disease.

High Sodium Intake, as Assessed by Urinary Sodium Excretion, Is Associated with Nonalcoholic Fatty Liver Disease or Sarcopenia.

Background/Aims: We explored whether high sodium intake, assessed by urinary excretion, determines the risk of sarcopenia and nonalcoholic fatty liver disease (NAFLD). Methods: We analyzed 10,036 adult participants with normal kidney function from the Korea National Health and Nutrition Examination Survey (2008-2011). NAFLD was identified using the fatty liver index, and the muscle mass was evaluated using dual X-ray absorptiometry. The dietary sodium intake was estimated using Tanaka's equation. Results: The mean 24-hour urinary sodium excretion was 144.2±36.1 mmol/day (corresponding to 3.3 g/day Na) in the total population. The 24-hour urinary sodium excretion showed moderate accuracy in predicting NAFLD (area under the receiver operating characteristic, 0.702; 95% confidence interval [CI], 0.692 to 0.712). A cutoff value of 99.96 mmol/day (corresponding to 2.30 g/day Na) for urinary sodium excretion in predicting NAFLD showed 76.1% sensitivity and 56.1% specificity. The results of multiple adjusted models indicated that the participants with the highest urinary sodium excretion had a significantly higher risk of NAFLD (odds ratio, 1.46; 95% CI, 1.27 to 1.66; p<0.001) and sarcopenia (odds ratio, 1.49; 95% CI, 1.28 to 1.73; p<0.001) than those with the lowest urinary sodium excretion. The association between a higher 24-hour urinary sodium excretion and NAFLD was independent of sarcopenia. Conclusions: Participants with a high sodium intake, as assessed by sodium excretion, had a substantial risk of NAFLD and sarcopenia.

Muscle fat contents rather than muscle mass determines nonalcoholic steatohepatitis and liver fibrosis in patients with severe obesity.

OBJECTIVE: This study aimed to investigate the association of muscle fat contents, nonalcoholic steatohepatitis (NASH), and liver fibrosis in patients with severe obesity. METHODS: Patients with severe obesity who underwent bariatric surgery were evaluated for NASH and liver fibrosis. Skeletal muscle was assessed by dual energy x-ray absorptiometry, and muscle fat contents (skeletal muscle fat index [SMFI]) were evaluated by computed tomography-based psoas muscle mass and density. RESULTS: A total of 104 patients with severe obesity were enrolled (57 with nonalcoholic fatty liver disease activity score <5 and 47 with NASH with nonalcoholic fatty liver disease activity score ≥5). SMFI was higher in patients with NASH than those without NASH (mean [SD], 39.0 [14.5] vs. 46.5 [14.2] for without NASH vs. with NASH; p = 0.009). SMFI was also correlated with hepatic steatosis grade, ballooning severity, and fibrosis stage. Multiple logistic regression analysis showed that SMFI was associated with higher risk of NASH and liver fibrosis (odds ratio = 2.37, 95% CI: 1.13-4.98, p = 0.022 for NASH; odds ratio = 2.93, 95% CI: 1.32-6.48, p = 0.008 for significant liver fibrosis). CONCLUSIONS: Muscle fat infiltration rather than muscle mass reflects the severities of hepatic steatosis and fibrosis in patients with severe obesity.

Evogliptin Directly Inhibits Inflammatory and Fibrotic Signaling in Isolated Liver Cells.

Chronic liver inflammation can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Kupffer cells (KC) secrete proinflammatory and fibrogenic cytokines in response to lipopolysaccharide (LPS), and so play an important role in liver inflammation, where they induce hepatocellular damage. LPS also activates hepatic stellate cells and induces extracellular matrix deposition. In this study, we used isolated primary KC, primary hepatocytes, and primary hepatic stellate cells (HSC) to investigate whether evogliptin directly inhibits inflammatory and fibrotic signaling. We found that evogliptin inhibited LPS-induced secretion of inducible nitric oxide synthase and transforming growth factor ß (TGF-ß) from KC. Moreover, evogliptin inhibited inflammatory mediator release from hepatocytes and hepatic stellate cell activation that were induced by KC-secreted cytokines. In hepatocytes, evogliptin also inhibited LPS-induced expression of proinflammatory cytokines and fibrotic TGF-ß. In addition, evogliptin inhibited TGF-ß-induced increases in connective tissue growth factor levels and HSC activation. These findings indicate that evogliptin inhibits inflammatory and fibrotic signaling in liver cells. We also showed that the inhibitory effect of evogliptin on inflammatory and fibrotic signaling is associated with the induction of autophagy.

Association between the Diabetes Drug Cost and Cardiovascular Events and Death in Korea: A National Health Insurance Service Database Analysis.

BACKGRUOUND: This study aimed to investigate the long-term effects of diabetes drug costs on cardiovascular (CV) events and death. METHODS: This retrospective observational study used data from 2009 to 2018 from the National Health Insurance in Korea. Among the patients with type 2 diabetes, those taking antidiabetic drugs and who did not have CV events until 2009 were included. Patients were divided into quartiles (Q1 [lowest]-4 [highest]) according to the 2009 diabetes drug cost. In addition, the 10-year incidences of CV events (non-fatal myocardial infarction, stroke, hospitalization for heart failure, and coronary revascularization) and CV death (death due to CV events) were analyzed. RESULTS: A total of 441,914 participants were enrolled (median age, 60 years; men, 57%). CV events and death occurred in 28.1% and 8.36% of the patients, respectively. The 10-year incidences of CV events and deaths increased from Q1 to 4. After adjusting for sex, age, income, type of diabetes drugs, comorbidities, and smoking and drinking status, the risk of CV events significantly increased according to the sequential order of the cost quartiles. In contrast, the risk of CV death showed a U-shaped pattern, which was the lowest in Q3 (hazard ratio [HR], 0.953; 95% confidence interval [CI], 0.913 to 0.995) and the highest in Q4 (HR, 1.266; 95% CI, 1.213 to 1.321). CONCLUSION: Diabetes drug expenditure affects 10-year CV events and mortality. Therefore, affording an appropriate diabetes drug cost at a similar risk of CV is an independent protective factor against CV death.

Increased Levels of Phosphorylated ERK Induce CTGF Expression in Autophagy-Deficient Mouse Hepatocytes.

Autophagy performs essential cell functions in the liver through an intracellular lysosomal degradation process. Several studies have reported that autophagy deficiency can lead to liver injury, including hepatic fibrosis; however, the mechanisms underlying the relationship between autophagy deficiency and liver pathology are unclear. In this study, we examined the expression levels of fibrosis-associated genes in hepatocyte-specific ATG7-deficient mice. The expression levels of the connective tissue growth factor (CTGF) and phosphorylated ERK (phospho-ERK) proteins were increased significantly in primary hepatocytes isolated from hepatocyte-specific ATG7-deficient mice compared to those isolated from control mice. In addition, the inhibition of autophagy in cultured mammalian hepatic AML12 and LX2 cells increased CTGF and phospho-ERK protein levels without altering CTGF mRNA expression. In addition, the autophagy deficiency-mediated enhancement of CTGF expression was attenuated when ERK was inhibited. Overall, these results suggest that the inhibition of autophagy in hepatocytes increases phospho-ERK expression, which in turn increases the expression of CTGF, a biomarker of fibrosis.

Improvement in Age at Mortality and Changes in Causes of Death in the Population with Diabetes: An Analysis of Data from the Korean National Health Insurance and Statistical Information Service, 2006 to 2018.

BACKGRUOUND: Diabetes is a leading cause of death that is responsible for 1.6 million annual deaths worldwide. However, the life expectancy and age at death of people with diabetes have been a matter of debate. METHODS: The National Health Insurance Service claims database, merged with death records from the National Statistical Information Service in Korea from 2006 to 2018, was analyzed. RESULTS: In total, 1,432,567 deaths were collected. The overall age at death increased by 0.44 and 0.26 year/year in the diabetes and control populations, respectively. The disparity in the mean age at death between the diabetes and control populations narrowed from 5.2 years in 2006 to 3.0 years in 2018 (p<0.001). In a subgroup analysis according to the presence of comorbid diseases, the number and proportion of deaths remained steady in the group with diabetes only, but steadily increased in the groups with diabetes combined with dyslipidemia and/or hypertension. Compared to the control population, the increase in the mean death age was higher in the population with diabetes. This trend was more prominent in the groups with dyslipidemia and/or hypertension than in the diabetes only group. Deaths from vascular disease and diabetes decreased, whereas deaths from cancer and pneumonia increased. The decline in the proportion of deaths from vascular disease was greater in the diabetes groups with hypertension and/or dyslipidemia than in the control population. CONCLUSION: The age at death in the population with diabetes increased more steeply and reached a comparable level to those without diabetes.

Non-alcoholic fatty liver disease and sarcopenia is associated with the risk of albuminuria independent of insulin resistance, and obesity.

BACKGROUND: Although non-alcoholic fatty liver disease (NAFLD) is associated with metabolic disorders, its influence on albuminuria has not been determined. The aim of this study was to identify the relationship between NAFLD and albuminuria in the general Korean population. METHODS: Data from the Korea National Health and Nutrition Examination Surveys (KNHANES) of 2008-2011 were analyzed (n = 1795). Albuminuria was defined as an albumin-to-creatinine ratio of ≥30 mg/g in random spot urine samples. NAFLD was defined as a fatty liver index (FLI) ≥60 or NAFLD liver fat score (LFS) > -0.64. RESULTS: A total of 289 (16.1 %) subjects were classified as having albuminuria. Subjects with NAFLD exhibited a higher rate of albuminuria than subjects without NAFLD (crude odds ratios [ORs] = 2.60-2.95, all P < 0.001). Regardless of hypertension, insulin resistance, or obesity, the risk for albuminuria was higher in the NAFLD group than in the group without NAFLD (measured by either FLI or LFS; all P < 0.001). When subjects with NAFLD had sarcopenia, the risk of albuminuria further increased (OR = 4.33-4.64, all P < 0.001). Multiple logistic regression analyses also demonstrated that NAFLD was independently associated with albuminuria (OR = 2.58, 95 % confidence interval [CI] = 1.66-4.02, P < 0.001 for FLI, OR = 1.87, 95 % CI = 1.28-2.75, P = 0.001 for LFS). CONCLUSIONS: NAFLD was associated with an increased risk of albuminuria in the general Korean population. This association was independent of hypertension, insulin resistance, chronic kidney disease, diabetes and obesity, and stronger in subjects with sarcopenia.

Development of an End-of-Life Nursing Care Protocol for Intensive Care Units: Delphi Survey Method.

Because of the lack of guidelines and standardized protocols for end-of-life nursing care in intensive care units in Korea, many nurses have reported facing difficulties when providing care for patients. This study attempted to develop a standardized end-of-life nursing protocol for use in intensive care units. A draft of the end-of-life nursing care protocol was developed after a literature review. A Delphi survey was carried out twice with 30 experts, and the content validity ratio of the items was investigated. The draft end-of-life nursing care protocol was divided into 3 separate stages with 24 items: 8 initial end-of-life care assessment items, 5 ongoing end-of-life care items, and 11 post-end-of-life care items. The content validity ratios of the first and second rounds were 0.33 or greater in each category, demonstrating the validity of the proposed draft as a standardized protocol. Furthermore, at the suggestion of the experts, an extra item was added in the last stage, resulting in 25 items. The results of this study are expected to help leading hospitals in South Korea outline the roles and range of tasks for end-of-life care in an intensive care unit and thereby resolve difficulties for nurses. Furthermore, this will improve the medical services that family members receive during end-of-life care.