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.

Myosteatosis predicts bariatric surgery response: A longitudinal study in patients with morbid obesity.

CONTEXT: Data on the preoperative factors for bariatric surgery response in patients with morbid obesity are limited, and there are no studies on the relationship between myosteatosis and surgery response. OBJECT: We investigated the preoperative factors determining bariatric surgery response and the impact of preoperative muscle fat infiltration on bariatric surgery response. METHODS: This retrospective longitudinal cohort study included 125 individuals (37 men, 88 women) with morbid obesity who underwent bariatric surgery. Muscle fat infiltration (skeletal muscle fat index [SMFI]) was evaluated using computed tomography-based psoas muscle mass and density at the 4th lumbar level. A bariatric surgery response was defined as ≥50% excessive weight loss at one year postoperatively. RESULTS: Before bariatric surgery, the patient mean body weight and body mass index (BMI) were 107.0 kg and 39.0 kg/m2, respectively. After one year, the mean body weight was 79.6 kg. The mean excessive weight loss at one year was 75.6% and 102 (81.6%) patients were categorized as responders. There were no statistically significant differences in initial BMI, age, sex, or proportion of diabetes between responders and non-responders. Responders were more likely to have lower SMFI and triglyceride and glycated hemoglobin A1c levels than non-responders at baseline (P<0.05). Multiple logistic regression analysis showed that a lower baseline SMFI was associated with bariatric surgery response (odds ratio=0.31, 95% confidence interval=0.14-0.69, P=0.004). CONCLUSIONS: Preoperative myosteatosis may determine the response to bariatric surgery.

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.