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Summary: Background: Non‐alcoholic fatty liver disease (NAFLD) affects obese and non‐obese individuals. However, mechanisms underlying non‐obese non‐alcoholic steatohepatitis (NASH) remain unclear. Aims: To attempt to identify metabolic perturbations associated with non‐obese and obese NAFLD using a lipidomics approach. Methods: A cross‐sectional analysis of 361 subjects with biopsy‐proven NAFLD (157 NAFL and 138 NASH) and healthy controls (n = 66) was performed. Individuals were categorised as obese or non‐obese based on the Asian cut‐off for body mass index. Circulating lipidomic profiling of sera was performed based on the histological severity of NAFLD. Circulating lipidomic alterations were validated with an independent validation set (154 NAFLD subjects [93 NAFL and 61 NASH] and 21 healthy controls). Results: Saturated sphingomyelin (SM) species were significantly associated with visceral adiposity in non‐obese NAFLD (SM d38:0; P < 0.001) but not in obese NAFLD. Additionally, SM levels were significantly associated with systemic and adipose tissue insulin resistance (SM d38:0; P = 0.002 and <0.001, respectively). Five potential lipid metabolites for non‐obese subjects and seven potential lipids for obese subjects were selected to predict NAFLD and NASH. These lipid combinations showed good diagnostic performance for non‐obese (area under the curve [AUC] for NAFLD/NASH = 0.916/0.813) and obese (AUC for NAFLD/NASH = 0.967/0.812) subjects. Moreover, distinctly altered patterns of diacylglycerol (DAG), triacylglycerol (TAG) and SM levels were confirmed in the validation set depending on the histological severity of NAFLD. Conclusion: Non‐obese and obese NAFLD subjects exhibit unique circulating lipidomic signatures, including DAGs, TAGs and SMs. These lipid combinations may be useful biomarkers for non‐obese and obese NAFLD patients. [ABSTRACT FROM AUTHOR]

Background and Aim: We investigated the effects of PNPLA3 rs738409, TM6SF2 rs58542926, and MBOAT7-TMC4 rs641738 variants on metabolic phenotypes and their combined effects on the histological severity of non-alcoholic fatty liver disease (NAFLD). Methods: We genotyped rs738409, rs58542926, and rs641738 in biopsy-proven NAFLD patients (n = 416) and healthy controls (n = 109). Homeostasis model assessment of insulin resistance and adipose tissue insulin resistance were calculated. Results: The rs738409 and rs58542926 variants, but not rs641738, were associated not only with non-alcoholic steatohepatitis (NASH) (odds ratio [OR], 2.00; 95% confidence interval [CI], 1.46-2.73 and OR, 1.91; 95% CI, 1.04-3.51) but also with significant fibrosis (≥ F2) (OR, 1.53; 95% CI, 1.11-2.11 and OR, 1.88; 95% CI, 1.02-3.46) in NAFLD, even after adjustment for metabolic risk factors. Of both variants, only rs738409 was associated with homeostasis model assessment of insulin resistance and adipose tissue insulin resistance even in healthy controls (P = 0.046 and 0.002, respectively) as well as in the entire study cohort (P = 0.016 and 0.048, respectively). PNPLA3 and TM6SF2 risk variants additively increased the risk of NASH and significant fibrosis (OR per risk allele, 2.03; 95% CI, 1.50-2.73 and 1.61; 95% CI, 1.19-2.17). Even in subjects with low insulin resistance, the risk of NASH or significant fibrosis increased as the number of risk alleles increased (P = 0.008 and 0.020, respectively). Conclusions: PNPLA3 and TM6SF2 determine the risk of NASH and significant fibrosis, even after adjustment for insulin resistance, and exert an additive effect on NASH and significant fibrosis. [ABSTRACT FROM AUTHOR]

Background & Aims Physical activity ( PA) is inversely associated with nonalcoholic fatty liver disease ( NAFLD) prevalence. However, few studies evaluated the effect of PA on NAFLD incidence in regard to visceral adipose tissue ( VAT) and insulin resistance ( IR). We investigated whether PA at baseline and change in PA during follow-up have any effect on incident NAFLD. Methods We enrolled subjects who underwent health screenings between 2007 and 2008 and participated in voluntary follow-up between 2011 and 2013 (median 4.42 years). Incident NAFLD was defined as NAFLD absence at baseline and presence at follow-up by ultrasonography. PA was measured using a detailed questionnaire-based metabolic equivalent at baseline and follow-up; the difference during follow-up was calculated. Results Of the 1373 subjects enrolled, 288 (21.0%) developed NAFLD. Both total and leisure-time PA at baseline were inversely associated with incident NAFLD ( P for trend=.005 and .003 respectively). Decreased PA at follow-up was associated with increased incident NAFLD risk after adjusting for age, gender, body mass index, smoking, hypertension, diabetes and diet [hazard ratio ( HR) 1.45, 95% confidence interval ( CI) 1.04-2.02, 4th (most decreased PA) vs 1st quartile (increased PA), P=.028]. This relationship was attenuated but remained statistically significant after adjustment for VAT( HR 1.48, 95% CI 1.06-2.06, 4th vs 1st quartile) and IR( HR 1.59, 95% CI 1.11-2.27, 4th vs 1st quartile). Conclusions This study shows an independent protective effect of PA at baseline on incident NAFLD after 4-year follow-up. Furthermore, sustained or increased PA had a preventive effect on incident NAFLD independent of VAT and IR. [ABSTRACT FROM AUTHOR]

Background and Aim Gallbladder polyps ( GBPs) appear to be strongly associated with obesity and metabolic disease. To date, the relationship between GBPs and fatty liver has not been adequately evaluated. The aim of the present study was to investigate whether GBPs are associated with fatty liver, which is an ectopic regional fat deposit, independent of visceral adipose tissue ( VAT). Methods A cross-sectional study using 2643 health checkup subjects (961 patients with GBP and 1682 age- and sex-matched healthy controls) was conducted. The subjects underwent various laboratory tests, abdominal fat computed tomography ( CT), and hepatic ultrasonography. Results The mean age of the subjects was 51.4 ± 8.3 years, and 74.1% were male. GBPs were significantly associated with fatty liver. Multivariate regression analysis revealed that GBPs were significantly associated with the presence of fatty liver (odds ratio [ OR] 1.23, 95% confidence interval [ CI]: 1.02-1.48), and adjusting for the homeostatic metabolic assessment index had little effect on this association ( OR 1.23, 95% CI: 1.02-1.48). Additionally, GBPs remained significantly associated with the presence of fatty liver after adjustments for CT-measured VAT and subcutaneous adipose tissue ( OR 1.24, 95% CI: 1.03-1.50). The degree of fatty liver showed an independent ( OR 1.37 95% CI: 1.03-1.80) and dose-dependent relationship (moderate-severe fatty liver: OR 1.55 95% CI: 1.07-2.23, P for trend = 0.014) with large GBPs (≥ 5 mm). Conclusion Fatty liver, an ectopic regional fat deposit, was found to be closely associated with GBPs independent of known metabolic risk factors, insulin resistance, and CT-measured VAT, confirming a relevant clinical relationship between the two diseases. [ABSTRACT FROM AUTHOR]