BACKGROUND. NAFLD ranges from simple steatosis (SS) to non-alcoholic steatohepatitis (NASH). The natural history of NAFLD and the optimal strategy to identify subjects with progressive liver disease are unclear. Objectives. To assess the evidence in: (1) natural history of NAFLD; and (2) non-invasive methods to differentiate NAFLD histological subtypes. DESIGN AND SETTING. Among 4185 articles published on MEDLINE, Cochrane Library, EMBASE, Pubmed, national and International meeting abstracts through July 2010, 40 articles assessing the natural history of NAFLD and 32 articles evaluating the diagnostic accuracy of non-invasive tests against liver biopsy (LB) were included. MEASUREMENTS. Two reviewers retrieved articles and evaluated study quality by appropriate scores. Main outcomes were pooled using random- or fixed-effects models. RESULTS. NAFLD has an increased overall mortality (OR: 1.57, 95% CI: 1.18-2.10), deriving from liver-related and cardiovascular disease, and a 2-fold risk of diabetes. Compared to SS, NASH has a higher liver-related (OR for NASH: 5.71, 2.31-14.13; OR for NASH with advanced fibrosis: 10.06, 4.35-23.25), but not cardiovascular mortality (OR: 0.91, 0.42-1.98). Three non-invasive methods received independent validation: pooled AUROC, sensitivity and specificity of cytokeratin-18 for NASH are 0.82 (0.78-0.88), 0.78 (0.64-0.92), 0.87 (0.77-0.98). For NASH with advanced fibrosis, pooled AUROC, sensitivity and specificity of NAFLD fibrosis score and Fibroscan are 0.85 (0.80-0.93), 0.90 (0.82-0.99), 0.97 (0.94-0.99) and 0.94 (0.90-0.99), 0.94 (0.88-0.99) and 0.95 (0.89-0.99). CONCLUSIONS. NAFLD warrants screening for cardio-metabolic risk and for progressive liver disease. The combination of three noninvasive tests with LB may optimally individuate patients with NASH, with or without advanced fibrosis.

The relations of dietary habits to insulin sensitivity and postprandial triglyceride metabolism were evaluated in 25 patients with nonalcoholic steatohepatitis (NASH) and 25 age-, body mass index (BMI)-, and gender-matched healthy controls. After a 7-day alimentary record, they underwent a standard oral glucose tolerance test (OGTT), and the insulin sensitivity index (ISI) was calculated from the OGTT; an oral fat load test was also performed in 15 patients and 15 controls. The dietary intake of NASH patients was richer in saturated fat (13.7% ؎ 3.1% vs. 10.0% ؎ 2.1% total kcal, respectively, P ‫؍‬ .0001) and in cholesterol (506 ؎ 108 vs. 405 ؎ 111 mg/d, respectively, P ‫؍‬ .002) and was poorer in polyunsaturated fat (10.0% ؎ 3.5% vs. 14.5% ؎ 4.0% total fat, respectively, P ‫؍‬ .0001), fiber (12.9 ؎ 4.1 vs. 23.2 ؎ 7.8 g/d, respectively, P ‫؍‬ .000), and antioxidant vitamins C (84.3 ؎ 43.1 vs. 144.2 ؎ 63.1 mg/d, respectively, P ‫؍‬ .0001) and E (5.4 ؎ 1.9 vs. 8.7 ؎ 2.9 mg/d, respectively, P ‫؍‬ .0001). The ISI was significantly lower in NASH patients than in controls. Postprandial total and very low density lipoproteins triglyceride at ؉4 hours and ؉6 hours, triglyceride area under the curve, and incremental triglyceride area under the curve were higher in NASH compared with controls. Saturated fat intake correlated with ISI, with the different features of the metabolic syndrome, and with the postprandial rise of triglyceride. Postprandial apolipoprotein (Apo) B48 and ApoB100 responses in NASH were flat and strikingly dissociated from the triglyceride response, suggesting a defect in ApoB secretion. In conclusion, dietary habits may promote steatohepatitis directly by modulating hepatic triglyceride accumulation and antioxidant activity as well as indirectly by affecting insulin sensitivity and postprandial triglyceride metabolism. Our findings provide further rationale for more specific alimentary interventions, particularly in nonobese, nondiabetic normolipidemic NASH patients. (HEPATOLOGY 2003;37:909-916.)

In a systematic review and meta-analysis, Giovanni Musso and colleagues examine the association between non-alcoholic fatty liver disease and chronic kidney disease. Please see later in the article for the Editors' Summary

Aims/hypothesis Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH): NAFLD causes an increased risk of cardiovascular disease, diabetes and liverrelated complications (the latter confined to NASH). The effect of proposed treatments on liver disease, glucose metabolism and cardiovascular risk in NAFLD is unknown. We reviewed the evidence for the management of liver disease and cardiometabolic risk in NAFLD. Methods Publications through November 2011 were systematically reviewed by two authors. Outcomes evaluated though standard methods were: histological/radiological/biochemical features of NAFLD, variables of glucose metabolism and cardiovascular risk factors. Seventy-eight randomised trials were included (38 in NASH, 40 in NAFLD): 41% assessed post-treatment histology, 71% assessed glucose metabolism and 88% assessed cardiovascular risk factors. Lifestyle intervention, thiazolidinediones, metformin and antioxidants were most extensively evaluated. Results Lifestyle-induced weight loss was safe and improved cardio-metabolic risk profile; a weight loss ≥7% improved histological disease activity, but was achieved by <50%