. 2021 Jun 15;6(4):100185. doi: 10.1016/j.esmoop.2021.100185

Table 1.

Bullet points on risk factors, diagnostic tools, histological readouts, and treatment options for patients with non-alcoholic fatty liver disease (NAFLD)

Prevalence?	NAFLD prevalence is estimated to range between 23% and 32% in most regions of the world. NAFLD summarizes two distinct disease courses: • NAFL = non-alcoholic fatty liver → steatosis, no inflammation • NASH = non-alcoholic steatohepatitis → steatosis and inflammation
Risk factors?	Lifestyle factors, obesity, diabetes mellitus, hyperlipidemia, arterial hypertension (= metabolic syndrome) and genetic risk factors (polymorphisms in PNPLA3, TM6SF2, HSD17B13)
Liver histology?	Should be evaluated for degree of steatosis (grade 0-3), inflammation (grade 0-3), ballooning (grade 0-2), and stage of fibrosis (stage 0-4) • Non-alcoholic fatty liver disease activity score (NAS) → NAS ≥5 points = highly suggestive of NASH • Advanced fibrosis = fibrosis stage ≥3 • Cirrhosis = fibrosis stage 4
Non-invasive tools?	• Abdominal ultrasound—steatosis? Liver surface indicative of cirrhosis (= irregular)? Suspicious liver nodules? • Vibration controlled transient elastography (i.e. FibroScan™) → Non-invasive staging of fibrosis • Magnetic resonance elastography → non-invasive staging of fibrosis • Laboratory based scores for ruling-in/-out advanced fibrosis: → FIB-4: formula containing the following variables: age (years), aspartate aminotransferase concentration (IU/l), alanine aminotransferase concentration (IU/l) and platelet count (∗10⁹/l); a score >3.25 is suggestive of advanced fibrosis → NAFLD Fibrosis Score: formula containing the following variables: age (years), body mass index (kg/m²), presence of impaired fasting glycaemia or diabetes (yes/no), aspartate aminotransferase concentration (IU/l), alanine aminotransferase concentration (IU/l), platelet count (∗10⁹/l), albumin concentration (g/dl); a score >0.675 is suggestive of advanced fibrosis
Staging/grading?	Stage and grade according to NAS and fibrosis stage, i.e. NASH patient with advanced fibrosis would be staged/graded: NAS 6, F3
Treatment options?	• Lifestyle factors, i.e. weight loss, Mediterranean diet, exercise • Treatment of comorbidities, i.e. metabolic syndrome (focus: glycemic control!) • Vitamin E or pioglitazone for selected patients only • Several phase III trials ongoing—referral to tertiary care center recommended for patients interested in participating in trials • If advanced fibrosis/cirrhosis → screen and treat associated complications (gastroesophageal varices, ascites, hepatic encephalopathy) • HCC surveillance in all cirrhotic NAFLD patients • HCC surveillance in selected non-cirrhotic NAFLD patients with high non-invasive fibrosis scores (VCTE, MRE, FIB-4, NAFLD Fibrosis Score)

FIB-4, fibrosis 4; HCC, hepatocellular carcinoma; HSD17B13, 17B-hydroxysteroid dehydrogenase type 13; MRE, magnetic resonance elastography; NAFLD, non-alcoholic fatty liver disease; NAS, non-alcoholic fatty liver disease activity score; PNPLA3, patatin-like phospholipase domain-containing protein 3; TM6SF2, transmembrane 6 superfamily 2 human gene; VCTE, vibration controlled transient elastography.