Diagnosis
Nonalcoholic fatty liver disease
Fatty liver disease is an acquired metabolic-related liver disease characterized by the presence of macrovesicular fat accumulation without inflammation (steatosis) or with lobular inflammation (steatohepatitis).
Also known as: Fatty liver, Hepatic steatosis, Liver steatosis, MASLD, Metabolic dysfunction-associated steatotic liver disease, NASH, Non-alcoholic steatohepatitis
Etiology
Cause [shp]
Insulin resistance --> elevated insulin --> influx and synthesis of hepatic triglycerides --> steatosis
Medications (tamoxifen, amiodarone, methotrexate)
Metabolic abnormalities (glycogen storage disorders, homocystinuria)
Alcohol
Nutritional status (total parenteral nutrition, severe malnutrition, overnutrition, or a starvation diet)
Other health issues: Wilson disease and celiac sprue
Pathophysiology: NAFLD --> NASH --> Cirrhosis --> HCC [shp]
Insulin resistance --> influx of free fatty acids into the liver --> NAFLD:
Hepatic fat accumulation without inflammation (steatosis)
NASH is characterised by the presence of: [sb4][1bq]
Hepatic steatosis (lipotoxicity)
Chronic inflammation
Hepatocyte ballooning
Eventually fibrosis/cirrhosis (pro-carcinogenic state)
The most rapidly rising indication for liver transplantation [sb4]
Risk factors
Metabolic Syndrome
Obesity
Family history of fatty liver disease
High cholesterol/triglycerides
Diabetes type 2/insulin resistance
Polycystic ovary syndrome
Obstructive sleep apnea
Hypothyroidism
Hypopituitarism
Complications [shp]
Cirrhosis
Ascites
Esophageal varices
Liver failure
Liver cancer
Type 2 diabetes
Epidemiology
Incidence per 100.000 [v2d][p7f][sb4][ta8][aso][wtc][1bq]
Symptoms & findings
Symptoms
Caput medusa, Confusion, Drowsiness, Edema, Fatigue, Lethargy, Loss of appetite, Malaise, Nausea, Pruritus, Spider nevus, Splenomegaly, Weakness, Weight loss
Clinical findings
Ascites, Gynecomastia, Jaundice, Palmar erythema
Anamneses
None listed.
Localized findings
Approach
Blood test: ASAT, ALAT, GGT, ALP, PT-INR, Bilirubin
Autoantibodies
Viral antibodies
Ultrasound
CT abdomen
MRI abdomen
Liver biopsy
Treatment
Lifestyle changes: [shp]
Losing weight
Exercise
Lowering cholesterol/triglycerides
Controlling diabetes
Abstain from alcohol or hepatotoxic drugs
Medications:
Metformin, Vitamin E, fish oil, GLP-1 agonist
Gastric bypass
Liver transplantation
Differential diagnoses
Alcoholic liver disease, Alpha1-antitrypsin deficiency, Autoimmune hepatitis, Cirrhosis, Drug-induced liver injury, Mitochondrial disease, Primary biliary cirrhosis, Primary sclerosing cholangitis, Reye's syndrome, Viral hepatitis, Wilson's disease
References
[1] Antunes C, Azadfard M, Hoilat GJ, et al. Fatty Liver. [Updated 2023 Jan 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441992/
[2] Wong VW, Ekstedt M, Wong GL, Hagström H. Changing epidemiology, global trends and implications for outcomes of NAFLD. J Hepatol. 2023 Sep;79(3):842-852.
[3] Younossi ZM, Henry L. Epidemiology of non-alcoholic fatty liver disease and hepatocellular carcinoma. JHEP Rep. 2021 May 11;3(4):100305.
[4] Pang J, Chen K, Chen S, Chen X. Global burden of nonalcoholic steatohepatitis-related liver cancer, 1990-2019: a systematic analysis for the GBD 2019. Diabetol Metab Syndr. 2022 Aug 9;14(1):112.
[5] Zhang T, Xu J, Ye L, Lin X, Xu Y, Pan X, Weng X, Ye C, Fan L, Ren Y, Shan PF. Age, Gender and Geographic Differences in Global Health Burden of Cirrhosis and Liver Cancer due to Nonalcoholic Steatohepatitis. J Cancer. 2021 Mar 15;12(10):2855-2865.
[6] Lin Y, Feng X, Cao X, Miao R, Sun Y, Li R, Ye J, Zhong B. Age patterns of nonalcoholic fatty liver disease incidence: heterogeneous associations with metabolic changes. Diabetol Metab Syndr. 2022 Nov 28;14(1):181.
[7] Nasr, P., von Seth, E., Mayerhofer, R. et al. Incidence, prevalence and mortality of chronic liver diseases in Sweden between 2005 and 2019. Eur J Epidemiol 38, 973–984 (2023).
[8] Jie Li, Qingzhi Wang, Wenjing Ni, Chuan Liu, Zhihui Li, Xiaolong Qi. Global health burden of cirrhosis and other chronic liver diseases (CLDs) due to non-alcoholic fatty liver disease (NAFLD): A systematic analysis for the global burden of disease study 2019, Global Transitions, Volume 5, 2023, Pages 160-169.