Non Alcoholic Fatty Liver Disease -NAFLD
Non-alcoholic fatty liver disease ( NAFLD ) can be diagnosed on the basis of Evidence of hepatic steatosis by imaging or histology Lack of secondary causes of hepatic fat accumulation ( eg significant alcohol consumption ) ie diagnosis of exclusion
NAFL-NAFL is defined as the presence of of > 5 % hepatic steatosis without evidence of hepatocellular injury in the form of hepatocyte ballooning This has a relatively benign course and is largely asymptomatic NASH- NASH > 5 % hepatic steatosis – this reflects a more profound inflammatory liver damage with presence of lobular inflammation and helatocellular damage ( ballooning ) This carries a worse prognosis with risk of progressive fibrosis leading to cirrhosis and hepatocellular carcinoma
NAFLD is the most common liver disorder in Western countries Due to rising obesity NAFLD is one of the most important cause of liver disease worldwide in adults and children Estimated to affect atleast 25 % – 30 % of adults in general population and 70-90 % of people with obesity or type 2 diabetes Prevalence of NAFLD has doubled over the past 20 yrs Projected to be leading indication for liver transplant within a decade
Features of metabolic syndrome – including ○ central obesity ○ impaired glucose regulation ( Type 2 diabetes ) ○ hypertension ○ hyperlipidemia Obstructive sleep apnoea Polycystic ovary syndrome Hypothyroidism Family h/o NAFLD Male sex Hyperuricemia ( Risk factors and biomarkers of non-alchoholic fatty liver disease : an observational cross-sectional population survey BMJ open Vol 8, Issue 4 ) Nutritional – TPN and refeeding syndromes mrapid weight loss and jejunoileal bypass surgery Drugs eg NSAIDs , amiodarone , corticosteroids , diltiazem , methotrexate , tamoxifen
Mostly detected incidentally following test for Liver function or US ( increased hepatic echogenicity ) Usually suspected with mild to moderate elevations of serum transaminases with alanine aminotransferase ( ALT ) exceeding those of aspartate aminotransferase ( AST ) GGT and AlkPo4 may also be elevated but PT , Bilirubin , Albumin levels are normal except in NAFLD associated cirrhosis Many patients with NAFLD will be obese asymptomatic and with normal LFTs Gold standard for diagnosis of NAFLD is liver biopsy Do not use routine liver blood tests to r/o NAFLD – LFT and US may be normal and not necessarily reflect the stage of disease
Non Invasive Liver Screen- LFT FBC ( eg low platelets ) Clotting screen Hepatitis serology ( B and C ) Auto-antibodies ( eg ANA , ASMA , AMA ) Ferritin – usually mildly elevated consider transferrin Ceruloplasmin Alpha 1 antitrypsin Immunoglobulins Hba1c Lipid profile , TFT, Renal profile Coeliac screen
Management –No specific drug treatment – NAFL A validated widely accepted procedure for the diagnosis and monitoring of NAFLD does not exist yet Give advice on lifestyle modification eg about ○ diet ○ physical activity ○ exercise ○ weight loss ○ alcohol Ensure optimal management of associated conditions as ○ hypertension ○ hyperlipidemia ○ type 2 diabetes
Scoring tests indicated risk of fibrosis Several score available as ○ NAFLD fibrosis score ○ Enhanced Liver Fibrosis ○ FIB4 ○ BARD Abnormal blood results as ○ raised immunoglobulins ○ hepatitis B or C ○ ↑↑ ferritin and transferrin ( iron overload ) ○ Autoantibody testing +ve ○ Low ceruloplasmin ○ Low alpha 1 antitrypsin
LINKS AND RESOURCES
British Liver Trust – NAFLD a complete patient information source for motivated patients – consider referring all patients and document https://britishlivertrust.org.uk/information-and-support/living-with-a-liver-condition/liver-conditions/non-alcohol-related-fatty-liver-disease/
American College of Gastroenterology NAFLD section a highly educative resource https://gi.org/topics/fatty-liver-disease-nafld/#tabs2
Abnormal Liver Test algorithm by British Liver Trust and RCGP-this is simply fabulous https://britishlivertrust.org.uk/wp-content/uploads/GP-Liver-blood-tests-Nov-19-FINAL-no-crops.pdf
RCGP Liver disease toolkit https://www.rcgp.org.uk/liverdisease
NAFLD score https://nafldscore.com/
European Association for the Study of Liver ( EASL ) – NAFLD management guideline https://easl.eu/publication/the-management-of-non-alcoholic-fatty-liver-disease-nafld/
World Journal of Gastroenterology – Current guidelines for the management of non-alcoholic fatty liver disease: A systemic review with comparative analysis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092580/
References
- EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease Journal of Hepatology, Volume 64, Issue 6, 1388 – 1402 https://doi.org/10.1016/j.jhep.2015.11.004
- Non-alcoholic fatty liver disease ( NAFLD ) : assessment and management NICE guideline NG 49 July 2016 https://www.nice.org.uk/guidance/ng49
- The Diagnosis and Management of Non-alcholic Fatty Liver Disease ; Practice Guidance From the American association for the study of Liver Diseases Naga Chalasani Naga Chalasani,1 Zobair Younossi ,2 Joel E. Lavine,3 Michael Charlton,4 Kenneth Cusi,5 Mary Rinella,6 Stephen A. Harrison,7 Elizabeth M. Brunt,8 and Arun J. Sanyal9 PRACTICE GUIDANCE | HEPATOLOGY, VOL. 67, NO. 1, 2018 https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1002/hep.29367
- Non-Alcoholic fatty liver disease in 2016 S.A Townsend et al British Medical Bulletin , 2016 , 116: 143-156
- Non-alcoholic fatty liver disease ( NAFLD ) : summary of NICE guidance BMJ 2012; 354 :i14428
- Tests for diagnosing and monitoring non-alcoholic fatty liver disease in adults BMJ 2018; 362: k2734
- Global burden of NAFLD and NASH : trends , predictions , risk factors and prevention Zobair Younossi et al Nature Reviews Gastroenterology & Hepatology Volume 15 January 2018 http://www.natap.org/2018/fattyLiver/nrgastro.2017.109.pdf
- CKS NHS Non-alcoholic fatty liver disease ( NAFLD ) Last revised in September 2016 https://cks.nice.org.uk/non-alcoholic-fatty-liver-disease-nafld
- Neuschwander-Tetri, B.A. Non-alcoholic fatty liver disease. BMC Med 15, 45 (2017). https://doi.org/10.1186/s12916-017-0806-8
- Fibrosis score http://www.nafldscore.com/