From the Guidelines
Diagnosis of non-alcoholic fatty liver disease (NAFLD) should be based on clinical suspicion, liver function tests, and imaging, with liver biopsy reserved for cases where diagnosis is uncertain or advanced disease is suspected, as recommended by the most recent guidelines 1. The diagnosis of NAFLD requires a comprehensive approach, considering the patient's risk factors, clinical presentation, and laboratory findings. Key steps in the diagnosis include:
- Clinical suspicion based on risk factors such as obesity, diabetes, dyslipidemia, or metabolic syndrome
- Liver function tests, including ALT and AST, which may be elevated but are not universal findings
- Imaging studies, with ultrasound being the first-line option due to its accessibility and ability to detect steatosis when fat content exceeds 20-30%
- Consideration of non-invasive fibrosis assessment tools like NAFLD Fibrosis Score, FIB-4 index, and Enhanced Liver Fibrosis (ELF) test to stratify patients who might benefit from biopsy
- Exclusion of significant alcohol consumption, defined as >30 g/day for men and >20 g/day for women, and other causes of liver disease such as viral hepatitis, autoimmune liver disease, and medication-induced liver injury, as emphasized in earlier guidelines 1 Recent guidelines have updated the approach to NAFLD diagnosis, emphasizing the importance of case-finding strategies in individuals with cardiometabolic risk factors and the use of non-invasive tests to rule out advanced fibrosis 1. Additionally, the guidelines highlight the need for lifestyle modification, including weight loss, dietary changes, and physical exercise, as well as optimal management of comorbidities, in the treatment of NAFLD 1. In lean individuals with NAFLD, the diagnosis and management approach may differ, with a focus on risk stratification for hepatic fibrosis and consideration of lifestyle intervention and other treatments as needed 1. Overall, the diagnosis and management of NAFLD require a multifaceted approach, taking into account the latest guidelines and evidence-based recommendations to optimize patient outcomes.
From the Research
Diagnosis of NAFLD
- NAFLD should be suspected in patients with elevated liver enzymes or hepatic steatosis on abdominal imaging that are found incidentally 2
- Risk scores or elastography tests can be used to identify those who are likely to have fibrosis that will progress to cirrhosis 2
- Liver biopsy should be considered for patients at increased risk of fibrosis and when other liver disorders cannot be excluded with noninvasive tests 2
- Biochemical markers and radiological imaging, along with liver biopsy in selected cases, help in diagnosis and prognostication 3
Risk Factors
- Individuals with obesity are at highest risk of NAFLD 2
- Other established risk factors include metabolic syndrome and type 2 diabetes mellitus 2
- Insulin resistance related to metabolic syndrome is the main pathogenic trigger that, in association with adverse genetic, humoral, hormonal and lifestyle factors, precipitates development of NAFLD 3
Diagnostic Tests
- Non-invasive diagnostic tests, such as imaging and serum biomarkers, offer acceptable accuracy and are globally more accessible 4
- Elastography tests can be used to identify those who are likely to have fibrosis that will progress to cirrhosis 2
- Liver biopsy can be used to confirm the diagnosis and assess the extent of liver damage 2, 3