Obesity Abstracts

Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of liver disease in the UK, with an estimated prevalence of 25% of the general population. It is a spectrum of disease ranging from simple liver steatosis, through to progressive liver inflammation (known as non-alcoholic steatohepatitis - NASH) and liver scar tissue (fibrosis). The latter can lead to thedevelopment of cirrhosis, liver failure and hepatocellular cancer (HCC). The main risk factors for NAFLD are type 2 diabetes, obesity and to a lesser extent other components of the metabolic syndrome. The severity of fibrosis is the main predictor of significant liver-related morbidity and mortality, whereby patients with cirrhosis have a 40-fold risk of liver death compared to those without fibrosis. However, patients with advanced fibrosis or cirrhosis may have no signs or symptoms and can have normal liver function tests (LFTs) on blood sampling and a falsely reassuring liver ultrasound. Simple scoring systems (Fib-4, NAFLD Fibrosis Score), specialist bloods tests (Enhanced Liver Fibrosis Test – ELF) and imaging modalities (Transient Elastography – Fibroscan) are now increasing available to ‘rule out’ or ‘rule in’ advanced liver fibrosis. All these modalities have negative predictive values (‘rule out’) for advanced liver fibrosis of greater than 85%, whereas the positive predictive value (‘rule in’) are less so, especially in the primary care setting. Clinical guidelines and referral pathways recommend the sequential algorithmic use of a simple scoring system (i.e. Fib–4) followed by a specialist tool (either ELF test or Fibroscan depending on their availability locally) to identify patients at risk of advanced fibrosis in primary care and/or in secondary care metabolic clinics. Identifying patients with cirrhosis enables 6–monthly HCC surveillance, screening for portal hypertension (i.e. varices) and more focused lifestyle and pharmaceutical management to prevent progression to liver failure and premature death.