Nd Asia Muhammad
Integr Med (Encinitas). 2019 Apr;18(2):42-49.
Nonalcoholic fatty liver disease (NAFLD) affects 25% of people worldwide. Patients with fatty liver disease are primarily asymptomatic. Currently, specialists are predicting that fatty liver related cirrhosis will the be leading reason for liver transplants in the next 10-20 years, displacing hepatitis C and alcohol related liver transplants. NAFLD exists on a spectrum of simple steatosis to steatosis with inflammation and different levels of fibrosis. It is currently estimated that 20% of simple steatosis patients will progress to nonalcoholic steatohepatitis (NASH). Patients with NASH are at risk for further progression to cirrhosis and hepatocellular carcinoma. There is no single factor that triggers progression from simple steatosis to NASH, however, we do know that NASH is more prevalent in patients with obesity, diabetes, and metabolic syndrome. NAFLD is thought to be the hepatic manifestation of metabolic syndrome, and is closely tied with hyperinsulinemia. Currently there are no approved FDA treatments for NAFLD. NAFLD is typically found incidentally on imaging such as abdominal ultrasound and CT. Elevations in alanine aminotransferase (ALT) may prompt the clinician to evaluate for NAFLD however ALT should not be used as a diagnostic tool. The gold standard for diagnosis of NAFLD and NASH is a liver biopsy. Only a liver biopsy can distinguish simple steatosis from NASH. In patients whom NAFLD is suspected, appropriate biochemical assessment and imaging should be evaluated. Also, the presence of fibrosis should be assessed. Weight loss and dietary modifications are currently the only recommendations provided to NAFLD patients. There is histological improvement seen in in patients whom lose 5-10% of their body weight. Certain dietary factors play a role in the development of NAFLD including excessive caloric intake and high fructose consumption. There are pharmacological treatments currently being studied as well as non-pharmacological agents. This overview focuses on evaluation, management and treatments in NAFLD.
非酒精性脂肪性肝病（NAFLD）影响着全球25%的人口。患有脂肪性肝病的患者大多没有症状。目前，专家预测，在未来10至20年内，与脂肪肝相关的肝硬化将成为肝脏移植的主要原因，取代丙型肝炎和酒精性肝病导致的肝脏移植。NAFLD涵盖了从单纯性脂肪变性到伴有炎症和不同程度纤维化的脂肪变性这一范围。目前估计，20%的单纯性脂肪变性患者会进展为非酒精性脂肪性肝炎（NASH）。患有NASH的患者有进一步发展为肝硬化和肝细胞癌的风险。没有单一因素会触发从单纯性脂肪变性进展为NASH，不过，我们确实知道NASH在肥胖、糖尿病和代谢综合征患者中更为普遍。NAFLD被认为是代谢综合征的肝脏表现，并且与高胰岛素血症密切相关。目前美国食品药品监督管理局（FDA）尚未批准用于治疗NAFLD的药物。NAFLD通常在腹部超声和CT等影像学检查中偶然发现。丙氨酸氨基转移酶（ALT）升高可能促使临床医生对NAFLD进行评估，然而ALT不应被用作诊断工具。NAFLD和NASH诊断的金标准是肝活检。只有肝活检才能区分单纯性脂肪变性和NASH。对于疑似患有NAFLD的患者，应进行适当的生化评估和影像学检查。此外，还应评估纤维化的存在情况。目前针对NAFLD患者的唯一建议是减重和饮食调整。体重减轻5%至10%的患者在组织学上有改善。某些饮食因素在NAFLD的发展中起作用，包括热量摄入过多和高果糖消耗。目前也在研究药物治疗以及非药物治疗手段。本综述重点关注NAFLD的评估、管理和治疗。
