However, the AASLD advises against the use of metformin as studies were inconclusive about the improvement of the liver's histological condition. [4][5] The EASL recommends the Fatty Liver Inhibition of Progression (FLIP) algorithm to grade the ballooning and classify NAFLD-associated liver injury, and the use of the NAFLD Activity Score (NAS) to grade the severity of NASH rather than for its diagnosis. [19][115][116] NAFLD is associated with metabolic syndrome, which is a cluster of risk factors that contribute to the development of cardiovascular disease and type 2 diabetes mellitus. [13], Treatment with medications is primarily aimed at improving liver disease and is generally limited to those with biopsy-proven NASH and fibrosis. An enlarged liver occurs in 30–40% of children with NAFLD. [108], The name "non-alcoholic steatohepatitis" (NASH) was later defined in 1980 by Jurgen Ludwig and his colleagues from the Mayo Clinic[109] to raise awareness of the existence of this pathology, as similar reports previously were dismissed as "patients' lies". [46], NAFLD warrants treatment regardless of whether the affected person is overweight or not. [2][4][5][11][13], NAFLD comprises two histological categories: NAFL, and the more aggressive form NASH. [43] The health benefits after bariatric surgery may also involve changes in the gut microbiota by increasing gut permeability. It is also associated with hormonal disorders (panhypopituitarism, hypothyroidism, hypogonadism, polycystic ovary syndrome), persistently elevated transaminases, increasing age and hypoxia caused by obstructive sleep apnea, with some of these conditions predicting disease progression. [104] Fatty liver was, however, linked to diabetes since at least 1784[106] — an obervation picked up again in the 1930s. [43], NAFLD is defined by evidence of fatty liver without another factor that could explain the liver fat accumulation, such as excessive alcohol use (>21 standard drinks/week for men and >14 for women in the USA; >30 g daily for men and >20 g for women in UK and EU, >140 g/week for men and >70 g/week for women in Asia-Pacific and most NIH clinical studies), drug-induced steatosis, chronic hepatitis C, heredity or by deficiencies in parenteral nutrition such as choline and endocrine conditions. [4][8][11][61] The EASL allows alcohol consumption below 30g/day for men and 20g/day for women. [103], The first acknowledged case of obesity-related non-alcoholic fatty liver was observed in 1952 by Samuel Zelman. [115] The mean age is usually above 10 years, as children can also report non-specific symptoms and are thus difficult to diagnose for NAFLD. [9] For these reasons and others, individuals with morbid obesity (BMI > 40 kg/m²) and NASH with cirrhosis may be considered unfit for liver transplantation until they follow lifestyle modifications to reduce bodyweight. However, even if statins are safe to use in people with NASH cirrhosis, the AASLD suggests avoiding them in people with decompensated cirrhosis. Non-alcoholic fatty liver disease (NAFLD), also known as metabolic (dysfunction) associated fatty liver disease (MAFLD), is excessive fat build-up in the liver without another clear cause such as alcohol use. [9] Diabetic people with poor glycemic control are at similar risks, and optimal glycemic control is essential before attempting transplantation. [8][13][56][59] Tentative evidence supports dietary interventions in individuals with fatty liver who are not overweight. [3] When NAFLD does progress to NASH, it may eventually lead to complications such as cirrhosis, liver cancer, liver failure, cardiovascular disease and hepatocellular carcinoma (HCC). [8][52][57] People with NAFLD can benefit from a moderate to low-carbohydrate diet and a low-fat diet. [21], Excessive fat build-up in the liver not caused by alcohol use. Non-alcoholic fatty liver disease is less dangerous than NASH and usually does not progress to NASH or liver cirrhosis. He then went on to design a trial for a year and a half on 20 obese people who were not alcoholic, finding that about half of them had substantially fatty livers. Transient elastography is not considered to be a replacement for liver biopsy. [14] Adipose tissue dysfunction also decreases secretion of the insulin-sensitizing adipokine adiponectin in people with NAFLD. [22][25][50][51], A liver biopsy (tissue examination) is the only test widely accepted (gold standard) as definitively diagnosing and distinguishing NAFLD (including NAFL and NASH) from other forms of liver disease and can be used to assess the severity of the inflammation and resultant fibrosis. [22][101] Overweight, or even weight gain, in childhood and adolescence, is associated with an increased risk of NAFLD later in life, with adult NAFLD predicted in a 31-year follow-up study by risk factors during childhood including BMI, plasma insulin levels, male sex, genetic background (PNPLA3 and TM6SF2 variants) and low birth weight, an emerging risk factor for adulthood NAFLD. [25] However, transient elastography can fail for people with pre-hepatic portal hypertension. As the name implies, the main characteristic of NAFLD is too much fat stored in liver cells.NAFLD is increasingly common around the world, especially in Western nations. [4], The AASLD further recommends for people with a cirrhotic NASH to be systematically screened for gastric and esophageal varices and liver cancer. For young people, guidelines recommend liver ultrasonography, but biopsy remains the best evidence. [35] Studies suggest an association between microscopic organisms that inhabit the gut (microbiota) and NAFLD. Oxidative stress, hormonal imbalances, and mitochondrial abnormalities are potential causes of this "second hit" phenomenon. [8][71] Vigorous training is preferable to moderate training, as only the high-intensity exercise reduced the chances of NASH developing into steatohepatitis or advanced fibrosis. [5] Hispanic persons have a higher prevalence of NAFLD than white individuals, whereas the lowest prevalence is observed in black individuals. [4] The EASL suggests using fibrosis tests such as elastography, acoustic radiation force impulse imaging, and serum biomarkers to reduce the number of biopsies. [21] Asian populations are more susceptible to metabolic syndrome and NAFLD than their western counterparts. [18] Guidelines are available from the American Association for the Study of Liver Diseases (AASLD), American Association of Clinical Endocrinologists (AACE) National Institute for Health and Care Excellence (NICE), the European Association for the Study of the Liver (EASL), and the Asia-Pacific Working Party on NAFLD. [11] Treatment with pentoxifylline is not recommended. [4], Also, people with NAFLD may be considered for screening for hepatocellular carcinoma (liver cancer) and gastroesophageal varices. Weblio英和対訳辞書はプログラムで機械的に意味や英語表現を生成しているため、不適切な項目が含まれていることもあります。ご了承くださいませ。, ライフサイエンス辞書での「Non-alcoholic fatty liver disease」の意味, Weblio英和対訳辞書での「Non-alcoholic fatty liver disease」の意味, 「Non-alcoholic fatty liver disease」を解説文に含む英和和英の用語の一覧, 英和辞書の「Non-alcoholic fatty liver disease」の用語索引. The course of progression varies with different clinical manifestations among individuals. [33] According to a meta-analysis of 34,000 people with NAFLD over seven years, these individuals have a 65% increased risk of developing fatal or nonfatal cardiovascular events when compared to those without NAFLD. [19], NAFLD incidence is rapidly rising, along with obesity and diabetes, and has become the most common cause of liver disease in developed countries, for adults, teenagers, and children. [46], There is no special treatment for liver cancer associated with NAFLD/NASH and are treated according to general guidelines on liver cancers. [38], Excessive macronutrient intake contributes to gut inflammation and perturbation of homeostasis, and micronutrients may also be involved. PNPLA3 may be relevant for the progression of NAFLD in lean people. … [9], Cardiovascular system screening is considered mandatory by the EASL, as NAFLD outcomes often result in cardiovascular complications,[13] which can manifest as subclinical atherosclerosis, the cause of the majority of NAFLD-related deaths. Weight loss is associated with improvements in biomarkers, NAFLD grade, and reduced chances of NASH, but their impact on long-term health is yet unknown. People with NAFLD are not at higher risk for serious liver injury from statins, according to AASLD and EASL. Low thyroid activity is more prevalent in people with NASH, which would be detected by determining the thyroid-stimulating hormone. [5] Diet composition and quantity, in particular omega-6 fatty acid and fructose, have important roles in disease progression from NAFL to NASH and fibrosis. [19][22] In a study, simple steatosis was present in up to 45% in children with a clinical suspicion of NAFLD. 24% in worldwide population, 80% in obese, 20% in normal-weight, This page was last edited on 24 November 2020, at 01:59. Non-alcoholic beer is available to people who drive. [14] Despite the accumulation of triglycerides in the liver, they are not directly toxic to liver tissue. [2][3] There are two types; non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH), with the latter also including liver inflammation. [11], Statin medications appear to improve liver histology and markers of liver biochemistry in people with NAFLD. The NICE advises regular screening of NAFLD for advanced liver fibrosis every three years to adults and every two years for children using the enhanced liver fibrosis (ELF) blood test. 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