“Fatty liver is not a disease, many people have it, no need to treat”, “fatty liver is a minor problem, drink wine as usual, smoke as usual, nothing!”. . We often hear this kind of “brave words”. Let’s look at the scientific findings of experts to see if this is true. Fatty liver disease, referred to as fatty liver, is a multi-causal (genetic/environmental/metabolic) clinicopathological syndrome in which the main lesion is in the lobules of the liver and hepatocellular steatosis is the main cause. Clinically, there are three types of fatty liver: alcoholic fatty liver and non-alcoholic fatty liver, and pathologically, there are three main types of fatty liver: simple fatty liver, steatohepatitis and fatty cirrhosis. With changes in dietary habits and lifestyle and the widespread use of imaging tests, the prevalence of fatty liver has tended to increase worldwide, and the incidence increases with age, while its etiology is mainly non-alcoholic fatty liver associated with metabolic syndrome. The prevalence of NAFLD among adults in Japan is reported to be 21.8%, and the prevalence of NAFLD in Europe and the United States is 20%. From October 2002 to September 2003, questionnaires, physical examinations, laboratory tests and liver ultrasound examinations were conducted in 3175 adults in Shanghai, of whom 1212 were men, aged 52+15 years. Hazards of fatty liver The results of this study found that the prevalence of fatty liver among adults in Shanghai is high and tends to be younger. The fatty liver detection rate among the study population in this survey was as high as 20.82%, and the prevalence of fatty liver in adults before the age of 30 was 7.58%. Due to the significant difference between the age and sex composition of the sampled population and the Shanghai population, the age- and sex-adjusted prevalence of fatty liver among adults in Shanghai was 17.29%. Among them, the prevalence of fatty liver in men and women was 19.30% and 15.08%, respectively, and the prevalence of fatty liver in men was significantly higher than that in women. The prevalence of fatty liver in men was significantly higher than that in women. The prevalence of fatty liver increased with age by gender and overall. However, the prevalence of fatty liver in men was higher than that in women before the age of 50, while the prevalence was lower than that in women after the age of 50, which may be related to the change of estrogen level in women before and after menopause, suggesting that estrogen has a preventive effect on fatty liver. Based on the 2000 national census of Shanghai population data, it is inferred that there are about 2.43 million adults with fatty liver in Shanghai, which is really a not small population. Since the course of fatty liver is not entirely benign, some patients are at risk of developing liver fibrosis, cirrhosis or even liver cancer. Currently, fatty liver is considered to be the main cause of chronic liver disease. Therefore, fatty liver should be taken seriously enough, and everyone should start by themselves, actively changing bad habits such as “eating more and moving less”, high fat and high calorie diet, drinking and smoking, etc. It is necessary to consult a specialist for comprehensive treatment. Metabolic syndrome is a group of metabolic disorders with insulin resistance as the central link, which can coexist with various diseases and is a combination of various cardiovascular risk factors. These diseases are highly susceptible to diabetes and adverse cardiovascular events, which can seriously affect human health. As early as 1988, some scholars proposed the concept of “syndrome X” and found that insulin resistance is not only a characteristic of diabetes, but also prevalent in many human diseases and pathological states. 1989, another expert proposed the concept of obesity, abnormal glucose tolerance, increased triglycerides (TG) and hypertension. “In 1999, the World Health Organization’s working definition of the metabolic syndrome centered on the presence of insulin resistance as the core of the metabolic syndrome, and also included the presence of hypertension, hyper-TGemia, central obesity, and microalbuminuria. 2001 National Cholesterol Education Program Adult Treatment Panel Third Report (NCEP-ATP III) working definition was introduced, which is a relatively loose accumulation of multiple indicators, and concluded that obesity, especially central obesity, is associated with insulin resistance and also significantly associated with multiple metabolic risk factors. Although there is no unified and universally accepted clear definition of metabolic syndrome internationally so far, the emergence of these concepts mentioned above has led to the recognition that these diseases are both relatively independent and intrinsically linked, and this intrinsic link is insulin resistance and its resulting disorders of glucose and lipid metabolism. Researchers believe that metabolic syndrome should include hyperuricemia, hypercoagulable state, vascular endothelial dysfunction, polycystic ovary syndrome, cholelithiasis, and fatty liver in addition to the above components. The American epidemiological survey found that the prevalence of metabolic syndrome in adults in the United States was 23.7% according to the third report of the National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP III). According to the results of a study in Shanghai (3,175 study subjects), the prevalence of metabolic syndrome in adults in Shanghai was 22.86%, with a prevalence of 10.67% in adult males and 12.18% in females. Early warning signs of metabolic syndrome The dangers of fatty liver are not limited to the liver itself; more and more scholars believe that fatty liver is a part of metabolic syndrome and even an important early warning sign! We used the World Health Organization Western Pacific obesity and central obesity criteria and fatty liver as cut points to determine the aggregation of metabolic disorder risk factors, respectively. We found that among the three cut points of BMI ≥ 25 kg/m2, waist circumference ≥ 90 cm and fatty liver in men, fatty liver had the highest specificity (87.41%), the highest positive predictive value (63.18%) and the highest percentage of attribution (91.67%) in determining the clustering of risk factors for metabolic syndrome; similar results were also obtained in the female population. It is suggested that fatty liver, as an indicator of risk factor aggregation in metabolic syndrome, has good stability compared with obesity and central obesity indicators, and is not affected by gender. On the other hand, the detection rate of fatty liver in patients with metabolic syndrome was 39 times higher than that in healthy controls. These studies suggest that fatty liver is closely related to metabolic syndrome and related diseases, that patients with fatty liver have a high prevalence of metabolic syndrome and related diseases, and that metabolic syndrome and related diseases increase the risk of developing fatty liver and may aggravate the severity of fatty liver. Pay attention to fatty liver, because the alarm has been sounded for your health!