Etiology and prevalence of abnormal serum alanine aminotransferase levels in a general population in Northeast China

Background Chronic liver diseases are a major burden in China. Alanine aminotransferase （ALT） can be used as an indicator of hepatocyte damage. In this study, we determined the prevalence and etiologies of elevated ALT in an adult population in Jilin, China. Methods A total of 4072 individuals aged between 18 and 79 years were first interviewed, and then underwent ultrasonography and blood tests. Results The prevalence of elevated ALT was 17.53%. The most noticeable risk factor for ALT elevation was non-alcoholic fatty liver disease （NAFLD） （accounting for 10.79%）, metabolic syndrome （16.25%）, or both （20.31%）. The development of NAFLD occured mostly in female peasants and small businessmen with increased income, age, fasting plasma glucose, body mass index, triglyceridemia, and low-density lipoprotein and decreased education level, high-density lipoprotein. Elevated ALT frequently occured in low education level, male peasants and small businessmen with increased income, body mass index and＇ triglyceride who had NAFLD and/or metabolic syndrome. However, elevated ALT with infection of hepatitis B or C virus was not associated with metabolic disorders, but rather with gender, occupation and increased age. Conclusion The results from the current study demonstrate that elevated ALT is fairly high in the Northeast population （17.53%） and that the cause of its elevation is mostly due to NAFLD and metabolic syndrome.