GPT and hepatitis B virus infection: We further excluded individuals with viral hepatitis B or whose liver fat was likely caused by excessive alcohol consumption: positive for hepatitis B virus surface antigen (n = 18530), GGT level (a common marker of alcohol consumption) >100 U/L (n = 1034 men) or 78 U/L (n = 368 women), AST/ALT concentrations >2 (n = 191), or heavy drinker (men > 140 g ethanol /per week or 50 g ethanol /each time; women >70 g ethanol/per week or 40 g ethanol /each time) (n = 3878) according to the suggestion of National Institutes of Health Clinical Research Network31.