RESUMO
OBJECTIVE: Nonalcoholic fatty liver disease is an increasingly recognized condition, but its exact prevalence is unknown. In this prospective, multicenter study, we evaluated the prevalence of elevated alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl-transpeptidase levels as indirect markers of nonalcoholic fatty liver disease in volunteer blood donors as well as their associations with epidemiological and anthropometrical characteristics. METHODS: Alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl-transpeptidase levels were determined in blood donors from four transfusion centers during the morning sessions of a 3-month period. Cases with positive hepatitis B surface antigen, anti-hepatitis C virus, anti-HIV or elevated liver enzymes and alcohol abuse were excluded. RESULTS: Abnormal liver enzymes were found in 17.6% of 3063 participants (alanine aminotransferase: 14.5%, aspartate aminotransferase: 4.6%, gamma-glutamyl-transpeptidase: 4.7%). Individuals with abnormal compared with those with normal liver enzymes or alanine aminotransferase values were more frequently men and had higher weight, body mass index, waist, hip and neck circumference (P<0.001 for all comparisons). The prevalence of abnormal liver enzymes was also associated with the transfusion center ranging between 8.8 and 22.1% (P<0.001) and alcohol consumption (P=0.001). In multivariate analysis, presence of elevated enzymes was independently associated with male sex, higher weight or body mass index, higher waist circumference and transfusion center. CONCLUSIONS: More than 15% of Greek blood donors exhibit elevated liver enzymes, most likely as a result of unrecognized nonalcoholic fatty liver disease. The prevalence of nonalcoholic fatty liver disease is mainly associated with male sex, obesity and waist circumference, but it may range significantly among different population groups.