Background and aim: Causes of elevated serum alanine aminotransferase (ALT) levels vary depending on the population under study. The aim of this study was to determine the prevalence and causes of elevated ALT levels among apparently healthy Iranian blood donors in Tehran.
Methods: A total of 1959 (1465 male) randomly selected blood donors were enrolled in the study. Body mass index (BMI), viral markers and ALT levels were measured. If ALT was elevated (> 40 U/L), it was rechecked twice within 6 months. Blood donors with > or =2 times elevated ALT levels (persistently elevated ALT) were invited for further evaluation.
Results: A total of 100 donors (5.1%) had elevated ALT levels at the first measurement. Fifty-two persons (2.65%) were found to have persistently elevated serum ALT. Among subjects with persistently elevated serum ALT, non-alcoholic steatohepatitis (NASH) was diagnosed in 46 (88.4%), chronic hepatitis C virus (HCV) infection in four (7.7%), alcoholic liver disease in one (1.92%), and drug-induced liver disease in one (1.92%). The prevalence of NASH and HCV infection in the studied population was 2.35% and 0.4%, respectively. The mean BMI of NASH subjects was 30.58 kg/m(2), compared with 27.28 kg/m(2) of those without NASH (P < 0.001).
Conclusion: Non-alcoholic steatohepatitis is the most common cause of persistently elevated serum ALT in the asymptomatic Iranian blood donors in Tehran.