Persistent alanine aminotransferase elevation among the general Iranian population: prevalence and causes

To determine the prevalence and causes of persistently elevated alanine aminotransferase (ALT) levels among the general population in northern Iran.

A total of 2292 (1376 female, aged 18-75 year), were selected by systematic clustered random sampling from the cities and villages of Gonbad and Kalaleh in Golestan Province and invited to participate in the study. A comprehensive history regarding alcohol drinking and medication was taken. Body mass index (BMI), viral markers and ALT levels were measured. If ALT level was > or = 40 U/L, it was rechecked twice within 6 mo. Those with > or = 2 times elevation of ALT were considered as having persistently elevated ALT level. Non-alcoholic fatty liver disease (NAFLD) was diagnosed based on evidence of fatty liver upon sonography and excluding other etiology.

A total of 2049 (1351 female) patients participated in the study, 162 (7.9%) had elevated ALT level at the first measurement. Persistently elevated ALT level was detected in 64 (3.1%) participants, with 51 (79.6%) with no obvious etiology, six (9.3%) with Hepatitis B, four (6.2%) with Hepatitis C virus (HCV) infection and three (4.6%) with alcoholic hepatitis. The prevalence of NAFLD and alcoholic hepatitis was 2.04% (42 patients) and 0.1% (three), respectively. There was correlation between NAFLD and male gender, overweight, diabetes and living in an urban area [odds ratio = 3.03 (95% CI: 1.6-5.72), 4.21 (95% CI: 1.83-9.68), 2.86 (95% CI: 1.05-7.79) and 2.04 (95% CI: 1.00-4.16) respectively].

NAFLD is the most common cause of persistently elevated serum ALT level among the general population of Iran.