2011 Volume 25 Issue 5 Pages 837-843
Purpose: We previously reported on new ultrasound diagnostic criteria for fatty liver using an advanced ultrasound system equipped with differential tissue harmonic imaging. Using these criteria, we studied ALT levels for various degrees of hepatic steatosis and estimated healthy ranges of ALT for health check-up subjects by excluding the slightest degree of hepatic steatosis using ultrasound.
Subjects and Methods: 1,000 subjects were chosen at random from 17,069 people who underwent health check-ups at our clinic in 2009. A “healthy” group was established by excluding the following: ① positive HBsAg and/or HCVAb ② habitual alcohol ingestion regardless of amount of alcohol,③ any use of drugs,④ elevation of γ-GTP, ⑤ hepatic steatosis (regardless of degree ). Still images were recorded by five sonographers using a commercially available ultrasonoscope (Toshiba XARIO-XG) and later diagnosed by a certified fellow of JSUM based on our criteria.
Results: 381 subjects were determined to be “healthy” based on the above and the 95th percentile of ALT was 17.4±12.0 IU/L (5.4~29.4). The proportion of subjects in whom fatty liver was detected was 17.2% and two thirds of them had an elevated ALT level of over 30 IU/L. ALT levels for fatty steatosis increased gradually according to the degree of hepatic steatosis.
Conclusion: Healthy levels of ALT were estimated to be below 30 IU/L through exclusion of hepatic steatosis in establishing a “healthy population”. Cases of hepatic steatosis amongst the healthy population seemed to be the cause of the existing higher healthy range for ALT levels.
