GPT and hepatitis C virus infection: The prevalence of hepatitis C infection was 80.7% and 80.9%, respectively, in Cohort 1 and Cohort 2, which was much higher than the estimated prevalence rate in the general population [26], and was associated with a high percentage of patients with abnormal serum levels of aspartate aminotransferase (46.1% vs. 49.2%), γ-glutamyltransferase (17.7% vs. 21.6%), and alanine aminotransferase (22.6% vs. 32%).