Normal Range of Serum Alanine Aminotransferase (ALT) Levels in Healthy Population of Yazd and Relation to Demographic Factors

Alanine aminotransferase (ALT) is the most useful laboratory marker of hepatic necroinflammation that is used for diagnosis of liver diseases. Based on recent data, the investigators suggested a new upper limit of normal, which was based on patient's sex and BMI criteria. This prospective study was done to determine the normal range of serum alanine aminotransferase (ALT) in healthy normal population of Yazd from October 2008 to June 2009. In this study, 565 randomly selected apparently healthy people without any defined diseases were selected. Cases who had any history of hepatic diseases, history of hepatotoxic drugs or alcohol were excluded. Patients positive for HBsAg or HCV were also excluded. ALT measurements were performed by the the same laboratory method using Pars Azmon kit made in Iran. Healthy ranges for ALT levels were computed. Univariate and multivariate analyses were performed to evaluate associations between clinical factors and ALT levels. The 95Th percentile of ALT was 35.6 I.U for males and 31.2 IU for females and the mean ALT was 23.03±9.93 IU/dL. In this study, ALT levels were related to gender, age, BMI, FBS and cholesterol, but there was no relation with triglyceride levels. (Age, r=-0.100, BMI. r=0.13 FBS r=0.119, cholesterol r=0.142.) The 95Th percentile of ALT was, 35.6 IU/dL for males and 31.2 IU/dL for females. Serum ALT is related to gender, BMI, FBS, cholesterol but is not related to triglyceride levels. ALT is inversely related to age.