Aspartate Aminotransferase and Alanine Aminotransferase Activities in Plasma: Statistical Distributions, Individual Variations, and Reference Values

Abstract

The determination of frequency value (percentile limits) and the classification of the different variation factors allow us to define more and more homogeneous subpopulations as we use these factors for sorting. Using as our study population those persons coming to the Centre for Preventive Medicine, we were able to: (a) Describe and measure the significance and importance of physiological variations or of variations attributed to age—the latter largely related only to excessive weight, which it seems to us is often the case. (b) Establish a classification for variation factors; the recapitulatory table should be useful to clinical chemists in helping physicians interpret a laboratory test result that falls within the zone of incertitude. (c) Suggest a preliminary group of reference values for healthy subjects, to be used in interpreting a laboratory test in this way.

Human amnion epithelial cells and their soluble factors reduce liver fibrosis in murine non‐alcoholic steatohepatitis

“…28 Serum ALT is consistently higher in patients with increased bodyweight, hypercholesterolemia, and insulin resistance but no indication of hepatocyte damage. 30,31 Alternatively, 33% of patients with NASH also had normal ALT. 32 Therefore, a potential limitation of our study is using ALT in isolation as a marker of hepatic injury.…”

Standard liver tests

“…13 AST levels are 15% higher in African American males as compared with Caucasians. 11 Some individuals may have asymptomatic AST elevation caused by a defect in clearance of the enzyme. 14…”

Prevalence of abnormal plasma liver enzymes in older people with Type 2 diabetes

“…Concerns have been raised that current cut-points may underestimate the population at risk if this reference group included individuals with undiagnosed liver disease. Normal ranges also vary by age, sex and ethnicity [17]. Reanalysis of our data using the lower ALT cut-points proposed by Prati et al [18] resulted in almost the entire study population being classified as abnormal, suggesting that these cut-points are too low in populations with Type 2 diabetes.…”