The effect of hyperlipidemia on Technicon SMAC measurements

The chemical measurements on our Technicon SMAC of lipemic sera before and after clearing lipemia by ultracentrifugation showed that uric acid, creatinine, carbon dioxide, calcium, phosphorus, potassium, and alkaline phosphatase were not affected significantly by lipemia, whereas sodium, urea, glucose, chloride and total protein showed small but significant increases with averages of less than 1.9 percent. Albumin showed a significant decrease of 1.2 percent. In contrast, the results for the enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) showed striking differences between pre- and post-centrifuged sera in a number of specimens. With lactate dehydrogenase, thirty-two of fifty specimens registered an increase in activity while with the aminotransferases, thirty-five and forty-one out of fifty specimens showed a decrease in aspartate aminotransferase and alanine aminotransferase activities, respectively. Although much of the lipemic interference can be explained by the volume displacement of serum by lipids or by interference by lipemia with colorimetry, the anomalous effects observed with the enzymes indicate the possibility of other, as yet, undetermined factor(s).