A comparison of fluoride-oxalate and plain (serum gel) tube on glucose measurement

Abstract

A continuing problem in the accurate measurement of glucose is its decline in concentration due to erythrocytic glycolysis after sampling, transport and processing. Eliminating this problem requires the use of an anti-glycolytic agent that can be added to the sampling tubes without altering cellular integrity while measuring blood glucose. This study was therefore conducted to compare fluorideoxalate and plain tube on glucose measurement at the Komfo Anokye Teaching Hospital. A total of 100 subjects were recruited from an adult population at the Komfo Anokye Teaching Hospital. Six milliliters of venous blood sample was collected from each patient and 1ml each was dispensed into three separate fluoride-oxalate and plain tubes and were centrifuged at different time intervals to obtain plasma and serum respectively. 1%, 4% and 8% of the subjects presented with hypoglycaemia at immediate, after 1 hour and 2 hours fluoride-oxalate while that of plain tubes were 3%, 6% and 14% respectively. 58%, 53% and 49% of the subjects presented with hyperglycaemia at immediate, after 1 hour and 2 hours for fluoride-oxalate while that of plain tubes were 58%, 49% and 47%. Decrease in glucose concentration after 1 hour and 2 hours in fluoride-oxalate tubes were 6.5% and 13% respectively while those in plain tubes were 8.9% and 16.7%. Though, fluoride-oxalate does not completely inhibit erythrocytic glycolysis within two hours, its effect when left on the bench at different time intervals does not show a significant change in test results. Plain tubes however show significant change in test results at different time intervals since they do not contain any antiglycolytic agents needed to preserve blood glucose.

Keywords: Glucose estimation, preservative, serum gel, glucose oxidase, Ghana