Effects of Transportation and Delay in Processing on the Stability of Nutritional and Metabolic Biomarkers

Abstract

The effects of transportation and delay in processing of blood samples on the concentration of biomarkers are significant in epidemiological studies for which specimens are collected from participants at locations other than a designated center or laboratory. These sources of variability in measurement were studied by collecting two sets of blood samples from 51 men between 26 and 50 years of age. The first set was sent immediately to the laboratory for processing. The second set was transported by car for one hour and then returned to the laboratory for processing. Both sets were stored together at -80 degrees C until the end of the study. Several blood constituents were evaluated. Vitamins, liver enzymes, and electrolytes showed no changes in concentration after transport by car for one hour. There were decreases in the concentrations of red and white blood cells, high-density-lipoprotein cholesterol, glucose, and creatinine after transportation. The transported total cholesterol, total testosterone, free testosterone, alkaline phosphatase, total bilirubin, and thiobarbituric acid-reactive substances increased in concentration. Although transportation and delay in processing of blood samples do not appear to greatly impact relative risk estimates, epidemiologists should be aware of these potential sources of variability in measurement and consider the consequences in their particular study.

Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan

“…Examples of temperature-sensitive diagnostic analytes include red and white blood cells, high-density-lipoprotein cholesterol, glucose, creatinine, total cholesterol, total testosterone, free testosterone, alkaline phosphatase, total bilirubin, thiobarbituric acid-reactive substances [11], glucose and potassium [12]. …”

Accuracy and Biological Variation of Human Serum Paraoxonase 1 Activity and Polymorphism (Q192R) by Kinetic Enzyme Assay

“…An additional sample set, designed for the estimation of biological variation, consisted of serial samples from 17 volunteers (7 men and 10 women) obtained at 0, 1, and 4 weeks. All study specimens (79 total) were collected, processed, and stored with standardized procedures that we have described previously (30 ). The experimental protocols were approved by the Institutional Review Board at the University of Buffalo and informed, written consent was obtained from all participants.…”

International Expert Committee Report on the Role of the A1C Assay in the Diagnosis of Diabetes

“…A recent analysis of the performance of a variety of clinical laboratory instruments and methods that measure glucose revealed that 41% of instruments have a significant bias from the reference method that would result in potential misclassification of >12% of patients (35). There are also potential preanalytic errors owing to sample handling and the well-recognized lability of glucose in the collection tube at room temperature (36,37). Even when whole blood samples are collected in sodium fluoride to inhibit in vitro glycolysis, storage at room temperature for as little as 1 to 4 h before analysis may result in decreases in glucose levels by 3–10 mg/dl in nondiabetic individuals (36–39).…”