Efficacy and Clinical Utility of Sodium Fluoride Tubes Versus Serum Tubes for Blood Glucose Estimation

Cureus. 2024 Oct 29;16(10):e72641. doi: 10.7759/cureus.72641. eCollection 2024 Oct.

Abstract

Introduction: Precise and accurate measurement of blood glucose is the key factor in both the diagnosis and effective management of diabetes mellitus. The blood glucose levels are influenced by the time interval between sample collection and measurement as glycolysis continues to take place in the blood cells. Laboratories make efforts to minimize this change. This study aimed to analyze the differences in blood glucose levels between routine serum tubes and sodium fluoride (NaF) tubes over time intervals.

Methods: The study included 50 participants from whom blood was collected in both serum and NaF tubes. The blood glucose values between the two were compared using the Wilcoxon signed-rank sum test at time intervals of one, two, and six hours and the level of agreement in measuring the blood glucose levels by the Bland-Altman plot.

Results: There were statistically significant variations in median glucose values between serum and NaF tubes across all the time intervals. The study found that 62%, 70%, and 100% of patients showed decreased glucose values in serum tubes at the end of one, two, and six hours, respectively, compared to NaF tubes. The Bland-Altman plot analysis indicated high agreement at all three time points. However, the difference in blood glucose levels varied from 5.6 mg/dL to 18.74 mg/dL from one to six hours, which was clinically very significant. All the values are clinically very significant as it would lead to underdiagnosing of diabetes mellitus and gestational diabetes mellitus.

Conclusion: The study demonstrated that NaF tubes may offer better preservation of glucose levels, especially over extended periods implying that NaF tubes will help prevent under-diagnosis of diabetes mellitus.

Keywords: blood glucose estimation; diabetes mellitus; glycolysis; serum tubes; sodium fluoride tubes.