Introduction:The aim of the study was to evaluate the effect of a single freeze/thaw cycle on HbA 1c concentrations measured by commercially available HPLC method.Materials and methods: Study included 128 whole blood samples collected from diabetic patients (N = 60) and healthy volunteers (N = 68).HbA 1c concentrations were measured in fresh blood samples.Then samples were frozen at -80 °C for up to 12 weeks.HbA 1c was assayed by ionexchange HPLC method on Bio-Rad D-10 ® analyzer.Variables were compared using Wilcoxon and ANOVA Kruskal-Wallis tests.Bias between HbA 1c measured in fresh and frozen samples was calculated.The comparability of HbA 1c concentrations was assessed by Bland-Altman plot.Results: Median (IQR) HbA 1c concentration was 45.3 (36.6-61.2) mmol/mol for fresh and 45.3 (36.6-60.6)mmol/mol for frozen/thawed samples.No significant difference in HbA 1c concentrations was found comparing fresh and frozen/thawed samples (P = 0.070) in the whole group, as well as in healthy and diabetic subjects.The median calculated bias between fresh and frozen/thawed samples was 0% in whole group and healthy subjects, and 1.19% in diabetic patients.No significant difference was found between the biases according to baseline HbA1c values (P = 0.150).The Bland-Altman plot analysis showed a positive bias of 0.4% (95% CI: -2.8 -3.7%), which indicates high compliance between HbA 1c values and no relevant influence of sample freezing on clinical significance of HbA 1c measurement.Conclusions: Storage for up to 12 weeks at -80 °C with a single freeze/thaw cycle does not affect HbA 1c concentrations measured with HPLC method on Bio-Rad D-10 ® analyzer.
No takes yet. Share an insight, caveat, or question.
Bergmann et al. (2016) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: