Background: HbA1c concentration is an indicator of the development of long-term complications in diabetic pa-tients. Different sample storage conditions could affect HbA1c values and consequently, clinician's diagnosis. In this study, we studied the effects of various temperatures of storage over time on HbA1c results.
Methods: A total of 40 fresh whole blood samples with various levels of HbA1c were selected for separate HbA1c measurements at three different temperatures (-20°C, 4°C, and 25°C) on subsequent days (0, 7, 14, and 21 days af-ter sample collection) with Cobas Integra 400 assays (Roche Diagnostics, Mannheim Germany).
Results: The value of HbA1c at initial measurement (7.05 ± 1.45) was insignificantly higher than results of temper-ature of -20°C and 4° but compared to results at the temperature of 25°C, (6.08% ± 0.86 % after day 7, 5.52% ± 0.80 after day 14, 4.81 % ± 0.66 after day 21) values of initial measurements were significantly higher.
Conclusions: We concluded that the refrigerator or freezer storage temperature is applicable for the measurement of HbA1c by Cobas Integra 400 without adverse effects on the stability of samples on subsequent days.