Short-term Biological Variation of Glycated Hemoglobin-A1c

  Objective  To study the short-term biological variation of glycated hemoglobin-A1c (HbA_1c).

  Methods  Blood samples from 30 healthy volunteers 17 men and 13 women; aged 23-34 years (median, 24 years) were drawn at 8:00 am, 12:00 pm, and 4:00 pm each day for 3 days (days 1, 3 and 5), and HbA_1c values were measured in duplicate by high performance liquid chromatography (Variant Ⅱ Yurbo Analyser, Bio-Rad).

  Results  The within-subject coefficient of variations (CV_I) of total, male, and female subjects in this study were 1.39%, 1.49%, and 1.32%, respectively. The between-subject coefficient of variations (CV_G) of the three groups mentioned above were 2.65%, 2.33%, and 2.90%, respectively. The analytical coefficient of variations (CV_A) of these three groups were all 0.6%. The index of individuality (II) of the three groups were 0.5, 0.6, and 0.5, respectively. The 95% probabilities of reference change value (RCV) of the three groups were 4.22%, 4.45%, and 4.02%, respectively. The 99% probabilities of RCV were 5.19%, 5.86%, and 5.29%, respectively. Furthermore, intra- and inter-day biological variations of HbA_1c were fairly constant among the population examined(P=0.28, 0.31), and no significant difference was observed between the male and female participants(P=0.18).

  Conclusions  The short-term CV_I and CV_G of HbA_1c in healthy individuals are minimal. The laboratory findings are quite constant and homogeneous for HbA_1c in short term and between genders.