Table 1.
Subject demographics and baseline characteristics.
Fig 1.
Percentage HbA1c reduction from baseline during 8 weeks post whole blood donation.
Data (Tosoh G8) is shown as box plots each representing one individual. Horizontal dotted lines represent the RCV calculated for SI units. Box plots exceeding the RCV represent a significant change or reduction in HbA1c concentration. A: Control group of 20 non-diabetic volunteers not donating whole blood.9 (Tosoh G8 two-tailed RCV ±5.1%) B: 23 non-diabetic blood donors after 475 mL whole blood donation. (Tosoh G8 one-tailed RCV -4.28%) C: 17 blood donors with type 2 diabetes after 475 mL whole blood donation. (Tosoh G8 one-tailed RCV -4.28%) D: 17 blood donors with type 2 diabetes after 475 mL whole blood donation represented in DCCT units. (Tosoh G8 one-tailed RCV -2.52%) E: 4 blood donors with type 2 diabetes with an increase in HbA1c after 475 mL whole blood donation which were excluded from further analysis. (Tosoh G8 one-tailed RCV -4.28%)
Fig 2.
Effect of ferritin concentration on maximum HbA1c reduction (Tosoh G8).
Horizontal dotted lines represent the Tosoh G8 one-tailed RCV (-4.28%) calculated for SI units. A: 23 non-diabetic blood donors after 475 mL whole blood donation. The predonation ferritin concentration correlated significantly with the maximum % decrease in HbA1c (Pearson’s r = -0.65, P = 0.0009). Volunteers without a significant decrease in HbA1c had predonation ferritin concentrations <30 μg/L. B: Volunteers with ferritin concentrations <30 μg/L had a significantly lower reticulocyte hemoglobin concentration compared to blood donors with ferritin concentrations >30 μg/L (two-tailed Mann Whitney P = 0.0004). Data is presented as box plots. C: non-diabetic blood donors and blood donors with type 2 diabetes divided into groups with low and normal predonation ferritin concentration in relation to maximum % decrease HbA1c is plotted. A significant difference in mean maximum % decrease HbA1c between low and normal ferritin concentration was observed for the non-diabetic blood donors (two-tailed Mann Whitney P < 0.0001) but not for the blood donors with type 2 diabetes (two-tailed Mann Whitney P = 0.69).
Fig 3.
Dynamics of HbA1c during 8 weeks post whole blood donation (Tosoh G8).
Horizontal dotted lines represent the Tosoh G8 one-tailed RCV (-4.28%) calculated for SI units. A: 23 non-diabetic blood donors after 475 mL whole blood donation. A low maximum % reduction in HbA1c correlated with an early time point in the study, a high maximum % reduction in HbA1c correlated with a late time point (Spearman r = -0.668; P = 0.0005). B: Individual changes of HbA1c in 23 non-diabetic blood donors. The orange lines represent non-diabetic blood donors with low ferritin (<30 μg/L). C: 17 blood donors with type 2 diabetes after 475 mL whole blood donation. A low maximum % reduction in HbA1c correlated with an early time point in the study, a high maximum % reduction in HbA1c correlated with a late time point (Spearman r = -0.547; P = 0.015). D: Individual changes of HbA1c in 17 blood donors with type 2 diabetes. The orange lines represent blood donors with type 2 diabetes with low ferritin (<30 μg/L).