Glycemic control and blood product quality of Canadian blood donors with diabetes

BACKGROUND: Many blood centers now accept donors with diabetes, provided their condition is "well-controlled". However, glycemic control is not routinely assessed at donation, and the impact of donor diabetes on blood product quality remains unclear. STUDY DESIGN AND METHODS: To screen glycemic control, glycated hemoglobin A1c (HbA1c) was measured in whole blood from 256 unique donors with either type 1 diabetes (T1D), type 2 diabetes (T2D), or without known diabetes. In parallel, routine quality control (QC) data were linked with donor metadata to assess the impact of donor diabetes on red cell concentrate (RCC) and apheresis platelet concentrate (PC) quality at the time of their expiry. RESULTS: Nearly half of donors with diabetes had suboptimal glycemic control (HbA1c >7 %) at donation, including 57.1 % of donors with T1D and 43.4 % with T2D. RCC units from donors with T2D (n = 1,329) had higher hemolysis (p <.001) and a greater proportion exceeding the clinical threshold of 0.8 % hemolysis (p <.001). These differences were not observed with T1D (n = 46). Apheresis PC units from donors with T2D (n = 164) had lower expiry pH (p = .014), with a trend toward more units below the clinical cutoff of pH 6.4 (p = .059). Differences in both products were most pronounced in donors with T2D using both metformin and insulin. CONCLUSION: Many donors with diabetes have suboptimal glycemic control, and RCC and PC from donors with T2D have reduced quality. The observed effects are modest, likely not driven by glycemic control alone, and do not support additional deferral criteria for donors with diabetes.