Background: Vascular complications of diabetes mellitus (DM) are associated with 5% of deaths globally every year. Early diagnosis and treatment could reduce this figure. The aim of this project was to investigate the frequency of undiagnosed DM among blood donors and the possibility of blood banks participating in DM screening.
Methods: Of the approximate 5,600 candidates for blood donation who were evaluated, 4,601 were considered suitable. Candidates with any type of DM, hypertension, thyroid disease, and/or continuous use of any drugs were excluded, resulting in the participation of 635 donors aged 18 - 69 years. Glycated hemoglobin (HbA1c) levels were used to classify the donors: HbA1c < 5.7% (low risk of DM), HbA1c 5.7 - 6.4% (pre-diabetes), and HbA1c ≥ 6.5% (diabetes). Another subsample (n = 576) that excluded donors with HbA1c levels < 5.0% or > 6.5% were classified according to the risk of developing DM in 5 years: HbA1c 5 - 5.5% (low risk, < 9%), HbA1c 5.6 - 6.0% (moderate risk, 9 - 25%), and HbA1c 6.1 - 6.5% (high risk, 26 - 50%).
Results: Three donors (0.5%) had HbA1c levels suggestive of DM, and 57 donors (9.0%) had levels associated with pre-DM. Regarding the risk of developing DM in 5 years, 111 donors (19.3%) were classified at moderate risk, and 10 donors (1.7%) were classified at high risk.
Conclusions: DM screening in blood banks using HbA1c can identify new cases of DM and individuals at an increased risk of DM. In summary, blood banks could participate in DM screening, benefitting the general public and public health care system in Brazil.