American Red Cross, District of Columbia, United States
Background/Case Studies: In March 2025 the American Red Cross (ARC) provided complimentary HbA1c testing to every successful blood donor, generating a uniquely healthy, community‑based dataset. We used the results to compare the prevalence of pre‑diabetes and diabetes in donors with national benchmarks, to explore how age, sex and race shape glycemic status, and to pinpoint the donor segments most likely to benefit from focused outreach that could forestall micro‑ and macro‑vascular complications.
Study
Design/Methods: HbA1c values and donor demographics were extracted from the ARC database and analyzed in SAS 9.4 and R 4.3; interactive dashboards were built in Power BI. Stage 2 hypertension within each glycemic category was used as a surrogate for heightened cardio‑renal risk. A regression‑tree model ranked the relative importance of age, race, sex and geography on HbA1c.
Results/Findings: Among 392,914 donors (median age 48 y; 53 % male), 81.5 % were in the normoglycemic range (HbA1c < 5.7 %), 13.9 % had a value indicating pre-diabetes (HbA1c 5.7–6.4 %), and 4.6 % tested in the diabetic range (HbA1c ≥ 6.5 %). The estimated frequency of pre‑diabetes and diabetes were less common than reported national rates (38 % and 11 %, respectively). Male donors displayed higher mean HbA1c at every age band, accounting for 59 % of pre‑diabetes and 70 % of diabetes cases; the sex gap was most pronounced between 30–54 y . Black, Asian and Native‑American donors were disproportionately affected (p < 0.001). Geographic mapping showed the greatest donor density for prediabetes and diabetes range testing results—and therefore outreach opportunity—in the Midwest . Stage 2 hypertension co‑existed in 17.7 % of normoglycemic, 30.5 % of pre‑diabetic, and 34.4 % of potentially diabetic donors, underscoring their elevated cardiovascular risk. In the regression tree, age, race and sex were the dominant predictors of HbA1c.
Conclusions: Routine HbA1c screening during blood donation uncovers a sizeable pool of otherwise healthy adults with unrecognized dysglycemia, particularly middle‑aged men and donors of color. Targeted education and referral of these sub‑groups could accelerate treatment initiation, curb clinical inertia, and ultimately reduce downstream end‑organ damage. The ARC donor base represents a scalable, community‑embedded platform for public‑health interventions that complement traditional health care access points.
