Staimez LR, Rhee MK, Deng Y, et al. - According to black African or white European ancestry, researchers conducted this retrospective cohort study to explore the correlation of HbA_1c and glucose levels with incident diabetic retinopathy. The sample consisted of 202,500 US Veterans with diabetes (2000–2014), measures involved HbA_1c, outpatient random serum/plasma glucose, and incident retinopathy [conversion from negative to ≥ 2 positive evaluations (ICD-9 codes), without a subsequent negative]. At baseline, the study population had a mean age of 59.3 years, their mean BMI was 31.9 kg/m², HbA_1c level was 57 mmol/mol (7.4%) and glucose level was 8.8 mmol/l, and 77% were of white European (white candidates) and 21% of black African ancestry (black candidates ). Because retinopathy occurs in black people at higher rates of HbA_1c for a given level of average plasma glucose, the interpretation of HbA_1c measurements may need strategies.