HbA1c Overestimates Glucose Levels in Black Patients with Type 1 Diabetes

By Kelly Young

Edited by David G. Fairchild, MD, MPH, and Jaye Elizabeth Hefner, MD

Glycated hemoglobin levels tend to overestimate mean glucose in black patients with type 1 diabetes, according to an Annals of Internal Medicine study.

Researchers enrolled some 200 patients aged 8 years and older with type 1 diabetes. Half were black, and half were white. Glucose concentrations were measured over 12 weeks using a continuous glucose monitoring device, while hemoglobin A1c levels were obtained at 4, 8, and 12 weeks.

The mean HbA1c level was higher in black people (9.1% vs. 8.3% for white people). Average HbA1c levels were 0.4 percentage points higher for black people than white people for any given mean glucose concentration.

The authors propose that these results are related to racial differences in hemoglobin glycation. Editorialists caution that the sample size was small and patients with type 2 diabetes were excluded.

Annals of Internal Medicine article (Free abstract)

Annals of Internal Medicine editorial (Subscription required)

Background: Physician’s First Watch coverage of HbA1c in black patients with sickle cell trait (Free)