Sickle cell trait may confound blood sugar readings among African-Americans

A new study in JAMA provides evidence that hemoglobin A1c (HbA1c), a common blood biomarker used to measure blood sugar over time, may not perform as accurately among African-Americans with sickle cell trait and could be leading to a systemic underestimation of blood sugar control among that population. Sickle cell trait (SCT) is a genetic hemoglobin variant found in 8 to 10 percent of African-Americans. It occurs in people with one copy of the mutation that, if they had two copies, would result in sickle cell disease. The analysis of data from more than 4,600 people participating in two major studies found that HbA1c readings were significantly lower in individuals with SCT than in those without SCT, even after accounting for several possible confounding factors.