Sickle Cell Trait Is Associated with Lower Glycosylated Hemoglobin Levels

In people with sickle cell trait (SCT; found in ≈10% of blacks), hemoglobin A (HbA) accounts for 60% to 70% of hemoglobin in erythrocytes and hemoglobin S (HbS) accounts for the remainder. Some research suggests that erythrocytes with HbS have shortened life spans, which could lead to lower glycosylated hemoglobin (HbA_1c) levels. In this retrospective cohort study, researchers identified 367 people with SCT and 4253 self-identified African-Americans without SCT in two community-based populations; concurrent measures of HbA_1c, fasting blood glucose, and 2-hour postprandial glucose levels were available from 10 to 25 years of follow-up.

For all fasting glucose level categories (in 10-mg/dL groups, from <80 mg/dL to ≥150 mg/dL), mean HbA_1c leve…