Glycemic Monitoring in Diabetics with Sickle Cell Plus β-Thalassemia Hemoglobinopathy

Abstract

OBJECTIVE: To report a case of diabetes management in a patient with a hemoglobinopathy that caused her clinician to seek a different measure of glycemic control, fructosamine, rather than glycosylated hemoglobin (HbA_1c). CASE SUMMARY: A 53-year-old African American woman presented with a past medical history of type 2 diabetes, hypertension, seizure disorder, rheumatoid arthritis, and sickle cell disease plus β-thalassemia. She reported fasting blood glucose values ranging broadly from 50 to 320 mg/dL, yet her HbA_1c result remained steady in a low range of >6%. A measure of fructosamine returned elevated at 340 μmol/L (reference range 200–300%). DISCUSSION: We believe that this patient's hemoglobinopathy resulted in falsely low levels of HbA_1c, and we substantiate this interpretation with the patient's self-monitored blood glucose values from home that appeared higher and inconsistent with the HbA_1c results. Although few reports on using the measure of fructosamine appear in the literature, this patient's high fructosamine result supports fructosamine as the more appropriate measure of glycemic control. CONCLUSIONS: Serum fructosamine levels may be considered as an appropriate laboratory measurement when monitoring long-term glycemic control in patients with type 2 diabetes mellitus and sickle cell disease.