Fetal Hemoglobin in Diabetic Patients

OBJECTIVE To determine the occurrence of elevated fetal hemoglobin (HbF) among the diabetic population and determine the clinical situation of importance. RESEARCH DESIGN AND METHODS A cross-sectional study was conducted. HbA1c. and HbF were measured with high-performance liquid chromatogra-phy in 1,104 consecutive diabetic patients attending our clinic for HbA1c determination. The expression of clinical correlations between the high and low HbF group was performed for adults (≥15 years). A nondiabetic control group (n = 258) with the same age and sex distribution was included. RESULTS HbF was elevated (>1.0% of total hemoglobin) in 7.5% of the total diabetic group. In the adult diabetic group, HbF was elevated in 6.5% of the patients, and in the control group, HbF was elevated in 1.9% (P < 0.01). In the insulin-treated adult group, HbF was elevated in 10.2% of the patients, and in the non-insulin-treated group, HbF was elevated in 3.8%. The mean HbA1c was 8.90 ± 2.00% among the patients and 5.52 ± 0.53% in the control subjects (P < 0.001). Patients with elevated HbF were younger (P < 0.02) and more often on insulin therapy (P < 0.001) or type I diabetic patients (P < 0.001). Sex, glycemic control, or duration of diabetes were not significantly different in the patients with high or low HbF. Correlation was not detected between the amount of HbF and HbA1c or age in the group of patients with elevated HbF. Hemoglobinopathies, anemias, or malignancies were not diagnosed from the patients with high HbF. CONCLUSIONS Level of HbF is increased (>1.0%) among 7.5% of unselected diabetic patients. In adult (≥15 years) diabetic patients, it is increased among 6.5%, which is 3.4 times more often than in the control population. Acute hematological conditions or malignancies do not explain the difference. Elevated HbF seems to be associated with type I diabetes and insulin treatment.