Glucose Metabolism in Sickle Cell Disease

Background. Whether glucose metabolism differs in sickle cell anemia (SCA) patients versus controls is not clear. Transfusional iron overload and Inflammation might enhance glucose intolerance, while lower BMI and increased hypoxic responses might be protective.

Methods: We prospectively determined indicators of glucose metabolism in 46 African-American hemoglobin SS or S/β⁰-thalassemia subjects >35 years of age who did not have the diagnosis of DM, and examined the relationship of these parameters to BMI and serum ferritin concentration. We compared the SCA subjects to 46 African-American controls from the National Health and Nutrition Examination Study (NHANES) who did not have the diagnosis of DM and were matched by age, sex, BMI and serum ferritin to the SCA subjects.

Results: The BMI was >25 kg/m² in 23 SCA subjects (48%) and the serum ferritin was >300 ng/ml in 30 (65%) consistent with increased body iron stores. The fasting blood glucose was >125 mg/dL in 3 of 46 SCA subjects (6.5%) suggesting unsuspected DM. The fasting glucose concentration independently correlated with serum ferritin concentration (r=0.336, P=0.024) and the fasting insulin level correlated independently with both BMI (r=0.583, P=0.00002) and serum ferritin (r=0.300, P=0.016). Measures of glucose metabolism did not differ significantly between the SCA subjects and NHANES controls, even though the SCA subjects had lower blood pressures, WBC counts and blood lipid levels.

Conclusions: Measures of glucose metabolism in older SCA patients are similar to controls matched for BMI and iron status despite marked differences in blood pressure, hemoglobin, WBCs and blood lipid levels.