Iron Depletion Improves Glycemic Control in Poorly Controlled Type 2 Diabetic Patients with Iron Overload and Negative Main HFE-Gene Mutations

Abstract

Iron overload increases the risk of diabetes via mechanisms of abnormal glucose metabolism: insulin deficiency, insulin resistance, and/or hepatic dysfunction. Iron reduction upregulates glucose uptake and improves hepatocytes insulin receptor activity. This study was conducted to examine the effects of iron depletion—via controlled phlebotomy—on the hypoglycemic treatment in poorly controlled type 2 diabetes mellitus (T2DM) patients with non-genetic iron overload. Forty three patients with poorly controlled T2DM and iron overload were divided into 2 groups: iron depletion group and control group. Regular phlebotomy was performed for iron depletion group on monthly basis until serum ferritin reached 20 μg/L or less. Both groups were examined and compared for blood pressure, serum ferritin, lipid profile, HFE-gene, HbA1c, HOMA-IR and number of medicines used for diabetic control. The results had revealed that group differences of HbA1c (−2.64, 95% CI −3.23 to 2.04, p < 0.001) and HOMA-IR (−0.68, 95% CI −0.98 to −0.37, p < 0.001) showed significant decreases in iron depletion group at end of study. Significant decrease in the numbers of hypoglycemic medicines in iron depletion group was shown at end of study (p < 0.001); 66.7% of iron depletion group patients were receiving 1 or 2 medicines at end of study versus none of the control group. Diastolic blood pressure (DBP), triglycerides and LDL-C decreased significantly while HDL-C levels showed significant rise after iron depletion. It can be concluded from the present study that iron depletion therapy is beneficial for improving the efficiency of glycemic control, DBP, and dyslipidemia in poorly controlled type 2 diabetics with iron over load.