Issue 136 Item 13 Iron Depletion Improves Vascular Dysfunction In Type 2 Diabete

Iron depletion improves vascular dysfunction in type 2 diabetics who have high ferritin concentrations. Researchers from University Hospital of Girona, Spain, enrolled 28 men with type 2 diabetes and serum ferritin levels over 200 ng/ml. This represented around 18 percent of the men attending the outpatient clinic.

Patients were divided into two groups. One group was observed while the other group underwent iron depletion through removal of 500 ml blood on three occasions, each session two weeks apart. The researchers assessed vascular reactivity using ultrasound at baseline as well as after 4 and 12 months.

Endothelium-dependent vasodilatation did not change in either group. However, glyceryl trinitrate induced vasodilatation improved in those patients that underwent iron depletion. The improvement was in parallel to decreases in transferrin saturation index and HbA(1c) levels.

Further analysis suggested that alterations in HbA(1c) levels offered the best predictor of changes in endothelium-independent vasodilatation, although this also correlated with changes in serum ferritin. However, after 12 months the transferrin saturation index and vasodilatation induced by glyceryl trinitrate returned to baseline in both groups.

The authors concluded that iron depletion improves vascular dysfunction in patients with type 2 diabetes and high ferritin concentrations. They also called for further studies to assess the mechanisms underlying these changes. Diabetes Care 2002;25:2249-55