Issue 137 Item 15 Blood Letting Improves Vascular Reactivity In High-Ferritin Ty

Iron depletion by blood letting improves endothelium-independent vasodilation in patients with type 2 diabetes who have high ferritin levels. "In a recent study, iron chelation with deferoxamine led to improvement of endothelial dysfunction in patients with coronary artery disease," Dr. Jose Manuel Fernandez-Real and colleagues from the University Hospital of Girona ‘Dr. Josep Trueta,’ Spain, note. The team examined whether decreasing circulating iron stores might benefit type 2 diabetic patients with increased serum ferritin concentration.

Twenty-eight patients with serum ferritin levels above 200 ng/mL were randomly assigned to iron depletion (group 1a) or to observation (group 1b). Patients were matched for age, body mass index, pharmacological treatment, and chronic diabetes complications. The iron-depletion group underwent three extractions of 500mL of blood at 2-week intervals.

The researchers evaluated vascular reactivity at baseline, 4 and 12 months. There were no significant changes in endothelium-dependent vasodilation in either group. On the other hand, glyceryl trinitrate- induced vasodilation improved significantly after iron depletion (p = 0.006).

"These changes occurred in parallel to decreases in transferrin saturation index and HbA1c levels (-0.6%, p < 0.05) only in group 1a patients," the investigators explain. "The best predictor of the modifications in endothelium-independent vasodilation was the change in HbA1c levels."

In both groups, transferrin saturation index and nitrate-induced vasodilation returned to baseline values at 12 months.

Dr. Fernandez-Real and colleagues note that a number of strategies to improve endothelial function and thereby delay atherogenesis are being examined currently, but "whether blood letting should be considered adjuvant therapy in high-ferritin type 2 diabetes requires further study.

"Diabetes Care 2002;25:2249-2255.