Evaluation of Vascular Health of E-Beta Thalassemia Patients: Effect of Iron Overload.

Hb E-β thalassemia is the most common form of hemoglobinopathy in Southeast Asia and eastern India. Iron overload resulting from blood transfusion and increased intestinal iron absorption promotes the formation of reactive oxygen species (ROS), leading to oxidative stress, organ dysfunction, and tissue damage. Of these, cardiovascular complications are the leading cause of mortality. Impaired endothelial function is a biomarker of vascular health in patients with cardiovascular risks. Therefore, assessment of endothelial function is a useful prognostic tool. In the present study, 60 E- β thalassemia patients and 60 healthy, age, sex matched control subjects were taken. The mean hemoglobin and ferritin of thalassemic patients were 7.43gm/dl and 1032 mcg/dl respectively. The vascular health was compared by measuring flow-mediated vasodialation (FMD), arterial elastic parameters, and carotid intima-medial thickness (CIMT). There was lower FMD (7.49%) and higher CIMT (0.46mm) in thalassemic group than control (10.52 % and 0.36mm respectively) (p value< 0.05). Also arterial stiffness is elevated and arterial distensibility is lower in thalassemic patients than control. Among the thalassemic patients FMD or CIMT did not correlate with serum ferritin value. So, the E- β thalassemia patients had poor vascular health and are at a higher risk of developing atherosclerosis and cardio-vascular complication than normal population. The vascular dysfunction does not correlate with serum ferritin value, so regular monitoring with Doppler study is required for early diagnosis of subclinical atherosclerosis in this group of patients. However the effects of chelation therapy, Hydroxyurea, or other targeted therapies needs to be validated by further study.