title: Association of iron overload and oxidative stress with insulin resistance in transfusion-dependent beta-thalassemia major and beta-thalassemia/HbE patients.
abstract: BACKGROUND
  Beta-thalassemia causes a severe hemolytic anemia in patients necessitating frequent transfusions leading to iron overload and endocrine complications, especially diabetes mellitus. We tried to determine the change or effect on carbohydrate physiology and oxidation markers and the association of these markers in chronic transfusion-dependent beta-thalassemia major and beta-thalassemia/HbE (beta-TM) patients.
  
  
  METHODS
  Prospective study on 60 beta-TM patients, receiving only regular blood transfusions, and 20 healthy controls were enrolled for oral glucose tolerance test, fasting insulin, Homeostasis Model Assessment of insulin resistance (HOMA-IR), liver function test, iron overload, oxidative stress, and lipid profile at baseline. The same tests were repeated after 6 months.
  
  
  RESULTS
  One beta-TM patient had impaired glucose tolerance. Fasting glucose, insulin, ferritin, MDA, TG concentrations, HOMA-IR, and liver profiles were significantly higher while Hb, Hct, TC, HDL-C, LDL-C concentrations and TAC were significantly lower in beta-TM patients than controls (p < 0.001). Fasting glucose, HOMA-IR and beta-cell function were significantly correlated with MDA and glucose, AST, ALT, MDA were significantly correlated with ferritin (p < 0.05). Multiple forward stepwise linear regression analyses of the significant variables showed that in these beta-TM patients, independent predictors of HOMA-IR were fasting glucose (beta = 0.634, r2 = 0.374, p < 0.001), HDL-C (beta = 0.249, r2 = 0.418, p = 0.043) and MDA (beta = 0.225, r2 = 0.466, p = 0.029).
  
  
  CONCLUSIONS
  Progression of iron overload, oxidative stress and hyperinsulinemia were substantially and persistently higher in beta-TM patients. We observed a positive association between oxidative stress, iron overload and insulin resistance in these beta-TM patients.
authors.affiliation: Chronic Diseases Research Unit, Department of Medical Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok, Thailand. surapon14@yahoo.com
authors.forename: Surapon
authors.initials: S
authors.lastname: Tangvarasittichai
authors.forename: Ampai
authors.initials: A
authors.lastname: Pimanprom
authors.forename: Anuchit
authors.initials: A
authors.lastname: Choowet
authors.forename: Orathai
authors.initials: O
authors.lastname: Tangvarasittichai
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001803:Blood Transfusion; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D019190:Iron Overload / Q000150:complications*; D008055:Lipids / Q000097:blood; D008297:Male; D018384:Oxidative Stress; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications* / Q000628:therapy
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids