title: Does Insulin Like Growth Factor-1 (IGF-1) Deficiency Have a "Protective" Role in the Development of Diabetic Retinopathy in Thalassamia Major Patients?
abstract: BACKGROUND
  Both insulin and IGF-1 have been implicated in the control of retinal endothelial cell growth, neovascularization and diabetic retinopathy. Recent findings have established an essential role for IGF-1 in angiogenesis and demonstrated a new target for control of retinopathy that explains why diabetic retinopathy initially increases with the onset of insulin treatment.
  
  
  OBJECTIVE
  This cross-sectional study was designed to give insights into relationship between Insulin-Growth-Factor 1 (IGF-1) levels and diabetic retinopathy (DR) in a sample of thalassemia major (TM) patients with insulin dependent diabetes mellitus (IDDM). This relation was not previously evaluated, despite the fact that both diseases co-exist in the same patient. The study also describes the clinical and biochemical profile of the associated complications in TM patients with and without IDDM.
  
  
  METHODS
  A population-based cross-sectional study.
  
  
  METHODS
  The study includes 19 consecutive TM patients with IDDM and 31 age- and sex-matched TM patients without IDDM who visited our out-patient clinics for an endocrine assessment.
  
  
  METHODS
  An extensive medical history, with data on associated complications and current medications, was obtained. Blood samples were drawn in the morning after an overnight fast to measure the serum concentrations of IGF-1, glucose, fructosamine, free thyroxine (FT4), thyrotropin (TSH) and biochemical analysis. Serologic screening assays for hepatitis C virus seropositivity (HCVab and HCV-RNA) were also evaluated; applying routine laboratory methods. Plasma total IGF-1 was measured by a chemiluminescent immunometric assay (CLIA) method. Ophthalmology evaluation was done by the same researcher using stereoscopic fundus biomicroscopy through dilated pupils. DR was graded using the scale developed by the Global Diabetic Retinopathy Group. Iron stores were assessed by direct and indirect methods.
  
  
  RESULTS
  Eighteen TM patients with IDDM (94.7 %) and ten non-diabetic patients (32.2 %) had IGF-1 levels below the 2.5(th) percentile of the normal values for the Italian population. The mean serum IGF-1 concentrations were significantly lower in the diabetic versus the non-diabetic TM groups (p < 0.001). DR was present in 4 (21 %) of 19 TM patients with IDDM and was associated with the main classical risk factors, namely inefficient glycemic control and duration of the disease but not hypertension. Using the scale developed by the Global Diabetic Retinopathy Group, the DR in our patients was classified as non proliferative diabetic retinopathy (NPDR). Only a few numbers of microaneurysms [1-3] were detected. Our data also confirm the strong association of IDDM in TM patients with other endocrine and non-endocrine complications.
authors.affiliation: Pediatric and Adolescent Outpatient Clinic, Quisisana Hospital, Ferrara, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Sanctis
authors.affiliation: Department of Ophthalmology, University of Ferrara, Ferrara, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Incorvaia
authors.affiliation: Department of Pediatrics, Division of Endocrinology, Alexandria University Children's Hospital, Alexandria.
authors.forename: Ashraf T
authors.initials: AT
authors.lastname: Soliman
authors.affiliation: Medical Physicists, Honorary Member of Italian Association of Medical Physics ( AIFM ), Ferrara, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Candini
authors.affiliation: Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Pepe
authors.affiliation: First Department of Paediatrics, University of Athens, Athens, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Kattamis
authors.affiliation: Ministry of Health, Alexandria, Egypt.
authors.forename: Nada A
authors.initials: NA
authors.lastname: Soliman
authors.affiliation: Department of Pediatrics, Ain Shams University, Cairo, Egypt.
authors.forename: Heba
authors.initials: H
authors.lastname: Elsedfy
authors.affiliation: Department of Pediatrics, Ain Shams University, Cairo, Egypt.
authors.forename: Mohamed El
authors.initials: ME
authors.lastname: Kholy