title: History of myocardial iron loading is a strong risk factor for diabetes mellitus and hypogonadism in adults with β thalassemia major.
abstract: Endocrinopathies are common complications of transfusional hemosiderosis among patients with β thalassemia major (TM). Previous studies had shown associations between some endocrinopathies and iron overload of the myocardium, liver and/or endocrine organs as assessed by MRI techniques. This retrospective analysis of 92 patients with TM (median age 36 yr) from a tertiary adult thalassemia unit in UK aimed to determine independent risk factors associated with endocrinopathies among these patients. Unlike previous studies, longitudinal data on routine measurements of iron load [worst myocardial and liver T2* values since 1999, worst LIC by MRI-R2 since 2008 and average 10-yr serum ferritin (SF)] up to April 2010 together with demographic features and age of initiating chelation were analyzed for associations with endocrinopathies. The most common endocrinopathies in this cohort were hypogonadism (67%) and diabetes mellitus (DM) (41%), and these were independently associated with myocardial T2* <20 ms (P < 0.001 and P = 0.008, respectively) and increased age (P = 0.002 and P = 0.016, respectively). DM and hypogonadism were independently associated with average SF >1250 μg/L (P = 0.003) and >2000 μg/L (P = 0.047), respectively. DM was also associated with initial detection of abnormal myocardial T2* at an older age (30 yr vs. 24 yr, P = 0.039). An abnormal myocardial T2* may therefore portend the development of DM and hypogonadism in patients with TM.
authors.affiliation: Department of Haematology, The Whittington Hospital, London, UK; Department of Haematology, Singapore General Hospital, Singapore.
authors.forename: Ai Leen
authors.initials: AL
authors.lastname: Ang
authors.forename: Ploutarchos
authors.initials: P
authors.lastname: Tzoulis
authors.forename: Emma
authors.initials: E
authors.lastname: Prescott
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Davis
authors.forename: Maria
authors.initials: M
authors.lastname: Barnard
authors.forename: Farrukh T
authors.initials: FT
authors.lastname: Shah
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002614:Chelating Agents / Q000737:chemistry; D048909:Diabetes Complications / Q000175:diagnosis; D003920:Diabetes Mellitus / Q000175:diagnosis*; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007006:Hypogonadism / Q000150:complications*; D007501:Iron / Q000737:chemistry*; D019190:Iron Overload / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications*
chemical_list: D002614:Chelating Agents; D005293:Ferritins; D007501:Iron
keywords: T2*; diabetes mellitus; hemosiderosis; hypogonadism; thalassemia major