title: Lower dose prednisone prevents radioiodine-associated exacerbation of initially mild or absent graves' orbitopathy: a retrospective cohort study.
abstract: BACKGROUND
  Radioiodine (RAI) therapy may cause progression of mild or absent Graves' orbitopathy (GO), preventable by oral prednisone. Optimal doses of prednisone are undefined.
  
  
  OBJECTIVE
  The aim of this study was to compare the effectiveness of reported doses [starting dose, >0.3 mg/kg body weight (bw)], and lower (<0.3 mg/kg bw)] doses of prednisone.
  
  
  METHODS
  We conducted a retrospective matched cohort study at a University Center.
  
  
  METHODS
  Of 111 RAI-treated Graves' patients with mild or no GO, 35 received no steroid prophylaxis (absence of GO and/or risk factors for RAI-associated GO progression); 28 received low-dose prednisone (starting dose, 0.16-0.27 mg/kg bw; mean +/- sd, 0.22 +/- 0.03 mg/kg bw; group 1); and 48 received higher doses (group 2). Among the latter, 28 (starting dose, 0.32-0.56 mg/kg bw; mean +/- sd, 0.36 +/- 0.05 mg/kg bw) were matched with group 1 according to several relevant variables. Prednisone was started 1 d after RAI and withdrawn after 6 wk.
  
  
  METHODS
  We assessed ocular changes (1, 3, and 6 months after RAI) and side effects of prednisone.
  
  
  RESULTS
  Two of 35 patients not receiving steroid prophylaxis (6%) developed mild-to-moderate GO (clinical activity score, 2/7 and 3/7) after RAI. No patients in group 1 or group 2 had GO progression. Side effects were very mild and inconstant, although more frequent in group 2. Both groups showed an increase in bw, an increase that was significantly higher in group 2.
  
  
  CONCLUSIONS
  Lower doses of oral prednisone (about 0.2 mg/kg bw) are as effective as previously reported doses (0.3-0.5 mg/kg bw). A shorter treatment period (6 wk) is probably sufficient. The increase in bw is less using lower doses of prednisone.
authors.affiliation: Department of Clinical Medicine, University of Insubria, Division of Endocrinology, Ospedale di Circolo, Viale Borri, 57, 21100 Varese, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Lai
authors.forename: Lorenza
authors.initials: L
authors.lastname: Sassi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Compri
authors.forename: Franca
authors.initials: F
authors.lastname: Marino
authors.forename: Paolo
authors.initials: P
authors.lastname: Sivelli
authors.forename: Eliana
authors.initials: E
authors.lastname: Piantanida
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Tanda
authors.forename: Luigi
authors.initials: L
authors.lastname: Bartalena
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006111:Graves Disease / Q000473:pathology / Q000532:radiotherapy*; D049970:Graves Ophthalmopathy / Q000188:drug therapy* / Q000473:pathology / Q000517:prevention & control*; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011241:Prednisone / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000139:chemically induced; D018709:Statistics, Nonparametric; D013961:Thyroid Gland / Q000187:drug effects / Q000473:pathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D015430:Weight Gain / Q000187:drug effects
chemical_list: D005938:Glucocorticoids; D007457:Iodine Radioisotopes; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine; D011241:Prednisone