title: The correct prednisone starting dose in polymyalgia rheumatica is related to body weight but not to disease severity.
abstract: BACKGROUND
  the mainstay of treatment of polymyalgia rheumatica (PMR) is oral glucocorticoids, but randomized controlled trials of treatment are lacking. As a result, there is no evidence from controlled studies on the efficacy of different initial doses or glucocorticoid tapering. The aim of this study is to test if 12.5 mg prednisone/day is an adequate starting dose in PMR and to evaluate clinical predictors of drug response.
  
  
  METHODS
  60 consecutive PMR patients were treated with a starting dose of 12,5 mg/day prednisone. Clinical, laboratory, and, in a subset of 25 patients, ultrasonographic features were recorded as possible predictors of response to prednisone. Remission was defined as disappearance of at least 75% of the signs and symptoms of PMR and normalization of ESR and CRP within the first month, a scenario allowing steroid tapering.
  
  
  RESULTS
  47/60 (78.3%) patients responded to 12.5 mg of prednisone after a mean interval of 6.6±5.2 days. In univariate analysis, body weight and gender discriminated the two groups. In multivariate analysis, the only factor predicting a good response was low weight (p=0.004); the higher response rate observed in women was explained by their lower weight. The mean prednisone dose per kg in the responders was 0.19±0.03 mg in comparison with 0.16±0.03 mg for non responders (p=0.007).
  
  
  CONCLUSIONS
  12.5 mg prednisone is a sufficient starting dose in ¾ of PMR patients. The main factor driving response to prednisone in PMR was weight, a finding that could help in the clinical care of PMR patients and in designing prospective studies of treatment.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT01169597.
authors.affiliation: Clinica Reumatologica, Dipartimento di Medicina Interna, Università di Genova, Viale Benedetto XV, 6, 16132 Genova, Italy. cimmino@unige.it
authors.forename: Marco A
authors.initials: MA
authors.lastname: Cimmino
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Parodi
authors.forename: Carlomaurizio
authors.initials: C
authors.lastname: Montecucco
authors.forename: Roberto
authors.initials: R
authors.lastname: Caporali
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D001835:Body Weight; D002097:C-Reactive Protein / Q000378:metabolism; D054796:Drug Dosage Calculations; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011111:Polymyalgia Rheumatica / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D011241:Prednisone / Q000008:administration & dosage*; D012044:Regression Analysis; D012074:Remission Induction; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D005938:Glucocorticoids; D002097:C-Reactive Protein; D011241:Prednisone