title: Effects of testosterone treatment on glucose metabolism and symptoms in men with type 2 diabetes and the metabolic syndrome: a systematic review and meta-analysis of randomized controlled clinical trials.
abstract: BACKGROUND
  The effects of testosterone treatment on glucose metabolism and other outcomes in men with type 2 diabetes (T2D) and/or the metabolic syndrome are controversial.
  
  
  OBJECTIVE
  To perform a systematic review and meta-analysis of placebo-controlled double-blind randomized controlled clinical trials (RCT) of testosterone treatment in men with T2D and/or the metabolic syndrome.
  
  
  METHODS
  A systematic search of RCTs was conducted using Medline, Embase and the Cochrane Register of controlled trials from inception to July 2014 followed by a manual review of the literature.
  
  
  METHODS
  Eligible studies were published placebo-controlled double-blind RCTs published in English.
  
  
  METHODS
  Two reviewers independently selected studies, determined study quality and extracted outcome and descriptive data.
  
  
  RESULTS
  Of the 112 identified studies, seven RCTs including 833 men were eligible for the meta-analysis. In studies using a simple linear equation to calculate the homeostatic model assessment of insulin resistance (HOMA1), testosterone treatment modestly improved insulin resistance, compared to placebo, pooled mean difference (MD) -1·58 [-2·25, -0·91], P < 0·001. The treatment effect was nonsignificant for RCTs using a more stringent computer-based equation (HOMA2), MD -0·19 [-0·86, 0·49], P = 0·58). Testosterone treatment did not improve glycaemic (HbA1c) control, MD -0·15 [-0·39, 0·10], P = 0·25, or constitutional symptoms, Aging Male Symptom score, MD -2·49 [-5·81, 0·83], P = 0·14).
  
  
  CONCLUSIONS
  This meta-analysis does not support the routine use of testosterone treatment in men with T2D and/or the metabolic syndrome without classical hypogonadism. Additional studies are needed to determine whether hormonal interventions are warranted in selected men with T2D and/or the metabolic syndrome.
authors.affiliation: Department of Medicine Austin Health, University of Melbourne, Heidelberg, Vic., Australia.|Endocrine Unit, Austin Health, Heidelberg, Vic., Australia.
authors.forename: Mathis
authors.initials: M
authors.lastname: Grossmann
authors.affiliation: Department of Medicine Austin Health, University of Melbourne, Heidelberg, Vic., Australia.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hoermann
authors.affiliation: Discipline of Medicine, Royal Adelaide Hospital, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Wittert
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia.|Department of Endocrinology and Diabetes, Fremantle and Fiona Stanley Hospitals, Perth, WA, Australia.
authors.forename: Bu B
authors.initials: BB
authors.lastname: Yeap
mesh_terms: D000728:Androgens / Q000627:therapeutic use; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004311:Double-Blind Method; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D013739:Testosterone / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000728:Androgens; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D013739:Testosterone