title: Metformin in prevention and treatment of antipsychotic induced weight gain: a systematic review and meta-analysis.
abstract: BACKGROUND
  Most antipsychotics are associated with weight gain and other metabolic complications. Several randomized trials have shown metformin to be effective, but this still hasn't been included in clinical guidelines on managing antipsychotic induced weight gain.
  
  
  METHODS
  All double blind placebo controlled trials assessing the efficacy of metformin in the treatment of antipsychotic induced weight gain were included. Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched for the period January 2000-December 2015. Meta-analysis was carried out using the random effects model.
  
  
  RESULTS
  Meta analysis of 12 published studies with a total of 743 patients found that in patients treated with antipsychotics, metformin treatment resulted in significantly better anthropometric and metabolic parameters than placebo. The mean change in weight was -3.27 kg (95 % CI -4.66 to -1.89) (Z = 4.64, p < 0.001). Metformin compared to placebo resulted in significant reduction in BMI [-1.13 kg/m2(95 % CI -1.61 to -0.66)] and insulin resistance index [-1.49 (95 % CI -2.40 to -0.59)] but not fasting blood sugar [-2.48 mg/dl (95 % CI -5.54 to 0.57].
  
  
  CONCLUSIONS
  This meta-analysis confirms that metformin is effective in treating antipsychotic induced weight gain in patients with schizophrenia or schizoaffective disorder.
authors.affiliation: Faculty of Medicine, University of Colombo, Colombo, Sri Lanka. varunidesilva2@yahoo.co.uk.
authors.forename: Varuni Asanka
authors.initials: VA
authors.lastname: de Silva
authors.affiliation: University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
authors.forename: Chathurie
authors.initials: C
authors.lastname: Suraweera
authors.affiliation: University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
authors.forename: Suhashini S
authors.initials: SS
authors.lastname: Ratnatunga
authors.affiliation: Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
authors.forename: Madhubashinee
authors.initials: M
authors.lastname: Dayabandara
authors.affiliation: University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
authors.forename: Nimali
authors.initials: N
authors.lastname: Wanniarachchi
authors.affiliation: Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
authors.forename: Raveen
authors.initials: R
authors.lastname: Hanwella
mesh_terms: D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004311:Double-Blind Method; D006801:Humans; D008687:Metformin / Q000627:therapeutic use*; D011618:Psychotic Disorders / Q000188:drug therapy*; D012559:Schizophrenia / Q000188:drug therapy*; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D014150:Antipsychotic Agents; D008687:Metformin