title: Association of olanzapine-induced weight gain with an increase in body fat.
abstract: OBJECTIVE
  The goal of this study was to explore the pathophysiology of weight gain during treatment with olanzapine for schizophrenia.
  
  
  METHODS
  The authors used a prospective, controlled, open study comparing body weight, body mass index, and related biological measures in mentally and physically healthy volunteers and olanzapine-treated patients with schizophrenia. Weight, eating behavior, leptin serum levels, body mass index, and body composition were assessed over an 8-week observation period.
  
  
  RESULTS
  A significant increase in body weight, leptin serum levels, and percentage of body fat was seen in patients treated with olanzapine, but the drug-free comparison group did not show any significant changes. The weight gain during antipsychotic treatment with olanzapine was mainly attributable to an increase in body fat; patients' lean body mass did not change.
  
  
  CONCLUSIONS
  In addition to the original finding that an increase in body fat is mainly responsible for olanzapine-induced weight gain, these findings confirm results obtained in other studies showing increases in body weight and serum leptin levels during treatment with second-generation antipsychotics.
authors.affiliation: Department of Biological Psychiatry, Innsbruck University Clinics, Innsbruck, Austria. birgit.mader@uibk.ac.at
authors.forename: U
authors.initials: U
authors.lastname: Eder
authors.forename: B
authors.initials: B
authors.lastname: Mangweth
authors.forename: C
authors.initials: C
authors.lastname: Ebenbichler
authors.forename: E
authors.initials: E
authors.lastname: Weiss
authors.forename: A
authors.initials: A
authors.lastname: Hofer
authors.forename: M
authors.initials: M
authors.lastname: Hummer
authors.forename: G
authors.initials: G
authors.lastname: Kemmler
authors.forename: M
authors.initials: M
authors.lastname: Lechleitner
authors.forename: W W
authors.initials: WW
authors.lastname: Fleischhacker
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects*; D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D001569:Benzodiazepines; D001823:Body Composition / Q000187:drug effects*; D015992:Body Mass Index; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood; D008297:Male; D000077152:Olanzapine; D010890:Pirenzepine / Q000009:adverse effects / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use; D011446:Prospective Studies; D012559:Schizophrenia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D014150:Antipsychotic Agents; D020738:Leptin; D001569:Benzodiazepines; D010890:Pirenzepine; D000077152:Olanzapine