title: Cannabinoid type 1 receptor gene polymorphisms are not associated with olanzapine-induced weight gain.
abstract: BACKGROUND
  Olanzapine is an atypical antipsychotic known to cause considerable weight gain. The cannabinoid type 1 receptor has been reported to be involved in energy balance control, appetite stimulation, and increases in body weight.
  
  
  METHODS
  In the present study, we investigated three polymorphisms (rs1049353, rs806368, and rs4707436) in the cannabinoid type 1 receptor gene (CNR1) and weight gain in Korean patients with schizophrenia receiving olanzapine treatment. Weight and height were measured prior to starting olanzapine and again after long-term treatment in 78 patients with schizophrenia. CNR1 polymorphisms were genotyped using PCR-RFLP methods.
  
  
  RESULTS
  The three CNR1 polymorphisms were not associated with body weight changes from baseline to the endpoint after olanzapine treatment (p > 0.05). There were also no significant differences in genotype, allele, or haplotype frequencies between the high weight gain (at least 7%) and low weight gain (less than 7%) groups.
  
  
  CONCLUSIONS
  Within the limitations imposed by the smallness of the clinical sample, our findings suggest that CNR1 polymorphisms are not associated with olanzapine-induced weight gain.
authors.affiliation: Department of Psychiatry, Inje University College of Medicine, Goyang, South Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Park
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Seung-Gul
authors.initials: SG
authors.lastname: Kang
authors.forename: Seung-Hoi
authors.initials: SH
authors.lastname: Koo
authors.forename: Leen
authors.initials: L
authors.lastname: Kim
authors.forename: Dongho
authors.initials: D
authors.lastname: Geum
authors.forename: Heon-Jeong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000483:Alleles; D054458:Amplified Fragment Length Polymorphism Analysis; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001569:Benzodiazepines / Q000009:adverse effects*; D015992:Body Mass Index; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D020641:Polymorphism, Single Nucleotide; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics* / Q000378:metabolism; D056910:Republic of Korea; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000077152:Olanzapine; D043884:Receptor, Cannabinoid, CB1; D017367:Selective Serotonin Reuptake Inhibitors; C571130:CNR1 protein, human