title: Differences in body mass index according to fat mass- and obesity-associated (FTO) genotype in Mexican patients with bipolar disorder.
abstract: OBJECTIVE
  The prevalence of obesity has dramatically increased in many countries and it is particularly high in patients with bipolar disorder (BD). A region in the first intron of the fat mass- and obesity-associated (FTO) gene, encompassing markers rs9939973, rs8050136, and rs9939609, has been consistently associated with obesity and body mass index (BMI) in different populations. We sought to determine whether FTO is associated with BMI and/or obesity in patients with BD.
  
  
  METHODS
  The sample included 129 Mexican Mestizo patients with bipolar I or bipolar II disorder. After obtaining informed consent, participants were evaluated with the Structured Clinical Interview for DSM-IV Axis I Disorders and weight, height, and body measurements were recorded. DNA was extracted from a 5-mL blood sample and real-time polymerase chain reaction was performed. The results were analyzed with Haploview v4.2 and SPSS v21.
  
  
  RESULTS
  Differences in mean BMI were explained by rs8050136 and rs9939609 genotypes, especially by comparing non-carriers and carriers of two copies of the risk allele (Tukey's p ≤ 0.019), with a mean difference in BMI as high as 7.81 kg/m(2) . Differences in BMI were also explained by the interaction of the genotype (rs8050136 and/or rs9939609), the use of second-generation antipsychotics, and the use of mood stabilizers (p ≤ 0.41). Obesity was also associated with these two markers when patients with and without obesity were compared.
  
  
  CONCLUSIONS
  In patients with BD, differences in BMI may be affected by the presence of FTO risk alleles, especially in homozygous individuals for these variants. Besides evaluating the possible metabolic effects of certain antipsychotics or mood stabilizers, it is important to evaluate the role of other factors such as FTO risk alleles.
authors.affiliation: Departamento de Genética, Subdirección de Investigaciones Clínicas, Instituto Nacional de Pisquiatría Ramón de la Fuente Muñiz (INPRF), Mexico D.F, Mexico.
authors.forename: Adriana
authors.initials: A
authors.lastname: Díaz-Anzaldúa
authors.affiliation: Departamento de Genética, Subdirección de Investigaciones Clínicas, Instituto Nacional de Pisquiatría Ramón de la Fuente Muñiz (INPRF), Mexico D.F, Mexico.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Ocampo-Mendoza
authors.affiliation: Departamento de Genética, Subdirección de Investigaciones Clínicas, Instituto Nacional de Pisquiatría Ramón de la Fuente Muñiz (INPRF), Mexico D.F, Mexico.
authors.forename: José Octavio
authors.initials: JO
authors.lastname: Hernández-Lagunas
authors.affiliation: Departamento de Genética, Subdirección de Investigaciones Clínicas, Instituto Nacional de Pisquiatría Ramón de la Fuente Muñiz (INPRF), Mexico D.F, Mexico.
authors.forename: Federico Alejandro
authors.initials: FA
authors.lastname: Díaz-Madrid
authors.affiliation: Departamento de Psiquiatría y Salud Mental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico D.F, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Romo-Nava
authors.affiliation: Dirección de Investigaciones Epidemiológicas y Psicosociales, INPRF, Mexico D.F, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Juárez-García
authors.affiliation: Dirección de Servicios Clínicos, INPRF, Mexico D.F, Mexico.
authors.forename: Hiram
authors.initials: H
authors.lastname: Ortega-Ortiz
authors.affiliation: Dirección de Servicios Clínicos, INPRF, Mexico D.F, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Díaz-Anzaldúa
authors.affiliation: Dirección de Servicios Clínicos, INPRF, Mexico D.F, Mexico.
authors.forename: Doris
authors.initials: D
authors.lastname: Gutiérrez-Mora
authors.affiliation: Dirección de Servicios Clínicos, INPRF, Mexico D.F, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Becerra-Palars
authors.affiliation: Subdirección de Investigaciones Clínicas, INPRF, Mexico D.F, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Berlanga-Cisneros
mesh_terms: D000483:Alleles; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D015992:Body Mass Index; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics / Q000523:psychology; D011506:Proteins / Q000235:genetics*
chemical_list: D014150:Antipsychotic Agents; D011506:Proteins; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human
keywords: FTO gene; antipsychotic agents; bipolar disorder; body mass index; gene for human fat mass- and obesity-associated protein; lithium carbonate; obesity; rs8050136; rs9939609; valproic acid