title: The influence of the brain-derived neurotropic factor Val66Met genotype and HMG-CoA reductase inhibitors on insulin resistance in the schizophrenia and bipolar populations.
abstract: BACKGROUND
  The brain-derived neurotrophic factor (BDNF) Val66Met variant and HMG-COA reductase inhibitors (statins) have been implicated in insulin resistance with a possible increased risk of diabetes. We sought to determine the effect of the BDNF Met variant and statin medication use on insulin resistance in schizophrenia and bipolar disorder using the homeostasis model assessment of insulin resistance (HOMA-IR).
  
  
  METHODS
  A cross-sectional design was used and patients with diabetes or on any medications affecting glucose regulation were -excluded. Associations between insulin resistance and genotype were then analyzed by ANOVA and regression analysis. Subjects were grouped by BDNF genotype as well as presence of statin.
  
  
  RESULTS
  Two hundred fifty-two subjects with a mean age of 44 years were included. The group was 53% male and 41% had a diagnosis of bipolar disorder; 78% and 19% were receiving atypical antipsychotics (AAPs) and statin medications, respectively. Analysis showed schizophrenia subjects with the BDNF met allele as well as schizophrenia subjects with both the BDNF met allele and were receiving a statin had significantly higher HOMA-IR values compared to the other groups (p= 0.046 and p= 0.016, respectively).
  
  
  CONCLUSIONS
  Our results suggest that in the metabolically high-risk population of schizophrenia the BDNF met allele alone and in combination with statin medications is associated with higher insulin resistance values. This was not seen in the bipolar population. Further validation of these associations remains necessary.
authors.affiliation: Department of Clinical Social and Administrative Sciences, College of Pharmacy, University of Michigan, Ann Arbor, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Burghardt
authors.forename: R
authors.initials: R
authors.lastname: Pop-Busui
authors.forename: M J
authors.initials: MJ
authors.lastname: Bly
authors.forename: T B
authors.initials: TB
authors.lastname: Grove
authors.forename: S F
authors.initials: SF
authors.lastname: Taylor
authors.forename: V L
authors.initials: VL
authors.lastname: Ellingrod
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution / Q000235:genetics; D001714:Bipolar Disorder / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003710:Demography; D005260:Female; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012559:Schizophrenia / Q000235:genetics*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors