title: Interaction between peroxisome proliferator- activated receptor gamma polymorphism and overweight on diabetic retinopathy in a Chinese case-control study.
abstract: BACKGROUND
  Peroxisome proliferator-activated receptors γ (PPAR γ) and overweight were both associated with diabetic retinopathy (DR), so the aim of this study was to investigate the association of four single nucleotide polymorphisms (SNPs) of PPAR γ with DR and additional role of gene-BMI interaction.
  
  
  METHODS
  A total of 500 patients with T2DM (236 men, 264 women), with a mean age of 54.3 ± 15.8 years old, were selected, including 247 diabetic retinopathy patients and 253 controls. Four SNPs were selected for genotyping in the case-control study: rs1805192, rs709158, rs3856806, rs4684847. Logistic regression model was used to examine the interaction between SNP and overweight on DR, odds ratio (OR) and 95% confident interval (95% CI) were calculated.
  
  
  RESULTS
  The carriers of C allele of the rs1805192 polymorphism revealed decreased DR risk than those with Pro/Pro variants (Pro/Ala+Ala/Ala versus Pro/Pro, adjusted OR (95% CI)=0.86 (0.65-0.96), P=0.012), after adjusting for covariates. We also found that obese subjects with Pro/Ala or Ala/Ala variants genotype have lowest DR risk, compared to obese subjects with Pro/Pro genotype or non- obese subjects with Pro/Ala or Ala/Ala (OR=0.40, 95% CI=0.32-0.63), after covariates adjustment.
  
  
  CONCLUSIONS
  Our results support an important association between rs1805192 minor allele (Ala allele) of PPAR γ and DR, the interaction analysis shown a combined effect of Ala- BMI interaction on DR.
authors.affiliation: Department of Ophthalmology, The Fourth people's Hospital of Shenyang City Shenyang 110031, Liaoning Province, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, The Fourth people's Hospital of Shenyang City Shenyang 110031, Liaoning Province, PR China.
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, The Fourth people's Hospital of Shenyang City Shenyang 110031, Liaoning Province, PR China.
authors.forename: Ruo-Xi
authors.initials: RX
authors.lastname: Li
keywords: Diabetic retinopathy; PPAR; interaction; overweight; polymorphism