title: The gene polymorphisms of UCP1 but not PPAR γ and TCF7L2 are associated with diabetic retinopathy in Chinese type 2 diabetes mellitus cases.
abstract: OBJECTIVE
  This study was designed to investigate the association between the polymorphisms in three insulin resistance-related genes, uncoupling protein-1 (UCP1), peroxisome proliferator-activated receptor γ (PPARγ) and transcription factor 7-like 2 (TCF7L2) and the susceptibility to diabetic retinopathy (DR) in a Chinese type 2 diabetes mellitus (T2DM) cohort.
  
  
  METHODS
  A total of 792 patients with T2DM were enrolled and categorized into two groups: (1) the DR group consisted of 448 patients, which was further subclassified into a proliferative DR (PDR) group with 220 patients and a non-proliferative DR (NPDR) group with 228 patients; (2) the diabetes without retinopathy (DNR) group, comprised 344 patients who had no signs of DR. Single-nucleotide polymorphisms (SNPs), rs1800592 in the UCP1 gene, rs1801282, rs3856806 and rs1249719 in the PPARγ gene and rs11196205 in the TCF7L2 gene were genotyped in this study.
  
  
  RESULTS
  For SNP rs1800592 of the UCP1 gene, the frequency of allele G and genotype GG was significantly higher in the PDR group than in the DNR group (allele OR: 1.32, 95% CI: 1.03-1.68, p = 0.03; genotype OR: 1.72, 95%CI: 1.06-2.79, p = 0.03). No evident association was found between the allele frequencies and genotype distributions of any individual SNP in the PPARγ or TCF7L2 genes and DR, PDR or NPDR. Haplotype analyses of the PPARγ gene did not provide any evidence for an association with DR, PDR or NPDR in this Chinese T2DM cohort.
  
  
  CONCLUSIONS
  This study suggests that the SNP rs1800592 in the UCP1 gene is associated with increased risk of PDR in the Chinese T2DM population.
authors.affiliation: Department of Health Care, Qilu Hospital of Shandong University, Jinan, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Nana
authors.initials: N
authors.lastname: Meng
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Lv
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Qu
mesh_terms: D000368:Aged; D044466:Asian People / Q000235:genetics; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics*; D003930:Diabetic Retinopathy / Q000097:blood / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D060005:Genotyping Techniques; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics; D007473:Ion Channels / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000235:genetics*; D047495:PPAR gamma / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D058118:Transcription Factor 7-Like 2 Protein / Q000235:genetics*; D014280:Triglycerides / Q000097:blood; D000071256:Uncoupling Protein 1
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D047495:PPAR gamma; D058118:Transcription Factor 7-Like 2 Protein; D014280:Triglycerides; D000071256:Uncoupling Protein 1; C544894:TCF7L2 protein, human; C000604371:UCP1 protein, human; C517652:hemoglobin A1c protein, human
keywords: diabetic retinopathy; peroxisome proliferator-activated receptor γ; polymorphism; transcription factor 7-like 2; uncoupling protein-1