Investigation of Variants in UCP2 in Chinese Type 2 Diabetes and Diabetic Retinopathy

<div><p>Purpose</p><p>The aim of this study was to investigate variants in <i>UCP2</i> genes in type 2 diabetes mellitus (DM) and diabetic retinopathy (DR) in Chinese population.</p><p>Materials and Methods</p><p>We conducted a single nucleotide polymorphism-based and haplotype-based case-control study between the variants of <i>UCP2</i> and DM and between the variants of <i>UCP2</i> and DR in 479 Chinese patients with type 2 DM and 479 control subjects without DM. Two SNPs (rs660339 and rs659366) were selected as genetic markers.</p><p>Results</p><p>The risk allele C at <i>UCP2</i> rs660339 was closely associated with DM in Chinese population. There was significant difference in rs660339 between DM and controls (P = 0.0016; OR [95%CI]  = 1.37 (1.14–1.65)). Subjects who were homozygous of the C allele were more likely to develop DM. The frequency of C allele was higher in DM (58%) than in control (51%). But this locus didn't have a definite effect on the onset of non-proliferative diabetic retinopathy (NPDR) (P = 0.44; OR [95%CI]  = 0.80 (0.56–1.14)) and proliferative diabetic retinopathy (PDR) (P = 1.00; OR [95%CI]  = 0.99 (0.74–1.34)) comparing to subjects with DM without retinopathy (DWR), respectively. Moreover, the <i>UCP2</i> rs659366 polymorphism showed no significant difference between DM and control (P = 0.66; OR [95%CI]  = 1.10 (0.91–1.32)). However, there was a significant difference between PDR and DWR (P = 0.016; OR [95%CI]  = 0.66 (0.49–0.90)), but there was no difference between NPDR and DWR (P = 1.00; OR [95%CI]  = 0.96 (0.67–1.37)). Participants who carried the G allele at rs659366 were more likely to develop PDR. For the haplotype, C-A was present more frequently in DM than in control (16% vs 7%), indicating that it was risky, and T-A was present less in DM than in control (29% vs 35%). Haplotype frequencies in DR and DWR showed no significant difference (P = 0.068).</p><p>Conclusion</p><p>It was indicated that <i>UCP2</i> may be implicated in the pathogenesis of type 2 DM and DR in Chinese population.</p></div

Distributions of genotypes and alleles for the two variants in the DM and controls.

<p>P value were calculated between DM and control.</p><p>Distributions of genotypes and alleles for the two variants in the DM and controls.</p

Distributions of genotypes and alleles for the two variants in the DR and DWR.

<p>P value were calculated between DR and DWR.</p><p>Distributions of genotypes and alleles for the two variants in the DR and DWR.</p

Distributions of genotypes and alleles for the two variants in NPDR, PDR and DWR.

<p>P value were calculated between NPDR or PDR and DWR, respectively.</p><p>Distributions of genotypes and alleles for the two variants in NPDR, PDR and DWR.</p

Demographic characteristics of the patients with DM and control subjects.

<p>The results are expressed as mean ± SD.</p><p>Demographic characteristics of the patients with DM and control subjects.</p