Diabetes mellitus, superoxide dismutase and peroxisome proliferator activated receptor gamma polymorphisms modify the outcome of end-stage renal disease patients of Han Chinese origin.

Aim: Increased oxidative stress significantly modifies the outcome of patients with diabetes mellitus (DM) and end-stage renal disease (ESRD), and is counteracted by antioxidative capacity. We aimed to investigate whether antioxidant single nucleotide polymorphisms (SNPs) influence the outcome of ESRD individuals and the influences exerted by DM, which has not been tested before.

Methods: We prospectively enrolled multi-centre ESRD patients of Han Chinese origin between 2002 and 2003, recording their antioxidant (superoxide dismutase [SOD2], glutathione peroxidase [GPX1]) and peroxisome proliferator activated receptor-γ (PPAR-γ) genotyping results, and stratified based on DM. They were followed up until 2008, with risk factors for mortality analyzed by Cox proportional hazard regression.

Results: We discovered that diabetic ESRD carriers of CC genotype of SOD2 exon 2 had an increased risk of mortality compared to non-diabetic ones with other genotypes (hazard ratio [HR] 4.04, P = 0.04), while GPX1 SNPs had no influence. Interactions between SOD2 and PPAR-γ SNPs regarding the mortality influence were also detected (for SOD2 CC genotype x PPAR-γ exon 6 CT genotype, HR 3.19, P = 0.008), suggesting the importance of considering a combination panel of SNPs on patient survival.

Conclusion: This might be the largest study focusing on the relationship between antioxidant SNPs and the outcomes of diabetic ESRD patients of Han Chinese origin. More studies are needed to validate our findings.