Objectives: To study the combined effect of polymorphisms in genes of the renin-angiotensin system on mortality in type 2 diabetic patients in dialysis.
Design and methods: From 1993 to 2007, we followed 89 patients from the start of dialysis until the end point, which was all-cause mortality. All patients were genotyped for the following polymorphisms: ACE (I/D), AGT (p.235M>T) and AGTR1 (g.1166A>C). The relative risks of death were examined by Cox-proportional hazard analysis after adjusting for age, sex, modality of dialysis, baseline and residual filtration rate, cardiovascular comorbidity, anemia, glycemic control, hypertension, nutritional status, risk of infection and dyslipidemia.
Results: We first assigned and quantified the number of risk alleles--D (I/D), M (p.235 M>T) and A (g.1166A>C)--each patient carried. The Cox-proportional hazard analysis showed that every single additional risk allele multiplied the mortality hazard ratio by 1.58 (95% CI: 1.16-2.15, P=0.003).
Conclusions: Our data suggest a combined effect among the polymorphisms of the Renin-Angiotensin-System genes on mortality in type 2 diabetic patients undergoing dialysis.