title: Oxidative DNA damage and mortality in hemodialysis and peritoneal dialysis patients.
abstract: OBJECTIVE
  Increased oxidative stress in dialysis patients is thought to contribute to increased mortality; however, confirmatory data are scarce. We analyzed the serum concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress, in relation to mortality in hemodialysis (HD) and peritoneal dialysis (PD) patients.
  
  
  METHODS
  Serum 8-OHdG, interleukin 6 (IL-6), other biochemical markers, Davies comorbidity score, and protein-energy wasting (PEW) were assessed in 303 prevalent patients treated with HD (n = 220; age: 63 ± 14 years) or PD (n = 83; age: 64 ± 14 years). Mortality was assessed after a median follow-up of 31 months.
  
  
  RESULTS
  The median (25th - 75th percentile) concentration of 8-OHdG was higher in HD than in PD patients: 1.3 ng/mL (0.9 - 1.8 ng/mL) versus 0.5 ng/mL (0.4 - 0.6 ng/mL), p < 0.001. The HD modality (standard β = 0.57, p < 0.001) and dialysis vintage (standard β = 0.12, p = 0.02) were independent predictors of serum 8-OHdG in a multivariable linear regression model including age, sex, body mass index, dialysis modality (HD or PD), preceding time on dialysis (dialysis vintage), PEW, comorbidity score, IL-6, and use of angiotensin converting-enzyme inhibitors or angiotensin II receptor blockers or statins. During follow-up, 107 patients died. In multivariable Cox regression models including all 303 patients and adjusted for age, sex, body mass index, dialysis modality, dialysis vintage, and comorbidity score, 8-OHdG was significantly associated with all-cause mortality (adjusted hazard ratio: 1.40; 95% confidence limits: 1.05, 1.87 for 1 standard deviation increase of 8-OHdG). In subgroup analyses according to dialysis modality, 8-OHdG was associated with mortality in HD patients but not in PD patients.
  
  
  CONCLUSIONS
  Oxidative stress as assessed by 8-OHdG is an independent predictor of all-cause mortality in dialysis patients. This association was seen in HD patients, but no such association could be demonstrated for PD patients.
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden Department of Nephrology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine Tokyo, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Abdul Rashid
authors.initials: AR
authors.lastname: Qureshi
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Heimbürger
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Bárány
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Anderstam
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Monica
authors.initials: M
authors.lastname: Eriksson
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Stenvinkel
authors.affiliation: Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004249:DNA Damage / Q000502:physiology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010530:Peritoneal Dialysis
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: End-stage renal disease; all-cause mortality; comorbidity; dialysis modality; oxidative stress