title: Oxidative stress markers and all-cause mortality at older age: a population-based cohort study.
abstract: BACKGROUND
  The free radical/oxidative stress theory of aging has recently received much attention but the association of oxidative stress markers with all-cause mortality was not yet assessed in humans.
  
  
  METHODS
  We measured derivatives of reactive oxygen metabolites (d-ROM) as a proxy for the reactive oxygen species concentration and total thiol levels (TTL) as a proxy for the redox control status in 2,932 participants of a population-based cohort study from Germany.
  
  
  RESULTS
  The median age of the population was 70 years and 120 (4.1%) study participants died during a mean follow-up of 3.3 years. Compared with the bottom tertiles, the top tertiles of d-ROM and TTL concentrations were both associated with all-cause mortality in models adjusted for age, sex, education, smoking, physical activity, and alcohol consumption (hazard ratios and 95% confidence intervals: 1.63 [1.01; 2.63] and 0.68 [0.53; 0.87], respectively). Adding diseases, the inflammatory marker C-reactive protein or a cumulative somatic morbidity index did not alter the results for TTL. However, the association of d-ROM and mortality was attenuated and no longer statistically significant after adding C-reactive protein and the somatic morbidity index to the model.
  
  
  CONCLUSIONS
  This study adds epidemiological evidence to the free radical/oxidative stress theory of aging. Both d-ROM and TTL were associated with mortality at older age. For TTL, this association was independent of baseline health status. Inflammation and higher general morbidity could be intermediate states on the pathway from high d-ROM levels to mortality. This hypothesis should to be explored by future studies with repeated measurements.
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany. b.schoettker@dkfz-heidelberg.de.
authors: Ben
authors: B
authors: Schöttker
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors: Kai-Uwe
authors: KU
authors: Saum
authors: Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, the Netherlands.
authors: Eugène H J M
authors: EH
authors: Jansen
authors: International Prevention Research Institute, Lyon, France. Institute for Translational Epidemiology and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York.
authors: Paolo
authors: P
authors: Boffetta
authors: Hellenic Health Foundation, Athens, Greece.
authors: Antonia
authors: A
authors: Trichopoulou
authors: Saarland Cancer Registry, Saarbrücken, Germany.
authors: Bernd
authors: B
authors: Holleczek
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors: Aida Karina
authors: AK
authors: Dieffenbach
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors: Hermann
authors: H
authors: Brenner
mesh_terms: D000368:Aged; D000375:Aging; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D002423:Cause of Death; D008076:Cholesterol, HDL / Q000097:blood; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008136:Longevity; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D011237:Predictive Value of Tests; D017382:Reactive Oxygen Species / Q000097:blood; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000097:blood; D011795:Surveys and Questionnaires; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D014280:Triglycerides; D002097:C-Reactive Protein; D003404:Creatinine
keywords: Inflammation.; Longevity; Morbidity; Multimorbidities; Oxidative stress