Oxidative stress is associated with an increased antioxidant defense in elderly subjects: a multilevel approach

PLoS One. 2014 Sep 30;9(9):e105881. doi: 10.1371/journal.pone.0105881. eCollection 2014.


Background: Studies of associations between plasma GSH-Px activity and cardiovascular risk factors have been done in humans, and contradictory results have been reported. The aim of our study was to assess the association between the scavenger antioxidant enzyme glutathione peroxidase (GSH-Px) activity in plasma and the presence of novel and classical cardiovascular risk factors in elderly patients.

Methods: We performed a cross-sectional study with baseline data from a subsample of the PREDIMED (PREvención con DIeta MEDiterránea) study in Spain. Participants were 1,060 asymptomatic subjects at high risk for cardiovascular disease (CVD), aged 55 to 80, selected from 8 primary health care centers (PHCCs). We assessed classical CVD risk factors, plasma oxidized low-density lipoproteins (ox-LDL), and glutathione peroxidase (GSH-Px) using multilevel statistical procedures.

Results: Mean GSH-Px value was 612 U/L (SE: 12 U/L), with variation between PHCCs ranging from 549 to 674 U/L (Variance = 013.5; P<0.001). Between-participants variability within a PHCC accounted for 89% of the total variation. Both glucose and oxidized LDL were positively associated with GSH-Px activity after adjustment for possible confounder variables (P = 0.03 and P = 0.01, respectively).

Conclusion: In a population at high cardiovascular risk, a positive linear association was observed between plasma GSH-Px activity and both glucose and ox-LDL levels. The high GSH-Px activity observed when an oxidative stress situation occurred, such as hyperglycemia and lipid oxidative damage, could be interpreted as a healthy defensive response against oxidative injury in our cardiovascular risk population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antioxidants / metabolism
  • Cross-Sectional Studies
  • Female
  • Glutathione Peroxidase / blood*
  • Humans
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Oxidative Stress*
  • Regression Analysis


  • Antioxidants
  • Glutathione Peroxidase

Grants and funding

This study was funded by the Spanish Ministry of Health (Networks G03/140, RD06/0045 and by the research grants PI040233, PI070240 and Miguel Servet SNS Contract CP06/00100 of the Instituto de Salud Carlos III). The CIBER Fisiopatología de la Obesidad y Nutrition and the CIBER Epidemiología y Salud Pública are initiatives of the Instituto de Salud Carlos III, Madrid, Spain, and the European Union (FEDER). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.