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Keywords:

  • Cardiovascular risk factors;
  • elderly;
  • enzymatic antioxidants;
  • oxidative stress

Eur J Clin Invest 2012; 42 (1): 42–48

Abstract

Background  Since oxidative stress might cause and promote cardiovascular risk factors such as oxidized low-density lipoproteins (oxLDL), apolipoprotein(a) [apo(a)], asymmetric dimethylarginine (ADMA) and fetuin A, we investigated antioxidant enzyme activities in relation to the vascular redox balance and these risk factors in elderly people.

Materials and methods  For this observational study, a total of 102 subjects were recruited and divided into three groups: A (70–74 years/n = 48), B (75–79 years/n = 35) and C (≥80 years/n = 19). Activities of the erythrocyte antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were determined photometrically oxLDL, apo(a), ADMA and fetuin A by ELISA. Plasma concentrations of the lipid peroxidation products malondialdehyde (MDA) and conjugated dienes (CD) were analysed with HPLC.

Results  There were no significant age-associated alterations in apo(a) levels, but there was a significant age-related decrease in activities of SOD (A>C, B>C: P < 0·01), CAT (A>C: P < 0·05) and GSH-Px (A>C: P < 0·05), accompanied by a significant increase in oxLDL (A<C: P < 0·001; B<C: P < 0·05), ADMA (A<B: P < 0·05; A<C: P < 0·001), MDA (A<C, B<C: P < 0·01) and CD (A<C, B<C: P < 0·01), and a significant decrease in fetuin A (A>C: P < 0·01; B>C: P < 0·05). Consequently, all groups showed significant negative age-associated correlations between CAT and MDA (A, B, C: P < 0·05), GSH-Px and CD (A, C: P < 0·01; B: P < 0·05), SOD and oxLDL (A, B: P < 0·05; C: P < 0·01), and fetuin A and MDA (A: P < 0·01; B, C: P < 0·05), and a significant positive correlation between oxLDL and ADMA (A, B: P < 0·05; C: P < 0·01).

Conclusions  This study indicates a significant age-related decrease in antioxidant enzyme activities accompanied by significantly increased systemic oxidative stress, which promotes the cardiovascular risk factors oxLDL, ADMA and fetuin A in elderly people.