Indicators of oxidative stress in blood samples of indigenous residents and newcomers in the Arctic zone of Yakutia

Abstract

Introduction. Oxidative stress is non-specific reaction of human organism in response to various damaging factors, including climatic. 
 The purpose of the study. To compare markers of oxidative stress and corresponding age dependences in blood samples of indigenous (evolutionarily adapted) and newcomer inhabitants of the Arctic zone of Yakutia. 
 Materials and methods. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and malondialdehyde content (MDA) were determined in blood lysates of indigenous (n=100) and newcomers (n=37) residents of Chokurdakh and Tiksi settlements. The compared subsamples did not differ in age (medians 34 and 37 years, p=0.407). 
 Results. No significant differences were found between newcomers and natives in terms of SOD, CAT and MDA content in the blood. The GPx activity of newcomers was 1.2 times higher than that of the natives (27.8 [22.4; 32.0] and 23.4 [19.2; 29.4] U/g Hb, p=0.042), but rapidly decreased with age (R= –0.549; p=0.001) 
 in parallel with the increase in MDA content (R=0.420; p=0.01), whereas the indigenous people had no age-related changes in GPx and MDA. 
 Limitations. Associated with a comparatively modest sample size (137 persons). 
 Conclusion. According to modern gerontology, age-related trends in enzyme activity arise due to changes in regulation of corresponding genes and reflect the rate of aging of the population. So it can be assumed that our data, which show accelerated aging of Arctic alien inhabitants compared to the indigenous ones, can be explained by genetic polymorphism of GPx1 transcription factors.