Effect of Chronic Altitude Hypoxia on Redox Balance in Preadolescents and Adolescents

Abstract

Introduction: Living at high altitude increases oxidative stress. Likewise, growth and maturation during adolescence can increase levels of reactive oxygen species (ROS). Changes in redox profiles have been evaluated in adults living at high altitudes; however, there are no studies on these changes in peripubertal populations living at moderate altitudes, we determine how living at moderate altitude affects the oxidative and inflammatory status of healthy preadolescents and adolescents. Materials and Methods: A cross-sectional study was conducted in healthy male Colombian preadolescents and adolescents (9–18 years old, Tanner scale classification) who lived at low altitude (n = 26) or moderate altitude (n = 26). Plasma oxidative and inflammatory status was assessed via spectrophotometry. Oxidative markers included malondialdehyde, 4-hydroxy-trans-2-nonenal, and carbonyl groups. Antioxidant markers included total antioxidant status, glutathione, catalase, superoxide dismutase, uric acid, and thiols. Inflammatory markers included interleukins-1, -6, and -10 and tumor necrosis factor. Results: Only uric acid levels were higher in adolescents (5.34 and 5.66 mg/dl) compared to preadolescents (3.85 and 4.07 mg/dl) in both moderate and low altitude groups, respectively. Participants who lived at moderate altitude presented significantly higher levels of malondialdehyde (4.82 and 3.73 nM/mg protein) and lower level of glutathione and thiols (1.21 and 1.26 μmol/mg protein) than in those at low altitude. Their inflammatory profiles did not differ. Conclusion: Oxidant profiles increased in peripubertal populations residing at moderate altitude; this could be owing to antioxidant consumption by ROS and active metabolism during puberty.

Keywords

• Oxidative stress
• hypoxia
• altitude
• children
• adolescents
• redox balance