Effects of hyperoxia on biomarkers of oxidative stress in closed-circuit oxygen military divers

Abstract

Oxygen toxicity is a problem in diving which can have fatal consequences in the water. When divers use closed-circuit oxygen rebreathing apparatus they are taking only oxygen 100% and this hyperoxic exposure increases the generation of reactive oxygen species (ROS) in biological tissues. The objective of the present study is to evaluate the effects of hyperoxia on biomarkers of oxidative stress in closed-circuit oxygen military divers. Fifteen professional divers of Spanish Navy Diving Centre participated in a training program which consisted of one-hour immersion at seven metres of depth breathing oxygen 100% with closed-circuit oxygen rebreathing apparatus. The training went on two or three times per week for the first six weeks and once a week for the last six weeks. Serum total antioxidant status (TAS), levels of glutathione peroxidase (GPx), nitrates (NO3(-)) and urinary concentrations of 15-isoprostane F2t were measured. The results show that TAS decreased significantly after 6 weeks (mean 1.38 versus 1.23 mmol/l), with a slight increase at the end (mean 1.31 mmol/l). GPx and F2-isoprostanes were significantly lower after 6 and 12 weeks and NO3(-) was significantly lower after 6 weeks and remained unchanged until the end. In summary, professional divers who use closed-circuit apparatus and therefore breathe oxygen 100%, do not suffer an important oxidative hyperoxia-induced stress, probably due an adaptive process after hyperoxia. The age and good physical form of the subjects studied could probably enhance the adaptive process to hyperoxia.

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

“…This is in accordance with previous studies where no changes in lipid peroxidation or oxidative stress marker were reported in patients with various pathologies [37]. Moreover, Alcaraz-García et al reported that, in professional divers, HBO 2 training (~1.7 ATA; 100% O 2 ) for 2-3 times per week during 12 weeks did not induce an important oxidative hyperoxia-induced stress due an adaptive process [38]. Taken together, these data suggest that training in a HBO 2 environment does not modify oxidative stress in human volunteers.…”

Oxidized LDL and its correlation with lipid profile and oxidative stress biomarkers in young healthy Spanish subjects

“…Measurements of specific F 2 -isoprostanes in urine may provide a sensitive biochemical end point for dosefinding studies of natural and synthetic inhibitors of lipid peroxidation. We have measured this lipid peroxidation biomarker in a young healthy Spanish population, and although it has been a relatively small [1,3]. We think that these differences can be explained due to the difference in ages of the patients.…”

Diaphragmatic Breathing Reduces Exercise‐Induced Oxidative Stress

“…For example, the oxidative stress that occurs in the hyperventilation syndrome can be cured by learning DB. Hyperventilation, in fact, induces hyperoxia which is known to be related with oxidative stress [81, 82]. The hyperventilation syndrome affects 15% of the population and occurs when breathing rates elevate to 21–23 bpm as a result of constricted non-DB.…”