Metabolomics approach to physiological adaptive mechanisms in repetitive confined-water scuba diving under mild hyperoxia using 1H-NMR.

BACKGROUND

This study aims to elucidate the multifaceted effects of scuba diving, particularly focusing on the physiological adaptive mechanisms and metabolic aspects involved in confined-water scuba diving.

METHODS

Selected 10 healthy male college students in their 20 s and conducted confined-water scuba diving sessions once a day, five times a week, for 80 min each session over a period of 8 weeks. Measurements were taken on changes in body composition, cardiorespiratory fitness, and hormonal levels. Additionally, alterations in metabolites of urine samples were observed using 1H-NMR.

RESULTS

Body fat percentage showed a statistically significant decrease at 4 weeks (4 w) and 8 weeks (8 w) (p < 0.05) compared to the level before confined-water scuba diving. Air consumption decreased significantly at 4 and 8 weeks (p < 0.001), while forced vital capacity increased at 4 w (p < 0.05) and 8 w (p < 0.01). The physical fitness index also showed significant improvements at 4 w (p < 0.01) and 8 w (p < 0.001). Dopamine levels increased progressively at IA (p < 0.05), 4 w (p < 0.01), and 8 w (p < 0.001). Norepinephrine also showed a marked elevation at 4 and 8 w (p < 0.001). Adrenocorticotropic hormone (ACTH) and epinephrine did not exhibit significant changes. Cortisol decreased immediately after diving and at 4 w (p < 0.001) but showed a significant rebound at 8 w (p < 0.01). Regarding endogenous metabolites, a total of 89 metabolites were identified in the confined-water scuba diving urine sample, of which 9 (urea, ethanol, hippurate, 2-octenoate, creatine phosphate, taurine, glucose, serine, and threonine) showed significant differences compared to before confined-water scuba diving.

CONCLUSION

Based on the metabolic findings regarding the adaptive mechanisms of confined-water scuba diving, these identified metabolites could serve as key factors and significant biomarkers for understanding the adaptation mechanisms of confined-water scuba diving.