Full-Face Mask Use during SCUBA Diving Counters Related Oxidative Stress and Endothelial Dysfunction

Area of Science:

• Cardiovascular Physiology
• Diving Medicine
• Respiratory Physiology

Background:

• SCUBA diving impairs flow-mediated dilation (FMD), a vascular stress marker, linked to nitric oxide (NO) dysfunction and redox imbalance from hyperbaric gas.
• Traditional half-face (HF) masks force oral breathing, potentially reducing nasal NO production crucial for vascular homeostasis.
• Full-face (FF) masks allow nasal breathing, but their comparative effects on vascular function post-dive are unstudied.

Purpose of the Study:

• To compare the effects of FF versus HF masks during SCUBA diving on vascular function, oxidative stress, and NO metabolism.
• To investigate if nasal breathing via FF masks mitigates diving-induced vascular dysfunction.

Main Methods:

• Assessed vascular function (FMD), oxidative stress markers (ROS, 8-iso-PGF2α), and NO metabolism (NO2, NOx, 3-NT, iNOS expression) after a standard dive.
• Compared outcomes between divers using FF masks (nasal breathing) and HF masks (oral breathing).
• Included data from a hypoxic gas mixture dive with an HF mask to explore hyperoxic/hypoxic effects.

Main Results:

• Nasal breathing during diving may significantly reduce vascular dysfunction.
• FF mask use appears to better maintain NO production and bioavailability.
• This improved NO status may enhance the counteraction of reactive oxygen and nitrogen species.

Conclusions:

• Nasal breathing, facilitated by FF masks, shows potential in preventing SCUBA diving-induced vascular dysfunction.
• Findings suggest FF masks improve vascular health by preserving NO pathways and redox balance.
• This research offers insights into diving safety and the physiological effects of oxygen concentrations.