A single air dive reduces arterial endothelial function in man.

Area of Science:

• Cardiovascular Physiology
• Hyperbaric Medicine
• Sports Medicine

Background:

• Gas bubbles form during decompression after dives, potentially affecting pulmonary artery endothelial function.
• Existing research lacks data on diving's impact on arterial endothelial function.
• This study addresses the gap by investigating diving and oxygen breathing effects on human arterial endothelial function.

Purpose of the Study:

• To determine if diving or breathing oxygen influences endothelial arterial function in humans.
• To assess changes in flow-mediated dilatation (FMD) as an indicator of endothelial function.
• To compare the effects of diving and oxygen breathing with a control group.

Main Methods:

• Twenty-one experienced divers participated, divided into a diving group (n=9) and an oxygen breathing group (n=5).
• The diving group underwent hyperbaric compression and decompression simulating diving conditions.
• Endothelial function was measured using ultrasound-assessed flow-mediated dilatation (FMD) of the brachial artery before and after exposure.

Main Results:

• Diving resulted in a significant reduction in FMD (9.2% to 5.0%), indicating acute arterial endothelial dysfunction.
• Arterial diameter increased significantly after diving (4.5 mm to 4.8 mm).
• Oxygen breathing led to a significant increase in arterial diameter (4.4 mm to 4.7 mm) but an insignificant decrease in FMD.

Conclusions:

• Diving can induce acute arterial endothelial dysfunction in humans.
• Oxygen breathing increases arterial diameter but does not significantly impair endothelial function.
• Further research is needed to explore the role of these mechanisms in diving-related tissue injury.