Marked increase in high density lipoproteins in mountaineers

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Lipid Metabolism

Background:

• High-density lipoproteins (HDL) play a crucial role in reverse cholesterol transport.
• Factors influencing HDL concentrations, particularly apolipoprotein AI (AI), require further investigation.
• Strenuous physical activity and environmental stressors like hypoxia may impact lipid profiles.

Purpose of the Study:

• To measure apolipoprotein AI (AI) concentrations in whole blood during a prolonged, strenuous climb.
• To assess the rate and magnitude of HDL changes in response to extreme exercise and environmental conditions.
• To explore potential contributing factors to observed HDL variations.

Main Methods:

• Whole blood samples were collected from 13 male mountaineers.
• Measurements were taken before, during (3 weeks), and after an 8-week strenuous climb.
• Apolipoprotein AI (AI) concentrations were quantified.

Main Results:

• Apolipoprotein AI (AI) concentrations nearly doubled within 3 weeks of the climb.
• Elevated AI levels were sustained throughout the 8-week climbing period.
• Peak whole blood AI levels reached 148 +/- 29 mg/dl.

Conclusions:

• High-density lipoprotein (HDL) levels, indicated by apolipoprotein AI (AI), can rise rapidly in response to strenuous exercise.
• Extreme conditions, including cold, hypoxia, and mental stress, may contribute to significant increases in HDL.
• The study highlights the potential for substantial HDL elevation in physically demanding scenarios.