Endothelial dysfunction assessment by flow-mediated dilation in a high-altitude population.

Area of Science:

• Cardiovascular Physiology
• Altitude Medicine
• Endothelial Biology

Background:

• Endothelial function assessment has been limited to populations genetically adapted to high altitude.
• This study investigates endothelial dysfunction (ED) in a non-adapted population at 3,250 meters in the Andes.

Purpose of the Study:

• To evaluate endothelial dysfunction in a high-altitude, non-genetically adapted population.
• To compare endothelial function between individuals with and without cardiovascular risk factors.

Main Methods:

• Flow-mediated vasodilation (FMD) of the brachial artery and carotid intima-media thickness were measured.
• Participants included 61 individuals: 28 cases (hypertension, diabetes, obesity, stroke, or CAD history) and 33 controls.
• Endothelium-independent vasodilation was assessed via sublingual nitrate administration.

Main Results:

• Endothelial dysfunction was prevalent: 100% in diabetics, 68.8% in obese, 55% in hypertensive, and 46.5% in controls.
• Cases had higher BMI and waist diameter; ED was present in 57.9% of cases and 45.2% of controls.
• Individuals with diabetes or hypertension showed increased carotid intima-media thickness; ED correlated with larger basal brachial artery diameter.

Conclusions:

• A high proportion of endothelial dysfunction exists in both controls and patients with risk factors at high altitude.
• Controls in this Andean population demonstrated better FMD compared to previously studied populations in Tibet and the Himalayas.