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Systemic vascular dysfunction in patients with chronic mountain sickness
Stefano F Rimoldi1, Emrush Rexhaj1, Lorenza Pratali2
1Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland; Department of Internal Medicine and Botnar Center for Clinical Research, University Hospital, Lausanne, Switzerland.
Chest
|June 25, 2011
Summary
Chronic mountain sickness (CMS) causes systemic vascular dysfunction, impairing blood vessel function and potentially increasing cardiovascular disease risk in affected individuals.
Area of Science:
- Cardiovascular Physiology
- Altitude Medicine
- Vascular Biology
Background:
- Chronic mountain sickness (CMS) is a prevalent health issue marked by low oxygen levels (hypoxemia) and elevated red blood cell counts (erythrocytosis).
- While pulmonary circulation changes are known in advanced CMS, systemic circulation effects are less understood.
- Systemic vascular dysfunction is observed in chronic hypoxemia at low altitudes, suggesting potential similar issues in CMS.
Purpose of the Study:
- To investigate systemic vascular function in patients with CMS.
- To determine if CMS is associated with endothelial dysfunction, arterial stiffness, and carotid intima-media thickness.
- To explore the relationship between arterial oxygen saturation and systemic vascular parameters in CMS.
Main Methods:
- Assessed systemic endothelial function via flow-mediated dilation (FMD), arterial stiffness (pulse wave velocity), and carotid intima-media thickness.
- Studied 23 CMS patients and 27 healthy, age-matched high-altitude dwellers (living at 3,600 m).
- Analyzed subjects based on baseline oxygen saturation (Sao(2)) quartiles, using the highest quartile (Sao(2) ≥ 90%) as a reference.
Main Results:
- CMS patients exhibited significantly impaired FMD (4.6% vs. 7.6%), increased pulse wave velocity (10.6 vs. 8.4 m/s), and greater carotid intima-media thickness (690 vs. 570 μm) compared to controls.
- A strong positive correlation was found between Sao(2) and FMD (r = 0.62).
- Oxygen inhalation improved FMD in CMS patients but did not normalize it, while it normalized FMD in hypoxemic controls.
Conclusions:
- Patients with CMS demonstrate significant systemic vascular dysfunction.
- Both structural and functional vascular alterations contribute to this dysfunction.
- This vascular dysfunction may increase the risk of premature cardiovascular disease in CMS patients.
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