Abstract
Background:
Chronic mountain sickness (CMS) is a major public health problem characterized by exaggerated hypoxemia and erythrocytosis. In more advanced stages, these patients often present functional and structural changes of the pulmonary circulation, but there is little information on the systemic circulation. In patients suffering from diseases associated with chronic hypoxemia at low altitude, systemic vascular function is altered. We hypothesized that patients with CMS display systemic vascular dysfunction that may predispose them to increased systemic cardiovascular morbidity.
Methods:
To test this hypothesis, we assessed systemic endothelial function (by flowmediated dilation, FMD), arterial stiffness and carotid intima-media thickness and arterial oxygenation (SaO2) in 23 patients with CMS without additional classical cardiovascular risk factors and 27 age-matched healthy mountain dwellers born and permanently living at 3600 m. For some analyses subjects were classified according to baseline SaO2 quartiles; FMD of the highest quartile subgroup (SaO2 ≥90%) was used as reference value for post-hoc comparisons.
Results:
Patients with CMS displayed marked systemic vascular dysfunction, as evidenced by impaired FMD (4.6±1.2 vs. 7.6±1.9%, CMS vs. controls, Pandlt;0.0001), greater pulse wave velocity (10.6±2.1 vs. 8.4±1.0 m/s, Pandlt;0.001) and carotid intima-media thickness (690±120 vs. 570±110 Nm, P=0.001). A positive relationship existed between SaO2 and FMD (r=0.62, Pandlt;0.0001). Oxygen inhalation improved (Pandlt;0.001), but did not normalize FMD in patients with CMS; whereas it normalized FMD in hypoxemic controls (SaO2 andlt;90%) and had no detectable effect in normoxemic (SaO2 ≥90%) control subjects.
Conclusions:
Patients with CMS show marked systemic vascular dysfunction. Structural and functional alterations contribute to this problem that may predispose these patients to premature cardiovascular disease.
Chronic mountain sickness (CMS) is a major public health problem characterized by exaggerated hypoxemia and erythrocytosis. In more advanced stages, these patients often present functional and structural changes of the pulmonary circulation, but there is little information on the systemic circulation. In patients suffering from diseases associated with chronic hypoxemia at low altitude, systemic vascular function is altered. We hypothesized that patients with CMS display systemic vascular dysfunction that may predispose them to increased systemic cardiovascular morbidity.
Methods:
To test this hypothesis, we assessed systemic endothelial function (by flowmediated dilation, FMD), arterial stiffness and carotid intima-media thickness and arterial oxygenation (SaO2) in 23 patients with CMS without additional classical cardiovascular risk factors and 27 age-matched healthy mountain dwellers born and permanently living at 3600 m. For some analyses subjects were classified according to baseline SaO2 quartiles; FMD of the highest quartile subgroup (SaO2 ≥90%) was used as reference value for post-hoc comparisons.
Results:
Patients with CMS displayed marked systemic vascular dysfunction, as evidenced by impaired FMD (4.6±1.2 vs. 7.6±1.9%, CMS vs. controls, Pandlt;0.0001), greater pulse wave velocity (10.6±2.1 vs. 8.4±1.0 m/s, Pandlt;0.001) and carotid intima-media thickness (690±120 vs. 570±110 Nm, P=0.001). A positive relationship existed between SaO2 and FMD (r=0.62, Pandlt;0.0001). Oxygen inhalation improved (Pandlt;0.001), but did not normalize FMD in patients with CMS; whereas it normalized FMD in hypoxemic controls (SaO2 andlt;90%) and had no detectable effect in normoxemic (SaO2 ≥90%) control subjects.
Conclusions:
Patients with CMS show marked systemic vascular dysfunction. Structural and functional alterations contribute to this problem that may predispose these patients to premature cardiovascular disease.
| Original language | English |
|---|---|
| Pages (from-to) | 139-146 |
| Journal | CHEST (Official publication of the American College of Chest Physicians) |
| Volume | 141 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 23 Jun 2011 |
Keywords
- systemic vascular dysfunction
- chronic
- mountain sickness
