Clinical trial NCT01182792: Chronic Mountain Sickness, Systemic Vascular Function
Official title: Chronic Hypoxemia and Systemic Vascular Function
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Mountain Sickness
Chronic
Keywords: Endothelial Function
Chronic Hypoxia
Oxidative Stress
Lead sponsor: University of Lausanne Hospitals
Sponsor class: OTHER
Collaborators: name: Instituto Boliviano de Biologia de Altura
name: Universitad Major de S. Andres, La Paz, Bolivia
First posted: 2010-08-17
Enrollment: 50
Sex: ALL
Minimum age (years): 10
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Diseases associated with chronic hypoxemia like chronic obstructive pulmonary disease (COPD) or emphysema, represent major medical and socio-economical problems and one of the leading cause of morbidity and mortality in the western countries. Recently, is has been shown that cardiovascular (CV) diseases contribute highly to the morbidity and mortality of these patients. Furthermore, increasing evidence suggest that systemic vascular dysfunction play a central role in the mediation of the increased CV risk in patients with COPD. However the underlying mechanisms of vascular dysfunction in these patients are incompletely understood. Chronic mountain sickness (CMS) is characterized by chronic hypoxemia related at least in part to hypoventilation; it affects relatively young adults, and may therefore allow to study the effects of chronic hypoxemia. The investigators therefore will assess systemic vascular function and test the hypothesis that increased oxidative stress is responsible for this dysfunction. Since polyglobulia is a hallmark of chronic hypoxemia and has been suggested to affect vascular function, the investigators will test the effects of hemodilution on vascular function. Then, the investigators will test the effects of acute oxygen application and 1 month antioxidative dietary supplement on vascular function.

Preliminary data suggest that offspring of CMS patients may display pulmonary and systemic vascular dysfunction. Antioxidant administration is know to improve vascular function. We will test the acute effect of Vitamin C in this setting.

Finally, since there is considerable inter-individual variability of pulmonary artery pressure among CMS patients and the presence of a patent foramen ovale (PFO)is increased in clinical conditions associated with pulmonary hypertension and hypoxemia, we will assess the prevalence of PFO in healthy high altitude dwellers and in CMS patients and its effects on pulmonary artery pressure at rest and during mild exercise.


Eligibility criteria: Inclusion Criteria:

* Patients with Chronic Mountain Sickness and their offspring

Exclusion Criteria:

* Smoking
* Lung disease
* Arterial Hypertension

Primary outcomes:
measure: Endothelial Function
timeFrame: 1 month
Secondary outcomes:
Other outcomes:
Locations:
city: La Paz
country: Bolivia
facility: Istituto Boliviano de Biologia de Altura, Universitad S. Andres
city: Lausanne
country: Switzerland
facility: University Hospital Lausanne, Botnar Center for Extreme Medicine
state: Vaud
Study officials:
References:
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