CMS: Chronic Mountain Sickness, Systemic Vascular Function

Sponsor

University of Lausanne Hospitals (Other)

Overall Status

Unknown status

CT.gov ID

NCT01182792

Collaborator

Instituto Boliviano de Biologia de Altura (Other), Universitad Major de S. Andres, La Paz, Bolivia (Other)

Enrollment

Locations

Arms

158

Duration (Months)

Patients Per Site

0.2

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Mountain Sickness Chronic	Dietary Supplement: Vitamin C and E Dietary Supplement: Placebo	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

50 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Participant, Investigator)

Primary Purpose:

Treatment

Official Title:

Chronic Hypoxemia and Systemic Vascular Function

Study Start Date :

Oct 1, 2008

Anticipated Primary Completion Date :

Jun 1, 2021

Anticipated Study Completion Date :

Dec 1, 2021

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Antioxidant	Dietary Supplement: Vitamin C and E 1 month, 1g Vitamin C and 400 IE Vitamin E or Acute, 1g Vitamin C (in the offspring)
Placebo Comparator: Control	Dietary Supplement: Placebo 1 month Placebo

Arm

Intervention/Treatment

Experimental: Antioxidant

Dietary Supplement: Vitamin C and E

1 month, 1g Vitamin C and 400 IE Vitamin E or Acute, 1g Vitamin C (in the offspring)

Placebo Comparator: Control

Dietary Supplement: Placebo

1 month Placebo

Outcome Measures

Primary Outcome Measures

Endothelial Function [1 month]

Eligibility Criteria

Criteria

Ages Eligible for Study:

10 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Patients with Chronic Mountain Sickness and their offspring

Exclusion Criteria:

Smoking
Lung disease
Arterial Hypertension

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Istituto Boliviano de Biologia de Altura, Universitad S. Andres	La Paz		Bolivia
2	University Hospital Lausanne, Botnar Center for Extreme Medicine	Lausanne	Vaud	Switzerland	1011