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Sleep Related Breathing Disturbances and High Altitude Pulmonary Hypertension in Kyrgyz Highlanders

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ClinicalTrials.gov Identifier: NCT01621061
Recruitment Status : Completed
First Posted : June 15, 2012
Last Update Posted : May 15, 2014
Information provided by (Responsible Party):

Study Description
Brief Summary:
High altitude pulmonary hypertension, a form of altitude illness that occurs in long-term residents at altitudes >2500 m, is characterized by dyspnea, hypoxemia, impaired exercise performance and hypertension in the pulmonary circulation. Whether sleep related breathing disturbances, common causes of nocturnal hypoxemia in lowlanders, are also prevalent in highlanders and promote pulmonary hypertension in highlanders is unknown. Therefore, the current study will investigate whether highlanders with high altitude pulmonary hypertension have a greater prevalence of sleep apnea than healthy highlanders and lowlanders.

Condition or disease
High Altitude Pulmonary Hypertension Sleep Apnea

Study Design

Study Type : Observational
Actual Enrollment : 125 participants
Observational Model: Case Control
Time Perspective: Prospective
Official Title: Sleep Apnea and High Altitude Pulmonary Hypertension in Kyrgyz Highlanders
Study Start Date : June 2012
Primary Completion Date : December 2013
Study Completion Date : December 2013

Groups and Cohorts

High altitude pulmonary hypertension
Highlanders with high altitude pulmonary hypertension
High altitude control
Healthy highlanders
Low altitude control
Healthy lowlanders

Outcome Measures

Primary Outcome Measures :
  1. Sleep related breathing disturbances [ Time Frame: 4 months ]
    Nocturnal oxygen saturation and apnea/hypopnea index

Secondary Outcome Measures :
  1. Pulmonary artery pressure [ Time Frame: 4 months ]

  2. Dyspnea [ Time Frame: 4 months ]
    NYHA functional class

  3. Vigilance [ Time Frame: 4 months ]
    Psychomotor vigilance

  4. Exercise performance [ Time Frame: 4 months ]
    6 min walk test

  5. Pulmonary function [ Time Frame: 4 months ]

  6. Cerebral oxygen saturation [ Time Frame: 4 months ]
    Near-infrared spectroscopy

  7. Mountain sickness [ Time Frame: 4 months ]
    Quinghai chronic mountain sickness score

  8. Generic quality of life [ Time Frame: 4 months ]
    SF-36 quality of life questionnaire

  9. Disease specific quality of life [ Time Frame: 4 months ]
    Kansas City Cardiomyopathy questionnaire

  10. Subjective sleepiness [ Time Frame: 4 months ]
    Epworth sleepiness scale

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   16 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Highlanders with high altitude pumonary hypertension living at an altitude of 2500-4000 m; healthy highlanders living at an altitude of 2500-4000 m; healthy lowlanders living at an altitude of <1000 m.

Inclusion Criteria:

  • high altitude pulmonary hypertension confirmed by clinical presentation and systolic pulmonary artery pressure >50 mmHg measured by echocardiography at altitude of residence.
  • healthy subjects (high altitude controls)
  • Both genders
  • Age >16 y
  • Kyrgyz ethnicity
  • born, raised and currently living at >2500 m
  • healthy subjects currently living at <1000 m (low altitude controls)

Exclusion criteria:

  • Pulmonary hypertension from other causes, in particular from left ventricular failure as judged clinically and by echocardiography
  • excessive erythrocytosis
  • other coexistent disorders that may interfere with the cardio-respiratory system and sleep
  • regular use of medication that affects control of breathing
  • heavy smoking
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01621061

National Center for Cardiology and Internal Medicine
Bishkek, Kyrgyzstan, 720040
Sponsors and Collaborators
University of Zurich
National Center of Cardiology and Internal Medicine, Kyrgyzstan
Principal Investigator: Konrad E Bloch, MD University of Zurich, Switzerland
Principal Investigator: Talant Sooronbaev, MD National Center of Cardiology and Internal Medicine, Kyrgyzstan
More Information

Responsible Party: Konrad E. Bloch, Professor, University of Zurich
ClinicalTrials.gov Identifier: NCT01621061     History of Changes
Other Study ID Numbers: 01-7/219
First Posted: June 15, 2012    Key Record Dates
Last Update Posted: May 15, 2014
Last Verified: May 2014

Keywords provided by Konrad E. Bloch, University of Zurich:
high altitude illness
pulmonary hypertension
sleep apnea

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Hypertension, Pulmonary
Altitude Sickness
Vascular Diseases
Cardiovascular Diseases
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases
Lung Diseases