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

Sleep Apnea and High Altitude Pulmonary Hypertension in Kyrgyz Highlanders

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.

Study Overview

• Status: Completed
• Conditions: Sleep Apnea; High Altitude Pulmonary Hypertension

• Study Type: Observational
• Enrollment (Actual): 125

Contacts and Locations

Study Locations

• Kyrgyzstan
  • Bishkek, Kyrgyzstan, 720040
    • National Center for Cardiology and Internal Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (ADULT, OLDER_ADULT, CHILD)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• 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.

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
High altitude pulmonary hypertension; Highlanders with high altitude pulmonary hypertension
High altitude control; Healthy highlanders
Low altitude control; Healthy lowlanders

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep related breathing disturbances	Nocturnal oxygen saturation and apnea/hypopnea index	4 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pulmonary artery pressure	Echocardiography	4 months
Dyspnea	NYHA functional class	4 months
Vigilance	Psychomotor vigilance	4 months
Exercise performance	6 min walk test	4 months
Pulmonary function	Spirometry	4 months
Cerebral oxygen saturation	Near-infrared spectroscopy	4 months
Mountain sickness	Quinghai chronic mountain sickness score	4 months
Generic quality of life	SF-36 quality of life questionnaire	4 months
Disease specific quality of life	Kansas City Cardiomyopathy questionnaire	4 months
Subjective sleepiness	Epworth sleepiness scale	4 months

Collaborators and Investigators

• Sponsor: University of Zurich
• Collaborators: National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov
• Investigators: Principal Investigator: Konrad E Bloch, MD, University of Zurich, Switzerland; Principal Investigator: Talant Sooronbaev, MD, National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov

Study record dates

Study Major Dates

• Study Start: June 1, 2012
• Primary Completion (ACTUAL): December 1, 2013
• Study Completion (ACTUAL): December 1, 2013

Study Registration Dates

• First Submitted: June 13, 2012
• First Submitted That Met QC Criteria: June 13, 2012
• First Posted (ESTIMATE): June 15, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): May 15, 2014
• Last Update Submitted That Met QC Criteria: May 14, 2014
• Last Verified: May 1, 2014

More Information

Terms related to this study

• Keywords: pulmonary hypertension; hypoxia; sleep apnea; high altitude illness
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Lung Diseases; Signs and Symptoms, Respiratory; Sleep Apnea Syndromes; Hypertension; Apnea; Altitude Sickness; Hypertension, Pulmonary
• Other Study ID Numbers: 01-7/219