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

Study Overview
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Brief Summary
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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.

Official Title
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Sleep Apnea and High Altitude Pulmonary Hypertension in Kyrgyz Highlanders

Conditions
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High Altitude Pulmonary Hypertension, Sleep Apnea

Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| High altitude pulmonary hypertension<br>Highlanders with high altitude pulmonary hypertension | |
| High altitude control<br>Healthy highlanders | |
| Low altitude control<br>Healthy lowlanders | |

What is the study measuring?
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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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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high altitude illness, pulmonary hypertension, sleep apnea, hypoxia