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