title: Association between sleep apnoea and pulmonary hypertension in Kyrgyz highlanders.
abstract: This case-control study evaluates a possible association between high altitude pulmonary hypertension (HAPH) and sleep apnoea in people living at high altitude.Ninety highlanders living at altitudes >2500 m without excessive erythrocytosis and with normal spirometry were studied at 3250 m (Aksay, Kyrgyzstan); 34 healthy lowlanders living below 800 m were studied at 760 m (Bishkek, Kyrgyzstan). Echocardiography, polysomnography and other outcomes were assessed. Thirty-six highlanders with elevated mean pulmonary artery pressure (mPAP) >30 mmHg (31-42 mmHg by echocardiography) were designated as HAPH+. Their data were compared to that of 54 healthy highlanders (HH, mPAP 13-28 mmHg) and 34 healthy lowlanders (LL, mPAP 8-24 mmHg).The HAPH+ group (median age 52 years (interquartile range 47-59) had a higher apnoea-hypopnoea index (AHI) of 33.8 events·h-1(26.9-54.6) and spent a greater percentage of the night-time with an oxygen saturation <90% (T<90; 78% (61-89)) than the HH group (median age 39 years (32-48), AHI 9.0 events·h-1(3.6-16), T<90 33% (10-69)) and the LL group (median age 40 years (30-47), AHI 4.3 events·h-1(1.4-12.6), T<90 0% (0-0)); p<0.007 for AHI and T<90, respectively, in HAPH+ versus others. In highlanders, multivariable regression analysis confirmed an independent association between mPAP and both AHI and T<90, when controlled for age, gender and body mass index.Pulmonary hypertension in highlanders is associated with sleep apnoea and hypoxaemia even when adjusted for age, gender and body mass index, suggesting pathophysiologic interactions between pulmonary haemodynamics and sleep apnoea.
authors.affiliation: Clinic of Pneumology and Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Tsogyal D
authors.initials: TD
authors.lastname: Latshang
authors.affiliation: Clinic of Pneumology and Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Furian
authors.affiliation: Clinic of Pneumology and Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Sayaka S
authors.initials: SS
authors.lastname: Aeschbacher
authors.affiliation: Clinic of Pneumology and Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ulrich
authors.affiliation: Dept of Respiratory, Critical Care and Sleep Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic.
authors.forename: Batyr
authors.initials: B
authors.lastname: Osmonov
authors.affiliation: Dept of Respiratory, Critical Care and Sleep Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic.|Kyrgyz State Medical Academy, Bishkek, Kyrgyz Republic.
authors.forename: Erkin M
authors.initials: EM
authors.lastname: Mirrakhimov
authors.affiliation: Research Institute for Molecular Biology and Medicine, Bishkek, Kyrgyz Republic.
authors.forename: Jainagul
authors.initials: J
authors.lastname: Isakova
authors.affiliation: Research Institute for Molecular Biology and Medicine, Bishkek, Kyrgyz Republic.
authors.forename: Almaz A
authors.initials: AA
authors.lastname: Aldashev
authors.affiliation: Dept of Respiratory, Critical Care and Sleep Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic.
authors.forename: Talant M
authors.initials: TM
authors.lastname: Sooronbaev
authors.affiliation: Clinic of Pneumology and Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland konrad.bloch@usz.ch.
authors.forename: Konrad E
authors.initials: KE
authors.lastname: Bloch
mesh_terms: D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000150:complications* / Q000503:physiopathology*; D001794:Blood Pressure; D016022:Case-Control Studies; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology; D007707:Kyrgyzstan; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017286:Polysomnography; D011446:Prospective Studies; D012044:Regression Analysis; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology*; D013147:Spirometry; D000070857:Walk Test