title: [Exacerbation of obstructive sleep apnea syndrome at altitude 3,850 m].
abstract: Recently more people visit extremely high-altitude places for sightseeing or business. As a result, patients with obstructive sleep apnea (OSAS) also are likely to stay at such places. However the changes of severity of OSAS at extremely high-altitude are not certain. A 44-year-old man was given a diagnosis of OSAS in 2004 and had been using continuous positive airway pressure CPAP at night. On a visit to Nepal the severity of his OSAS was evaluated at Kyanjing Gompa (3,850 m) and at other places. At Kyanjing Gompa, his apnea-hypopnea index (AHI) was 41.8/hr on one night and 52.2/hr on another night, and the periods of SpO2 less than 85% were 51.4% of total sleeping duration and 83.2% respectively. When he returned to Hachioji (altitude 150 m), his AHIs were 10.5/hr and 9.5/hr on two consecutive nights. These results suggested that OSAS worsened by persistent hypobaric hypocapnia and by developing periodic breathing.
authors.affiliation: Department of Medicine, Tokai University Hachioji Hospital.
authors.forename: Tetsuri
authors.initials: T
authors.lastname: Kondo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishii
authors.forename: Gen
authors.initials: G
authors.lastname: Tazaki
authors.forename: Manatsu
authors.initials: M
authors.lastname: Toda
mesh_terms: D000328:Adult; D000531:Altitude; D006801:Humans; D008297:Male; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*