[Daytime pulmonary hypertension in the obstructive sleep apnea syndrome].
Patients with obstructive sleep apnea syndrome (OSAS) may have daytime pulmonary hypertension (PH). Transient and sometimes severe elevations of pulmonary arterial pressure during sleep as a result of intermittent upper airway obstruction may lead to daytime PH. We sought to study the factors involved in the development of daytime PH. Right-heart catheterization, pulmonary function tests, and arterial blood gas measurements were done in 25 patients in whom OSAS was diagnosed by whole-night polysomnography. Eight of the patients (32%) had PH, defined by a mean pulmonary arterial (PA) pressure > or = 20 mmHg. For the group as a whole, mean PA pressure was positively and significantly correlated with daytime PaCO2 (r = 0.79), percent of ideal body weight (r = 0.45), and Hb (r = 0.40). Mean PA pressure was negatively and significantly correlated with PaO2 (r = -0.54), FEV 1% (r = -0.52), and %FVC (r = -0.68). In contrast, mean PA pressure was not significantly correlated with apnea index or with sleep desaturation. These data indicate that daytime PH was not directly related to sleep-disordered breathing, but was related to daytime hypoxemia, daytime hypercapnia, obesity, obstructive and restrictive respiratory impairments, and secondary polycythemia.
Shinozaki
T
T
Department of Chest Medicine, School of Medicine, Chiba University, Japan.
Tatsumi
K
K
Sakuma
T
T
Masuyama
S
S
Kato
K
K
Okada
O
O
Kimura
H
H
Kuriyama
T
T
D000328:Adult; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000150:complications; D006976:Hypertension, Pulmonary / Q000209:etiology*; D000860:Hypoxia / Q000150:complications; D008173:Lung Diseases, Obstructive / Q000150:complications; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D011086:Polycythemia / Q000150:complications; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000503:physiopathology