title: Exhaled nitric oxide in patients with sleep apnea.
abstract: Cardiovascular diseases are frequent in patients with obstructive sleep apnea syndrome (OSAS), but the mechanisms underlying this association are largely unknown. Nitric oxide (NO) is a key regulatory element of vascular physiology. The concentration of NO in the exhaled air ([NOexh]) appears to be reduced in patients with systemic and pulmonary hypertension. This study sought to investigate whether [NOexh] is abnormal in patients with OSAS, and to explore potential relationships between [NOexh] and the severity of OSAS. We measured [NOexh] in 24 patients with OSAS (apnea-hypopnea index (AHI), 55 +/- 4 hour-1) (x +/- SEM), and in 7 healthy volunteers in whom OSAS was excluded clinically. [NOexh] was measured on line by a chemiluminescence analyzer (Dasibi Environmental Corporation, Glendale, Calif). Seven patients with OSAS (29%) had a positive history of cardiovascular disease. Mean [NOexh] was 19.7 +/- 3.2 ppb in healthy subjects, and 22.2 +/- 3.0 ppb in patients with OSAS (p = ns). [Noexh] was not significantly different in those patients with or without cardiovascular disease. [NOexh] was not significantly related to the AHI, the body mass index, or the arterial O2 saturation at night. These results show that [NOexh] is not abnormal in patients with OSAS, and that it does not relate to the presence of cardiovascular disease or to any of various common indices of disease severity.
authors: Servei de Pneumologia, Hospital Universitari Son Dureta, Palma, Mallorca, Spain. agagusti@separ.es
authors: A G
authors: AG
authors: Agustí
authors: F
authors: F
authors: Barbé
authors: B
authors: B
authors: Togores
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D012119:Respiration; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis*
chemical_list: D009569:Nitric Oxide