Circulation Journal
Online ISSN : 1347-4820
Print ISSN : 1346-9843
ISSN-L : 1346-9843
Clinical Investigation
Amelioration of Vascular Endothelial Dysfunction in Obstructive Sleep Apnea Syndrome by Nasal Continuous Positive Airway Pressure
Possible Involvement of Nitric Oxide and Asymmetric NG, NG-Dimethylarginine
Yumiko OhikeKoichi KozakiKatsuya IijimaMasato EtoTaro KojimaEijiro OhgaTomofumi SantaKazuhiro ImaiMasayoshi HashimotoMasao YoshizumiYasuyoshi Ouchi
Author information

2005 Volume 69 Issue 2 Pages 221-226


Background Asymmetric NG,NG-dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide (NO) synthase and its plasma concentration is elevated in patients with cardiovascular risk factors, including hyperlipidemia, hypertension, diabetes, and hyperhomocysteinemia. Obstructive sleep apnea syndrome (OSAS) has been attracting attention as a risk factor for cardiovascular disorders because it often accompanies hypertension, obesity, glucose impairment, and dyslipidemia, all of which are factors in metabolic syndrome and risk factors for cardiovascular disease. Methods and Results In the present study, flow-mediated vasodilatation (FMD) of the brachial artery and plasma concentrations of ADMA were measured before and after nasal continuous positive airway pressure (nCPAP) therapy, which abrogates apnea, in 10 male patients aged 36-69 years old, who were given a diagnosis of OSAS by polysomnography. The percent FMD (%FMD) improved significantly from 3.3±0.3% to 5.8±0.4% (p<0.01) and 6.6±0.3% (p<0.01), before, 1 week, and 4 weeks after nCPAP, respectively. At the same time, the plasma NOx concentrations, metabolites of NO, tended to increase, but the plasma ADMA concentration decreased inversely to %FMD and NOx. A negative correlation between %FMD and plasma ADMA concentration, and a positive correlation between %FMD and plasma NOx concentrations were observed. Conclusion Nasal CPAP improves endothelial function, in part by the decreasing ADMA concentration, thereby potentiating NO production. (Circ J 2005; 69: 221 - 226)

Content from these authors
Previous article Next article