Circulating nitric oxide (NO), asymmetric dimethylarginine (ADMA), homocysteine, and oxidative status in obstructive sleep apnea-hypopnea syndrome (OSAHS)

Sleep Breath. 2008 May;12(2):149-54. doi: 10.1007/s11325-007-0148-4.


Obstructive sleep apnea-hypopnea syndrome (OSAHS) with episodic hypoxia-reoxygenation is associated with increased cardiovascular morbidity and mortality. Therefore, increased homocysteine, asymmetric dimethylarginine (ADMA), oxidative status, and decreased nitric oxide levels have been implicated as possible mechanisms for development of cardiovascular diseases. We aimed to investigate changes in the levels of these substances in patients with OSAHS in comparison with nonapneic controls. Thirty-four OSAHS patients and 15 healthy controls were included in this study. In the blood samples, oxidative status and nitric oxide levels were measured with spectrophotometric methods. Plasma ADMA and homocysteine levels were determined by using high-performance liquid chromatography with fluorescence detection. Nitric oxide levels were significantly low in OSAHS patients (p < 0.05) and correlated with mean SaO(2) (r = 0.513, p < 0.002) and lowest SaO(2) (r = 0.363, p < 0.03). Oxidative status, ADMA, and homocysteine levels were higher in OSAHS patients, but difference did not reach statistical significance. After dividing patients into moderate (AHI = 5-29) and severe (AHI > or = 30) OSAHS groups, significantly increased homocysteine levels were observed in the severe OSAHS group (p < 0.05). Nitric oxide levels negatively correlated with oxidative status in total OSAHS patients (r = -0.415, p < 0.02) and also in severe OSAHS group (r = -0.641, p < 0.007). Hyperhomocysteinemia and diminished NO production may be causal factors in endothelial dysfunction seen in OSAHS and may explain the association between OSAHS and cardiovascular diseases. These modifiable factors should be monitored in patients suspected of having OSAHS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arginine / analogs & derivatives*
  • Arginine / blood
  • Body Mass Index
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / metabolism
  • Female
  • Homocysteine / blood*
  • Humans
  • Male
  • Middle Aged
  • Nitric Oxide / blood*
  • Oxidative Stress / physiology*
  • Polysomnography
  • Severity of Illness Index
  • Sleep Apnea, Obstructive / diagnosis
  • Sleep Apnea, Obstructive / epidemiology
  • Sleep Apnea, Obstructive / metabolism*


  • dimethylarginine
  • Homocysteine
  • Nitric Oxide
  • Arginine