Clinical significance of daytime plasma orexin-A-like immunoreactivity concentrations in patients with obstructive sleep apnea hypopnea syndrome.
BACKGROUND
Polysomnography (PSG) tests are very complicated and time consuming, despite their clinical benefits in the diagnosis of patients with obstructive sleep apnea hypopnea syndrome (OSAHS). A plasma marker would be desirable to select patients suspected of OSAHS for further PSG studies. We have recently reported that orexin-A concentrations in plasma collected immediately after waking early in the morning were significantly lower in patients with OSAHS than in controls.


OBJECTIVE
We conducted the present study to assess the clinical usefulness of the measurement of orexin-A concentrations in plasma obtained in the daytime as a diagnostic predictor to screen patients with OSAHS.


METHODS
Blood samples were collected in the daytime from 19 male patients with suspected sleep-disordered breathing. Plasma orexin-A concentrations were measured by radioimmunoassay before performing PSG.


RESULTS
PSG was conducted in all 19 subjects. PSG showed that 14 subjects had OSAHS and 5 subjects did not. Plasma orexin-A concentrations were significantly lower in patients with OSAHS (4.9 +/- 0.8 pmol/l, mean +/- SE, n = 14) than in control subjects (12.3 +/- 1.9 pmol/l, n = 5) (p = 0.0004).


CONCLUSIONS
These findings suggest that the orexin-A concentration in plasma obtained even in the daytime may be a useful plasma marker for screening OSAHS.
Third Department of Internal Medicine, Iwate Medical University School of Medicine, Morioka, Japan. ssakurai@iwate-med.ac.jp
Shigeru
S
Sakurai
Tsuguo
T
Nishijima
Susumu
S
Takahashi
Kohei
K
Yamauchi
Zenei
Z
Arihara
Kazuhiro
K
Takahashi
D001143:Arousal / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000097:blood*; D000068797:Orexins; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000097:blood*
C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins