Evaluation of arterial endothelin-1 levels, before and during a sleep study, in patients with bronchial asthma and chronic obstructive pulmonary disease.
BACKGROUND
Endothelin (ET)-1 has been implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). The ET-1 levels are elevated during exacerbations of asthma and COPD in bronchoalveolar lavage, serum, and sputum, falling with treatment of the exacerbations.


OBJECTIVE
The aim of this study was to examine the ET-1 blood levels in stable asthmatic patients and stable COPD patients during alertness and sleep.


METHODS
We examined 48 COPD and 20 asthmatic patients. All underwent forced spirometry, measurement of SaO2 and of arterial ET-1 levels and nocturnal polysomnography. ET-1 levels were also determined during nocturnal oxyhaemoglobin desaturation.


RESULTS
The daytime SaO2 level of our asthmatic patients was higher than that of our COPD patients (p < 0.001). Daytime SaO2 level of our non-desaturator COPD patients was higher than that measured in desaturator COPD patients. Nightime SaO2 level in our asthmatic patients was higher than that in our desaturator COPD patients (p < 0.001). Daytime ET-1 levels in desaturator COPD patients were higher than those observed in normal individuals, in non-desaturator COPD patients and in asthmatic patients. The COPD desaturator patients had higher levels of ET-1 during nighttime than during daytime (p < 0.001).


CONCLUSIONS
Asthmatic patients did not exhibit desaturation of haemoglobin during the night. ET-1 levels are significantly higher in desaturator COPD patients compared with non-desaturator COPD patients, both during the day and during the night. ET-1 levels in stable COPD patients are significantly higher than in patients with stable asthma. These findings are consistent with the hypothesis that ET-1 is implicated in the pathogenesis of COPD and asthma.
Nikolaou
E
E
Sleep Laboratory, Immunology Laboratory of Onashion Cardiorsurgery Hospital, Athens, Greece.
Trakada
G
G
Prodromakis
E
E
Efremidis
G
G
Pouli
A
A
Koniavitou
A
A
Spiropoulos
K
K
D001249:Asthma / Q000097:blood* / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology*; D019332:Endothelin-1 / Q000097:blood*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D012890:Sleep / Q000502:physiology*
D019332:Endothelin-1; D006454:Hemoglobins; D010100:Oxygen