The severity of oxygen desaturation is predictive of carotid wall thickening and plaque occurrence.
OBJECTIVE
To characterize carotid intima-media thickness (IMT) and plaque occurrence in patients with newly diagnosed obstructive sleep apnea (OSA) without known cardiovascular disease.


METHODS
Prospective study.


METHODS
Sleep Laboratory and Department of Cardiology of Grenoble University Hospital.


METHODS
OSA syndrome is associated with an increased cardiovascular risk. Carotid IMT is recognized as a marker of preclinic atheroma. A small number of studies have analyzed large-artery wall modifications in OSA syndrome. Eighty-three patients (74 men; mean age +/- SD, 48 +/- 11 years; mean body mass index, 27.4 +/- 4.2 kg/m(2)) were included. Mean respiratory disturbance index was 40.7 +/- 19.2/h, mean nocturnal arterial oxygen saturation (Sao(2)) was 93.1 +/- 2.0%, and mean percentage of recording time spent at Sao(2) < 90% was 8.6 +/- 16.8%. Clinical BP was measured following European Society of Hypertension/European Society of Cardiology recommendations, and 24-h ambulatory BP monitoring was assessed. Ultrasonography was used to determine the carotid IMT and atheromatous plaque occurrence.


RESULTS
Twenty-five of 83 patients (30%) had carotid wall hypertrophy (IMT > 0.8 mm). In a logistic regression model, mean nocturnal Sao(2) < 92% (odds ratio [OR], 3.9; 95% confidence interval [CI], 1.1 to 12.7) was associated with carotid wall hypertrophy. ORs were even higher after adjustment for BP status (OR, 10.6; 95% CI, 1.6 to 50.9 in normotensive patients) and glucose levels (OR, 4.5; 95% CI, 1.0 to 20.9). Mean nocturnal Sao(2) < 92% and minimal nocturnal Sao(2) < 80% (ORs, 3.1 and 3.1; 95% CIs, 1.0 to 9.4 and 1.0 to 8.5, respectively) were associated with the presence of carotid plaque formation independently of the BP status (hypertensive or normotensive).


CONCLUSIONS
The severity of oxygen desaturation appears to be one of the best predictors for carotid IMT and plaque occurrence in OSA patients without known cardiovascular disease. Thus, carotid IMT and plaque formation appeared as early cardiovascular consequences in OSA patients.
Baguet
Jean-Philippe
JP
Department of Cardiology and Hypertension, University Hospital, EFCR University Hospital, Grenoble, France. JPBaguet@chu-grenoble.fr
Hammer
Laure
L
Lévy
Patrick
P
Pierre
Hélène
H
Launois
Sandrine
S
Mallion
Jean-Michel
JM
Pépin
Jean-Louis
JL
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002340:Carotid Artery Diseases / Q000473:pathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D045422:Continuous Positive Airway Pressure; D005260:Female; D006339:Heart Rate; D006801:Humans; D006984:Hypertrophy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000473:pathology* / Q000503:physiopathology; D017539:Tunica Intima / Q000473:pathology*; D017540:Tunica Media / Q000473:pathology*; D014463:Ultrasonography
D010100:Oxygen