Aortic stiffness, flow-mediated dilatation and carotid intima-media thickness in obstructive sleep apnea: non-invasive indicators of atherosclerosis.
OBJECTIVE
Obstructive sleep apnea (OSA) has a critical association with cardiovascular mortality and morbidity. Carotid intima-media thickness (IMT), flow-mediated dilatation (FMD) and aortic stiffness are early signs of atherosclerosis. The presence of subclinical atherosclerosis was assessed in OSA patients using these parameters.


METHODS
40 patients with OSA showing an apnea-hypopnea index (AHI) > or =5 (mean age 51.3 +/- 9 years, 32 males) and 24 controls (AHI < 5, mean age 51.9 +/- 5.2 years, 19 males) were enrolled in the study. In all subjects, polysomnographic examination and recordings were performed during sleep. IMT of the carotid artery, endothelium-dependent/-independent vasodilation of the brachial artery and aortic elastic parameters were investigated using high-resolution Doppler echocardiography.


RESULTS
The demographic data of the patients with OSA and controls were not significantly different. Subjects with OSA demonstrated higher values of aortic stiffness (7.1 +/- 1.88 vs. 6.42 +/- 1.56, respectively) and IMT (0.85 +/- 0.13 vs. 0.63 +/- 0.11 mm, p = 0.0001, respectively) but lower distensibility (9.47 +/- 1.33 vs. 11.8 +/- 3.36 cm(2)/dyn/10(6)) and FMD (4.57 +/- 1.3 vs. 6.34 +/- 0.83%, p = 0.0001, respectively) than the controls. The respiratory disturbance index correlated positively with aortic stiffness and IMT and negatively with distensibility and FMD.


CONCLUSIONS
We observed blunted endothelium-dependent dilatation, increased carotid IMT and aortic stiffness in patients with OSA compared with matched control subjects. This is evident in the absence of other diseases, suggesting that OSA is an independent cause of atherosclerosis. These simple and non-invasive methods help to detect subclinical atherosclerosis in OSA.
Tanriverdi
Halil
H
Department of Cardiology, Pamukkale University School of Medicine, Denizli, Turkey. htanriverdi@posta.pamukkale.edu.tr
Evrengul
Harun
H
Kara
Cuneyt Orhan
CO
Kuru
Omur
O
Tanriverdi
Seyhan
S
Ozkurt
Sibel
S
Kaftan
Asuman
A
Kilic
Mustafa
M
D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017539:Tunica Intima / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler; D014664:Vasodilation / Q000502:physiology*