Factors Associated With Increased Carotid Intima-Media Thickness in Obstructive Sleep Apnea/Hypopnea Syndrome

BACKGROUND: Obstructive sleep apnea/hypopnea syndrome (OSAHS) is strongly associated with the increase of cardiovascular and cerebrovascular disorders. Carotid intima-media thickness (IMT) is used as a surrogate marker for subclinical or early atherosclerosis. Knowledge regarding early atherosclerosis in patients with OSAHS is scarce, and factors predicting carotid IMT have not been well studied. OBJECTIVE: To compare IMT in patients with OSAHS versus controls and explore the factors associated with increased IMT in OSAHS. METHODS: One hundred fifty-six OSAHS patients and 35 controls without history of vascular events, hypertension, and diabetes mellitus who underwent polysomnography were consecutively enrolled. Carotid IMT was measured using B-mode ultrasonography. Body mass index, waist circumference, hip circumference, waist-to-hip circumference ratio, Epworth Sleepiness Scale, and polysomnographic variables including arousal index, apnea/hypopnea index, mean oxygen saturation, and lowest oxygen saturation were assessed. Fasting plasma glucose, blood lipid profile, and high-sensitivity C-reactive protein were measured. RESULTS: Average carotid IMT of OSAHS patients was significantly thicker than controls (0.66 vs. 0.58 mm, P=0.002) and multivariable logistic regression analysis revealed that arousal index [odds ratio (OR), 0.77; confidence interval (CI), 0.63-0.95; P=0.01] and lowest oxygen saturation (OR, 1.91; CI, 1.24-2.95; P=0.003) were significantly associated with OSAHS patients. Among the OSAHS patients, age (OR, 1.16; CI, 1.10-1.22; P<0.0001), fasting plasma glucose (OR, 1.05; CI, 1.01-1.10; P=0.04), low-density lipoprotein cholesterol (OR, 1.03; CI, 1.02-1.05; P<0.0001), and high-sensitivity C-reactive protein (OR, 1.48; CI, 1.13-1.95; P=0.005) were significantly associated with patients with IMT≥0.65 mm. CONCLUSIONS: IMT was thicker in OSAHS patients without history of vascular events, hypertension, and diabetes mellitus. This study demonstrates that early atherosclerosis exists in this group of patients.