title: Factors associated with increased carotid intima-media thickness in obstructive sleep apnea/hypopnea syndrome.
abstract: 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.
authors.affiliation: Department of Neurology, Division of Cerebrovascular Disease, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Teng-Yeow
authors.initials: TY
authors.lastname: Tan
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Liou
authors.forename: Michael
authors.initials: M
authors.lastname: Friedman
authors.forename: Hsin-Ching
authors.initials: HC
authors.lastname: Lin
authors.forename: Hsueh-Wen
authors.initials: HW
authors.lastname: Chang
authors.forename: Meng-Chih
authors.initials: MC
authors.lastname: Lin
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D059168:Carotid Intima-Media Thickness / Q000145:classification* / Q000706:statistics & numerical data; D016022:Case-Control Studies; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D017286:Polysomnography; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D049629:Waist-Hip Ratio
chemical_list: D001786:Blood Glucose; D008078:Cholesterol, LDL; D002097:C-Reactive Protein