title: Objectively measured sleep characteristics and prevalence of coronary artery calcification: the Multi-Ethnic Study of Atherosclerosis Sleep study.
abstract: BACKGROUND
  We tested whether objectively measured indices of obstructive sleep apnoea (OSA) and sleep quality are associated with coronary artery calcification (CAC) prevalence independent of obesity, a classic confounder.
  
  
  METHODS
  1465 Multi-Ethnic Study of Atherosclerosis participants (mean age 68 years), who were free of clinical cardiovascular disease, had both coronary CT and in-home polysomnography and actigraphy performed. OSA categories were defined by the Apnea-Hypopnea Index (AHI). Prevalence ratios (PRs) for CAC >0 and >400 (high burden) were calculated.
  
  
  RESULTS
  Participants with severe OSA (AHI ≥30; 14.6%) were more likely to have prevalent CAC, relative to those with no evidence of OSA, after adjustment for demographics and smoking status (PR 1.16; 95% CI 1.06 to 1.26), body mass index (1.11; 1.02 to 1.21) and traditional cardiovascular risk factors (1.10; 1.01 to 1.19). Other markers of hypoxaemia tended to be associated with a higher prevalence of CAC >0. For CAC >400, a higher prevalence was observed with both a higher arousal index and less slow-wave sleep. Overall, associations were somewhat stronger among younger participants, but did not vary by sex or race/ethnicity.
  
  
  CONCLUSIONS
  In this population-based multi-ethnic sample, severe OSA was associated with subclinical coronary artery disease (CAC >0), independent of obesity and traditional cardiovascular risk factors. Furthermore, the associations of the arousal index and slow-wave sleep with high CAC burden suggest that higher nightly sympathetic nervous system activation is also a risk factor. These findings highlight the potential importance of measuring disturbances in OSA as well as sleep fragmentation as possible risk factors for coronary artery disease.
authors.affiliation: Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Lutsey
authors.affiliation: Department of Biostatistics, University of Washington, Seattle, Washington, USA.
authors.forename: Robyn L
authors.initials: RL
authors.lastname: McClelland
authors.affiliation: Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Duprez
authors.affiliation: Departments of Medicine and Epidemiology, Columbia University, New York, New York, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Shea
authors.affiliation: Division of Epidemiology & Biostatistics, University of Arizona, Tucson, Arizona, USA.
authors.forename: Eyal
authors.initials: E
authors.lastname: Shahar
authors.affiliation: Department of Community Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Mako
authors.initials: M
authors.lastname: Nagayoshi
authors.affiliation: Department of Medicine, University of California-Los Angeles, Torrance, California, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Budoff
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kaufman
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000150:complications*; D002114:Calcinosis / Q000150:complications* / Q000453:epidemiology; D003324:Coronary Artery Disease / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D015995:Prevalence; D012307:Risk Factors; D012890:Sleep / Q000502:physiology*; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology
keywords: Sleep apnoea