Objectively measured sleep characteristics and prevalence of coronary artery calcification: the Multi-Ethnic Study of Atherosclerosis Sleep study

• Published in: Thorax Vol. 70; no. 9; p. 880
• Main Authors: Lutsey, Pamela L, McClelland, Robyn L, Duprez, Daniel, Shea, Steven, Shahar, Eyal, Nagayoshi, Mako, Budoff, Matthew, Kaufman, Joel D, Redline, Susan
• Format: Journal Article
• Language: English
• Published: England 01-09-2015
• Subjects: Aged; Aged, 80 and over; Atherosclerosis - complications; Calcinosis - complications; Calcinosis - epidemiology; Coronary Artery Disease - complications; Coronary Artery Disease - epidemiology; Coronary Artery Disease - physiopathology; Ethnic Groups; Female; Humans; Male; Middle Aged; Polysomnography; Prevalence; Risk Factors; Sleep - physiology; Sleep Apnea, Obstructive - complications; Sleep Apnea, Obstructive - physiopathology; Sleep apnoea
• ISSN: 1468-3296
• DOI: 10.1136/thoraxjnl-2015-206871

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.
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.
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.
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.