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 apnea (OSA) and sleep quality are associated with coronary artery calcification (CAC) prevalence independent of obesity, a classic confounder. Methods A total of 1,465 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. OSA categories were defined by apnea-hypopnea index (AHI). Prevalence ratios 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 [1.16 (95% CI: 1.06–1.26)], body mass index [1.11 (1.02–1.21)], and traditional cardiovascular risk factors [1.10 (1.01–1.19)]. Other markers of hypoxemia tended to be associated with 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 multiethnic 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 in measuring disturbances in OSA as well as in sleep fragmentation as possible risk factors for coronary artery disease.

Obstructive sleep apnoea and cardiovascular calcification

“…The study by Lutsey et al ,2 published in this issue of Thorax adds another piece to the puzzle of the link between OSA and cardiovascular risk by showing significant associations between parameters of sleep-disordered breathing and coronary atherosclerotic calcification.…”

“…Increased coronary artery calcification (CAC) has been associated with increased cardiovascular risk and shown to provide further prognostic information in addition to traditional cardiovascular risk factors. Evidence is now accumulating linking sleep disturbances with increased CAC,2 4 5 and inflammation may represent an important factor when it comes to OSA-induced atherosclerotic calcification.…”

“…The association of increased sleep fragmentation and low sleep quality with increased CAC2 5 implicates sympathetic nervous activation, which in turn may activate inflammatory circuits. However, it is, above all, the typical breathing pattern in OSA causing an intermittent hypoxia, which is a potent proinflammatory stimulus 1.…”

Deleterious systemic effects of OSA: how much evidence do we need?

“…What do the three papers published in the current issue of the journal add to the literature?6–8 Two of the three papers6 7 stem from the Multi-Ethnic Study of Atherosclerosis (MESA), a multisite cohort study of community-dwelling men and women aged 45–84 years without known cardiovascular disease at enrolment 9. A subset of these patients participated in the MESA sleep ancillary study from which the presented data were drawn.…”

“…A subset of these patients participated in the MESA sleep ancillary study from which the presented data were drawn. In the study by Lutsey et al ,6 the hypothesis was tested whether polysomnography-derived indices of OSA severity and sleep quality are associated with the prevalence of coronary artery calcification (CAC) in coronary CT. The authors found that patients with severe OSA were more likely to have prevalent CAC relative to those with no evidence of OSA (1.10, 95% CI 1.01 to 1.19).…”