Coronary artery calcification is a subclinical predictor of coronary heart disease. Recent studies have found that sleep duration is correlated with established risk factors for calcification including glucose regulation, blood pressure, sex, age, education, and body mass index.
To determine whether objective and subjective measures of sleep duration and quality are associated with incidence of calcification over five years and whether calcification risk factors mediate the association.
Observational cohort 2000–2006. Potential confounders (age, sex, race, education, apnea risk, smoking status) and mediators (lipids, blood pressure, body mass index, diabetes, inflammatory markers, alcohol, depression, hostility, self reported medical conditions) were measured at both baseline and follow-up. We examined sleep metrics (wrist actigraphy measured duration and fragmentation, daytime sleepiness, overall quality, self-reported duration) for association with incident calcification.
Home monitoring of healthy middle-aged population.
494 participants from the CARDIA cohort Chicago site (African American and white men and women aged 35–47 at baseline) with sleep, demographic and calcification measurements and no detectable baseline calcification.
Coronary artery calcification was measured by CT in 2000–2001 and 2005–2006; incidence of new calcification over that time was the primary outcome.
Five-year calcification incidence was 12.3% (n=61). Longer measured sleep duration was significantly associated with decreased adjusted odds of calcification (OR = 0.67 per hour, p=.011; 95% CI 0.49–0.91). No potential mediators appreciably altered the magnitude or significance of sleep (adjusted OR estimates ranged from 0.64 to 0.68 per sleep hour, maximum p-value=.020). Alternative sleep metrics were not significantly associated with calcification.
Longer measured sleep is associated with lower calcification incidence independently of examined potential mediators and confounders.