Relation of obstructive sleep apnea to coronary artery calcium in non-obese versus obese men and women aged 45-75 years.

Sleep apnea and obesity are strongly associated, and both increase the risk for coronary artery disease. Several cross-sectional studies have reported discrepant results regarding the role obesity plays in the relation between sleep apnea and coronary artery calcium (CAC), a marker of subclinical coronary disease. The aim of the present study was to investigate the association between sleep apnea and the presence of CAC in a community cohort of middle-aged men and women without preexisting cardiovascular disease, stratified by body mass index (<30 vs ≥30 kg/m(2)). Participants underwent electron-beam computed tomography to measure CAC and underwent home sleep testing for sleep apnea. The presence of CAC was defined as an Agatston score >0. Sleep apnea was analyzed categorically using the apnea-hypopnea index. The sample was composed of primarily men (61%) and Caucasians (56%), with a mean age of 61 years. The prevalence of CAC was 76%. In participants with body mass indexes <30 kg/m(2) (n = 139), apnea-hypopnea index ≥15 (vs <5) was associated with 2.7-fold odds of having CAC, but the effect only approached significance. Conversely, in participants with body mass indexes ≥30 kg/m(2), sleep apnea was not independently associated with CAC. In conclusion, sleep apnea is independently associated with early atherosclerotic plaque burden in nonobese patients.