How are sleep characteristics related to cardiovascular health? Results from the population-based hypnolaus study

Abstract

Background-Although sleep characteristics have been linked to cardiovascular disease and cardiovascular risk factors, the association between sleep characteristics measured by polysomnography and cardiovascular health (CVH) remains unknown. Methods and Results-In a population-based sample (n=1826), sleep characteristics were assessed by both sleep questionnaires and polysomnography. Global, behavioral, and biological CVH were defined according to the American Heart Association. Multinomial logistic regressions were performed to estimate relative risk ratios and 95% CI. Strong dose-response associations were found between all oxygen saturation-related variables (oxygen desaturation index, mean oxygen saturation, and percentage of total sleep time spent under 90% oxygen saturation) and obstructive sleep apnea (severity categories and apnea/hypopnea index) and global, behavioral, and biological CVH. Mean oxygen saturation had the strongest positive association (relative risk ratios 1.31 [CI 1.22-1.41]; 1.78 [CI 1.55-2.04] for intermediate relative to ideal CVH), and oxygen desaturation index had the strongest negative association (relative risk ratios 0.71 [CI 0.65-0.78]; 0.45 [CI 0.34-0.58] for intermediate relative to ideal CVH) with global CVH, and these associations were also the most robust in sensitivity analyses. The impacts of sleep architecture and sleep fragmentation were less consistent. Conclusions-Mean oxygen saturation, oxygen desaturation index, and apnea/hypopnea index were associated with CVH. Conversely, most variables related to sleep architecture and sleep fragmentation were not consistently related to CVH. Sleepdisordered breathing and the associated oxygen (de)saturation were associated with CVH more strongly than with sleep fragmentation.