Study: Sleep deprivation can cause heart attack
The study was part of the Lifepath project and pooled data from eight cohorts totaling 111,205 participants from four European countries. Socioeconomic status was classified as low, middle, or high according to the father's occupation and personal occupation. History of coronary heart disease and stroke was obtained from clinical assessment, medical records, and self-report.
Average sleep duration was self-reported and categorized as recommended or normal sleep (6 to 8.5), short sleep (6), and long sleep (more than 8.5) hours per night. The contribution of insufficient sleep was investigated using a statistical approach called mediation analysis. It estimates the contribution of an intermediate factor (sleep) to an association between the main exposure (socioeconomic status) and the main outcome (coronary heart disease or stroke).