Mortality associated with short sleep duration: The evidence, the possible mechanisms, and the future

Abstract

This review of the scientific literature examines the widely observed relationship between sleep duration and mortality. As early as 1964, data have shown that 7-h sleepers experience the lowest risks for all-cause mortality, whereas those at the shortest and longest sleep durations have significantly higher mortality risks. Numerous follow-up studies from around the world (e.g., Japan, Israel, Sweden, Finland, the United Kingdom) show similar relationships. We discuss possible mechanisms, including cardiovascular disease, obesity, physiologic stress, immunity, and socioeconomic status. We put forth a social-ecological framework to explore five possible pathways for the relationship between sleep duration and mortality, and we conclude with a four-point agenda for future research.

Copyright 2009 Elsevier Ltd. All rights reserved.

Figures

Figure 1. Model for socioecological influences upon sleep duration/behavior and associated outcomes

A – Direct causal relation between sleep duration and mortality B1 & B2 – Intermediary role of sleep (mediator and moderator roles) C – Cause of outcomes that, in turn, confer increased mortality D – Linked with phenomena that are associated with increased mortality