A previous meta-analysis assessing the relationship between sleep duration and health found significantly increased mortality for ≥ 9 hours of sleep, and increased cancer mortality for ≥ 9 hours of sleep.  In a new meta-analysis, researchers investigated whether the association between sleep duration and all-cause mortality, cardiovascular disease mortality, and cancer mortality differs between men and women. The subjects were 34,311 participants with detailed assessment of sleep at baseline and up to 20.5 years of follow-up. The results indicated that both long and short sleep duration were associated with increased all-cause, CVD and cancer mortalities in all subjects.  Men with short sleep (<5 hours) did not show a significantly increased all-cause mortality, while women who slept < 5 hours had a greater all-cause mortality risk than men. For cardiovascular disease mortality and cancer mortality, women and men did not differ on long or short sleep. However, subjects who slept five hours per night had the lowest cancer mortality risk.