A study reports that shorter the sleep one takes during the midlife higher is the risk of late-onset dementia. The study included 7959 participants of the Whitehall II study to examine the association between sleep duration and incidence of dementia using over 25 years. 521 participants developed dementia mostly after the age of 70 years. These participants had sleep duration of six hours or less at age 50 and 60 compared with a normal 7h sleep duration. Also, sleep duration of at least 7 hours was associated with better cardiometabolic and mental health profile. Persistent short sleep duration at age 50, 60 and 70 lead to 30% increase in risk of dementia compared to persistent normal sleep duration. This risk was independent of behavioural, cardiometabolic, sociodemographic and mental health factors. There was an association of change in sleep duration with subsequent dementia.
