NBC News:   “The time you go to bed may affect your risk for heart disease. In fact, researchers say, there is a heart health sweet spot for falling asleep: from 10 to 11 p.m.

“An analysis of data from more than 88,000 adults tracked for around six years revealed a 12 percent greater risk among those who dropped off from 11 to 11:59 p.m. and a 25 percent higher risk of developing cardiovascular disease among people who fell asleep at midnight or later. Falling asleep earlier than 10 p.m. was associated with a 24 percent increase in risk, according to a report published Monday in the European Heart Journal—Digital Health. ‘The body has a 24-hour internal clock, called circadian rhythm, that helps regulate physical and mental functioning,’ a co-author of the study, David Plans, a neuroscientist and experimental psychologist who is a senior lecturer in organizational neuroscience at the University of Exeter in the U.K., said in a statement. ‘While we cannot conclude causation from our study, the results suggest that early or late bedtimes may be more likely to disrupt the body clock, with adverse consequences for cardiovascular health.’

“To explore how different bedtimes might affect heart health, Plans and his colleagues turned to UK Biobank, which maintains information about more than 500,000 volunteers ages 37 to 73 who were recruited from 2006 to 2010 and provided information about their demographics, lifestyles and health. Their physical health was also assessed.”