Night Owls or Early Birds: Who Gets Diabetes?

Evening chronotype — or circadian preference to go to sleep late at night — has been associated with unhealthy lifestyle behaviors, obesity, and disrupted glycemic control. Although cross-sectional studies have linked evening chronotype to diabetes risk, prospective investigations are lacking. Researchers used data from the prospective Nurses' Health Study II to determine diabetes incidence among ≈64,000 middle-aged women — mostly white and middle-class — with no history of diabetes who reported a definite evening or morning chronotype (about half of participants said neither category clearly fit their circadian pattern).

Participants with evening chronotype were 1.5 times more likely to have unhealthy lifestyle behaviors than were those wit…