Night owls beware – you could be at higher risk of developing type 2 diabetes.
A new study indicates that people with later sleep and wake times had less healthy lifestyles and were at greater risk of developing diabetes than those with early-bird sleep habits.
Researchers found night owls had a 72% increased risk of developing diabetes over the eight years of the study.
"Chronotype, or circadian preference, refers to a person's preferred timing of sleep and waking," coauthor Tianyi Huang, assistant professor of medicine at Harvard Medical School and associate epidemiologist of medicine at Brigham and Women's Hospital, said in a statement. "People who think they are 'night owls' may need to pay more attention to their lifestyle because their evening chronotype may add increased risk for type 2 diabetes."
Researchers previously found that people with more irregular sleep schedules are at higher risk of developing diabetes and cardiovascular disease, and that people with evening chronotypes are more likely to have irregular sleep patterns. For this study, they wanted to understand the relationship between chronotype and diabetes risk and looked at the role of lifestyle factors as well.
The team analyzed data from 63,676 female nurses from the Nurses' Health Study II -- aged 45 to 62 years with no history of cancer, cardiovascular disease, or diabetes -- collected from 2009-2017. They found that night owls overall were more likely to have a poor diet, to be less physically active, to use alcohol in higher quantities, to smoke and to sleep less or more than the seven to nine hours that's recommended each night.
The team found that participants with a "definite evening" chronotype were 54% more likely to have an unhealthy lifestyle than participants reporting a "definite morning" chronotype. Persons with evening chronotype also had a 72% higher risk of developing diabetes during the follow-up period.
Researchers say further investigation is needed in other populations to determine whether of not the findings are applicable to men, non-White racial or ethnic groups, or other socioeconomic classes.
The study findings are published in the Annals of Internal Medicine.