People who stay up late — or all night — are more likely to develop Type 2 diabetes and have unhealthy lifestyle behaviors than morning people, according to a new study.
Scientists say, you can’t necessarily change these habits to improve your health — sleep patterns are actually defined by a person’s circadian preference, or chronotype (Chronotype is the natural inclination of your body to sleep at a certain time). Having an internal body clock that is, in part genetically, set for staying up late makes it hard for a night owl to become an early bird, who naturally wakes up at dawn and goes to bed early.
Researchers from Brigham and Women’s Hospital in Boston had previously discovered that people with irregular sleep patterns are at a higher risk of diabetes and cardiovascular disease, and that those with an evening chronotype tend to have irregular sleep schedules — which led to studying the correlation between chronotype and diabetes risk.
The researchers looked at 63,676 nurses participating in the Nurses’ Health Study II, all between the ages of 45 and 62 and with no history of cancer, cardiovascular disease or diabetes from 2009 to 2017.
Data included self-reported chronotype — whether participants perceived themselves as either a morning or night person — quality of diet, weight and body mass index, sleep timing, smoking behaviors, alcohol use, physical activity and family history of diabetes. Diabetes status was also determined from medical records.
“Chronotype, or circadian preference, refers to a person’s preferred timing of sleep and waking and is partly genetically determined so it may be difficult to change,” said corresponding author Tianyi Huang, an associate epidemiologist in Brigham’s Channing Division of Network Medicine.
About 11% of participants self-reported having a “definite evening” chronotype, while 35% reported a “definite morning” chronotype. Everyone else was categorized as “intermediate” — meaning either they didn’t identify with either chronotype, or identified with one just slightly more than the other.
Before accounting for the destructive lifestyle of night owls, the evening chronotype had a 72% increased risk for diabetes.