Night owls are 20% more like to suffer from a major chronic disease, study suggests

  • Women who classify themselves as ‘evening people’ have a higher risk of diabetes
  • American researchers say that this group is more likely to lead an unhealthy lifestyle

Being a ‘night owl’ increases the risk of diabetes in women by almost a fifth, according to a new study.

Researchers have found that women who classify themselves as a “night owl” (going to bed late and getting up late) are at greater risk of the health disease than “early risers.”

Experts say that this group also more often has an unhealthy lifestyle: drinking more alcohol and not exercising enough.

A team from Brigham and Women’s Hospital in Boston analyzed data from nearly 64,000 middle-aged nurses between 2009 and 2017.

This included self-reported sleep habits, diet, weight and BMI, sleep timing, smoking behavior, alcohol consumption and physical activity.

Researchers have found that women who classify themselves as a “night owl” — going to bed late and getting up late — are at greater risk for the health disease compared to “early risers.”

The researchers also looked at medical records to see if the women had diabetes.

Of all participants, 11 percent indicated they had a clear evening chronotype, also known as circadian preference.

Meanwhile, 35 percent said they definitely had a morning chronotype.

The rest were labeled as in-betweeners, meaning they did not identify as morning or evening people.

Analysis found that an evening chronotype was associated with a 19 percent increased risk of diabetes, the researchers said.

Study author Tianyi Huang said: ‘Chronotype, or circadian preference, refers to a person’s preferred timing of sleep and waking and is partly genetically determined, so it can be difficult to change.

‘People who think they are ‘night owls’ may need to pay more attention to their lifestyle, as their evening chronotype may put them at increased risk for type 2 diabetes.’

Of those in the study with the healthiest lifestyles, only 6 percent were night owls. However, of those with the unhealthiest lifestyle, 25 percent preferred to go to bed late.

Evening people were also more likely to drink alcohol in larger amounts, have a low-quality food diet, get fewer hours of sleep per night, currently smoke and have a weight, BMI and physical activity in the unhealthy range, the team added.

Dr. Sina Kianersi, first author of the study, said: ‘When we controlled for unhealthy lifestyle behaviours, the strong association between chronotype and diabetes risk was reduced but still remained, meaning lifestyle factors explain a significant part of this association.’

The association between evening chronotype and diabetes risk was stronger among day shift nurses than night shift workers, “suggesting that more personalized work scheduling could be beneficial,” the team added.

The scientists now plan to investigate the genetic causes of chronotype and its link to heart disease.

Dr. Kianersi said, “If we can establish a causal relationship between chronotype and diabetes or other diseases, physicians can better tailor prevention strategies to their patients.”

The findings were published in the journal Annals of Internal Medicine.