Sleeping late could increase your risk of diabetes by nearly 20%

Being a night owl and having an evening chronotype increases the risk of diabetes by 19% compared to being an early riser, according to research.

New research has suggested that being a “night owl” or having an “evening chronotype” – which means going to bed and waking up late increases the risk of diabetes by 19% compared with being an early riser.

Scientists found that women who have this sleep pattern are also more likely to have unhealthy lifestyles.

Tianyi Huang, an associate epidemiologist at Brigham and Women’s Hospitals’ Channing Division of Network Medicine in the US, said, “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.”

“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.”

The researchers analyzed data from nearly 64,000 women from the Nurses’ Health Study II – which is among the largest investigations into the risk factors for major chronic diseases in women in the US – collected from 2009 to 2017.

The study encompassed participant-provided information on a range of factors, including self-reported sleep patterns, dietary habits, weight and body mass index, sleep schedules, smoking habits, alcohol consumption, levels of physical activity, and family history of diabetes.

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

Of those taking part in the study, 11% reported having a definite evening chronotype and about 35% reported a definite morning chronotype.

The rest were labelled as intermediate, meaning they identified as neither a morning nor an evening person.

After accounting for lifestyle factors, evening chronotype was associated with a 19% increased risk of diabetes, the researchers said.

Among those with the healthiest lifestyles, only 6% had evening chronotypes, compared with 25% of night owls who reported having unhealthy lifestyles.

The team noted that individuals with an evening chronotype were also more inclined to consume higher quantities of alcohol, maintain a lower-quality dietary intake, obtain fewer hours of nightly sleep, engage in current smoking habits, and exhibit unhealthy weight, BMI, and physical activity levels.

Dr. Sina Kianersi, a postdoctoral research fellow at the Channing Division of Network Medicine, explained, “When we controlled for unhealthy lifestyle behaviours, the strong association between chronotype and diabetes risk was reduced but still remained, which means that lifestyle factors explain a notable proportion of this association.”

The association between evening chronotype and diabetes risk was stronger in nurses who worked day shifts as opposed to night shift workers, “suggesting that more personalised work scheduling could be beneficial”, according to the researchers.

Researchers are now gearing up to explore the genetic origins of chronotype and its potential connections to heart disease.

Dr. Kianersi said, “If we are able to determine a causal link between chronotype and diabetes or other diseases, physicians could better tailor prevention strategies for their patients.”

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