Why night owls’ ‘misaligned’ biological clocks may increase their risk of type 2 diabetes
Experts warn that night owls are at a greater risk of developing type 2 diabetes because their biological clocks are out of sync with the rest of society.
It is already known that people who stay up late and are more active in the evening are more likely to smoke, eat unhealthy food and have a higher BMI, all of which are factors associated with the condition.
However, the increased risk of diabetes may not be due to lifestyle alone, the researchers said.
They argue that the connection may also be because a night owl’s biological clock is out of sync with the rest of society.
A team from Leiden University Medical Center analyzed the sleep timing, waist circumference and BMI of more than 5,000 people.
Night owls are at greater risk of developing type 2 diabetes because their biological clocks are out of sync with society, experts warn. Pictured: stock photo of security guard
Researchers suggest the link may also be because a night owl’s biological clock is out of sync with the rest of society (stock image)
Of the group, 1,576 participants underwent MRI scans to measure visceral and liver fat. Electronic health records were also used to check how many people had type 2 diabetes.
Patients were divided into three groups, or “chronotypes,” based on their sleep timing: late, early, and average.
Dr Jeroen van der Velde, lead researcher, said: ‘Previous studies have shown that a late chronotype – that is, a person who likes to go to bed late and wake up later – is associated with an unhealthy lifestyle.
‘For example, late chronotypes are more likely to smoke or have an unhealthy diet. This is thought to be the reason they have a higher risk of obesity and metabolic disorders, including type 2 diabetes.’
The group was followed for an average of 6.6 years. During that period, 225 patients were diagnosed with type 2 diabetes.
The study found that people who liked to stay up late were still 46 percent more likely to have type 2 diabetes than people in the intermediate group, after taking into account age, gender, body fat and lifestyle factors such as exercise, diet and smoking.
Dr. van der Velde suggested that other mechanisms may play a role than just lifestyle.
Researchers also found that night owls tend to have a higher BMI, larger waist circumference, more visceral fat, and higher liver fat content (stock image)
“A likely explanation is that the circadian rhythm or biological clock of late chronotypes is out of sync with society’s work and social schedules,” he said.
‘This can lead to circadian disruption of the biological clock, which can lead to metabolic disorders and ultimately to type 2 diabetes.’
Researchers also found that night owls tend to have higher BMIs, larger waist circumferences, more visceral fat, and higher liver fat levels.
Dr. van der Velde adds: ‘People with a late chronotype are more likely to eat later in the evening.
Although we did not measure this in our study, there is growing evidence that time-restricted eating, where you do not eat after a certain time, such as 6:00 PM, can lead to metabolic benefits.
Night owls who are concerned about their increased risk of type 2 diabetes may want to try this or at least try to avoid eating late at night.
‘The evidence is not yet available, but in the long term we want to provide specific advice on the timing of lifestyle behavior.’
The research will be presented at the annual meeting of the European Association for the Study of Diabetes in Madrid.