While being a night owl has a certain cachet, a new study shows that staying up into the wee hours can be downright dangerous. The late-night lifestyle was shown to dramatically raise diabetes risk and cause several other health-damaging effects.
The research, which was led by scientists at Leiden University Medical Centre in the Netherlands, looked at 5,000 overweight individuals who were participating in the Netherlands Epidemiology of Obesity study, an ongoing effort aimed at finding out the ways in which body fat contributes to disease.
The participants had a mean age of 56 years and a mean BMI of 30, which is at the border between being classified as overweight and obese. They were asked to fill out a survey indicating their typical sleep and waking times and, from this data, the researchers calculated their midpoint-of-sleep, or MPS times.
Using MPS data, the research participants were divided into three chronotype groups. The first 20% had the earliest MPS at 2:30 AM; the second 20% had intermediate MPS at between 2:30-4 AM; and the final 60% were considered to be late chronotypes with an MPS of later than 4 AM. The participants were followed up for a median of 6.6 years.
After adjusting for factors including total body fat, diet, age, sex, education and lifestyle factors including smoking, sleep quality and duration, and alcohol intake, the researchers found that those with late chronotypes had a whopping 46% higher risk of developing type 2 diabetes than those who had the intermediate chronotype.
They also found that those in the late chronotype group had higher BMIs than the other two groups as well as waistlines that were 1.9 cm (0.7 in) larger. They also had 7 cm (1 inch) more visceral fat and 14% higher liver fat content than those in the intermediate chronotype.
Late-night munchies
While the research has established the link between staying up late and developing diabetes, causality is still unknown. One theory the researchers have is that night owls might simply eat more.
“People with a late chronotype are probably more likely to eat until later in the evening,” says lead researcher Jeroen van der Velde. “While we did not measure this in our study, there is growing evidence that time-restricted eating, not eating anything after a certain time, such as 6 pm, may lead to metabolic benefits. Night owls who are concerned about the increased risk of type 2 diabetes might want to try this or, at least, try to refrain from eating late in the evening."
The team will also be investigating if changing sleep patterns could shift the health effects from staying up late.
Trying to sleep earlier certainly seems like a good idea considering that another 2022 study linked a light-night lifestyle to diabetes and increased heart disease risk and a study earlier this year linked late-night living to an increased risk of dying earlier.
“We believe that other mechanisms are also at play,” says van der Velde. “A likely explanation is that the circadian rhythm or body clock in late chronotypes is out of sync with the work and social schedules followed by society. This can lead to circadian misalignment, which we know can lead to metabolic disturbances and ultimately type 2 diabetes.”
The findings will be reported at the Annual Meeting of the European Association for the Study of Diabetes to be held in Madrid this week.
Source: Diabetologia via EurekAlert
