There is an ongoing debate about whether it is better to be a night owl or a morning person. The new evidence Nocturnal voyagers have been found to be about 50% more likely to develop type 2 diabetes than those who end their nights quickly.
Dark-dwellers are slow chronotypes who prefer to sleep late and wake up late — a behavior that’s associated with a higher likelihood of smoking and unhealthy eating habits, as well as a higher risk of obesity and type 2 diabetes, a chronic metabolic disease.
“However, we believe that lifestyle alone cannot fully explain the relationship between chronotype and metabolic disorders in later life,” said Jeroen van der Velde, a researcher at Leiden University Medical Center in the Netherlands.
“Furthermore, slower chronotypes are more likely to [body mass index]”However, it is unclear to what extent chronotype influences body fat distribution,” van der Velde added.
His team studied the relationship between sleep duration, diabetes and body fat distribution in more than 5,000 participants in the Netherlands Obesity Epidemiology Study.
Most of the volunteers were in their mid-50s and shared their typical wake-up and bedtimes.
Participants were divided into three groups: early sleepers (20% of participants with the earliest bedtime), late sleepers (20% of participants with the latest bedtime), and intermediate sleepers (the remaining 60%).
Participants were followed for almost seven years, during which time 225 were diagnosed with type 2 diabetes.
After adjusting the results for lifestyle factors such as age, sex, education, body fat, physical activity, diet quality and alcohol intake, the researchers determined that participants with a later chronotype had a 46% higher risk of diabetes than those with an intermediate chronotype.
The results suggest that lifestyle alone is not responsible for the increased diabetes risk for slower chronotypes, van der Velde said.
“What’s likely happening is that slow chronotypes’ circadian rhythms, or body clocks, are out of sync with the work and social schedules that society follows,” he reasoned. “This leads to misalignment of circadian rhythms, which we know leads to metabolic disorders and ultimately type 2 diabetes.”
Van der Velde’s team expected that early-rising chronotypes would have a similar risk of diabetes as intermediate chronotypes, but they found that early risers actually had a slightly higher risk, although “this was not statistically significant.”
The researchers also found that late chronotypes had higher BMIs, larger waist circumferences, more visceral fat (the harmful fat that wraps around the internal organs), and higher fat content in their livers than their mid-chronotype counterparts.
“Late chronotypes appear to be at higher risk of developing type 2 diabetes compared with intermediate chronotypes, probably due to having more body fat, including visceral and liver fat,” van der Velde says.
“The next step is to study whether lifestyle timing changes in slow chronotypes can improve metabolic health,” he added.
Night owls should consider finishing their meals at a specific time, such as 6 p.m., as meal timing can affect digestion and metabolism, van der Velde said.
“We don’t have the evidence yet, but our aim is to eventually provide specific advice on the timing of lifestyle actions,” van der Velde said.
His findings, to be presented this week at the European Association for the Study of Diabetes annual meeting, are in line with recent research suggesting that a night-time lifestyle may be good for cognitive function but bad for mental health.
Dr. Mitchell RoslinPoor sleep habits can increase the risk of obesity and diabetes and increase the production of stress hormones such as cortisol, said Dr. Schneider, chief of the obesity and metabolic surgery department at Northern Westchester Hospital and Lenox Hill Hospital.
“Cortisol and stress further increase blood sugar levels, which in turn promotes weight gain,” Rothlin, who was not involved in the new study, told The Post. “Weight gain increases your risk for sleep apnea and insulin resistance. We’re just seeing things get worse.”
