Nighttime sleeping habits have a significant impact on the risk of diabetes. Those who go to bed late and wake up late seem to be particularly at risk.
A new study involving experts from Harvard Medical School examined the role modifiable lifestyle habits play in the connection between the so-called chronotype and the risk of diabetes. The results are published in the journal “Annals of Internal Medicine”.
Differences between night owls and larks
Our usual sleep and wake times are partly genetic and are referred to as chronotype or circadian preference. For example, there are larks who go to bed early and get up early in the morning, while night owls go to bed late and get up later in the morning.
The researchers have now analyzed the extent to which these chronotypes influence the risk of diabetes using data from a total of 63,676 nurses who were part of the Nurses’ Health Study II. In addition to the chronotype of the participants, many other factors were also recorded, such as the quality of the diet, alcohol consumption, smoking and physical activity.
In addition, the researchers determined whether diabetes was present by evaluating self-reports and also using medical records.
More morning people than night people
According to the experts, around eleven percent of the participants stated that they could clearly be assigned to the night owl chronotype. In contrast, 35 percent of the participants belonged to the Lerche chronotype.
Increased risk of diabetes due to sleeping habits
Without taking lifestyle factors into account, there was a clear connection between sleep habits and an increased risk of diabetes among night owls. The researchers report that their likelihood of developing diabetes was increased by 72 percent compared to the larks.
Taking lifestyle factors into account, night owls still had a 19 percent increased risk of developing diabetes, the experts continued.
It was striking that among the participants who had the healthiest lifestyle, only six percent were assigned to the night owl chronotype. In contrast, 25 percent of the women who were assigned to the unhealthiest lifestyle were participants who went to bed late and got up late, the researchers emphasize.
According to the study results, participants who were assigned to the night owl chronotype drank more alcohol, consumed more low-quality foods, slept fewer hours at night, smoked more often and their weight, body mass index and physical activity were more often in an unhealthy range.
Strong association between chronotype and diabetes risk
“When we took unhealthy lifestyle habits into account, the strong association between chronotype and diabetes risk decreased but remained, meaning that lifestyle factors explain a significant portion of this association,” emphasizes study author Dr. Sina Kianersi in a press release.
In addition, the team emphasizes that the association between the night owl chronotype and an increased risk of diabetes was only found in nurses who worked day shifts, while there was no increased risk when working night shifts.
“When the chronotype did not match work hours, we saw an increased risk of type 2 diabetes. “This was another very interesting result that suggests that more individualized work planning could be beneficial,” explains study author Tianyi Huang.
Effects of disturbed sleep
The new results confirm previous research that has shown a connection between sleep and an increased risk of diabetes. For example, a 2022 study demonstrated a link between disturbed sleep and various risk factors for type 2 diabetes.
The researchers made it clear that poor sleep is not only due to too short a sleep, but that other factors such as the times at which you go to bed and get up in the morning also play a significant role.
Additionally, another research has suggested that inadequate sleep leads to higher blood sugar levels and may play a direct role in the development of type 2 diabetes.
Taken together, the results make it clear that sleep has a significant impact on diabetes risk. According to the researchers, not only lifestyle factors such as diet or alcohol consumption, but also sleeping habits should be taken into account in the future to protect against diabetes.
However, “chronotype, or circadian preference, describes a person’s preferred sleep and wake times and is partly genetic, so it can be difficult to change,” explains Huang.
Huang believes that night owls may need to pay more attention to their lifestyle in general, as their chronotype may put them at increased risk of type 2 diabetes. (as)
