Sleep is important for overall health, and in patients with type 2 diabetes, short nighttime sleep duration can interfere with their ability to control blood sugar. Researchers determine whether midday naps are able to reverse the negative effects of short nighttime sleep duration in patients with type 2 diabetes.
Diet, physical activity, and sleep are essential for optimal health. In today’s society, people are often consumed by late night activities that interfere with obtaining adequate sleep such as shift work and late-night entertainment. In the last few decades, people claim they are experiencing reduced sleep satisfaction that is associated with morbidity and mortality. Midday naps may be able to compensate for lost nighttime sleep and reverse the associated negative health effects.
Midday naps may increase the risk of type 2 diabetes
Midday naps are popular in some countries around the world; in Spain, a midday nap, or siesta, is part of Spanish traditional culture. However, midday naps may be detrimental to nighttime sleep by increasing the time it takes to fall asleep, increasing nighttime awakenings, and decreasing nighttime sleep duration. Midday naps have also been suggested to increase the risk of mortality in people who have long nighttime sleep duration of over nine hours, but the evidence thus far has been contradictory.
Midday naps are shown to increase the risk of developing type 2 diabetes. Further, short and long sleep duration, as well as midday naps, seem to affect the ability of patients with type 2 diabetes to control their blood sugar. In a study published in Sleep Medicine, researchers sought to determine how midday naps contribute to blood sugar control in patients with type 2 diabetes with different sleep durations.
How do midday naps contribute to blood sugar control?
The researchers recruited 398 Japanese patients with type 2 diabetes or impaired glucose tolerance and asked them to complete a self-administered questionnaire. The questionnaire gathered information regarding their sleep duration, and sleep quality, including factors like length for sleep induction, awakening during the night, and awakening earlier than desired in the morning, as well as daytime sleepiness. The researchers took blood samples from the participants to analyze their HbA1c levels. HbA1c is a biomarker for diabetes and indicates blood sugar levels over the past weeks or months, and therefore the ability of patients with type 2 diabetes to control blood sugar levels. In patients with diabetes, higher HbA1c levels indicate a higher risk of complications from diabetes.
The results showed that type 2 diabetes patients with short nighttime sleep duration of fewer than five hours had significantly higher HbA1c levels than other nighttime sleep durations (six or more hours), putting short nighttime sleepers at greater risk for complications. However, midday naps for type 2 diabetes patients with short nighttime sleep duration seemed to reduce HbA1c levels to healthier levels similar to patients with longer sleep durations. Overall, the researchers found that poor sleep satisfaction correlated with an impaired ability to control blood sugar in patients with type 2 diabetes, thereby increasing the risk for complications. Midday naps may reduce the risk of complications for patients with short nighttime sleep duration and could be beneficial for controlling blood sugar.
Midday naps may be beneficial for short sleepers
Midday naps may be harmful to many health status parameters in long nighttime sleepers, but in short nighttime sleepers, midday naps may have protective effects in specific circumstances. Life circumstances may interfere with healthy nighttime sleep duration putting people at greater risk for morbidity and mortality.
Short nighttime sleep duration is associated with increased appetite, obesity, and insulin resistance, which all contribute to the development of type 2 diabetes. It is encouraging to learn that in patients with type 2 diabetes, the negative effects of short nighttime sleep duration can be potentially reversed by midday naps when these patients are unable to obtain adequate nighttime sleep.
Written by Mallory Wiggans
Reference: Makino, S., Hirose, S., Kakutani, M., Fujiwara, M., Nishiyama, Terada, Y. & Ninomiya, H. (2018). Association between nighttime sleep duration, midday naps, and glycemic levels in Japanese patients with type 2 diabetes. Sleep Medicine, 44, 4–11.