A new study has found that people who sleep too little or go to bed late may experience greater fluctuations in their blood sugar levels, which could increase their risk of diabetes and other metabolic problems.
Researchers from Westlake Laboratory of Life Sciences and Biomedicine in China discovered that both short sleep duration and late bedtimes are linked to higher glycemic variability, meaning blood sugar levels fluctuate more throughout the day.
The study, published in JAMA Network Open, suggests that consistent, adequate sleep and earlier bedtimes could play a key role in maintaining stable blood sugar levels and preventing diabetes.
How Sleep Affects Blood Sugar
Blood sugar regulation is essential for good health. When glucose levels rise and fall too much, it can increase the risk of diabetes complications. Previous research has already shown that poor sleep can impair the body’s ability to process glucose, but this study is one of the first to track long-term sleep habits and their direct effects on blood sugar fluctuations.
The researchers analyzed data from 1,156 adults aged 46 to 83 as part of the ongoing Guangzhou Nutrition and Health Study in China. Participants reported their sleep habits over multiple years, and their blood sugar levels were monitored in real time using continuous glucose monitoring (CGM) devices for 14 consecutive days.
The Impact of Sleep Duration and Bedtime
Based on sleep patterns, the researchers identified four groups:
- Severe inadequate sleep (4.7 to 4.1 hours per night)
- Moderate inadequate sleep (6.0 to 5.5 hours per night)
- Mild inadequate sleep (7.2 to 6.8 hours per night)
- Adequate sleep (8.4 to 8.0 hours per night)
They also classified participants into two bedtime categories:
- Early sleep onset (going to bed earlier)
- Late sleep onset (going to bed later)
Key Findings
- People in the severe inadequate sleep group had 2.87% higher glycemic variability and a 0.06 mmol/L increasein daily blood sugar fluctuations compared to those who got adequate sleep.
- Participants who went to bed late had 1.18% greater glycemic variability and a 0.02 mmol/L increase in daily blood sugar fluctuations.
- The worst effects were seen in those who both slept too little and went to bed late—they had even greater blood sugar fluctuations than those with just one of these poor sleep habits.
What This Means for Health
These results suggest that both sleep duration and bedtime habits influence blood sugar regulation. People who consistently sleep too little or go to bed late may have more unstable glucose levels, increasing their risk of developing diabetes and other metabolic issues over time.
Maintaining sufficient sleep and going to bed earlier could help improve blood sugar control and reduce the risk of diabetes-related complications. This research highlights the importance of sleep as part of a healthy lifestyle—not just for energy and mental function but also for blood sugar stability and long-term metabolic health.
While more research is needed to fully understand the biological mechanisms behind these effects, the findings suggest that improving sleep habits could be a simple yet powerful way to support better blood sugar management.
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The research findings can be found in JAMA Network Open.
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