- The estimated glucose disposal rate is a test that can help measure insulin resistance, a primary driver of type 2 diabetes.
- A cross-sectional study found that 7.32 hours of sleep was ideal for the estimated glucose disposal rate.
- Increasing sleep until 7.32 hours was associated with improved estimated glucose disposal rates, while increasing it to or above this amount was associated with worse estimated glucose disposal rates.
- Further analysis suggested that moderate weekend catch-up sleep may be helpful for insulin resistance, but possibly harmful for people already getting enough sleep.
Experts are interested in finding the optimal amount of sleep for different aspects of health. One area of interest is how sleep relates to
One recent study explored how sleep duration relates to insulin sensitivity, which can be a driving factor for type 2 diabetes.
The authors of this study explain that in metabolic syndrome, the body is less responsive to insulin.
The study, published in BMJ Open Diabetes Research & Care, found that a little less than seven and a half hours of sleep is linked to the best level of insulin sensitivity.
For this cross-sectional study, researchers gathered their data from the
They looked at how sleep was related to estimated glucose disposal rate. This measurement takes into account hemoglobin A1C, high blood pressure, and waist circumference, which also reflects insulin resistance. An increased estimated glucose disposal rate (eGDR) would indicate less insulin resistance.
They also examined how catching up on sleep over the weekend played into things.
Researchers excluded certain individuals, such as pregnant participants and individuals younger than age 20, ultimately including 23,475 participants in their analysis. They had access to participants’ answers to how much they typically slept on weekdays. For about 11,000 participants, they also had data on about how many hours participants slept on weekends.
They then broke down the amounts of weekend catch-up sleep into four categories, ranging from no weekend catch-up sleep to more than two hours of weekend catch-up sleep.
Seven and a half hours of sleep was the median for sleep during the week, while eight hours was the median over the weekend.
Researchers identified a non-linear relationship between weekday sleep and eGDR, specifically an inverted U-shape. They estimated the turning point to be about 7 hours and 19 minutes of sleep, or 7.32 hours. Up to this amount, getting more sleep was linked to higher eGDR. But once people slept 7 hours and 19 minutes or more, getting even more sleep was linked to lower eGDR.
When they looked at different groups separately, the results were mostly the same. The connection between sleeping 7 hours and 19 minutes or more and having lower eGDR was especially strong for women, adults aged 40 to 59, and people with a body mass index (BMI) of 30 or higher.
Next, researchers looked at how weekend catch-up sleep came into play. They found that for people with sleep duration of less than 7.32 hours, getting up to two hours of extra sleep on the weekend was linked to increased eGDR levels.
The greatest benefit was seen in participants who were in the more than one hour and up to two hours of extra sleep group. For participants who were getting at least 7.32 hours or more, weekend catch-up sleep didn’t have a significant link to eGDR.
Further analysis revealed that getting more than two hours of weekend catch-up sleep moderated the negative link between the amount of sleep during the week and eGDR, compared to no weekend catch-up sleep. This suggests that getting higher amounts of weekend catch-up sleep could ultimately worsen blood sugar control.
With additional analysis, the authors suggest that getting excessive amounts of weekend catch-up may not be “recommended for optimal health outcomes.” They did find that for people getting less than 7.32 hours of sleep, the ideal amount of weekend catch-up sleep was 1.16 hours, and for people getting at least 7.32 hours, the amount was 1.12 hours.
David Cutler, MD, board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, who was not involved in the study, noted that the study showed that getting enough sleep during the week was important for health.
“[An] interesting aspect of this study’s findings was that while 7.32 hours was found to be the ideal sleep duration, getting weekend catch-up sleep when a sleep debt occurred, was only beneficial in moderation, not when it exceeded two hours. The take-home message seems to be to get 7 – 8 hours’ sleep per night and only use the weekends to make up for 2 hours of lost sleep during the week.”
— David Cutler, MD
This data has some limitations. First, it cannot establish a causal relationship, so the sleep durations don’t necessarily cause insulin resistance, and researchers note that reverse causality is possible. More long-term data will be helpful.
Second, it relies on participant reporting about things like sleep duration, which might not be accurate. Researchers note that reports of sleep on the weekend may have a decrease in accuracy.
They also note that “the proportion of the extreme population in this study is approximately 3.0%,” which could impact the effect size.
It’s also possible that researchers didn’t adjust for important confounders, like sleep quality, and this could have led to residual confounding and ultimately bias. There may also be problems with generalizability, and more work in other countries and populations may be helpful.
Researchers also only had data about weekend sleep for less than half of the participants they analyzed. Another challenge was that researchers couldn’t distinguish between sleep that occurred at night and sleep that occurred during the day.
Kaushik Govindaraju, DO, board certified internist with Medical Offices of Manhattan, and contributor to https://www.labfinder.com/, who was also not involved in the study, noted the following about the limits and possibilities of this research:
“This has major implications for potentially predicting incidence of metabolic syndrome and cardiovascular disease in adults. The limitation is that it excludes pregnant individuals and those under 20 years of age, which limits the findings’ potential utility as a longitudinal predictive measure for young adults and pregnant adults.”
“[I]t is interesting to be able to better put into objective scientific parameters why 7-8 hours of sleep serves a true benefit. Furthermore, it gives clinicians objective clinical evidence guidance as to the risks and benefits of napping and ‘catching up’ on sleep during weekends and vacations.”
— Kaushik Govindaraju, DO
A major emphasis from the study authors is the need for personalized sleep recommendations. They also note that guidelines should encourage consistent sleep rather than trying to catch up on sleep over weekends.
Cutler also noted how addressing sleep could ultimately help address diabetes.
“Diet and exercise are also major determinants in controlling the development of diabetes. But since poor sleep will often trigger a worse diet and a diminished capacity for exercise, focusing on sleep can target many birds with one stone,” he said.
“While this connection between sleep and diabetes may seem remote, the increasing prevalence of obesity and diabetes in our society should make everyone take notice of any factors which may prevent this major contributor to cardiovascular morbidity and mortality. This is especially true when it is something as cheap, easy, and safe to get as more sleep.”
— David Cutler, MD
People who are interested in improving their sleep habits can talk with their doctors about strategies that may help in their situation.
