The Link Between Blood Sugar Levels and Sleep, Explained

The Link Between Blood Sugar Levels and Sleep, Explained

Some people say “sleep is for the weak,” but the truth is, sleep plays a role in so many aspects of our health—including blood sugar.

Regardless of whether or not you have diabetes, “blood sugar naturally rises at night in all of us, including healthy adults who regularly get the recommended amount of sleep,” explains Brittany Lubeck, a registered dietitian (RD) based in Colorado.

Why? Overnight, your liver—which makes and stores glucose for later use—releases glucose into the bloodstream to ensure you have enough energy to wake up in the morning. As a result, it’s common for blood sugar to rise in the early morning hours (think: between 3 a.m. and 8 a.m.), an experience known as the dawn phenomenon.

However, says Lubeck, blood sugar can continue to remain high throughout the day in those with diabetes or insulin resistance.

How Blood Sugar Can Affect Sleep

We’re still learning about why (and how) blood sugar may affect sleeping patterns. But, according to Erin Decker, a registered dietitian (RD) and certified diabetes care and education specialist (CDCES), one theory is that, since high blood sugar typically makes you go to the bathroom more frequently, that means more disruptions in your sleep as well.

“High blood sugar can also lead to increased thirst and headaches, which may interfere with sleep, too,” adds Michelle Routhenstein, CDCES, RDN, who specializes in preventive cardiology.

On the other hand, low blood sugar at night—known as nocturnal hypoglycemia—can leave you feeling sweaty, shaky, and restless, making it difficult to sleep.

Generally speaking, the relationship between sleep and blood sugar can be so rocky that, for some, it may lead to insomnia, explains Routhenstein. Not only do blood sugar levels themselves seem to influence sleep quality, but health-related stress about your blood sugar (and the way it’s affecting your sleep) can keep you up at night, too, according to the National Sleep Foundation.

However, it’s often unclear which comes first: poor sleep or unbalanced blood sugar levels.

How Sleep Can Affect Blood Sugar

Sleep’s effects on blood sugar can be both biological and behavioral, says David Ahn, MD, an endocrinologist, program director, and Kris V. Iyer Endowed Chair in Diabetes Care at the Mary and Dick Allen Diabetes Center.

“Biologically, inadequate sleep can lead to higher levels of cortisol (a stress hormone) and increased insulin resistance, both of which raise blood sugar,” he explains. “Behaviorally, people tend to consume more calories and experience more hunger with less sleep.”

Why? Poor sleep is associated with disturbances in our appetite hormones, explains One Drop coach Sandra, RDN, CDCES. Lack of rest seems to trigger production of ghrelin, a hormone that makes you feel hungry, while simultaneously decreasing production of leptin, a hormone that makes you feel full.

You’ve been there: After a sleepless night, you wake up craving caffeine, carbs, and sugary treats—anything to give you an energy boost that takes your mind off of how tired you feel, right?

But, of course, all of these indulgences can make it that much harder to maintain balanced blood sugar levels (and, in turn, a good sleep schedule).

Healthy Ways to Manage Sleep and Blood Sugar At the Same Time

You’re probably already on top of details such as your nutrition, exercise regimen, and any medications you might take to manage your blood sugar. But, thanks to the pervasive “we’ll sleep when we’re dead” culture, many of us leave the importance of sleep out of the equation, says Sandra.

“It can be motivating to keep track of your blood sugar levels and see how sleep quality impacts them over time,” notes Decker. “A continuous glucose monitor (CGM) makes this really easy.” (If you have a Dexcom, here’s how to sync your CGM data with the One Drop app.)

So, what can you do to maintain a healthy sleep schedule *and* solid blood sugar levels? Here are some expert tips to help you stay on the right track:

  • Keep a consistent sleep schedule. Do your best to go to sleep and wake up at the same time every day—even on the weekends, says Sandra. Consistency in your sleep schedule keeps your circadian rhythm (a.k.a. your body’s internal clock) happy, and research shows that your circadian rhythm is key in regulating how your body produces and uses glucose.
  • Create a relaxing bedtime routine. That means leaving enough time, even on busy days, to unwind by reading, listening to music, meditating, doing yoga, taking a bath—whatever bedtime ritual serves you personally. Managing stress with these types of self-care activities can help you avoid a potential rush of cortisol that will spike your blood sugar and disturb your sleep. “Even something simple but predictable works, like brushing your teeth followed by reading in bed,” suggests Decker.
  • Get some fresh air. Daylight is a crucial component of healthy sleep patterns, says Sandra. Exposing yourself to natural light helps balance out your body’s melatonin production at night, setting you up for a restful sleep, explains Decker. Plus, getting outside more usually means you’re staying active. Regardless of how you spend that time, a little movement can go a long way in promoting both healthy blood sugar levels and sleep patterns, explains Sandra.
  • Minimize nighttime snacking. Sandra says it’s best to stop eating and drinking around two hours before going to sleep to avoid frequent bathroom trips and indigestion, which may cause high blood sugar and disrupt your sleep. If a nightcap of beer or wine helps you relax before bed, remember that too much alcohol at night can unsettle your sleep as well as your blood sugar levels, so moderation is key. (Need more advice on bedtime snacking? Here’s how to improve your nutrition for better sleep and blood sugar.)

This article has been clinically reviewed by Jamillah Hoy-Rosas, MPH, RDN, CDCES, and VP of clinical operations at One Drop.

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Allie Strickler
Aug 20, 2021

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