The Importance of Sleep Health for Diabetes

Sleep — both quantity and quantity — is a lesser-known but key element to good diabetes health. It may get less attention than diet, exercise, and the proper use of medications (including insulin), but it’s a shockingly critical contributor to your overall health.

Sleep is important for everyone, but is especially so for people with diabetes. That’s because poor sleep has surprising connections to metabolic health, both direct (it can provoke insulin resistance) and indirect (it can lead to depression and binge eating).

This article will outline the many connections between sleep and diabetes. We will also offer ideas on how much sleep you should be getting, and how you can change your bedtime rituals to help make it happen more easily.

Sleep and Glucose Control

There is a mountain of evidence linking poor sleep and diabetes, especially type 2 diabetes. In large observational studies, many elements of suboptimal sleep — including short sleep duration, obstructive sleep apnea, shift work, and insomnia — have been found to correlate to type 2 diabetes development and progression, enough for poor sleep to be named a significant risk factor for the disease. Unsurprisingly, sleep disorders are unusually common among people with type 2 diabetes.

It’s not always clear whether these associations indicate causation; it’s possible that people with type 2 diabetes tend to sleep less as a consequence of other risk factors or of the disease itself. And if poor sleep does cause metabolic dysfunction, it’s still up for debate whether the causes are primarily behavioral or physiological.

The mechanisms linking sleep quality and insulin resistance haven’t been perfectly elucidated yet, but many studies have shown that sleep deprivation can cause significant metabolic dysfunction:

• A landmark 1999 study found that when healthy adults were forced into a state of sleep deprivation, their baseline levels of both insulin and glucose shot up, as did measures of insulin resistance. Other studies have confirmed the effect, constituting “the strongest evidence physiologically linking sleep loss to the increased rates of diabetes.”
• A 2022 experiment examined sleep and glucose data from 953 healthy adults. The researchers found that multiple sleep variables were significantly associated with glycemic control. When participants got less sleep, or even when they just fell asleep later than usual, their blood sugar levels spiked higher after breakfast.
• A 2021 review of seven sleep intervention studies found that “sleep deprivation and poor sleep quality are connected with blood glucose disturbance and reduction of insulin sensitivity.”

High blood sugar is also correlated with poor sleep, even in people without diabetes. Poor sleep habits appear to interrupt a complex range of hormonal and metabolic changes, resulting in increased inflammation and insulin resistance.

The causation appears to go in both directions here, too, as high blood sugar and insulin resistance are thought to contribute to common sleep problems such as sleep apnea and sleep-disordered breathing.

The blood sugar consequences of sleep deprivation can be subtle — a poor night of sleep will not necessarily cause glucose management nightmares the very next day. But routine or chronic sleep deprivation, if it leads to rising insulin resistance and carbohydrate intolerance, can magnify the difficulties of diabetes management.

We shouldn’t be too confident that proper sleep will help your glucose control numbers. According to the experts at the National Institute of Diabetes and Digestive and Kidney Diseases, there is little direct evidence as of yet that improving sleep can lead directly to improved glucose metabolism. But the subject has lately become an area of intense interest: “the efficacy and effectiveness of interventions that optimize sleep and circadian function to prevent the development or reduce the severity of these metabolic disorders need to be urgently evaluated.”

But there’s a lot more to sleep and diabetes than just the immediate metabolic effects. Poor sleep also triggers a variety of knock-on effects that can really frustrate your diabetes management efforts.

Insulin Treatment and Sleep

People with type 1 diabetes, and those with type 2 diabetes that use insulin, have an additional problem to worry about: overnight glucose management challenges.

Blood sugar highs and lows, when they occur in the middle of sleep, can be downright dangerous. Most people with these conditions know what it’s like to wake up in the cold sweat of hypoglycemia and stumble towards the kitchen, ready to eat all the world’s sugar at once. Less critical diabetes events can cause sleep disturbances, too. Insulin pumps and continuous glucose monitors, for example, will sound erroneous alarms or beep when they temporarily lose connectivity. As a result, disordered sleep is common among such patients. These sleep disturbances are also linked with poor blood sugar control.

Of course, there are times when diabetes means that we need to lose sleep to attend to our health needs. As our writer Sysy Morales once reminded us, losing sleep to deal with acute blood sugar issues is worth it. It can be tempting to ignore a high or low blood sugar in the middle of the night, but these situations can get dangerous and even deadly.

Solving for sleep issues can also be especially difficult for people using intensive insulin management. As an example, while exercise usually helps healthy adults sleep better, it can have the opposite effect for people with type 1 diabetes, because it also creates an enhanced likelihood of nocturnal hypoglycemia.

Put it all together, and people that use insulin to treat their diabetes are likely to have even greater sleep challenges. Good sleep hygiene habits aren’t just a matter of getting cozy at the right time, but of making the right exercise, insulin, and eating decisions hours before bedtime. But by the same token, insulin users may stand to benefit most of all from making the right decisions to foster a good night of deep sleep.

Sleep and Food

Poor sleep habits go hand in hand with poor eating habits. The science suggests that each might cause the other.

The following is a mere smattering of the many studies to have demonstrated that poor sleep can lead to suboptimal diet choices:

• A 2012 study found that “reduced sleep may lead to greater propensity to overeat.”
• A 2014 review found that sleep reduction experiments cause both physiological and behavioral changes that promote weight gain.
• A 2014 study showed that sleep deprivation changes brain activity leading to “a significant increase in the desire for weight-gain promoting high-calorie foods.”
• A 2022 study randomized adolescents to five consecutive nights of healthy sleep (9.5 hours “sleep opportunity”) or short sleep (6.5 hours). The youngsters with less sleep ended up eating more added sugar, more carbohydrates, more sweetened beverages, and fewer fruits and vegetables.

It’s pretty simple — a poor night of sleep makes you more likely to binge on unhealthy foods.

The cause-and-effect likely goes both ways, too, as there is plenty of evidence suggesting that food quality also affects sleep quality. If it’s true that bad food leads to bad sleep, it suggests that there may be a vicious cycle at play — poor sleep causes us to reach for unhealthy foods, which just causes more poor sleep.

There needs to be more study to tease out correlation from causation. But in the meantime, it must be unsurprising that so many surveys of sleep habits and diets, whether they examine Danish school children or middle-aged Japanese women, find that poor diets and poor sleep go hand in hand.

What type of diet is best for a good night’s sleep? The science isn’t settled by any means, but we identified a few research papers to address the topic:

• A 2016 study found that a diet low in fiber but high in saturated fat and sugar was associated with “lighter, less restorative sleep with more arousals.” The authors concluded that “it is possible that a diet rich in fiber, with reduced intake of sugars and other non-fiber carbohydrates, may be a useful tool to improve sleep depth and architecture in individuals with poor sleep.”
• A 2020 review showed that a Mediterranean diet predicts healthier sleep.
• A 2022 review recommends “whole diets rich in fruits, vegetables, legumes, and other sources of dietary tryptophan and melatonin.” Tryptophan, an amino acid that can help regulate sleep patterns, is also found in lean meats and seafood. Melatonin, a hormone essential to sleep, is found in nuts, whole fruit, and animal products such as milk, eggs, and seafood.

Finally, sleep may also be important for weight loss. While good sleep quality will not help you lose weight all on its own, there is evidence that it is necessary to maximize a diet’s efficacy.

This small but thought-provoking 2010 study took 10 overweight adults and asked them to eat the same diet for two weeks. Half were told to sleep 5.5 hours per night, the other half 8.5 hours. Remarkably, the dieters that got plenty of sleep lost 55% more fat than the sleep-deprived group, suggesting that lack of sufficient sleep can really sabotage your weight loss efforts.

Sleep and the Immune System

Whether it’s the flu, gum disease, or cuts and scrapes, experts always caution people with diabetes to be extremely careful about infections and illnesses. The reason is simple: the high blood sugar characteristic of diabetes hinders the body’s natural defenses. People with diabetes are generally considered at least somewhat immunocompromised, and are cautioned to take more than usual care to avoid infections.

The immune system, as it turns out, is strongly related to the body’s circadian rhythms and sleep cycles. Many studies have demonstrated that low sleep quality makes the body more susceptible to infection. One 2009 experiment, for example, found that healthy adults that got fewer than seven hours of sleep every night were an extraordinary 2.94 times more likely to develop a cold than those who got eight hours of sleep or more.

If you have diabetes, you may already know that even minor illnesses, like the common cold, can cause serious blood sugar management challenges. Now you also know that a proper night of sleep represents a significant line of defense.

Sleep and Mental Health

The connections between sleep and mental health are too numerous to detail in this article. This overarching review by experts at the CDC is just one of many similar authoritative reports to note that inadequate sleep is associated with a great variety of types of mental distress. To put it simply: If you don’t get enough sleep, it’s almost certainly bad for your mental health.

What does this have to do with diabetes? Unfortunately, mental health and diabetes coexist far too often. Studies show that depression, for example, is “more than three times higher in people with type 1 diabetes … and nearly twice as high in people with type 2 diabetes.” Mental health issues are also associated with a higher likelihood of diabetic complications and early death.

Nobody with diabetes should be surprised at the link, as it is much harder to manage your physical health when suffering from mental issues, even minor ones. And it’s harder still if you’re exhausted, too.

Lack of sleep is also associated with other unhealthy hedonistic behaviors like drinking alcohol and smoking cigarettes. Of course, it’s more difficult to exercise if you haven’t slept well. Lack of sleep is even correlated with risky behaviors, such as texting while driving or biking without a helmet.

Sleep deprivation can help touch off a vicious cycle by triggering mental distress, which only frustrates your diabetes management efforts, which only triggers even more mental distress. A good night’s sleep is not likely to solve all your problems, but it may be a surprisingly effective way of addressing so many of them all at once.

Sleep and Cardiovascular Risk

As if we haven’t already given you enough to worry about, sleep also has a significant effect on cardiovascular health. As the American Heart Association reports, not getting enough restful sleep is correlated with inflammation, stroke, heart attack and early death. People with common sleep disorders “are also far more likely to have heart arrhythmias, plaque buildup, heart failure and coronary artery disease than the general public.”

That spells double trouble for people with diabetes, who are already at a greatly increased risk of these conditions. Cardiovascular disease is the single leading cause of death in people with diabetes. A huge percentage of everything you’ve been taught about diabetes management — health, nutrition, exercise, and medication — was designed with the intent to lower your risk of pain and death from these related diseases. Prioritizing healthy sleep may well be another effective way of addressing those risks.

Sleep Apnea

This condition deserves a few extra words, because something like half of all people with type 2 diabetes experience obstructive sleep apnea. The condition is also more prevalent in type 1 diabetes.

Sleep apnea is a disorder in which breathing becomes very shallow or stops temporarily during sleep. These pauses can last 10 seconds or longer, and occur repeatedly throughout the night. Sleep apnea is often characterized by loud snoring, gasping, and breathing interruptions that cannot be perceived easily be the sleeper in question.

Sleep apnea should be considered an especially serious form of sleep disturbance for people with diabetes, one that definitely requires professional help. The condition can increase the risk of metabolic illnesses (including diabetes progression), heart disease and other cardiovascular illnesses, mental health issues such as depression, and even glaucoma and certain cancers. Diagnosis may require a sleep study overnight at a special clinic.

Sleep apnea is treated the same way that diabetes is — with lifestyle interventions intended to confer weight loss and good metabolic health — but there are more targeted treatments available as well, such as the CPAP machine, which gently forces air into your lungs as you sleep. Treating sleep apnea also can lead to glucose control improvements.

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How Much Sleep Do You Need?

The CDC recommends that adults get seven or more hours of sleep per night. That’s seven hours of “good quality” sleep — if your sleep is frequently interrupted during those seven hours, you’re probably not getting all the rest that you need.

How much sleep is ideal for people with diabetes? A meta-analysis of ten different studies found that a nightly average of seven to eight hours of sleep is associated with the lowest risk of type 2 diabetes. Perhaps that’s the sweet spot for metabolic health.

Surveys show that most of us fail to get as much sleep as we should. The CDC reports that a third of Americans “usually get less than the recommended amount of sleep,” and that nearly 11 percent of Americans are only getting 6 or fewer hours of sleep per night.

There are many reasons why people aren’t getting enough sleep these days: 24/7 technology, ever-increasing workloads, light and noise pollution in cities. It may take some concerted effort to develop and stick to the healthy rituals and habits that can help you get a full night of sleep.

And by the way — it looks like catching up on sleep on the weekends doesn’t really work. The best practice, if you can manage it, is to get a complete and steady night of sleep, every night.

Creating Healthy Sleep Habits

Our partners at Everyday Health have put together an excellent guide to getting the right amount of high-quality sleep: Sleep 101: The Ultimate Guide to a Better Night’s Sleep.

Among their recommendations, consider the following:

• Stick to a consistent sleep schedule, going to bed and waking up at the same times, even on weekends.
• Reduce your caffeine and alcohol intake.
• Exercise regularly (but be careful about the risk of overnight hypoglycemia).
• Avoid screens (television, phones, computers) before bed. Consider banishing such electronics from the bedroom — unless they’re used to manage your blood sugar, that is.
• Don’t linger in bed if you’re not asleep.
• Improve the atmosphere in your bedroom. You’ll probably sleep better in a room that is dark and cooled to the right temperature.

The above ideas can work for anybody, but here are a few extra tips for people with diabetes:

• Try to steady your blood sugar before bedtime. At dinner time, consider avoiding high-carb meals that require high insulin doses. Be aware that dishes that combine large amounts of carbs and fats, like pizza, often prompt glucose spikes hours after you’ve finished eating.
• Try to go sleep with less fast-acting insulin “on board.”
• Avoid excessive alcohol — it can create overnight blood sugar drops.
• Be strategic with late night snacks; they should enhance your overnight glucose control, not frustrate it.

The Bottom Line

Sleep is a surprisingly important factor in diabetes management. A poor night of sleep has all sorts of consequences, both direct and indirect; it can negatively impact your insulin sensitivity and may even compel you to engage in a variety of less healthful behaviors. Chronic sleep can also exacerbate the risk of mental and cardiovascular health issues.

Getting the right amount of sleep isn’t a cure-all, but it is a terrific way of putting your health on the right track, putting you in the best possible position to manage your diabetes optimally.

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