Sleep and Diabetes: Understanding The Connection

Written by Rama Manikumar on Fri, 11 November 2022

Key Highlights

  • People who have poor sleep habits are at greater risk for becoming overweight or obese and developing type 2 diabetes, according to several studies.
  • Chronic sleep deprivation may lead to insulin resistance, which can result in high blood sugar and diabetes.
  • Some studies show that chronic sleep deprivation can affect hormones that control appetite. 
  • In addition to medications, recommendations to improve sleep are: learn relaxation and breathing techniques, listen to relaxing music and get regular exercise.

Glucose comes from the Greek word which means "sweet". It is a type of sugar one gets from the food one consumes, and the body uses it for energy. As it travels from the bloodstream to cells, it is called blood glucose or blood sugar.

Insulin is a hormone that moves glucose from the blood to cells for energy and storage.

What Are Normal Blood Sugar Levels

They are less than 100mg/dL after fasting for at least 8 hours and they are less than 140mg/ dl 2 hours after eating. During the day, levels tend to be at their lowest just before meals. For most people without diabetes, normal blood sugar levels before meals hover around 70 to 80 mg/dL.

How Much Sugar in The Blood is Too Much?

Level over 200 mg/dl 2 hours after a meal or over 125mg/dL fasting is high blood glucose also called hyperglycemia. High glucose levels lead to diabetes.

There are two types of diabetes:

  • Type 1 diabetes: The body doesn't have enough insulin. The immune system attacks and destroys cells of the pancreas, where insulin is made.
  • Type 2 diabetes: The cells don't respond to insulin as they should. So, the pancreas needs to make more and more insulin to move glucose to the cells. Eventually, the pancreas is damaged and can't make enough insulin to meet the body's needs.

Without enough insulin, glucose can't move into the cells. As a result, the blood glucose levels stay high.

Relation Between Blood Sugar and Sleep

Blood sugar levels and sleepGetting really good, consistent sleep is one of the most important and kind of fundamental aspects of health. Unfortunately, a lot of people have issues with sleep.

Some people have issues falling asleep such that you get all ready for bed and your body just seems revved up and it has a hard time dropping into sleep. Other people have no problem falling asleep but say at 2 or 3 in the morning, they wake up and have a hard time getting back to sleep.

One of the most common causes of waking up in the middle of the night is something called nocturnal hypoglycaemia. This is where blood sugar level drops low during the night and you end up waking up.

As you eat food throughout the day some of the glucose from that food is used for energy and some of the glucose gets stored in the form called glycogen. When one falls asleep, the body releases the stored glycogen and converts it back into glucose, and feeds it back into the bloodstream. This is how blood sugar levels remain stable.

Some people just don't eat enough calories: for instance, having just coffee for breakfast or skipping lunch altogether. This when done over long periods can lead to a situation where there are not enough calories and not enough stored glycogen to be released throughout the night to keep blood sugar levels stable, leading to nocturnal hypoglycemia.

Hypoglycemia & Hyperglycemia

Both hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) can affect sleep in those with diabetes. Hypoglycemia may occur when you have not eaten for many hours, such as overnight, or if you take too much insulin or other medications.

Hyperglycemia occurs when the sugar level rises above normal. This may happen after eating too many calories, missing medication, or having an illness. Emotional stress can also cause your blood sugar to rise.


Obesity, or too much body fat, is often associated with snoring, sleep apnea, and sleep disturbance. Obesity increases the risk of sleep apnea, type 2 diabetes, heart disease, hypertension, arthritis, and stroke.

Does Sugar Affect Your Sleep

It all depends upon timing. If someone is going from one meal to another, craving lots of sugary foods, then not only does sleep affect blood sugar levels, but blood sugar levels can also affect sleep.

If there is a fluctuation in one's energy levels, and blood sugar levels keep going up and down, then it can potentially affect the hormone cortisol which results in waking up a lot at night.

How Sleep Affects Blood Sugar

Sleep habits play a key role in controlling blood sugar (or glucose), which increases the chances of getting diabetes.

  • Blood sugar levels surge when one is sleeping. In a healthy person, insulin can handle the surge by telling muscle, fat, and liver cells to absorb the glucose from the blood, which keeps blood sugar levels stable.
  • For people who have diabetes or who are likely to get It, Insulin can't do that job very well which results in more rise in blood sugar levels.

How Does Lack of Sleep Raise Your Risk of Diabetes

Many studies have suggested that short sleepers (those who get less than 6 hours per night) have irregular eating habits, snack more, and are more likely to eat unhealthy food. Other research has found that short-changing sleep can directly affect how the body makes other hormones, which in turn affect blood sugar.

For example, when you stay up late, your body makes more of the hormone cortisol, which affects how insulin works. Also, growing evidence has shown that disrupting one's biological clock by being awake at night can make cells more resistant to insulin.

Decreased sleep is a risk factor for increased blood sugar levels. Even partial sleep deprivation over one night increases insulin resistance, which can in turn increase blood sugar levels. As a result, a lack of sleep has been associated with diabetes.

The following factors have been found to influence the relationship between sleep and blood sugar levels.

  • The amount of time a person sleeps
  • The time of day a person sleeps
  • A person's age
  • A person's eating habits

How Blood Sugar Levels Impact Sleep

Just as sleep affects blood sugar levels, blood sugar levels may also impact sleep quality. A study has found that those with higher blood sugar levels experience poorer sleep as compared to the ones with normal blood sugar levels.

Another study found that people with glucose levels in the pre-diabetes range are likely to have poor sleep, compared to people with normal glucose levels.

Can Low Blood Sugar Cause Sleep Problems

Low blood sugar called hypoglycemia can cause sleep problems. Hypoglycemia can occur in people with or without diabetes. Nocturnal hypoglycemia is a form of hypoglycemia that occurs at night.

Low blood glucose levels and hypoglycemia can have a negative impact on sleep. If one is taking insulin or other blood sugar medication, one may be at risk of low blood sugar levels during the night.

Low blood sugar levels overnight can disrupt the sleep pattern and lead to difficulty waking in the morning and tiredness throughout the day. According to the National Institute of Diabetes and Digestive and Kidney Diseases, low blood sugar during sleep can cause the following symptoms

  • Nightmares
  • Sweating profusely
  • Feeling irritable or confused upon waking

Researchers have found the following connections between sugar and lack of sleep or sleep problems:

  • Sleep-disordered breathing is associated with high glucose levels
  • Obstructive sleep apnea is associated with impaired glucose tolerance
  • More severe sleep breathing issues are associated with increased fasting glucose
  • Lack of sleep is associated with reduced ability to control glucose levels in diabetic patients
  • Lack of sleep is associated with type 2 diabetes even in children

High blood sugar during the night can lead to insomnia and next-day fatigue. As with many chronic conditions, feeling of depression or stress about the disease itself may also keep one awake at night.

When blood sugar levels are high, the kidneys overcompensate causing them to urinate more often. During the night, these frequent trips to the bathroom lead to disrupted sleep. High blood sugar may also cause headaches, increased thirst, and tiredness that can interfere with falling asleep.

Common Sleep Disorders in People with Diabetes

  • Restless legs syndrome: Persons with type 2 diabetes may have restless legs syndrome. It causes tingling or irritating sensations in the legs that can interfere with getting to sleep.
  • Obstructive Sleep Apnea: Obstructive sleep apnea is a sleep disorder in which a person momentarily stops breathing at recurring intervals throughout the night. In most cases, the person is not aware this is happening, though a bed partner may observe snoring and gasping. These lapses in breathing cause micro-arousals (very brief awakenings) that interfere with the natural progression of the sleep stages and impair sleep quality.

Sleep Apnea & Diabetes

tips for diabetics for better sleep healthSleep Apnea is a common breathing disorder that affects many people whilst they sleep. This could be an early warning that diabetes development is underway.

Numerous medical studies have linked obstructive sleep apnea with a greater risk of developing type 2 diabetes. According to experts, side effects directly related to sleep apnea could influence the metabolism of people as they sleep.

A potential treatment is continuous positive airway pressure (CPAP). With CPAP, patients wear a mask over their nose and/or mouth. An air blower forces air through the nose and/or mouth. The air pressure is adjusted so that it is just enough to prevent the upper airway tissues from collapsing during sleep. The pressure is constant and continuous. CPAP prevents airway closure while in use, but apnea episodes return when CPAP is stopped or is used improperly.

The correlation between lack of sleep and diabetes is well-proven, with interruptions to deep sleep a key part of diabetes risk.

How Are Sleep Problems Diagnosed

  • Your doctor will ask you about your sleep patterns, including whether you have trouble falling or staying asleep, are sleepy during the day, have difficulty breathing while asleep (including snoring), have pain in your legs, or move or kick your legs while sleeping.
  • Your doctor may refer you to a sleep specialist who may do a special sleep study called a polysomnogram to measure activity during sleep.
  • The results of the sleep study can help your doctor make an accurate diagnosis and prescribe an effective and safe treatment.

How Can People with Diabetes Cope with Sleep Issues

Careful management of blood sugar levels can help to improve sleep for people with type 2 diabetes. Good sleep hygiene habits are important. These include both daytime and night-time habits, such as:

Adhering to a diet plan that works for you helps keep blood sugar under control.

  • If you work night shifts or rotating shifts, try and maintain regular meal and sleep times. Also, get some exercise during breaks.
  • Have a good bedtime snack which helps to keep blood sugar levels steady throughout the night. These include oatmeal and other whole grain cereals, whole grain bread, and other complex carbohydrates.
  • One should eat a protein-rich snack within an hour before bed, which could be an egg or 2 or a good scoop of peanut butter or almond butter. These foods will not only help maintain blood sugar levels; they actually can help promote sleep by increasing the level of serotonin in the brain.
  • Avoiding stimulants like caffeine or nicotine before bed.
  • Maintain a regular sleep schedule. Getting a good night's sleep on a regular basis will go a long way towards helping a body to use insulin efficiently. Along with getting enough sleep, one should avoid eating late at night and should try to get some exercise after dinner, like going for a walk.
  • Proper sleep hygiene and by keeping the bedroom cool, dark, and quiet.


By now, you would have understood the intrinsic connection between sleep and diabetes.

Lack of sleep can affect blood sugar levels whereas blood glucose control can also affect sleep, which results in trouble sleeping. Low blood sugar levels also known as hypoglycemia can disrupt sleep pattern and lead to difficulty waking in the morning and tiredness throughout the day.

High blood sugar levels also have a negative impact on sleep and can lead to insomnia and next-day fatigue. There are various ways where one can cope with sleep issues & maintain normal blood sugar levels like exercising, having proper meals, and maintaining a proper sleep schedule.


Rama Manikumar

Rama is a nutritionist and a lifestyle consultant. Having worked in the health industry for more than 20 years, her expertise in health and well-being brings a fresh and healthy approach to everyday habits- food and lifestyle. She walks the talk and delivers excellent quality nutrition, and helps develop habits that peak health & Well- being. Rama Holds a Batchelor’s degree in Biology; Extended/Specialized degree in Nutrition & Dietetics (Pennsylvania State Univ. USA).

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