We think of sleep as downtime when the brain shuts off and the body rests. But it is much more than that. Research shows that a number of vital tasks are carried out during sleep to help individuals maintain good health and function at their best.
During sleep, the brain works at forming the pathways for learning and creating memories. Without adequate amounts, you can’t focus, pay attention or respond quickly. In addition, there is growing evidence that shows a chronic lack of sleep increases the risk for developing obesity, diabetes, cardiovascular disease, and infections.
Recent surveys show the average adult now gets less than 7 hours a night, and more than one-third of adults report daytime sleepiness so severe that it interferes with work and social functioning at least a few days each month. New research suggests adults need at least 7–8 hours each night to be well rested.
Sleep used to be considered a long block of time when you are not awake. Now we know it has distinct stages. How well rested you are and how well you function depend, not just on your total sleep time, but on how much of the various stages of sleep you get each night. Your brain stays active throughout sleep, and each stage of sleep is linked to a distinctive pattern of electrical activity known as brain waves.
Types of Sleep
Sleep may be broken down into two types’ rapid eye movement (REM) sleep and non-REM sleep (with four different stages).
REM. During REM sleep, your eyes move rapidly in various directions, even though your eyelids remain closed. Your breathing becomes more rapid, irregular, and shallow. Your heart rate and blood pressure increase. Dreaming typically occurs during REM cycles. During this phaseyour arm and leg muscles are temporarily paralyzed so that you cannot “act out” any dreams that you may be having.
Non-REM Stage 1. Light sleep; easily awakened; muscle activity; eye movements slow down.
Non-REM Stage 2. Eye movements stop; slower brain waves, with occasional bursts of rapid brain waves.
Non-Rem Stage 3. Considered deep sleep; difficult to awaken; brain waves slow down more, but still have occasional rapid waves.
Non-Rem Stage 4. Considered deep sleep; difficult to awaken; extremely slow brain waves.
The first period of REM sleep usually occurs about an hour to an hour and a half after falling asleep. After that, the stages repeat themselves continuously while you sleep. As the night progresses, REM time becomes longer, while time spent in non-REM stages 3 and 4 becomes shorter. By morning, nearly all your time is spent in stages 1 and 2 of non-REM and in REM.
Diabetes and Sleep
“There is some evidence that sleep deprivation could lead to pre-diabetic state,” says Mark Mahowald, MD, director of the Minnesota Regional Sleep Disorders Center. According to Mahowald, the body’s reaction to sleep loss can resemble insulin resistance, a precursor to diabetes. One study found that, when healthy young men slept only 4 hours a night for 6 nights in a row, their insulin and blood sugar levels mimicked those in people who were developing diabetes.
A study published in the Archives of Internal Medicine found that women who slept only five hours a night were 2 ½ times more likely to have diabetes as those who slept seven or eight hours. One explanation for this link is that sleep-deprivation increases insulin resistance, which contributes to diabetes.
Diabetes and sleep problems often go hand in hand. People who have diabetes often have poor sleep habits, including difficulty falling or staying asleep. Some people with diabetes get too much, while others have problems getting enough.
Sleep Problems and Type 2 Diabetes
Causes of sleep problems for people with type 2 diabetes include: sleep apnea, pain or discomfort from neuropathy, restless legs syndrome, the urge to go to the bathroom, and other complications associated with type 2 diabetes.
Apnea. Apnea results in pauses in breathing. The periods of stopped breathing are called apneas, which are caused by an obstruction of the upper airway.
Apneas may be disrupted by a brief stirring that does not awaken you completely. You may not realize that your sleep was disturbed, yet if measured in a laboratory, changes in the brain waves that are characteristic of awakening would be recorded.
One of the factors may be excess weight, which can cause fat deposits around the upper airway that obstruct breathing. Up to two-thirds of the people who have apnea are overweight.
Apnea alters the cycles and stages of sleep. Some studies have linked altered sleep stages with a decrease in growth hormones, which play a key role in body composition such as body fat, muscle, and abdominal fat.
Researchers have found a possible link between apnea and the development of diabetes and insulin resistance (the inability of the body to use insulin).
There are many effective treatments for apnea. These include weight loss for mild cases and a device known as continuous positive airway pressure (CPAP) to open up blocked airways for more significant cases. With CPAP treatment, patients wear a mask over their nose and/or mouth while sleeping. 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 collapsingThe pressure is constant and continuous.
Obesity. Obesity is often associated with snoring, apnea, and sleep disturbance. People who report an average total sleep time of 5 hours a night, for example, are much more likely to be or become obese compared to people who sleep 7–8 hours a night.
There is growing evidence that sleep is an important regulator of appetite, energy use, and weight control. During sleep, the body’s production of the appetite suppressor leptin increases, and the appetite stimulant grehlin decreases.
Rising and falling of blood sugar levels during sleep appears to be linked to various stages of sleep. The less people sleep, the more likely they are to be overweight or obese and prefer eating foods that are higher in calories and carbohydrates.
Neuropathy. Neuropathy, or damage to the nerves in the body, is another cause of sleep disruption. This nerve damage can cause a loss of feeling or symptoms such as tingling, numbness, burning, and pain.
Simple pain relievers such as aspirin or ibuprofen may be helpful however, because of potential kidney damage from these medications be sure to discuss your kidney function with your doctor before taking them. Antidepressants or anti-convulsants may also be prescribed. Other treatments include: Lyrica, lidocaine injections, or creams containing capsaicin (the “hot” in peppers).
Restless Legs Syndrome. Restless legs syndrome is a specific sleep disorder that causes an intense, often irresistible urge to move your legs. This disorder is often accompanied by other sensations in the legs such as tingling, pulling, or pain, making it difficult to fall or stay asleep.
Various medications are used to treat restless legs syndrome, including dopamine agents, sleeping aids, anti-convulsants, and pain relievers.
Hypoglycemia and Hyperglycemia. Both hypoglycemia and hyperglycemia can affect sleep in those with diabetes. Lynn Maarouf, RD, the diabetes education director of the Stark Diabetes Center at the University of Texas Medical Branch in Galveston sees it frequently in her practice. “Any time your blood sugar is really high, your kidneys try to get rid of it by urinating,” says Maarouf “So you are probably getting up and going to bathroom all night long — and not sleeping well.”
Maarouf says high blood sugar is a problem for people with diabetes for another reason. “People who are tired will eat more because they want to get energy from somewhere,” she adds. “That can mean consuming sugar or other foods that can spike blood sugar levels.”
“I really push people to eat properly throughout the day and get their blood sugars under control so they sleep better at night,” Maarouf says. “If you get your blood sugar under control, you will get a good night sleep.”
According to Susan Zafarlotfi, PhD, clinical director of the Institute for Sleep and Wake Disorders at Hackensack University Medical Center in New Jersey, “People with diabetes have to be very careful about sleep because anything that throws off their routine can make them feel a lack of energy and fatigue”. “Proper sleep is as important as diet for people with diabetes,” she concluded.
Are You Sleep Deprived?
It’s clear from studies that many of us are feeling sleep deprived. But are we? It’s a tricky question because it’s an individual matter. “There is no formula for how much sleep you need,” Zafarlotfi says. “It depends on you.”
Even if you are getting more than 7 hours a night you could still be sleep deprived if your sleep is interrupted. Mahowald says an easy test to know if you are sleep deprived is this: “If you use an alarm clock, you are. If you were getting adequate sleep, your brain would awaken you before the alarm goes off.”
What Can You Do to Improve Sleep?
As a person with diabetes you can improve the quality of your sleep by making sure that your diabetes is in control. You can achieve those results by working with your health care team to bring blood glucose levels, blood pressure and cholesterol under control. You can also work with your medical team to treat/manage diabetes complications such as neuropathy or apnea.
A good night’s sleep doesn’t begin in bed. Help your body prepare for getting rested by developing “sleep-smart” habits during the day. Try to wake up at the same time every day to set a schedule for your body.
Getting regular exercise often helps individuals sleep better. You have to be careful not to exercise to close to bedtime, or the adrenalin from the workout, may keep you awake.
Avoid caffeine or nicotine in the evening. Both of these substances have a stimulant affect and can interfere with sleep. Alcohol, though technically a depressant, can impact sleep patterns after the effects of the alcohol have worn off.
Don’t hang out in bed. Some sleep specialists suggest that you only use the bed for sleeping not watching TV or reading. They believe this way, your bed becomes a cue for sleeping, not for lying awake. Another suggestion is to get out of bed and do something in another room when you can’t sleep. Go back to bed when you are feeling drowsy.
Learn relaxation and breathing techniques. These technique can calm or relax you so you can fall asleep or listen to nature sounds on CD.
How Are Sleep Problems Diagnosed?
If all of your careful planning and preparation for sleep doesn’t work you may wish to discuss the issue with your doctor. They 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. Because it can be tricky to remember all that information it might be helpful to keep a journal.
Your doctor may also 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 study can help your doctor make an accurate diagnosis and prescribe an effective and safe treatment.
Archives of Internal Medicine study “Role of Sleep Duration and Quality in the Risk and Severity of Type 2 Diabetes Mellitus” by Kristen L. Knutson, PhD; Armand M. Ryden, MD; Bryce A. Mander, BA; Eve Van Cauter, PhD.
National Institutes of Health: Your Guide to Healthy Sleep