According to a recent study, sleep and A1c blood glucose levels may definitely be linked. The researchers found that people with type 1 diabetes who slept less than an average of 6.5 hours a night had higher A1cs than those who slept longer (for more about A1c measurements, see the chapter “Taking Charge of Diabetes”). In addition to the finding of sleep length and A1cs, the researchers found that these shorter-term sleepers were “non-dippers,” or people who also have blood pressure levels that do not get lower at night, a definite indicator of health problems.
What is nocturnal hypoglycemia?
Nocturnal hypoglycemia is as the words indicate: a low blood glucose level during nighttime sleep.
Often an episode of nocturnal hypoglycemia wakes a person, but sometimes it does not.
If it does, it is often treated by the eating of fast-acting carbohydrates, such as glucose tablets or gel, to boost glucose levels back to normal.
Thus, for safety reasons, most health care professionals suggest that a person with diabetes check his or her blood sugar at bedtime, and consider it one of the most important checks of the day.
What did a recent study find about insulin sensitivity and sleep duration in men?
I n yet another recent study from the Netherlands, researchers found that there was a connection between insulin sensitivity and how long a male slept.
Insulin sensitivity in this study was based on how sensitive a person is to the effects of insulin.
High insulin sensitivity means less insulin is needed to lower blood glucose levels, whereas low insulin sensitivity means more insulin is needed to lower them.
High or low sensitivity depends on how well the pancreas is producing or the body is using insulin.
The researchers found that men who sleep for less than or more than seven or eight hours of sleep had lower insulin sensitivity.
In addition, men who slept for shorter periods had lower beta cell function (beta cells produce and release insulin) in the pancreas.
More research is needed because no one knows the real cause and effect.
What can occur if a person with diabetes has high or low blood glucose levels at night?
If a person with diabetes experiences high or low blood glucose levels at night, most of the time the episode has no effect, especially if the highs or lows are not too extreme.
But if the levels become extreme, there may be certain problems if they are too high or low.
For example, if people with diabetes have high blood sugar levels at night, it may be harder for them to sleep because they may feel too warm, irritable, and unsettled.
If the levels are very low, it may cause problems within the person’s central nervous system, including nightmares, sleepwalking, restlessness, and confusion.
Why should a person with type 2 diabetes be aware of the “dawn phenomenon”?
Most people have a rise in hormones, for example, cortisol and glucagon, during the early hours of the morning, usually from about 2 A.M. to 8 A.M.
Called the dawn phenomenon, it occurs as various organs attempt to keep a person’s blood glucose levels from going too low at night.
This hormonal activity helps to tell the liver to produce more glucose.
In response, there is an increase in insulin to handle the extra glucose.
And this, in turn, allows a person to wake and start the day after fasting all night.
But for a person with diabetes, such a rise in insulin may cause fasting glucose levels to be dramatically elevated as the system cannot handle the extra glucose.
Could daytime sleepiness be associated with lower blood glucose levels in type 2 diabetics?
Yes, some people with type 2 diabetes who have excessive sleepiness during the day could be at a higher-than-normal risk for hypoglycemia (low blood glucose levels). In a recent study, researchers speculated that when the blood glucose level dips low during nighttime sleep, it disrupts the diabetic person’s sleep, creating daytime sleepiness. In fact, that daytime sleepiness can make a person less aware of a hypoglycemia event during the day, thinking instead that he or she is just tired, and thus, a person who has not been diagnosed with diabetes may ignore the early warning signs of disease.
What is sleep apnea?
Sleep apnea, clinically called obstructive sleep apnea (or OSA, the most common form of sleep apnea), is a condition in which a person’s windpipe is temporarily closed as he or she sleeps, usually causing the person to pause his or her breathing.
This commonly occurs when the upper respiratory airway is blocked, either because the throat muscles collapse, the tongue falls back into the airway, or the tonsils and/or adenoids are enlarged, impeding the air flow.
The lapses in breathing also cause the individuals to wake up briefly because their breathing has been interrupted and may even stop for a brief period.
Sleep apnea is often further described as a condition in which a person frequently stops breathing for ten seconds or more during sleep, with some experiencing a lack of breathing sometimes hundreds of times a night.
A person who has apnea awakens frequently during the night gasping for breath.
It is thought to be a medical problem for many reasons.
For example, this pause in breathing can reduce the blood oxygen in the body, putting a strain on the cardiovascular system (especially the heart), which is why many people with sleep apnea are considered at risk for cardiovascular disease.
It can also have an effect on a person with diabetes, causing a fluctuation in blood glucose levels during sleep (see below).
One symptom of type 2 diabetes can be a chronic feeling of being sleepy and tired.
Is there a connection between type 1 diabetes and sleep apnea?
Although it has not been investigated as much as sleep apnea in people with type 2 diabetes, recent studies have shown that people with type 1 diabetes may have more sleep apnea (and associated problems) than previously thought.
For example, in 2015, a study showed that 67 people with type 1 diabetes had a high prevalence of obstructive sleep apnea.
Sleep apnea was also associated with kidney complications and retinopathy (for more about the eyes and retinopathy, see the chapter “Diabetes and Inside the Human Body”).
One interesting result of the study was that it was uncommon for people with type 1 diabetes and sleep apnea to be obese or have daytime sleepiness, which may be why a sleep apnea diagnosis was overlooked.
Who gets sleep apnea?
S leep apnea (OSA) most often occurs when air cannot flow into or out of the person’s nose or mouth as he or she breathes. According to the National Sleep Foundation, sleep apnea often occurs in conjunction with snoring. And although snoring may be harmless for most people, it can be an indication of sleep apnea, especially if it is accompanied by mild to severe daytime sleepiness, which is why it is also often responsible for people’s having auto accidents owing to daytime grogginess.
Of course, most people who have sleep apnea may not know it as they are asleep when snoring or not breathing.
Men seem to have apnea more than women, as do people who are obese, but it can occur in anyone at any age for various other reasons.
For example, it can happen to people with a large neck, people with small airways (the nose, throat, or mouth), people who sleep on their backs, and people who have a misaligned jaw.
Another cause can be that, as an individual ages, the muscles around the back of the throat become relaxed.
One of the telltale signs of this condition is snoring.
Another sign can be complaints of lack of sleep by the person’s bed partner.
Although there were few people in this study, other more recent studies are indicating the same results.
For example, one study indicated that sleep apnea was higher in people who have been affected by type 1 diabetes the longest.
Also, people with poorly controlled type 1 diabetes have more sleep apnea problems than those who have more control over their blood glucose levels.
And, like people with type 2 diabetes and sleep apnea, people with type 1 often are fatigued and depressed, not only from lack of sleep but also from difficulty controlling their blood sugar levels both day and night.
Is there a connection between type 2 diabetes and sleep apnea?
Yes.
Overall, it is estimated that up to 80 percent of people with diabetes, at this writing, mostly people with type 2 diabetes, have the condition.
In particular, heavier people who have sleep apnea appear to have more health problems, including an increased risk for diabetes (no doubt because of being heavier or obese, which is connected to the risk of type 2 diabetes).
If they already have type 2 diabetes, sleep apnea sufferers have difficulty controlling their blood sugar levels.
For people with type 2 diabetes, sleep apnea also increases the risk of developing other diseases and conditions, including heart disease, high blood pressure, acid reflux, dementia, and depression.
What device may help stabilize blood sugar levels in people with sleep apnea (OSA) and type 2 diabetes?
In a preliminary study conducted in 2016, researchers found that people with diabetes who used a device called a continuous positive airway pressure (CPAP) device had improved blood glucose levels.
The researchers evaluated the effects of a CPAP machine on people with both OSA and poorly controlled type 2 diabetes.
They found that people using the CPAP experienced statistically significant improvements in insulin sensitivity at three to six months after using the device.
There was also a decrease in insulin resistance and HbA1c levels at six months (for more about HbA1c, or A1c, testing, see the chapter “Taking Charge of Diabetes”).
Another positive result was that the participants had lower levels of certain inflammatory molecules and LDL cholesterol (considered the “bad” cholesterol; for more about LDL, see the chapter “How Diabetes Affects the Circulatory System”), along with higher levels of adiponectin, a hormone involved in regulating blood glucose levels.
But there are a few caveats: the number of people tested was small, and there was no placebo testing.
Thus, more research is necessary to see whether the CPAP can truly help many people with type 2 diabetes.
Sleep apnea can be greatly eased by wearing a CPAP mask at night to assist with breathing. A good night’s rest has health benefits, including reducing the risk of diabetes.
Should pregnant women be aware of sleep apnea?
Y es.
A study conducted in 2013 of 1,673 women discovered that sleep apnea was linked to emergency C-sections or babies with low birth weight.
The researchers believe that because sleep apnea is linked to heavier people, the weight gain during pregnancy may increase the risk for sleep apnea.
Some of the symptoms of sleep apnea, snoring, moodiness, excessive daytime sleepiness, trouble staying alert during the day, are also thought to be standard side effects of pregnancy.
But if a pregnant woman knows that she has many of these symptoms, she may want to discuss the possibility that some may be caused by sleep apnea (and learn some possible remedies) with her doctor.
Is there a connection between gestational diabetes and sleep apnea?
Yes, some studies indicate that sleep apnea may be more common than previously believed in women with gestational diabetes. (For more about gestational diabetes, see the chapter “Other Types of Diabetes.”) One study in particular looked at a group of pregnant Asian women who were obese and had gestational diabetes.
The researchers found that the majority of women in this group also had sleep apnea, which also caused their blood glucose levels to rise.
The study did not determine causality, whether the sleep apnea led to the high blood sugar or high blood glucose levels led to the sleep apnea, but other studies seem to indicate that gestational diabetes is associated with the increased risk for obstructive sleep apnea.