The link between sleep disturbances and diabetes

Dr Louise Johnson lists several sleep disturbances that may affect people living with diabetes and the treatment thereof.

It’s estimated that one in two people with diabetes have sleep disturbances due to unstable blood glucose and accompanying diabetes related symptoms. High and low blood glucose levels during the night can lead to insomnia and fatigue the next day. As with many chronic conditions, feelings of depression or stress about the disease itself may keep you awake at night.

Sleep disturbances in diabetes

1. Insomnia (too little or no sleep)
2. Hypersomnia (too much sleep)
3. Sleep apnoea
4. Restless leg syndrome
5. Peripheral neuropathy

Insomnia

This can be due to high or low blood glucose levels. With hyperglycaemia, the kidneys overcompensate by causing more frequent passing of urine at night to try and get rid of blood glucose. You may also be excessively thirsty.

In the case of hypoglycaemia, the body’s alarm system adrenaline is triggered causing hunger, palpitations, sweating and shivering. You may also have severe nightmares with low blood glucose. These conditions will make you tired and irritated the next day due to poor quality of sleep.

Sleep deprivation raises the hormone ghrelin (hunger hormone) and decreases levels of leptin (hormone that makes us feel full). To compensate for lower energy levels, people who sleep poorly may be more likely to seek relief in foods that raise blood glucose and put them at risk of obesity, which is a risk factor for diabetes.

Hypersomnia

Too much sleep may be due to extreme high blood glucose or can also be a sign of depression. One quarter of people with diabetes report sleeping more than eight hours per night which puts them at higher risk for elevated blood glucose.

Studies have also found that later or irregular sleeping schedules are correlated with higher blood glucose even in non-diabetic people. One of the reasons is that irregular sleeping schedules are more likely to follow an erratic diet.

Adults with Type 2 diabetes who experience disturbed sleep or frequent night-time awakenings may also be less likely to follow other standards for diabetes self-care such as getting enough exercise and closely monitoring blood glucose.

In addition to its immediate effects on blood glucose, poor sleep can take a long-term toll on individuals with Type 2 diabetes. Those who resort to sleep medication or having trouble staying asleep are more likely to report feeling serious psychological distress. There is also tentative evidence to suggest that people with diabetes who don’t get enough sleep may be at higher risk of cognitive decline later in life.

Obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a sleep disorder in which a person momentarily stops breathing at recurring intervals throughout the night. In most cases the person isn’t aware this is happening, though a bed partner may observe snoring and gasping. These lapses in breathing cause micro-arousals (very brief awakenings without knowing it) that interfere with the natural progression of the sleep stages and impair quality of sleep.

OSA typically occurs in people who are overweight or obese as they have a thicker neck circumference that interferes with the airway. The condition can be treated with weight loss and a continuous positive airway pressure (CPAP) device that keeps the airway open to restore normal breathing and reduce interruptions to sleep. This better sleep pattern also aids in losing weight more easily with a diet. Should you experience daytime fatigue or night time snoring, speak to your doctor for a sleep laboratory evaluation.

The connection between sleep apnoea and diabetes

Though sleep apnoea doesn’t directly cause diabetes, it’s a risk factor for Type 2 diabetes and has been shown to increase insulin resistance, even in non-diabetic and non-overweight people.

The American Diabetes Association estimates that up to one in four people with Type 2 diabetes also suffers from OSA, and a further quarter of Type 2 diabetes suffer from another sleep-related breathing disorder.

Both OSA and Type 2 diabetes are more common in people who are overweight and obese. However, OSA appears to affect insulin resistance and glucose control even after controlling obesity. Not only does OSA cause sleep fragmentation that interferes with slow-wave sleep, but it also periodically cuts off the body’s oxygen supply. Together these effects lead to insulin resistance and impaired glucose metabolism.

In many studies, short-term sleep apnoea treatment appears to improve blood glucose levels while long-term CPAP treatment improves blood glucose and insulin resistance.

Restless leg syndrome

Approximately one in five people with diabetes have restless leg syndrome (RLS), marked by tingling or other irritating sensations in the legs that can interfere with getting to sleep.

This sensation causes an irresistible urge to move the legs. Diabetes is a common cause of restless legs syndrome but also remember to ask your doctor to check your iron, since iron deficiency and kidney failure are also main causes of restless legs. Other body parts such as upper extremities can also be involved.

Females suffer from RLS twice as much as their male counterparts across all different populations and ages. There is evidence linking an increased risk for RLS in patients with diabetes. Many people with diabetes and RLS also suffer from peripheral neuropathy.

Peripheral neuropathy

Painful feet at night is a prominent symptom of peripheral neuropathy. In diabetes, this is caused by nerve damage. The feet can also feel numb, burning or tingling. Other causes can be thyroid disease, liver disease or vitamin B12 deficiency. Always let your doctor examine your feet properly to distinguish the correct cause and treatment.

How can people with diabetes cope with sleep disturbances?

Careful management of blood glucose is of the utmost importance. If blood glucose is up and down despite a good diet and exercise and medication plan, consider the use of a sensor to help warn you about low and high blood glucose. There are a variety of continuous glucose monitors (CGM) on the market.

If you have sleep apnoea, use your CPAP mask regularly. Peripheral neuropathy and restless leg syndrome have specific mediation that your doctor will prescribe.

Practise good sleep hygiene

• Keep a regular bedtime schedule.
• Keep your bedroom dark, cool and quiet.
• Avoid stimulants such a caffeine, nicotine and alcohol before bedtime.
• Don’t exercise too close to bedtime as this may stimulate the body and cause low blood glucose.
• Learn relaxation and breathing techniques.
• Listen to relaxation CDs of nature sounds or water.
• Avoid or minimise napping during the day.
• Get out of bed and do something in another room when you can’t sleep. Go back to bed when you feel drowsy.
• Use the bed only for sleeping or sexual activity. Don’t lie in bed watching TV.
• Try cognitive behavioural therapy as first-line for insomnia.

The significance of good sleep can’t be overemphasised when it comes to chronic medical conditions like diabetes. Poor sleep quality, apart from its usual effect of daytime sleepiness, has ramifications that affect every aspect of life. The pertinent ones are exacerbations of seizures, short-term memory deficits, long-term cognitive effects and headache. These when combine to already worsened quality of life in patients with chronic diseases, can have several deleterious consequences in an individual’s life. Don’t lie awake counting sheep, speak to your doctor or sleep physician.

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