How sleep and the metabolic system work together

Sheradin Williamson, a diabetes specialist nurse, explains the science of how sleep and the metabolic system work together.

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Sleep is a basic human need, just like eating, drinking, and breathing. According to The Centers for Disease Control and Prevention Centre about one in three adults in the USA aren’t getting enough rest or sleep every day.

Your life is organised around 24-hour rhythms of day- and night-time activities and when you don’t sleep properly that can lead to poor health.

When you don’t sleep, you lose the rest and digest phase and the fight and flightstate continues when you’re awake. Timing of sleep is controlled by your circadian clock, which causes lows and highs of wakefulness and sleepiness throughout the day.

Most adults feel tired between 2 – 4am and between 1 – 3pm. Your body’s internal clock is controlled by the suprachiasmatic nucleus – SCN. The SCN is sensitive to light and dark and triggers the release of cortisol and other hormones to wake you up. When darkness comes your SCN releases melatonin to help you sleep.

Causes of sleep disruptions

• Attending to crying children
• Alarms, strange noises
• Fear of attacks, feeling unsafe, living in dangerous area
• Shift work
• Sleep apnoea
• Lights from electronic devices
• In people living with diabetes, it might be the fear of having a hypo during the night or increased urination

The effects of lack of sleep

Sleep deficiency is linked to a number of chronic health problems.

• Impairs metabolism – Metabolism is a biochemical process that involves two activities that go on at the same time: building up body tissues and energy stores (anabolism) and breaking down body tissues and energy stores to get more fuel for body functions (catabolism).
• Sleep loss can affect metabolic functions of storing carbohydrates and regulating hormones, like thyroid-stimulating hormone which is lower when sleep-deprived and cortisol levels which are higher. This can induce insulin resistance.
• Increases risk of cardiovascular diseases.
• Triggers physiological and hormonal changes that increase blood pressure and inflammation.
• Can potentially trigger a build-up of plaques, which can cause heart attack or stroke.
• Sleeps affects your weight by controlling hunger hormones, ghrelin (increases appetite) and leptin (increases sense of fullness). Lack of sleep increases ghrelin and supresses leptin so short sleepers may feel hungrier and eat more unhealthy foods.

Sleep is important

While you sleep, your breathing slows down, your heart rate and blood pressure drops, muscle activity drops, your brain clears out toxins, which can cause neurogenerative diseases. Your metabolism slows down by 15%. Sleep is needed to restore cells and shouldn’t be a luxury, it’s needed to restore bodily functions.

Sleep hygiene tips

The Mayo Clinic suggests:

• Sticking to a sleep schedule. Most adults need six to eight hours of sleep a night.
• Pay attention to what you eat and drink before bedtime. Do not go to bed on a full or empty stomach. Pay attention to your intake of caffeine, alcohol, and nicotine intake.
• Stress management.
• Including physical activity into your daily activities.
• Limit daytime naps unless you are a shift worker.
• Create a restful sleeping environment. Dark room, avoid light-emitting screens; consider ear plugs.

People living with diabetes or parents of young children living with diabetes could be finding it a challenge to sleep uninterrupted due to hypo or hyperglycaemia, please speak to your diabetes educator or doctor.

If you’re waking up feeling unrested, ask your sleeping partner about your snoring and breathing patterns. You might want to speak to your doctor about conducting sleep studies.

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