The body's natural response to disease or injury is inflammation. When you get a cold or cut yourself, your immune system activates white blood cells, which release cytokines and other inflammatory substances to protect the body's tissues and ward off invaders. Though an effective defence mechanism in the short term, prolonged inflammation can lead to serious health conditions, including heart disease, stroke, diabetes, cancer, and Alzheimer's disease.

Research has linked sleep deprivation with inflammation markers in the body, including cytokines, interleukin-6, and C-reactive protein (CRP: a protein made by the liver — circulating concentrations rise in response to inflammation in the body or an infection). CRP levels seem to be elevated in people who aren't sleeping well. High concentrations of CRP have been shown to reflect systemic and vascular inflammation and predict future cardiovascular events.[1-3]

While these inflammatory indications could be attributable to other factors, such as stress, smoking, or obesity, they show that sleep deprivation plays a part in the inflammatory process. They may also help to explain why people who sleep poorly are more likely to develop cardiovascular disease, hypertension, and diabetes, among other chronic conditions.

How does sleep deprivation contribute to inflammation?

The focus seems to be on blood vessels. During sleep, blood pressure drops and blood vessels relax. Lack of sleep can impact how your body regulates blood pressure and may trigger cells in blood vessel walls that activate inflammation. It can also make it harder for your body to balance the stress response (HPA axis dysregulation) and oxidative stress (free radical damage), which can drive inflammatory dysfunction, even more so if sleep deprivation is ongoing.

During deep sleep, the brain undergoes cleaning, healing and repair. Therefore, lack of sleep can affect the glymphatic system (the waste clearance system, acting a bit like a garbage truck).[4] During deep sleep, cerebrospinal fluid actively flows through the brain and clears away metabolic byproducts, unwanted beta-amyloid proteins that can damage brain cells. As such, the glymphatic system may play a key role in brain immunity, neuroinflammation and neurodegenerative disorders.[5]

When sleep is disrupted, this cleaning process is compromised, leading to the accumulation of unwanted waste and proteins and inflammation. This, in turn, creates a harmful cycle where beta-amyloid buildup impairs non-REM slow-wave sleep and memory consolidation. This is one of the links between neuroinflammation and neurodegeneration, with long-term sleep deficit as the driver. Associated symptoms also include blood sugar and lipid dysregulation, mood problems, anxiety disorders and depression, and caffeine addiction.

Just one night of lost sleep can keep beta-amyloid levels higher than usual. The problem is not so much a single night’s poor sleep, which you can compensate for, but a cumulative pattern of sleep loss, leading to decreases in the structural integrity, size, and function of certain brain regions, like the entorhinal cortex and hippocampus (and its connected structures), which are especially vul­nerable to damage during the early stages of Alzheimer’s disease.[6]

Insomnia and other sleep disorders

How many people report daytime sleepiness, irritability and memory (and concentration) issues after just one bad night's sleep?

While some people feel they can cope with very little sleep, ongoing sleep problems can have devastating effects on the brain and its function, and predispose individuals to neurodegenerative disorders. Another issue with chronic sleep problems is blood sugar dysfunction, which can lead to stress hormone imbalances and affect your sleep deeper: you may thus feel “tired-but-wired” and falling asleep, your greatest challenge.

This is why sleep is so important to health.

Your Goal: Prioritising quality sleep as a key component of overall wellness and disease prevention.

Lack of sleep and Immune dysfunction

Lack of sleep has been found to have a significant impact on individuals with rheumatoid arthritis (RA). RA is a chronic inflammatory disorder that primarily affects the joints. Studies have shown that individuals with RA often experience disturbed sleep patterns, including difficulty falling asleep and staying asleep, as well as poor sleep quality. Thus creating a vicious cycle, chronic lack of sleep can exacerbate the symptoms of RA, leading to increased pain, stiffness, and fatigue, which further disturbs sleep.

It is believed that inflammation in the joints disrupts the normal sleep-wake cycle, further contributing to the sleep disturbances experienced by individuals with RA. Furthermore, lack of sleep can also weaken the immune system and result in increased inflammation, worsening the progression of the disease.

Research also found that individuals who suffer from sleep disorders, such as insomnia or sleep apnea, have a higher risk of developing autoimmune diseases.[7]

Lack of quality sleep can disrupt the immune system's functioning, leading to an imbalance and potential overactivation of immune responses. This can contribute to the development or worsening of autoimmune conditions. As discussed, sleep deprivation can increase inflammation in the body, which is a key factor in autoimmune diseases.

Your Goal: Prioritising quality sleep and natural pain control (and identifying the causes of immune over-reactivity) to promote deeper sleep

Lack of Sleep and IBS

Lack of sufficient sleep can have a significant impact on individuals suffering from Irritable Bowel Syndrome (IBS). Sleep deprivation has been shown to worsen IBS symptoms and increase the frequency and severity of flare-ups.

The digestive system and the gut microbiome are highly influenced by the body's circadian rhythm, which regulates various physiological processes including cellular and liver detoxification.

According to the London Gastroenterology Centre, half of IBS sufferers struggle with insomnia – and those that do get poor sleep may experience more severe symptoms the next day. Furthermore, chronic lack of sleep has been shown to exacerbate symptoms such as abdominal pain, bloating, and irregular bowel movements.[8] According to a meta-analysis totalling 63,620 participants, the prevalence of sleep disorders among IBS can be up to 75%.[9]

Since more women appear to suffer from IBS, it may be possible that they also report frequent sleep problems.[10]

If it wasn’t enough, sleep deprivation can also lead to increased stress levels (and anxiety), which further aggravates IBS symptoms.[11]

Your Goal: Prioritising quality sleep with meditation and relaxation techniques; and addressing the causes of gut dysfunction, including food intolerances and allergies, and prioritising digestion (promote the release of stomach acid and support digestive enzymes) and nutrient assimilation

Sleep and Obesity

While research is still inconclusive when it comes to chronic lack of sleep and increased risk of obesity, one of the most common factors in sleep disorders is that people may eat when they should be sleeping (high-carb snacks) and exceed their calorie intake, especially if stress or anxiety are drivers to poor sleep habits.

Additionally, people that do not get their required sleep may also exercise less and favour high-calorie foods as a result of the higher concentrations of stress hormones in their bloodstream.

What studies have also shown is that chronic lack of sleep may dysregulate hormone concentrations, especially those involved in the stress response (cortisol) and in hunger (ghrelin). Experimental sleep restriction was associated with increased levels of ghrelin, salt retention and inflammatory markers as well as decreased levels of leptin (regulate appetite and fat storage) and insulin sensitivity.[12]

Fat cells also release oestrogen and other pro-inflammatory messengers when they’re full (as is the case in obesity). Interestingly, oral contraceptives have been found to damage sleep by increasing body temperature.[13] Oestrogens seem to also be involved in sleep disorders in menopausal women.[14]

Obese individuals are also at an increased risk of sleep apnoea, which may considerably disturb their sleep and exacerbate inflammatory responses.

Pregnancy may also become a time when sleep may be more difficult. Make sure you sleep in a comfortable position and not too cold or hot.

References

1. Sheikh, AS. et al. (2012). C-reactive protein as a predictor of adverse outcome in patients with acute coronary syndrome. Heart Views. 13(1), pp. 7-12. doi:10.4103/1995-705X.96660

2. Best, LG. et al. (2005). C-reactive protein as a predictor of cardiovascular risk in a population with a high prevalence of diabetes. Circulation. 112, pp. 1289–1295

3. Dhal, M. et al. (2006). C-reactive protein as a predictor of prognosis in chronic obstructive pulmonary disease. American Journal of Respiratory and Critical Care Medicine. 175(3). doi:10.1164/rccm.200605-713OC

4. Natale, G. et al. (2021) Glymphatic system as a gateway to connect neurodegeneration from periphery to CNS. Frontiers in Neuroscience. 15, 639140. doi:10.3389/fnins.2021.639140

5. https://www.nutrunity.com/updates/under-the-spotlight-inflammation

6. Mrdjen, D. et al. (2019). The basis of cellular and regional vulnerability in Alzheimer's disease. Acta Neuropathologica. 138(5), pp. 729-749. doi:10.1007/s00401-019-02054-4

7. Garbarino, S. et al. (2021). Role of sleep deprivation in immune-related disease risk and outcomes. Communication Biology. 4, 1304. doi:10.1038/s42003-021-02825-4

8. Patel, A. et al. (2016). Effects of disturbed sleep on gastrointestinal and somatic pain symptoms in irritable bowel syndrome. Alimentary Pharmacology & Therapeutics. 44(3), pp. 246-58. doi:10.1111/apt.13677

9. Wang, B. Duan, R. Duan, L. (2018). Prevalence of sleep disorder in irritable bowel syndrome: A systematic review with meta-analysis. Saudi Journal or Gastroenteroly. 24(3), pp. 141-150. doi:10.4103/sjg.SJG_603_17

10. Lovell, RM. Ford, AC. (2012) Global prevalence of and risk factors for irritable bowel syndrome: A meta-analysis. Clinical Gastroenteroly & Hepatology. 10, 712–721.e4. doi:10.1016/j.cgh.2012.02.029

11. Ford, AC. Lacy, BE. Talley, NJ. (2017). Irritable bowel syndrome. New England Journal of Medicine. 376(26), pp. 2566-2578. doi:10.1056/NEJMra1607547

12. Cooper, CB. et al. (2018). Sleep deprivation and obesity in adults: a brief narrative review. BMJ Open Sport & Exercise Medicine. 4(1): e000392. doi:10.1136/bmjsem-2018-000392

13. Baker, FC. Mitchell, D. Driver, HS. (2001). Oral contraceptives alter sleep and raise body temperature in young women. Pflügers Archiv - European Journal of Physiology. 442, pp. 729–737. doi:10.1007/s004240100582

14. Tandon, VR. et al. (2022). Menopause and Sleep Disorders. Journal of Midlife Health. 13(1), pp. 26-33. doi:10.4103/jmh.jmh_18_22