7 consequences of lack of sleep

Overweight, diabetes, cardiovascular disease, digestive problems ... these are some of the consequences of lack of sleep or poor quality sleep.

When you ask politicians or certain intellectuals how they manage to do so many things, they classically answer "I don't sleep much". And in a world where there is no shortage of artificial light, it can be tempting to snack on your nighttime rest. This is how some people come to completely disrupt their natural cycles and accumulate lack of sleep (around 17% of French people).

Others have slept badly for years, without finding a solution, because of undiagnosed sleep apnea or chronic insomnia (which affects 12% of French people). And without knowing it, everyone is putting their health at risk. In fact, according to a study published in the journal Sleep Medicine in August 2016 which analyzed 153 sleep studies including a total of more than 5 million people, a short sleep duration is associated with greater mortality (this is the strongest link found), diabetes, hypertension, cardiovascular disease and obesity (1). 

Let us see in more detail, scientific studies in support, and the consequences of a chronic lack of sleep on health.

Overweight

This is probably the most documented result of lack of sleep: when you don't get enough sleep, you get fat. This is mainly explained by the fact that we then tend to eat more, especially calorie foods. And as we move the same, or even less, this leads to weight gain. According to a meta-analysis of studies on the consequences of partial sleep deprivation on energy balance, sleeping little would lead to eating 385 kcal (calories) more without the energy expenditure does not vary (2). People who do not get enough sleep ingest more fatty foods, less protein (no variation for carbohydrates). In adolescents, however, lack of sleep leads to greater consumption of sugary foods (3).

In children, as in adults, the link between chronic lack of sleep and obesity is well established (4, 5).

Diabetes

Lack of chronic sleep seems to lead, according to scientific studies, to a decrease in insulin sensitivity and to a higher risk (by 37% on average) of developing type 2 diabetes (5). The loss of insulin sensitivity explains weight gain and is one of the first stages of diabetes. In addition, in people already diabetic, sleep disturbances are accompanied by a deterioration in blood sugar control. Results: more complications. Sleeping well therefore seems crucial when one is at risk of diabetes (family history, overweight, high blood sugar…) or diabetic.

Cardiovascular illnesses

For scientists, the lack of chronic sleep induces different types of biological effects, including an increase in oxidative stress and an alteration of the inflammatory response, mechanisms at play in cardiovascular disease (6). And epidemiological studies show that chronic lack of sleep is associated with coronary heart disease, hypertension and arrhythmia (regardless of economic or demographic factors). Sleeping little, or conversely too much, can also increase the risk of having a stroke, according to a recent European study (7).

Mood disorders

Sleep and depression are strongly linked, there is a lot of evidence to support this. People with depression generally tend to sleep too long. By depriving these people of sleep, they can improve their depressive symptoms. But lack of sleep can also increase mood disorders or induce depression. In this context, the link between sleep and depression remains difficult to grasp. What is known, however, is that chronic lack of sleep can worsen the symptoms of depression, and insomnia is frequently among the earliest symptoms of depression (8).

The cancer?

Night workers are at greater risk for cancer, which suggests that there is a link between sleep and this disease. Chronic lack of sleep leads in particular to the formation of reactive oxygen species, thus increasing oxidative stress, which could promote the occurrence of cancer. However, studies on the link between cancer and lack of sleep are not very numerous and often contradictory. The link between lack of sleep and cancer therefore does not seem to be really established.

The vicious circle of digestive problems

Poor sleep can lead to an exacerbation of digestive disorders via the formation of inflammatory molecules, this is the case for gastroesophageal reflux for example. But reflux, dyspepsia or irritable bowel syndrome can also affect sleep cycles and lead to chronic lack of sleep. (9)

To feel fit, avoid accidents, perform well at work and for all the health reasons mentioned above, it is better to sleep with quality sleep, ideally between 7 and 9 hours per night. If not, and you want a good night's sleep again, get help from a specialist, or apply the Shawn Stevenson program in  14 days to sleep well  .

Neurodegenerative diseases

Recently, sleep disorders have been associated with the risk factors involved in neurodegenerative diseases, notably Alzheimer's and Parkinson's disease. Lack of chronic sleep causes changes in the brain through the accumulation of beta-amyloid proteins and Tau (biological markers of Alzheimer's disease). A study that followed patients for 6 years indicates a 1.5 times higher risk of developing Alzheimer's disease in patients whose sleep is very fragmented compared to people who sleep well (10). Other researchers have determined that people who subjectively report insomnia have a 33% increased risk of dementia overall and 51% Alzheimer's disease compared to people without insomnia.

Other research is underway to assess the responsibility of sleep disorders in other neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and dementia.

Adolescent mental health

Sleep and mental health are intimately linked. At puberty, teens experience changes in their circadian rhythm called "phase lag" preventing them from falling asleep early enough to get their necessary 9 hours of sleep, given the very early hours of school. Attempting to make up for those missed hours of sleep over the weekend does not make up for the lost sleep.

If this chronic lack of sleep in adolescents leads to increased inattention, drowsiness, bad mood and has an immediate impact on their academic results, it can also lead to mental health problems (depression, anxiety). )  These disorders are linked to poor brain development, especially of the areas involved in the management of emotions, due to lack of sleep.

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