"Sleep is not always a relaxing experience"
By Dr Gérard de Bataille, Medical Advisor of the Mutuelle Saint-Martin
Sleep represents about 1/3 of our life time. It reflects our biological rhythms and represents a human “activity” that is essential to life.
Sleep and physiology
The sleep-wake continuum has a specific architecture that is unique to each individual. It is made up of cycles repeating 4 to 6 times during the night, each one being made up of 2 types of sleep:
- Slow wave sleep: first light and then deep “body and brain at rest
- Paradoxical sleep: “body at rest, brain as active as when awake”, activity partly illustrated by dreams.
Sleep has a fundamental role in information management, memory and emotional control.
Sleep regulation is the result of an interaction between :
- The homeostatic process (proportional to the duration of the waking period),
- The circadian process (internal biological clock),
- Temperature (correlation between temperature rhythm and variation, and the sleep/wake rhythm),
- Melatonin: a hormone secreted in the brain during darkness (circadian rhythm) and seasonally, inhibited by light, its function being to inform the organism of the day/night alternation,
- Neuromediators such as serotonin, acetylcholine, etc. are also involved.
GOOD TO KNOW
There are various sleep tests. The phases and cycles of sleep can be recorded using a hypnogram. Writing a sleep diary can help your doctor to better understand your problems.
With age, even if the “good or bad night” remains an individual and often subjective notion, physiological changes can be observed.
Sleep changes with age
- From birth, the sleep of the newborn is double: “calm” sleep (immobile newborn, regular breathing, a few rare jolts…) and “agitated” sleep (facial mimics, irregular breathing…); sleep is already specific to each individual from 13 to 20 hours per day.
- In adolescence, “restless” sleep becomes paradoxical sleep: the day/night periodicity is gradually established; there are already “short and long sleepers, early sleepers, early risers, late sleepers, late risers”. School schedules can interfere. Needs remain high and the adolescent is often in chronic sleep deficit.
- In adulthood, sleep is “fixed” in an organisation that is specific to each individual and relatively “rigid”. Paradoxal sleep (about 1/5 of the night) is favoured after midnight and the slow wave/deep sleep phase is important to know and respect before midnight.
- With advancing age, sleep is more fragmented, lighter and unstable. Awakenings are more frequent in the second part of the night, which often gives the impression of “having slept badly”. Slow/deep sleep decreases, REM sleep is preserved for a long time before it also decreases.
Factors that can influence your sleep
When faced with a sleep disorder, one must object to what is related to the evolution of sleep with advancing age, what is related to a cause external to sleep or a sleep disorder itself.
There are several possible causes for this :
Change in external synchronisers
- Change or cessation of professional or social obligations
- Social isolation
- Low exposure to light
- Excessive time spent in bed
- Sedentary lifestyle
- Medical co-morbidities
- Joint pain, muscle pain, etc.
- Heart and/or respiratory failure
- High digestive disorders (gastroesophageal reflux…) or low digestive disorders (transit disorders…)
- Mycturia related to a prostate adenoma or excessive drinking after 9pm
- Degenerative disease (Parkinson’s, Alzheimer’s, etc.)
- Anxiety, depression, bereavement…
- Psychotropic drugs: antidepressant, benzodiazepine, neuroleptic
- Anti-epileptic drugs
- Alcohol, caffeine…
Pathologies specific to sleep
- Sleep apnea syndrome
- Restless legs syndrome
- Behavioural disorders related to Paradoxical sleep
Sleep and dementia syndrome
Most often we note multiple awakenings, a reversal of the nycthemeral rhythm, shifts in relation to external synchronizers, an alteration in hormonal secretions (melatonin, etc.), changes in circadian rhythms and daytime activities, etc.
Our recommendations : You think you have a sleep disorder? Talk to your doctor to differentiate between a pathology, an iatrogenic condition and a normal evolution of sleep with age.
There is no such thing as an “ideal” hypnotic and prescribing for short durations should be limited to specific indications as recommended by the treating physician. Maintain regularity (getting up and going to bed) and reduce the duration of naps (less than 60 minutes). Similarly, it is important to maintain regularity in the timing of your activities and meals, your social and temporal reference points.
Avoid caffeine, nicotine, tea, alcohol, etc. before bedtime, as well as intense cognitive or physical activities after 7pm. Use the bed only for sleep, not for reading or watching television; lie down only when you feel the need to sleep.
If you cannot fall asleep or return to sleep after 10 minutes, it is best to get up.
Encourage physical activity and sun exposure during the day; respect the night-time environment (darkness, silence, temperature, etc.).
Monitor the condition and quality of your bedding, especially if you are prone to low back pain or chronic spinal pain.
Neuromediators: chemical substances produced by the body that enable nerve cells (neurons) to transmit nerve impulses (e.g. serotonin and acetylcholine)
Medical co-morbidities: diseases that are added to an initial disease. To give an example, diabetes is a disease with a high degree of comorbidity: it is common for other diseases to be associated with it.
Nycturia: heavy urination at night
Prostate adenoma: benign tumour of the prostate
External synchronisers: temperature, luminosity, work rhythm, etc.
Iatrogenic: a disorder or disease caused by a medical procedure or by medication, even if the doctor is not mistaken
Nycthemeral rhythm: biological cycle of 24 hours
Circadian rhythm: a rhythm that is defined by the alternation between wakefulness and sleep