The Importance of Sleep

Sleep attracts considerable public attention because it is relevant to everyone; we all need sleep. Majority of people know how great it feels to have a good night sleep: feeling refreshed and rested, ready to embrace the day.
The consequences of insufficient sleep are also known practically to everyone as we all have occasional experiences of sleepless nights or just not getting enough sleep. The feelings are completely opposite: heavy headed, irritable, fighting sleepiness and being unable to concentrate.

How much Sleep do we need?

The general public is well informed nowadays about how many calories and fluids they need to consume per day, how many pieces of fruit to eat daily, how frequently to exercise. Sleep is a necessary and vital biological function of the humans and yet, majority of people do not know recommended requirement of sleep and are unaware of the risks of sleep deficiency. Many people may not realize that they are sleep deficient and even with limited or poor-quality sleep, they may still think that they can function well. Subjective perception of own sleepiness due to sleep deprivation can be highly unreliable (5, 7).

Sleep is still perceived as a commodity, which could be traded for, more useful, like work or study, or more entertaining activities, like late parties, watching television or searching the net.  One of the reasons in public interest in sleep is the desire to supress sleepiness. Celebrity cases that allegedly can live fulfilling lives on 4 hours of sleep hit the media and cause envy to many young aspiring individuals who then try to train themselves to sleep less and work more.
It is only last year when American Academy of Sleep Medicine and Sleep Research Society published Consensus Statement on the recommended amount of sleep for healthy adults. It is recommended that adults should sleep 7 or more hours per night on a regular basis to promote optimal health (13).
The relationship between duration of sleep and mortality can be described as a “U-shaped association”. Both short and long duration of sleep are significant predictors of death. Short sleepers (sleeping less than 7 hours per night, often less than 5 hours per night) have a 12% greater risk, and long sleepers (sleeping longer than 8 or 9 hours per night) a 30% greater risk of dying than those sleeping 7 to 8 hours per night. The effect concerning long sleepers is stronger in older adults over 60 years old (2).

Consequences of insufficient Sleep

People frequently unaware of the long term effect of insufficient sleep and that the negative consequences of sleep deprivation can lead to multiple health problems such as:

• high blood pressure,
• cardiovascular disease,
• metabolic abnormalities including weight gain and type 2 diabetes,
• reduced immunity and
• reduced threshold for pain.

Lack of sleep also can negatively affect emotional and cognitive function leading to depressed mood, irritability, impulsive and risk taking behaviour, impairment in memory and concentration, increasing frequency of mistakes and accidents and reduced motor performance (7, 13).

Quantity versus Quality of Sleep

Quantity and quality of sleep has been shown to be a consistent and significant prediction of the increased risk of the development of type 2 diabetes. The risk varies between 28% in people who report habitual sleep of less than 5–6 hours per night, 48% in people who sleep longer than 8-9 hours per night and 84% in those with difficulties in maintaining their sleep (3).
Poor sleep quality and short sleep duration have been associated with elevated risk for several cancer types and may influence cancer survival. Phipps et all (2016) shown that women who reported sleeping less than 6 hour per night combined with frequent snoring, defined as more than 5 nights per week experienced significantly poorer cancer-specific survival than those who reported 7–8 h of sleep per night and no snoring (10).

Insomnia

Many people might experience temporary disturbances in sleep, but about 10% of population suffer from chronic insomnia (1), the most common sleep disorder which manifest but persistent difficulties in getting off to sleep and maintaining sleep. Insomnia is associated strongly with a wide range of medical conditions and frequently co-occurs with several mental disorders especially depression and anxiety.
Sivertsen et al in large longitudinal Norwegian study HUNT (12) examined to what extent insomnia represent a risk factor for developing physical and mental conditions. In analyses at 11 years, insomnia was a significant risk for many medical conditions, including:

• angina,
• arthritis,
• asthma,
• fibromyalgia,
• headache,
• hypertension,
• myocardial infarction,
• obesity,
• osteoporosis,
• rheumatoid arthritis and
• stroke.

Insomnia at baseline also was associated with more than twice the odd for incidents of anxiety, depression and help-seeking behavior.

Management of Chronic Insomnia

In 2016 the American College of Physicians developed guideline for management of chronic insomnia in adults.

The evidence presented is based on a systematic review of randomized, controlled trials and recommend that all adult patients receive cognitive behavioural therapy for insomnia as the first line treatment for chronic insomnia disorder (11).  This opinion is shared by NICE (National Institute for Clinical Excellence) clinical pathway although NICE has not yet issued guidelines for clinicians on management of insomnia.
Access to cognitive behavioural therapy is very variable in the UK and hypnotics are frequently prescribed for chronic insomnia and used long term that is not supported by available evidence (8).

Taking hypnotic agents 30 minutes before bedtime is the usual suggested administration time, but some patients report dissatisfaction with their sleeping pills. Chung et al has shown that taking sleeping pills at a later time and a shorter interval between pill administration and wake up time may increase patient subjective satisfaction with hypnotic agents.
Different groups of sleep disorders accumulatively contribute to more than 57% of excessive day sleepiness, when the rest could be attributed to physical or mental disorders (9). Large proportion of people suffering from sleep disorders may be unaware of causes to their subjective complaints of broken unrefreshing sleep with frequent night awakenings.

Krakow et all (2012) demonstrated that 90% of all night awakenings in patients with chronic insomnia were preceded by sleep breathing events (apnoea, hypopnea, or respiratory effort-related event) (6).

However, self-reported reasons for awakenings were: uncertain cause (50%), nightmares (45%), nocturia i.e. urinating at night (35%), bedroom distractions (20%), or pain (15%).

Author Comments

This article aimed to look at the importance of adequate duration and quality of sleep for medical and mental wellbeing and to review the association and causality between common sleep disorders and physical and mental conditions.

Treatment of sleep disorders may contribute to the prevention and more successful treatment outcomes of both physical and mental disorders.
If you are concerned about your wellbeing or sleep and wish to make an appointment to see Dr Olga Runcie please contact ROC Private Clinic – Aberdeen. Dr Runcie is a Consultant Psychiatrist who has a particular interest in sleep disorders.

References

1. American Academy of Sleep Medicine. International Classification of Sleep Disorders, 3rd Edition. Darien, IL: American Academy of Sleep Medicine, 2014.
2. Cappucio FP, D’Elia L, Srazzullo P, Miller M. Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies. Sleep. 2010 May 1; 33(5): 585–592.
3. Cappucio FP, D’Elia L, Srazzullo P, Miller M Quantity and Quality of Sleep and Incidence of Type 2 Diabetes. Diabetes Care 2010, vol 35, 414-420.
4. Chung S, Youn S, Yi K, Park B, Lee S. Sleeping pill administration time and patient subjective satisfaction. J Clin Sleep Med 2016; 12(1):57–62.
5. Dang R, Mayer M, Haack M, Mullington JM. The effect of repetitive sleep restriction on neurobehavioral output of healthy adults, Sleep 2015. 47: 0316.
6. Krakow B et all. Prospective Assessment of Nocturnal Awakenings in a Case Series of Treatment-Seeking Chronic Insomnia Patients: A Pilot Study of Subjective and Objective Causes. SLEEP, Vol. 35, No. 12, 2012
7. Maric A, Lustenberger C, Leemann J, Werth E, Tarnutzer A, Pangalu A, Huber R, Baumann CR, Poryazova R. Vigilance and Cortical excitability after acute sleep deprivation and chronic sleep restriction. Sleep 2015. 47: 0299.
8. NICE (2004) Guidance on the use of zaleplon, zolpidem and zopliclone for the short-term management of insomnia (NICE technology appraisal 77). National Institute for Health and Care Excellence. www.nice.org.uk
9. Ohayon MM. From wakefulness to excessive sleepiness: What we know and still need to know. Sleep Medicine Reviews, 2008: 12, 129-141.
10. Phipps AI, Bhatti P, Neuhouser ML, Chen C, Crane TE, Kroenke CH, Ochs-Balcom H, Rissling M, Snively BM, Stefanick ML, Treggiari MM, Watson NF. Pre-diagnostic sleep duration and sleep quality in relation to subsequent cancer survival. J Clin Sleep Med 2016; 12(4):495–503.
11. Qaseem A, Kansagara D, Forciea MA, Cooke M, Denberg TD Management of Chronic Insomnia Disorder in Adults: A Clinical Practice Guideline From the American College of Physicians. Annals of Internal Medicine, 2016 May 3. doi: 10.7326/M15-2175.
12. Sivertsen B, Lallukka T, Salo P, Pallesen S, Hysing M, Krokstad S, Overland S. Insomnia as a risk factor for ill health: results from the large population-based prospective HUNT Study in Norway. J Sleep Res, 2014. 23, 124-132.
13. Watson NF, Badr MS, Belenky G, Bliwise DL, Buxton OM, Buysse D, Dinges DF, Gangwisch J, Grandner MA, Kushida C, Malhotra RK, Martin JL, Patel SR, Quan SF, Tasali E. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Journal of Clinical Sleep Medicine, 2015; 11(6):591–592.