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Sleep

Sleep is an important biological function, essential for good health and wellbeing. During sleep the brain and body rest and recover.

Without sufficient sleep we are more likely to have problems with thinking, concentration, memory, mood and reaction times all of which impact on ability to perform daily tasks and increases risks of mistakes and accidents. Sleep problems due to sleep disordered breathing such as; Obstructive Sleep Apnoea (OSA), Insomnia, shift work or modern lifestyles are known to be associated with increased risk of obesity, cardiovascular disease and stroke, type 2 diabetes and kidney disease. The relationship between sleep and health problems is often bi-directional.

Asking about sleep should be a key part of any health assessment.

Sleep problems and disorders;

Obstructive Sleep Apnoea (OSA)

OSA is a characterised by repeated collapse of the pharynx during sleep causing upper airway obstruction leading to recurrent oxygen desaturation and hypoxemia, hypercapnia, arousals from sleep and sleep fragmentation. These contribute to the adverse consequences of OSA, including cardio-metabolic and neurocognitive effects.

Significant (moderate-to-severe) obstructive sleep apnoea affects 50% of adult men and 25% of adult women (see Heinzer R, Vat S, Marques-Vidal P, et al. Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study. The Lancet Respiratory medicine. 2015;3(4):310-318. doi:10.1016/S2213-2600(15)00043-0).

People with obstructive sleep apnoea report snoring, witnessed apnoeas, waking up with a choking sensation, and excessive daytime sleepiness. Other common symptoms are non-restorative sleep, insomnia (difficulty initiating or maintaining sleep), fatigue or tiredness, nocturia, and morning headache. Daytime symptoms can include irritability and mood changes.

Although obesity is a common risk factor, many people with OSA are not obese. Other physiological factors that influence OSA risk in individuals include: the activity of the upper airway dilator muscles, instability of the respiratory control system (high loop gain) and the propensity to arouse from sleep (arousal threshold). Fluid retention and fluid shifts overnight may also play a role. Cranio-facial anatomy can be important in some people.

Consequences of OSA include excessive daytime sleepiness and fatigue, and reduced quality of life, particularly in younger and middle-age individuals. A large body of evidence has shown OSA leads to hypertension. These problems have been shown in randomised clinical trials to improve with treatment. OSA has also been linked in a large number of studies to increased mortality risk, cardiovascular disease (including stroke, myocardial infarction and heart failure), diabetes, nocturia, erectile dysfunction, renal impairment, depression, cognitive impairment and risk of accidents.

Referral for investigation should be considered in any person with any symptoms (see above). There are a number of treatment options for OSA. All people with OSA can benefit from weight loss, and in mild OSA this may be all that is needed. For others, commonly used treatments include Continuous Positive Airflow Pressure (CPAP) or oral devices (mandibular advancement device). Studies show adherence to CPAP is 60–70%, much the same as adherence to asthma inhalers, oral anti-convulsants and maintenance of good glycemic control in diabetes. Newer therapies include hypoglossal nerve stimulation.

Fitness to drive is an important consideration in assessing people with OSA. Guidelines require practitioners to consider excessive daytime sleepiness, drowsiness while driving, history of accidents as well as adherence to treatment when making an assessment of fitness to drive. Commercial licence standards are more stringent.

Further information

  • Jordan AS, McSharry DG, Malhotra A. Adult obstructive sleep apnoea. Lancet. 2014;383(9918):736-747. doi:10.1016/S0140-6736(13)60734-5
  • Assessing fitness to drive. Austroads Ltd, 2012. ISBN: 978-1-921991-86-8 

Insomnia

Insomnia symptoms, where people have difficulty getting to sleep or staying asleep or where sleep is non-restorative or poor quality, occur in around 30% of adults.Around 10% of the population have insomnia symptoms and experience various forms of daytime distress or impairment, such as fatigue, memory or concentration problems, reduced motivation or being accident-prone (see Mai E, Buysse DJ. Insomnia: Prevalence, Impact, Pathogenesis, Differential Diagnosis, and Evaluation. Sleep medicine clinics. 2008;3(2):167-174. doi:10.1016/j.jsmc.2008.02.001).

Clinical definitions of insomnia also involve daytime distress or impairment related to the nighttime sleep difficulty, including: fatigue or malaise; attention, concentration, or memory impairment; social or vocational dysfunction or poor school performance; mood disturbance or irritability; daytime sleepiness; motivation, energy, or initiative reduction; proneness for errors or accidents at work or while driving; tension, headaches, or gastrointestinal symptoms in response to sleep loss; concerns or worries about sleep (International Classification of Sleep Disorders (ICSD-2) (American Academy of Sleep Medicine, 2005).

Insomnia can be associated with a number of medical and mental health conditions. Risk factors for insomnia include: female sex, advanced age, depressed mood, snoring, low levels of physical activity, comorbid medical conditions, nocturnal micturation, regular hypnotic use, onset of menses, previous insomnia complaints, and high level of perceived stress. Insomnia can be precipitated by life events, work or school stresses and job dissatisfaction. Hyperarousal is thought to be the underlying physiological impairment in insomnia.

Assessment of the individual should include discussion of the sleep-wake routine, daytime routine, including work eating and exercise times. Sleep habits, including sleep conditions and environment, sleep times and pre-sleep routine, as well as overnight behaviour, especially clock-watching and anxiety levels, should be discussed. Daytime functioning and symptoms (see above), including safety issues need to be considered. Other conditions, including other sleep disorders such as restless legs and sleep apnoea, other medical or psychiatric conditions should be assessed. Use of substances, such as nicotine, alcohol and caffeine as well as previous treatments for insomnia tried, also need to be reviewed. Sleep diaries over 1-2 weeks can be a useful way to track sleep-wake patterns.

Management of insomnia can include cognitive behavioural therapy (CBT). 

This can involve the following:

  • Sleep hygiene training - correcting habits around sleep;
  • Sleep restriction - initially limiting time in bed then gradually increasing sleep time;
  • Stimulus control - regular wake times, going to bed when sleepy, avoiding naps, avoiding computers, tablets, phones, TV in bed (“use the bed only for sleep and sex”), getting up from bed if not sleeping;
  • Cognitive therapy - exercises to change attitudes and beliefs hindering sleep;
  • Relaxation training - to relax mind and body.

CBT can be delivered in person individually, in groups or online and on devices.

Some people may benefit from sedatives as an adjunct to CBT.

Circadian rhythm disorders

Circadian rhythm sleep-wake disorders are common. People have persistent or recurrent patterns of sleep disturbance due to alterations of the circadian timing of sleep. Disorders include delayed phase sleep syndrome, which is common in teenagers, where sleep is delayed until very late at night. Other disorders include advanced sleep-wake rhythms, irregular and non-24 rhythms. Jet lag or shift work patterns occur when external factors cause the person’s rhythm to become out of phase with the environmental demands. These conditions can be managed with behaviour changes and such treatments as bright light therapy and melatonin, so clinical assessment is crucial.

Further information

Understanding sleep and sleep-related health problems

  • Australasian Sleep Association
  • Sleep Health Foundation
  • Harvard University Sleep & Health
  • Sleep Disorders: a practical guide for Australian health care practitioners. (ed: Mansfield D.R. and McEvoy R.D.) 2013. MJA: 199 (8) Supplement.
  • The Relationship between Functional Health Literacy and Obstructive Sleep Apnea and its Related Risk Factors and Comorbidities in a Population Cohort of Men. Li J.J., Appleton S.L., Wittert G.A., Vakulin A., McEvoy R.D., Antic N.A., Adams R.J. (2014).Sleep: 37 (3): 571-8.
  • Impact of Five Nights of Sleep Restriction on Glucose Metabolism, Leptin and Testosterone in Young Adult Men.Reynolds A.C., Dorrian J., Liu P.Y., Van Dongen H.P.A., Wittert G.A., Harmer L.J. Banks S. PLoS ONE (2012) 7 (7): e41218.
  • An Official American Thoracic Society Statement: The Importance of Healthy Sleep Recommendations and Future Priorities.Mukherjee S., Patel S.R., Kales S.N., Ayas N.T., Strohl K.P., Gozal D., Malhotra A. on behalf of the American Thoracic Society ad hoc Committee on Healthy Sleep.American Journal of Respiratory and Critical Care Medicine 191 (12): 1450-9.

Assessing sleep and diagnosing sleep problems

Treatment and management of sleep problems 

Sleep Clinics

This information has been developed by SA Health and The University of Adelaide

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