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in Sleep Disorders 2014

Andrew G Veale

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Light and Health

 Effects through the eye  Effects through the skin

 Positive effects  Negative effects  Mood  Seasonal affective disorder  Vitality  Light at Night  Alertess  Shift work  Light on skin  Disturbance to Sleep-wake cycle  Light and cancer  production  Light at night may lead to breast cancer  light therapy through the skin  blue-light hazard  UV radiation to eye --> cell deaths in the eye  Light on skin

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Biological effects of light

 Light is not just for vision any more  All non-visual effects of light

 Biological clock  Surrounding world have external rhythms, where people have to adapt.  Organisms have built an internal clock, which can react to external cues

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Biological effects of light

 Biological clock

 External cues / stimulation  Light  Auditive stimulants  Physical exercise  Drugs  Eating habits  Social stimulus  temperature

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Structure of biological clock

 Non visual photoreceptor in  Retinohypothalamic track (RHT)  Suprachiasmatic nuclei (SCN)  In hypothalamus  Master clock of biological rhythms  Pineal gland  secretion

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Circadian rhythms

 Circa dies = day  Biological rhythms: cycles around 24 h  Well-known circadian cycles  Sleep-wake cycle  Hormonal endocrine secretion  Melatonin, cortisol  Blood pressure cycle  Body temperature  Alertness

 Light is the strongest syncroniser

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Circadian rhythms

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND CIRCADIAN RHYTHMS Melatonin

 Night , secretion from pineal gland  Strongest regulator is light  Melatonin, CBTemp, cortisol and sleep-wake cycles are in strong correlation

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND CIRCADIAN RHYTHMS Sleep-wake cycle

 What happens without external cues?  What happens without sleep?

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Other biological cycles and correlation between them

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Biological effects of light

Important dates  Light is shown to influence plants 24 h cycle (Bunning 1936)  Light on melatonin suppression (Alfred J. Lewy 1980)  Light is shown to impact human circadian system (Czeisler 1981)  Light alleviates depressive symptoms (Alfred J. Lewy 1982)  Seasonal Affective disorder – discription of the syndrome was presented (Rosenthal 1984)  New light sensitive photoreceptor in human retina detected (David Berson 2002)

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Light can affect

 More alert on night (Cajochen 2000) and daytime (Phipps-Nelson 2003)  More productivity in office environment (Mills 2007)  more alert, less daytime sleepiness, more vitality  Cognitive performance (Lehrl 2007)  alerness, speed of information processing

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Seasonal affective disorder

 Depressive symptoms  Lack of energy 96%  Sadness 96%  Social withdrawal 92%  Irritation 86%  Daytime tiredness 81%  Seasonal symptoms  Prolonged sleep 76%  Weight gain 74%  Carbohydrate craving 70%

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Seasonal affective disorder

 Why we have this?  Short light period is the strongest trigger of SAD  phase delay  Genes

 Treatment  Bright light therapy 2500 - 10000 lux  Dawn simulation 250 lux  Fitness training  In combination with light exposure

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Subsyndromal SAD

 similar to SAD, but patients don’t fill definition of major depressive disorder  More common (Finland 27%)  Symptoms as:  craving to food and carbohydrate,  difficult awakening and and  exhaustion and daytime sleepiness similar to SAD

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light therapy

 2500 – 10000 lux  30 min – 2 h per day  4000 Kelvin  History of research and treatment to SAD 25 years  Best result after awakening  Effect mechanism  Synchronize circadian rhythms and sleep-wake cycle

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light therapy

 Applications  SAD  Response 60-90 % to alleviating depressive symptoms (Lam RW, Levitt AJ. 1999. Canadian Consensus Guidelines for the Treatment of Seasonal Affective Disorder)  Subsyndromal SAD  Non-seasonal  12-35% alleviating depressive symptoms, equal to traditional pharmaceutigal drug (Kripke 1998)  Meta-analysis: “light therapy offers modest though promising antidepressive efficacy” (Tuunainen 2004)  Light therapy: effective adjuvant therapy to medication (Even 2007, Martiny 2004) 

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light beyond SAD

• illumination and seasonal changes in mood and behavior are associated with the health-related quality of life (Partonen 2008) • Seasonal changes in mood and behavior are common in a general population (Partonen 2008). • Disfunction of biological clock may lead to and metabolical disturbances (Partonen 2008).

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light beyond SAD

Office environment • Bright light alleviate sub-SAD symptoms, improve the mood, vitality, alertness and productivity (Avery 2001) • Improved vitality and mood people with or without sub-SAD (Partonen 2000) • Continous exposure to bright light may improve quality of life, because it will improve the vitality (Partonen 2000)

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light therapy and physical exercise

 4 study by National Public Health Institute (Leppämäki, Partonen 1998- 2004) • Combination: bigger alleviation of typical depressive symptoms and more vitality than exercise alone • Carbohydrate craving, prolonged sleep, weight gain

• Effective combination to improve mood and certain components of health related quality of life in wintertime  Social activity, overall mental heath

• Affect also to ”healthy” people

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND The effect of exercise and light on mood (2006)

 Depressive symptoms alleviated 40-66% and atypical depressive symptoms alleviated 45-88%  Bright light alone is more effective on atypical depressive symptoms than physical exercise alone  Bright light dosing two times a week (with or without exercise) is effective to alleviate atypical depressive symtoms, which are associated with wintertime depression

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND New applications of bright light therapy  Strong seasonality  Adult with attention-deficit disorder  Bulimia

 Circadian system disorders  Bright light and elderly, Phase Advance  Alzheimer disease and dementia, Parkinson disease  Phase delay Syndrome

 When medication is unwanted  Depression during pregnancy/

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light and bulimia

 Bulimia is mainly eating disorder, but atypical depressive symptoms are prevalent  Binge eating problems are strongly depentent on season  Morning bright light significantly alleviated bulimia symptoms (Lam RW, Am J Psychiatry. 1994)  Significant improvement in eating disorders during bright light treatment (Braun DL, Compr Psychiatry. 1999)

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Bright light and weight control

 Seasonal symptoms  Carbohydrate craving 70%  Weight gain 74%  Seasonal affective disorder and metabolic syndrome are strongly related (Partonen 2008)  Obesity, high blood sugar level, high blood pressure

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Dawn simulation

 Research subjects  SAD, sub-SAD  hypersomnia, difficult awakening, quality of sleep and morning-time alertness  synchronisation of delayed sleep-wake cycle  Treatment parameters  Illuminance 150-300 lux  Time 15 min to 60 min

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Dawn simulation

 Effect mechanism  Same as in bright light therapy  Synchronisation of circadian cycles  Effect size almost same as in bright light therapy on SAD (Golden 2005)  Dawn simulation is more user-friendly, because treatment happens at the time when subject is waking from sleep

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Dawn simulation

 Effect mechanism  Same as in bright light therapy  Synchronisation of circadian cycles  hypersomnia, difficult awakening, quality of sleep and morning-time alertness  Dawn simulation is more user-friendly, because treatment happens on time when subject is waking

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND We live in a light-deprived world...

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Why we are ‘light deprived’

 Work indoors  Play indoors  Travel indoors  Many now believe that = bad  ozone layer depletion = > UV radiation  > risk of skin cancer  Avg. exposure 57 mins/day in sunny San Diego

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Other Indications for Light Therapy:

 Shift-work  Jet lag  Sleep Disorders – Delayed Phase (DPSD) Advanced Phase Sleep Disorder (APSD)  Fatigue Management (CFS, MS, Chemo pts.)  Performance enhancement – athletes, execs  ‘Baby Blues’ & Post-partum depression

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Melatonin Suppression Curve

Primary = 464nm (blue) Secondary = 550nm (green)

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Traditional Light therapy

 Litebook ‘Knock-offs’

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND Litebook Usage:

NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND NZ Respiratory & Sleep Institute Auckland, NEW ZEALAND