Course Information
California State University, Fresno
Department of Public Health
PH90 Contemporary Health Issues
Instructor: Dr. Qiwei Li
Daily Sleep Cycle
Homeostatic Sleep Drive vs. Circadian Drive
Sleep Gate: the transition to wakefulness and sleep
Typical sleep hours: 7 AM to 11 PM
Key Concepts
Zeitgeber: Environmental cues that regulate biological clocks
Role of the Retinohypothalamic tract and Suprachiasmatic Nuclei in syncing sleep patterns
Macula and the Retina
Blue Light: Impact on the retina and sleep disruption
Different types of light: Near IR, Visible Light, UVB, UVA
Literature Review
Reference: Kryger, M. H., Roth, T., & Dement, W. C. (2016)
Sleep Patterns Variations:
Younger adults vs. older adults typical hypnograms (Neubauer, 1999)
Age-Based Guidelines
Newborns (0-3 months): 14-17 hours
Infants (4-11 months): 12-15 hours
Toddlers (1-2 years): 11-14 hours
Preschool (3-5 years): 10-13 hours
School Age (6-13 years): 9-11 hours
Teens (14-17 years): 8-10 hours
Young Adults (18-25 years): 7-9 hours
Adults (26-64 years): 7-9 hours
Older Adults (65+ years): 7-8 hours
Types of Sleep Disorders
Primary Sleep Disorders:
Sleep apnea
Insomnia
Other conditions: Restless Legs Syndrome, Narcolepsy, and Circadian Rhythm Disorders
Definition & Symptoms
OSA characterized by recurrent airway obstruction during sleep
Symptoms: Loud snoring, witnessed apneas, daytime sleepiness, morning headache
Apnea Hypopnea Index (AHI)
None/Minimal: AHI < 5
Mild: 5 ≤ AHI < 15
Moderate: 15 ≤ AHI < 30
Severe: AHI ≥ 30
Risks Associated With OSA
Cognitive decline, depression, cardiovascular diseases, daytime lethargy
Polysomnography (PSG): Gold standard for diagnosing sleep conditions
Other assessment techniques include:
Sleep diaries, smartphone apps, in-home testing
Use of Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS)
Interventions
Positive Airway Pressure (PAP) therapy
Weight management
Sleep hygiene practices
Surgical intervention may be necessary
Definition & Types
Symptoms include difficulty in sleep initiation and maintenance, early awakenings
Types: Acute, Chronic, Primary, Secondary
Demographic Variance
More prevalent in older adults
Risk factors: Medical conditions, gender, stress
Characteristics
Affects 1 in 3000 individuals; characterized by involuntary daytime sleep
Potential genetic basis for the disorder
Description
Neurological disorder with uncomfortable leg sensations; urge to move legs
Treatment options: Medications, lifestyle adjustments, physical therapies
Biological Purposes
Restores physical and mental health, enhances learning, and consolidation of memories
Sleep Environment and Habits
Maintain a cool room, create a relaxing atmosphere, establish a routine
Avoid screen time and stimulants before sleep
Recommendations
Get natural light exposure, balanced diet, and manage physical activity
Regulate caffeine, nicotine, and liquid intake before bed
Institution: California State University, Fresno
Department: Public Health
Course: PH90 Contemporary Health Issues
Instructor: Dr. Qiwei Li
The human body operates on a daily sleep cycle, which is influenced by both internal biological processes and external environmental cues.
Recognizes the homeostatic sleep drive (the body's need for sleep) versus the circadian drive (the body's internal clock).
Sleep Gate: A physiological mechanism that dictates the transitions between wakefulness and sleep, often tied to levels of adenosine in the brain.
Typical sleep hours are often defined as from 7 PM to 11 AM, acknowledging variations based on individual lifestyles.
Zeitgeber: These are environmental cues, such as light and temperature, that regulate the body's biological clocks, helping to synchronize sleep-wake cycles.
The retinohypothalamic tract and the suprachiasmatic nuclei play critical roles in transporting light information from the retina to the brain, which influences sleep patterns.
The macula and the retina are crucial components in how we perceive light and its effects on sleep.
Blue Light: A type of light known to disrupt sleep by suppressing melatonin production, making devices like smartphones and LED lights particularly problematic in the evening.
Different types of light:
Near IR: Often used for therapeutic purposes.
Visible Light: Essential for visual perception and regulating sleep.
UVB: Important for Vitamin D synthesis but can also affect sleep.
UVA: Less understood in the context of sleep but can still impact health.
Reference: Kryger, M. H., Roth, T., & Dement, W. C. (2016)
Sleep Patterns Variations:
Differences in typical hypnograms for younger adults versus older adults as summarized by Neubauer (1999).
Age-Based Guidelines:
Newborns (0-3 months): 14-17 hours
Infants (4-11 months): 12-15 hours
Toddlers (1-2 years): 11-14 hours
Preschool (3-5 years): 10-13 hours
School Age (6-13 years): 9-11 hours
Teens (14-17 years): 8-10 hours
Young Adults (18-25 years): 7-9 hours
Adults (26-64 years): 7-9 hours
Older Adults (65+ years): 7-8 hours
Primary Sleep Disorders include conditions like sleep apnea, insomnia, restless legs syndrome, narcolepsy, and circadian rhythm disorders.
Obstructive Sleep Apnea (OSA):
Definition: A serious sleep disorder characterized by recurrent airway obstruction during sleep.
Symptoms: Include loud snoring, witnessed apneas, daytime sleepiness, and morning headaches.
Measured through the Apnea Hypopnea Index (AHI):
None/Minimal: AHI < 5
Mild: 5 ≤ AHI < 15
Moderate: 15 ≤ AHI < 30
Severe: AHI ≥ 30
Risks associated with untreated OSA:
Cognitive decline, depression, increased risk of cardiovascular diseases, and persistent daytime lethargy.
Polysomnography (PSG): Considered the gold standard for diagnosing sleep disorders.
Other assessment techniques include:
Sleep diaries - personal logs detailing sleep patterns.
Smartphone apps for sleep tracking.
In-home testing for sleep quality.
The Insomnia Severity Index (ISI) and Epworth Sleepiness Scale (ESS) are tools used to evaluate sleep quality and daytime sleepiness.
Interventions include:
Positive Airway Pressure (PAP) therapy as a common treatment.
Weight management strategies to alleviate symptoms.
Implementation of sleep hygiene practices to improve sleep quality.
In some cases, surgical intervention may be necessary.
Insomnia is characterized by difficulty in sleep initiation and maintenance, including early awakenings.
Types include:
Acute: Short-term insomnia often linked to stress or trauma.
Chronic: Long-lasting insomnia usually requiring clinical intervention.
Primary: Insomnia not attributable to other conditions.
Secondary: Insomnia resulting from other medical or psychiatric conditions.
Notably more prevalent among older adults.
Common risk factors: Include various medical conditions, differences in gender, and psychological stress.
Narcolepsy affects approximately 1 in 3000 individuals and is marked by episodes of involuntary daytime sleep.
Emerging research suggests a potential genetic basis for this disorder.
A neurological disorder characterized by uncomfortable sensations in the legs and an overwhelming urge to move them, often worsening during periods of inactivity.
Treatment options include a range of medications, lifestyle adjustments, and physical therapies.
Sleep serves several biological functions, including restoring physical and mental health, enhancing learning, and facilitating memory consolidation.
Recommendations for improving sleep environment:
Maintain a cool bedroom temperature.
Create a relaxing atmosphere to promote sleep.
Establish a consistent bedtime routine.
Avoid electronic devices and stimulants (like caffeine) prior to sleep.
Recommendations:
Get ample natural light exposure during the day.
Maintain a balanced diet conducive to sleep health.
Manage physical activity levels to promote better sleep.
Limit intake of caffeine, nicotine, and liquids close to bedtime to minimize disruptions during the night.