Sleep efficiency refers to the percentage of time a person sleeps to the amount of time a person spends in bed. It is calculated by the ratio of the total time spent asleep (TST) in a night compared to the total amount of time spent in bed. An efficient sleep leads to a deeper sleep of better quality with lesser disturbances that may result in good stamina and sufficient rest upon waking, while an inefficient sleep may lead to uneasiness and fatigue.
Sleep Efficiency Rates
Sleep efficiency rates tend to vary from person to person. Normal sleep efficiency is considered to be 80% or greater. For example, if an individual spends 8 hours in bed, at least 6.3 hours or more should be spent sleeping to achieve 80% or greater sleep efficiency. Most healthy and young adults have sleep efficiencies above 90%.
How Does Genetics Influence Sleep Efficiency?
UFL1 is one of the genes in the ubiquitin pathway - the principal mechanism behind protein breakdown.
This pathway has also been implicated in schizophrenia, a condition in which poor sleep efficiency is a common symptom.
The relevance of this pathway in sleep disturbances was further explored in another study.
The study indicated that the expression of a protein UFM1, a part of UFL1, increased after partial sleep restriction.
A GWAS analysis found a significant correlation between a variant (rs75842709) near the UFL1 gene and sleep efficiency.
The T-allele was associated with a 5.7% decreased sleep efficiency.
Non-genetic Influences Of Sleep Efficiency
Some factors that lower sleep efficiency:
- Pain
- Higher fatigue
- Less activity during the day
- Light at night
- Jet lag
- Sleep environment
Tips To Improve Sleep Efficiency
Summary
Reference
https://pubmed.ncbi.nlm.nih.gov/27126917/
Sleep latency (also known as sleep onset latency) refers to the amount of time it takes for a person to fall asleep. Usually, normal sleep latency is 5-15 minutes. If sleep latency is less than five minutes, it may suggest some level of excessive sleepiness, and if it is greater than 15 minutes, it may be due to sleep initiation issues.
Sleep latency varies from person to person. An ideal sleep latency period lays the foundation for a solid night's sleep. Sleep latency directly affects sleep efficiency, because if a person is able to fall asleep quickly, they are more likely to have an efficient sleep.
How Does Genetics Influence Sleep Latency?
Research studies have demonstrated the association between certain variants in RBFOX3 and DRD2 genes and sleep latency. The RBFOX3 gene plays a key role in neuron-specific alternative splicing (a process that removes the "unwanted" portions from the DNA and connects useful portions to form a functional gene).
RBFOX3 also influences the release cycle of neurotransmitters, including GABA (gamma-aminobutyric acid) and various monoamines, vital to the human circadian clock.
The DRD2 gene encodes a dopamine receptor. Dopamine is a 'happy hormone' that is crucial for signaling pleasure and reward. Dopamine and its receptors also play a part in controlling the sleep-wake cycle. Mainly, dopamine can help keep you awake and alert. The DRD2 gene variations may affect this wake/sleep switch, leading to a tendency for shorter sleep duration and sleep onset latency.
The rs17601612 is a G>C polymorphism located in the DRD2 gene, which might affect the wake/sleep cycle. A study, Cade, Brian E., et al.2016, has shown that the rs17601612 C allele was strongly associated with shorter sleep latency than the G allele.
Non-genetic Influences on Sleep Latency
A variety of other factors influence sleep latency. They include:
- Age
- Gender
- Dietary intake
- Sedentary life
- Consumption of stimulants
- Illness such as depression
Effects of Delayed Sleep Latency on Health?
Prolonged sleep latency may shorten sleep duration and lead to a variety of problems, including depression, loss of productivity, irritability, cognitive impairment, poor academic performance in children, and adolescents. Persistently increased sleep latency is also a key indicator of delayed sleep phase syndrome, insomnia, sleep deprivation, and narcolepsy.
Tips To Improve Sleep Efficiency
Summary
References
https://pubmed.ncbi.nlm.nih.gov/27142678/
https://pubmed.ncbi.nlm.nih.gov/26464489/
Restless Leg Syndrome (also known as Willis-Ekbom Disease) is a neurologic and sleep-related movement disorder characterized by an irresistible urge to move in the legs, which typically occurs or worsens at rest. Affected people may experience abnormal, uncomfortable sensations ( paresthesia or dysesthesias ) that are often linked to cramping, crawling, burning, aching, itching, or prickling deep within the affected areas.
This condition has a 10% prevalence rate, with an increase in incidences as age advances. Since the symptoms occur during sleep and relaxation, it could disrupt a good night's sleep.
Restless leg syndrome causes an uncomfortable urge to move, which can be relieved by walking or moving the extremities. This interferes with sleep maintenance
How Does Genetics Influence the Risk of Restless Leg Syndrome (RLS)?
Restless leg syndrome shows an anticipation inheritance - with each generation, the age of onset of this condition advances.
A GWAS meta-analysis study of restless leg syndrome (RLS) in European ancestry has demonstrated the significant association of RLS with MEIS1, BTBD9, PTPRD, and other genes.
BTBD9 gene variants have been associated with RLS, with two experimental models providing better insights. The loss of this gene was associated with increased waking from sleep, motor activity, higher motor restlessness, and altered serum iron levels.
The MEIS1 gene is a transcription factor that plays a key role in hematopoiesis, endothelial cell development, and vascular patterning.
It also plays a role in neurodevelopment.
Research studies have shown that the reduced MEIS1 levels and function of the gene may contribute to the pathogenesis of sleep-related disorders.
rs113851554 And RLS
The rs113851554 is a G>T polymorphism located in the MEIS1 gene, which is found to be correlated with multiple sleep disorders.
A GWAS meta-analysis study of RLS in European ancestry has demonstrated that the rs113851554 T allele is associated with an increased risk of developing RLS susceptibility.
Non-genetic Influences on RLS Risk
Some nutritional deficiencies have been implicated in RLS. They include:
- Vitamin D deficiency
- Iron deficiency
Some medical conditions associated with RLS are:
- Depression
- Diabetes
- Fibromyalgia
- Rheumatoid arthritis
- Hypothyroidism
Effects of Restless Legs Syndrome on Health
Tips for Managing Restless Leg Syndrome (RLS)
Iron Supplements : Iron deficiency is one of the leading causes of RLS. If you test positive for iron deficiency, you may get started on iron supplements after consulting a qualified healthcare professional.
Baths and massages : Warm showers and massages can help relax muscles and prevent unnecessary leg movements.
Exercise : Restless Legs Syndrome foundation recommends moderate exercising to help manage RLS.
Avoid caffeine : High caffeine intake can worsen RLS. Either limit or avoid caffeine intake.
Summary
Reference
https://pubmed.ncbi.nlm.nih.gov/29029846/
Introduction: What is Sleep Bruxism?
Sleep Bruxism (also known as Teeth Grinding) is defined as repetitive jaw muscle activity during sleep. It is characterized by an unconscious act of grinding or clenching one's teeth tightly together. Over time, it could lead to damage of teeth, oral health conditions, facial muscle pain, sleep disturbances, difficulty while speaking or eating.
Sleep Bruxism is more common in children, adolescents, and young adults than middle-aged and older adults.
The prevalence of sleep bruxism is estimated to be around 15% in adolescents, around 8% of middle-aged adults, and only 3% in older adults.
According to statistical studies 6-50% of children experience nighttime teeth grinding.
How Does Genetics Influence Sleep Bruxism Risk?
Multiple studies have demonstrated that there may be a degree of inherited susceptibility to develop sleep bruxism. According to a study, around 21-50% of affected individuals have an immediate family member who had sleep bruxism during childhood.
Few studies have shown the significant associations of certain variants in neurotransmitters like dopamine, serotonin, and others ( DRD3, HTR2A, COMT, MMP9, and others) with sleep bruxism.
The DRD3 gene encodes the D3 subtype of the dopamine receptor, which is localized to the regions of the brain involved in cognitive, emotional, and endocrine functions.
Variations in DRD3 are implicated in the physiopathology of diseases affecting those functions.
The rs6280 is a T>C polymorphism located in the DRD3 gene, where the C allele may increase dopamine affinity and efficacy. Studies have shown that the Gly variant (C) is significantly associated with increased susceptibility to sleep bruxism.
Non-genetic Influences on Sleep Bruxism Risk
Sleep bruxism may be accelerated by lifestyle factors as well. Some of them include:
- Stress
- Alcohol consumption
- Anxiety
- Cigarette smoking
- Upper airway resistance
- Caffeine consumption
Effects of Bruxism on Health
Tips for Managing Bruxism
Mouth guards - Mouth guards help keep the teeth separated and hence prevent grinding.
Stress management - Stress is one of the major contributors to teeth grinding. So finding ways to alleviate stress can help prevent teeth grinding.
Avoid alcohol and caffeine - Teeth grinding tends to intensify upon alcohol and caffeine consumption.
Avoid chewing on pens and pencils - This practice gets your jaws used to grinding movement and may increase your tendency to grind your teeth.
Summary
References
https://pubmed.ncbi.nlm.nih.gov/32471213/
https://pubmed.ncbi.nlm.nih.gov/27611726/
https://pubmed.ncbi.nlm.nih.gov/28451935/
https://pubmed.ncbi.nlm.nih.gov/30092895/
https://pubmed.ncbi.nlm.nih.gov/25628080/
Sleep fragmentation is one of the symptoms of sleep disorders characterized by repeated, short sleep interruptions during the night, which leads to excessive tiredness during the day.
People with fragmented sleep tend to fall asleep quickly but wake up multiple times during the night for short periods. The other symptoms of fragmented sleep include morning headaches, daytime sleepiness, difficulty in concentrating, and memory lapses.
Fragmented sleep due to situational illness (like a cough or a sore back)is called short-term sleep fragmentation and goes away after some time.
Research studies have documented a greater impact on physical and emotional health when sleep quality and quantity are poor.
How Does Genetics Influence Sleep Fragmentation Risk?
A study reported the genetic and environmental variance in sleep complaints. The proportions were as follows:
1. At 8 years: 63% genetic, 32% non-shared environment
2. At 10 years: 66% genetic, 27% nonshared environment, 7% shared environment
The study also suggests that genetics affects sleep problems more strongly during the preschool/school age (63-69%) . Certain variants in HLA-DQB1, CRY1, and other genes might influence the risk of having fragmented sleep.
The CRY1 gene encodes a protein called flavin adenine dinucleotide-binding, a key component of circadian clock regulation.
Variations in the CRY1 gene are found to be associated with altered sleep patterns.
The rs184039278 is an A>C gain of function mutation located in the CRY1 gene, associated with a prolonged period of circadian molecular rhythms.
A study, Patke, Alina, et al.2017, demonstrated that both CC and AC carriers are strongly associated with late sleep times and sleep fragmentation.
Non-genetic Factors That Influence The Fragmented Sleep Risk
Some sleep-related disorders can result in fragmented sleep. A few examples are:
1. Snoring
2. Obstructive sleep apnea
3. Sleep-maintenance insomnia
4. Restless leg syndrome
Poor sleep is also caused by lifestyle habits such as:
1. Alcohol and caffeine consumption
2. Napping for a long time in the day
3. Exercising close to bedtime
Effects of Sleep Fragmentation on Health
Tips for Managing Sleep Fragmentation
You can follow these tips to have a peaceful night of sleep and avoid sleep fragmentation.
1. Tire yourself out: As fatigue accumulates throughout the day, it’ll be easier to fall asleep in the night.
2. Stay away from distractions: Switch off your phone, wear an eye mask, and shut the windows to prevent your sleep from being disturbed.
Summary
References
https://pubmed.ncbi.nlm.nih.gov/20975052/
https://pubmed.ncbi.nlm.nih.gov/28388406/
https://pubmed.ncbi.nlm.nih.gov/24179306/