Sleep Latency: How Long Does It Take You to Fall Asleep?
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 Gene and Sleep Latency
RBFOX3 also influences the release cycle of neurotransmitters, including GABA (gamma-aminobutyric acid) and various monoamines, vital to the human circadian clock.
DRD2 Gene and Sleep Latency
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.
rs17601612 And Sleep 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
- Get some exercise during the day and be active.
- Try to do a calm and relaxing activity, like taking a shower or reading a book before you sleep.
- Avoid watching television or using your mobile at least an hour before bedtime.
- Try to associate your bed with falling asleep and avoid doing other activities like reading or watching television on the bed before you fall asleep. Read at your table or any other convenient spot, and then fall asleep on your bed.
- If you’re awake in the middle of your sleep time for more than 15-20 mins, try to move around and do some relaxing activity to fall asleep again.
- Try to restrict your bedtime if most of it is spent laying awake. This can help meet your sleep needs but should be followed under the guidance of a doctor.
Summary
- Sleep latency is the amount of time it takes for a person to fall asleep. It is usually in the range of 5-15 minutes. It varies from person to person.
- Certain variants of RBFOX3 and DRD2 genes have an association with sleep latency. The DRD2 gene is a dopamine ('happy hormone') receptor. The C allele of an SNP rs17601612 located on this gene is associated with shorter sleep latency compared to the G allele.
- Poor sleep latency shortens sleep duration and can lead to a variety of health issues.
- Being active, doing calm and relaxing activities before sleeping, avoiding television and mobile usage before sleeping, and restricting bedtime to establish a proper sleep schedule can improve sleep efficiency.
References
https://pubmed.ncbi.nlm.nih.gov/27142678/
https://pubmed.ncbi.nlm.nih.gov/26464489/
