It’s been estimated that about 40% of adults have snored, at least intermittently, at some point in their lives . So, those reading this may already be familiar with the characteristics of snoring.
Snoring occurs when we sleep, and is characterised by a hoarse sound that happens when air flows past relaxed tissues in our throats, which causes these tissues to vibrate as we breathe . Occasional snoring is quite common, but in some cases it can be a far more long term trait that can carry with it an increased risk of experiencing sleep apnea, where your breathing stops and starts while you sleep. Not to mention, other people we live with may also find it a nuisance.
What makes some people more likely to snore than others?
There are a number of factors that can make us more or less likely to snore. A number of physical traits that can increase your likelihood have been identified in research. Starting with our airways, it's been identified that those with narrower throats, receded chins, smaller jaws, larger tongues, and softer palates are more likely to snore than those without these physical traits. You don’t need to exhibit all these traits to be a snorer, but the more of these you have, the more likely you are to snore.
In addition to physical traits, there are everyday behavioural traits which can increase our likelihood of snoring. For example, those that sleep on their backs are more likely to snore than those who sleep on their sides and front. Additionally, those who enjoy an alcoholic drink before bed are more likely to snore, as alcohol relaxes the throat muscles, causing them to vibrate as air passes through.
The Genetics of Snoring
Research has shown that there’s a substantial heritable component to our likelihood of snoring. For example, children of snorers are 3x more likely to snore than children of those who don’t snore. It’s thought that the heritability of snoring is somewhere between 12% and 31% ,.
Snoring is a highly polygenic trait. This means that no single variant has a large contribution to your overall likelihood of snoring but rather, the combination of hundreds, and sometimes thousands of variants throughout your genome, make a small but significant contribution to your overall likelihood of showing the trait. To date, scientists have discovered more than 100 genetic variants that have a significant association with snoring. Here we’ll try to provide an overview of some of the most significant of these, as established by researchers at the University of Brisbane .
The variant at rs62064921 nearby the CBX1 gene has been shown to hold a small association with snoring. CBX1 carries the instruction for a protein in our body known as Chromobox 1. Chromobox 1 plays a number of roles in the body, one of which, as determined by studies on animals, appears to be regulating what genes switch ‘on and off’ depending on the time of day. This implies it may play a small role in actually regulating our circadian rhythm, and therefore might influence our breathing behaviours during sleep. Furthermore, studies in mice that experiment with the gene have found that altering it on purpose leads to significant changes into oxygen intake and carbon dioxide exhalation .
The researchers also discovered variants with a significant association with snoring nearby the SNX11 gene. This gene carries the instructions for a protein known as sorting nexin 11. This protein plays a regulatory role in the body, but geneticists have established that some changes to this gene can sometimes result in what is known as ‘Coffin-Siris Syndrome’ . Some of the characteristics of this condition are abnormalities in the development of the face, as well as respiratory issues. Researchers have established that variants rs118127175 and rs76586925 can significantly increase your likelihood of being a snorer relative to people who do not have these variants.
What can I do about it?
While snoring is, for the most part, harmless, it can increase your risk of developing sleep apnea. In these cases individuals may seek ways to treat their snoring, for their own or others sake. While the genetic contribution to our likelihood of being a snorer can’t be helped, our behavioural traits can. Drinking less alcohol, losing weight if you’re overweight, and sleeping on your side can all contribute to snoring less at night. There are also oral appliances that have been developed which have been shown to help in some cases, which may help you (and any other members of your household) enjoy a better night's sleep.