A study that looked into the genes of close to half a million Britons has identified 78 gene variants that could be influencing the amount of sleep people are getting and found that this discovery could lead to better treatments for sleep problems such as insomnia.
In previous studies it has been found that between 10% and 40% of variation in sleep duration could be genetically linked and two associated genes were discovered. It has also been proven that both too much and too little sleep can cause a number of health related problems. However, it had not yet been proven why some individuals need less sleep than others.
In this study, researchers at the University of Exeter and the Massachusetts General Hospital looked at genetic data from 446,000 people who had self reported the amount of sleep they were getting. They were able to identify a further 76 genes that influenced sleep, making a total of 78 and discovered that the number of gene variants each person had directly correlated to their likelihood to report less sleep. Those who carried the largest number of the sleep-increasing genes reported an average of 22 minutes more sleep than those with the fewest.
As well as influencing the amount of sleep people get, the research also pointed to shared genetic links to health problems that also correlated to the amount of sleep. These included higher levels of body fat, type 2 diabetes and heart disease and even lower education levels. Those who genetically were prone to getting less sleep were also more likely to suffer with mental health issues such as schizophrenia and depression.
The co-author Dr Samuel Jones stated that this is a huge leap forward in the understanding of why some people need more sleep than others and could lead to the development of new treatments for sleep and sleep disorders. He points out that while people spend up to a third of their life asleep, there is still little understanding of the specific genes and pathways that regulate the actual amount of sleep people get.
Dr Richa Saxena from Harvard Medical School, and co-author, has pointed out that follow up studies are required to see how these genes actually function, but it is known that associated genes can play a role in brain development and the transmission of signals between neurons. This study suggests that it may be possible to understand each person’s individual need for sleep and therefore have a better understanding of targeted treatments for disordered sleep.