Women tend to be more greatly affected by chronic pain, which may be due to differences in the group of genes that influence the severity of the condition.
A team of researchers, led by Kiera Johnston of the University of Glasgow, conducted a genetic study investigating chronic pain in men and women. They found that there were 31 genes in women associated with chronic pain and 37 in men, with only one overlapping gene associated with chronic pain in both sexes.
The team conducted a Genome Wide Association Study (GWAS), which screens the genome for genes that are associated with disease. The study consisted of 209,000 women and 178,000 men.
They also compared the genes to see whether they interacted with each other and found that many of the genes would help others perform, suggesting that chronic pain could be influenced by multiple genes and gene interactions.
In addition, the team found that all of the genes in men and all but one of the genes in women were actively switched on in cells around the dorsal root ganglion, a nerve cluster in the spinal cord responsible for transmitting pain signals from around the body back up to the brain.
In their paper, published in PLOS Genetics, the authors say this builds on previous work that shows chronic pain originates largely in the brain, and sometimes in the sites where the pain is experienced.
They also suggest that the differences in chronic pain between sexes is at least somewhat genetically based and needs to be considered when developing treatments.
Overall, they argue that chronic pain research would benefit from taking individual experiences based on sex into account.
“Our study highlights the importance of considering sex as a biological variable and showed subtle but interesting sex differences in the genetics of chronic pain,” says Johnston.