Chronic Pain Happens Differently in Men and Women

Women often feel colder than men due to physical differences. Now, a new study shows that the two sexes have different biological processes underlying a specific kind of pain, too. As WIRED reports, research published in the journal Brain revealed that different cells and proteins were activated in men and women with neuropathic pain—a condition that is often chronic, with symptoms including a burning or shooting sensation. While scientists say further research is needed, these findings could potentially change the way we treat conditions involving chronic pain.

A team of Texas-based neurologists and neuroscientists looked for RNA expressions in the sensory neurons of spinal tumors that had been removed from eight women and 18 men. Some of the patients had pain as a result of nerve compression, while others had not experienced any chronic pain. While studying the neurons of women with pain, researchers noticed that protein-like molecules called neuropeptides, which modulate neurons, were highly activated. For the men, immune system cells called macrophages were most active.

"This represents the first direct human evidence that pain seems to be as sex-dependent in its underlying biology in humans as we have been suggesting for a while now, based on experiments in mice," Jeffrey Mogil, a professor of pain studies at Montreal's McGill University, who was not involved in the Brain study, tells WIRED.

So what exactly do these new findings mean for sufferers of chronic pain? Considering that clinical trials and drug manufacturers have traditionally failed to distinguish between the sexes when it comes to developing pain medication, the study could potentially form a foundation for sex-specific pain therapies that could prove more effective. This might be especially promising for women, who are more likely to have some condition that cause persistent pain, such as migraines or fibromyalgia.

"I think that 10 years from now, when I look back at how papers I've published have had an impact, this one will stick out," Dr. Ted Price, a neuroscience professor and one of the paper's authors, said in a statement. "I hope by then that we are designing clinical trials better considering sex as a biological variable, and that we understand how chronic pain is driven differently in men and women."

[h/t WIRED]