A genetic link has been traced between four common chronic pain syndromes (CPS) for the first time. Researchers at King’s College London published the study in the journal Pain, which examined sets of twins to find a connection between irritable bowel syndrome (IBS), musculoskeletal pain, pelvic pain, and dry eye disease.
The common syndromes are often overlooked, according to researchers, which is why there is a lack of research and understanding of their causes and connections. With approximately 1.5 billion people worldwide suffering from chronic pain, and of those 100 million are Americans, researchers have begun to turn their attention to four CPS conditions that need further.
“This study is one of the first to examine the role of genetic and environmental factors in explaining the links between different chronic pain syndromes. The findings have clearly suggested that CPS may be heritable within families,” said Dr. Frances Williams, lead researcher from the Department of Twin Research at King's College London.
The research, which was funded by the Pain Relief Foundation, studied more than 8,000 pairs of twins from the TwinsUK cohort study, and compared them to non-identical twin sets. Identical twins share the 100 percent of the same DNA, while non-identical twins only share 50 percent. Researchers found that out of the four CPS conditions they were studying, all of the conditions were more prevalent in identical sets of twins, which indicates a genetic component to chronic pain conditions.
Female identical twins were shown to have stronger links between syndromes than their non-identical twin counterparts. The symptoms that were often shared between the pairs were fatigue, memory loss, and sleep disturbance. This genetic linkage indicates that there is a 66 percent likelihood of inheriting a chronic pain condition, however further investigation needs to be explored in order to make a definitive claim.
Acute pain is the pain that we’re all familiar with because it is a normal sensation that is triggered by the nervous system to alert your brain of a possible injury, such as stubbing your toe or touching a hot plate. It’s a signaling system used to protect and treat your pain quickly, while those who suffer from chronic pain have other much more to worry about. Chronic pain persists, as if the signal in the nervous system has never been turned off for weeks, months, and sometimes years.
Common chronic pain is usually initially started with some sort of sprained back, ear infection, or arthritis; however a problem persists when there is no injury of evidence of bodily harm anymore. The injury or ailment has passed but the pain remains a daily, throbbing reminder. There are certain medication, acupuncture treatments, electrical or brain stimulation, and surgical procedures that show promise for alleviating chronic pain, however for some the pain just doesn’t leave, according to the American Academy of Pain Medicine.
There has been difficulty in both diagnosis and treatment because there are no biomarkers, which is a biological molecule found in a bodily fluid or tissue to indicate a normal or abnormal process, to test or evidence of inflammation. Ultimately, their diagnosis relies on the personal communication of symptoms and the condition could hold a psychological element, making it more of an elusive cause and effect.
In the past, researchers have that found pain patients have lower-than-normal levels of endorphins in their spinal fluids, which is why acupuncture and nerve ending stimulation has shown promise. Stress factors are also currently being looked at while chemists synthesize new painkillers and discover alternative routes for treatment, according to the National Institute of Neurological Disorders and Stroke.
This new discovery that chronic pain conditions hold a higher risk of genetic susceptibility is a cornerstone in research for CPS. This could explain why sufferers have multiple chronic pain diseases at once.
“With further research, these findings could then lead to therapies which may change the lives of those suffering with chronic pain,” Williams said.