Dec. 14 (UPI) -- Some patients experience chronic pain after surgery. New research suggests genetics likely plays a role.
In addition to those with a genetic predisposition, researchers found males, patients younger than 65 and those with history of chronic pain were more likely to experience lost lasting post-surgical pain.
"Until now, the genetic variations associated with chronic postsurgical pain have not been well identified," Dr. Matthew T.V. Chan, a researcher at the Chinese University of Hong Kong in China, said in a news release.
The findings of Chan and his colleagues -- detailed in the journal Anesthesiology -- could be used to identify those at risk of developing chronic pain after surgery.
Wildly varying estimates suggest anywhere from 9 to 80 percent of patients experience some form of chronic pain after surgery. Authors of the latest study believe millions of Americans experience recurring pain near their wound for months, and sometimes years, after surgery. The pain, which may limit physical activity and socializing, can affect a patient's physical and mental health.
To analyze the role of genetics in chronic post-surgical pain, researchers collected blood samples from 1,152 surgical patients. Scientists used genomic analysis to identify the prevalence of 54 "pain-related" genes among the sampled patients.
A year after surgery, researchers inquired with patients about their pain levels. Patients rated the levels of pain experienced, from zero to 10, near the wound. Some 21 percent reported chronic post-surgical pain. Of the 21 percent, roughly a third said their pain was severe.
Those experiencing pain a year after surgery said their pain negatively affected their activity levels, mood, sleep, relationships and overall enjoyment of life.
Analysis showed a genetic marker called the brain-derived neurotrophic factor, or BDNF, was most correlated with chronic post surgical pain. Statistical analysis showed genetic variation was responsible for between 7 and 12 percent of a person's risk of experience chronic pain after surgery. Factors like age, sex, smoking history or anesthesia technique were responsible for only 3 to 6 percent of a person's risk.