A new study from Northwestern University in Evanston, IL, found that smoking puts people at a higher risk of developing chronic back pain, as compared to non-smokers.
This is not the first time that the link between smoking and chronic pain has been established, but this is the first study that suggests smoking’s interference with a brain circuit associated with pain. This interference makes smokers more likely to develop chronic back pain.
Back pain is one of the most common medical problems in the US, estimated to affect 8 out of 10 Americans at some point in their lives. According to the American Chiropractic Association, back pain is the main reason for missed days at work and the second most common reason for doctor's visits.
To reach their findings, the researchers analyzed 160 participants who had recently developed subacute back pain, defined as back pain lasting 4-12 weeks. They also assessed 32 participants with chronic back pain - defined as having back pain for 5 years or more - and 35 participants with no back pain.
On five separate occasions over a 1-year period, all participants completed questionnaires that gathered information about their smoking status and other health conditions. They also underwent magnetic resonance imaging (MRI) brain scans.
The researchers found that compared with non-smoking participants, those who smoked had a stronger connection between the nucleus accumbens and the medial prefrontal cortex, increasing their risk of chronic back pain. The team calculated that smokers are three times more likely to develop chronic back pain than non-smokers.
"But we saw a dramatic drop in this circuit's activity in smokers who - of their own will - quit smoking during the study," explains Petre. "So when they stopped smoking, their vulnerability to chronic pain also decreased."
"We conclude that smoking increases risk of transitioning to chronic back pain, an effect mediated by corticostriatal circuitry involved in addictive behaviour and motivated learning."
Read more Health News.