Quebec researchers identify biomarkers linked to chronic pain

Two biomarkers identified by a research team at Université Laval could lead to improved management of chronic musculoskeletal pain (CMP).

Professor Clermont Dionne’s team found that the presence of acrylamide and cadmium in the body increased the risk of CMP by 24 per cent and 56 per cent, respectively.

“We don’t really understand what causes a large proportion of these syndromes,” said Dionne, a professor in the Department of Social and Preventive Medicine and a researcher at the CHU de Québec-Université Laval Research Centre and VITAM-Centre for Sustainable Health Research.

“It causes a lot of disability. And even if patients eventually recover within a few weeks, these syndromes are recurrent, so the pain will return.”

Acrylamide and cadmium are toxic compounds found in cigarette smoke, but also in food and other products to which we are exposed daily.

Researchers therefore speculate that their accumulation in the body could have an effect on the nervous system and contribute to CMD, at least in some of the people who suffer from it.

For reasons that are still poorly understood, CMD is very frequently associated with smoking. By analyzing data from a large American National Health and Nutrition Examination Survey, Professor Clermont and his colleagues observed an increased risk of CMD with tobacco consumption.

The presence of acrylamide in the body increased the risk of CMD by 26 per cent, compared to 56 per cent for the presence of cadmium. The combined effect of the two substances doubled the risk compared to what is observed in non-smokers.

“These results suggest that the link between smoking and CMD is mediated by acrylamide and cadmium, and that these substances, also present in food and the environment, could serve as biomarkers for CMD,” summarize the study authors.

A previous study measured a statistical association between blood concentrations of acrylamide and cadmium and CMD in the neck, shoulders, and lower back in a group representative of the general population.

“Smoking is a risk factor that has been known for a very long time,” said Professor Dionne. “People who smoke have more pain, but those who smoke the most also have the most, so it’s a sign of causality.”

The data from the new study, said Dionne, could initially lead to a less subjective assessment of this pain. They could also make it possible to evaluate the effectiveness of interventions offered to patients. We could finally consider measures to reduce exposure to these substances or even develop treatments to reduce their concentrations in the body.

Currently, Dionne lamented, the management of CMDs is “at a dead end,” and patients are too often advised to simply learn to “manage their pain”—a situation made all the more complex by the fact that, in the majority of cases, the cause of the problems remains mysterious.

“(The study) could lead to better personalization of these syndromes,” he said. “If it allowed us to identify some of the people who suffer from these problems and treat them differently because they have a different source of problems, then we could advance knowledge and prevention.”

We often look, at least for the moment, for a biomechanical explanation for the problem, added Professor Dionne, pointing to certain movements, “but we could imagine that there are potentially other mechanisms involved in some people.”

“It somewhat changes the biomechanical paradigm,” he emphasized. “It could change the way we approach research and, eventually, the treatment of chronic musculoskeletal pain.”

It is estimated that CMD affects approximately 5 per cent of the Canadian population.

The findings of this study were published in the medical journal Pain.

–This report by La Presse Canadienne was translated by CityNews