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A new study suggests chronic pain may raise the risk of all-cause dementia and Alzheimer’s. Eddie Pearson/Stocksy
  • Patients who reported experiencing widespread pain had an increased incidence of all-cause dementia, Alzheimer’s disease, and stroke.
  • This increased risk is independent of factors such as age, health, or sociodemographic circumstance.
  • Researchers analyzed data from 2,464 participants of the Framingham Offspring Study Cohort, who underwent examination by health practitioners between 1990 and 1994.

A study by scholars at Chongqing Medical University in China, which appears online in the journal Regional Anesthesia & Pain Medicine, found patients who reported widespread pain had an increased incidence of dementia and stroke.

Researchers Dr. Kanran Wang and Dr. Hong Liu found this increased risk to be independent of facets such as age, health, or sociodemographic factors.

The World Health Organization’s (WHO) 11th revision of the International Statistical Classification of Diseases and Related Health Problems defines widespread chronic pain as pain in at least four of five body regions. Widespread pain is a hallmark symptom of fibromyalgia.

Earlier studies found individuals who report experiencing widespread pain have an increased risk of a cardiovascular cause of death as well as an increased incidence of cancer and reduced cancer survival. However, the researchers believe this is the first study to use a detailed review of medical records and autopsies to consider whether there is an association between widespread pain, dementia, and stroke.

For their study, the Chongqing Medical University researchers pulled data from the Framingham Heart Study (FHS). FHS is a large cohort study that started in 1948, with 5,209 white men and women between the ages of 30 and 62 years from the town of Framingham, Massachusetts. Originally, the purpose of the study was to understand heart disease better.

Now studying its third generation of participants, the FHS has encompassed more than 15,000 participants. For their work, the Chongqing Medical University researchers looked at about 2,464 participants of the Framingham Offspring Study Cohort. Health practitioners examined these participants between 1990 and 1994.

The participants also underwent laboratory tests and received a questionnaire to determine whether or not they experienced pain. Of the participants, 347 reported experiencing widespread pain.

The researchers found that these participants had:

  • a 43% higher risk for all-cause dementia
  • a 47% higher risk of Alzheimer’s disease
  • a 29% higher risk of stroke

The researchers presented three hypotheses for why individuals experiencing widespread pain might have an increased risk of developing dementia or having a stroke.

It could relate to lifestyle factors associated with experiencing chronic pain. For example, people who have chronic pain might not feel well enough to exercise regularly or shop for the groceries they need for a nutritious diet.

The researchers also theorize that widespread pain could directly compete for resources in the brain that handle cognitive processing. “The affective stress of [widespread pain] maybe, as other stressful exposures are, involved in quick cognitive decline via acknowledged cortisol-based pathways,” the study’s authors write.

Finally, the team hypothesized that widespread pain could be a preclinical phase of all-cause dementia and Alzheimer’s disease.

However, the observational nature of the study prevents the researchers from establishing the underlying mechanisms behind the increase in risk. They also advise that with small numbers of stroke and dementia, the relationship is likely to be multifactorial.

The authors also note that with the study sample being homogeneously white, the results may not be generalizable to people of other races or ethnicities.

In an interview with Medical News Today, Dr. Rebecca Edelmayer, senior director of scientific engagement for the Alzheimer’s Association, called the Chongqing Medical University study “a very first step in trying to understand whether there’s any relationship” between pain and increased risk for developing all types of dementia and having a stroke.

“I was actually excited to read this paper because I was hoping to see a really in-depth study looking at the different types of pain that might put people at more risk for dementia,” said Dr. Edelmayer, who completed her Ph.D. and postdoctoral training in medical pharmacology with a focus on neuropharmacology. “I think this paper brings up more questions actually than answers.”

Dr. Edelmayer also pointed out that widespread pain is a broad category. She told MNT:

“What causes pain is very different across the body. It could be cancer-induced pain, inflammatory pain — like arthritis, bone pain — like osteoarthritis, [and] neuropathic pain, which is sort of abnormal pain signaling and damaged nerves. There’s so many different reasons for people to be in pain.”

Additionally, one type of pain may play more of a role in changing cognition than other types of pain, according to Edelmayer. “I think much more research is still needed,” she said.

Dr. Vernon Williams, founding director of the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, CA, told MNT he’s hopeful the results of the Chongqing Medical University study will shine a spotlight on the importance of treating pain.

“What this is telling us is that, hopefully, as we improve pain management, we reduce the risk of people having cognitive dysfunction. We reduce the risk of people having strokes,” Dr. Williams said.

A 2019 report found 83% of primary care doctors believe it is difficult to treat people with chronic pain because of the risks associated with opioid intake and the wider opioid crisis. Dr. Williams hopes this new study will remind health practitioners about the importance of managing pain.

“I think it also helps reinforce to other stakeholders — and that can be physical therapists, insurers, patients, and family members — about how important it is to be aware of widespread pain and to manage it effectively because not only does it improve function and performance and quality of life right now, it may also have an effect on cognitive function down the line,” Dr. Williams said.

“We don’t want people to suffer in silence.”

– Dr. Vernon Williams