Is Widespread Chronic Pain Associated With a Higher Dementia Risk?

An increased number of chronic pain sites is associated with an increased risk for all-cause dementia, according to study findings published in the journal BMC Medicine. 

Previous studies have demonstrated a link between chronic musculoskeletal pain and dementia. Musculoskeletal pain can occur in several sites, with some studies showing an association between pain in multiple sites and worsened physical and mental health. Researchers conducted a retrospective population-based study to assess the relationship between chronic pain in multiple sites and the risk for all-cause dementia.

Data was collected from the UK Biobank Study, which included over 500,000 participants aged 40 to 69 years. Participants answered a baseline survey to report chronic pain sites and duration of pain. 

The primary outcome was a diagnosis of dementia, which was identified from hospital inpatient records and death registry records. The International Classification of Diseases (ICD-9 and ICD-10) coding system was used to classify diagnoses. 

Of the 502,492 participants recruited at baseline, 356,383 participants were included in the analysis. 

The average age of participants was 56.5 years (standard deviation [SD], 8.1 years) and 51.6% of participants were women. The median follow-up period was 13.3 years (interquartile range [IQR], 12.6-14.0). During the follow-up period, there were 4,959 new dementia diagnoses reported, including 2,083 with Alzheimer disease (AD), 1,092 vascular dementia, and 166 frontotemporal dementia cases.

At the start of the study, patients reporting pain in 1, 2, 3, and 4 sites and full-body pain were 24.4%, 10.3%, 3.9%, 1.3%, and 1.3%, respectively. A total of 58.8% of participants reported no chronic pain at baseline.

Univariable analysis and the fully adjusted model revealed a significant association between the number of pain sites and an increased risk for all-cause dementia (hazard ratio [HR], 1.08 per 1 site increase; 95% CI, 1.05-1.11).

There was a dose-response relationship identified for participants reporting at least 1 chronic pain site, showing an increased risk for incident all-cause dementia, compared with those without chronic pain. 

Compared with patients without chronic pain, those reporting 2, 3, and 4 pain sites and full body pain had a 29%, 27%, 30%, and 37% higher risk for incident AD, with 4 pain sites and full body pains having borderline significance.

“These findings suggest that chronic pain in multiple sites may represent an accessible marker to assess an individual’s dementia risk and identify ‘at-risk’ individuals at early stages,” the researchers concluded. 

Study limitations included the lack of generalizability to other ethnicities, relatively short follow-up periods, and potential misclassification in dementia subtypes.