Widespread pain, a common subtype of chronic pain, is associated with an increased risk of dementia and stroke, a new study has found.
New research published in the journal Regional Anesthesia & Pain Medicine has determined a link between widespread pain and a heightened likelihood of all types of dementia, including Alzheimer’s disease, and stroke. Researchers say the findings indicate that this association is independent of potentially influential factors, such as age, general health, and lifestyle.
Chronic widespread pain is characterised by long-lasting pain in multiple body regions and is associated with other physical symptoms, such as fatigue, concentration problems, and psychological distress.
Previous research has suggested that experiencing symptoms of widespread pain could be a reliable predictor of cancer, peripheral arterial disease, and cardiovascular disease, and it has also been linked to a heightened mortality risk. Additionally, whilst chronic pain has been found to be a possible early indicator of cognitive decline, there is a lack of research to determine whether widespread pain could also lead to a greater risk of dementia and stroke.
To investigate the above, the researchers analysed data from 2464 second generation participants of the US long-term, multigenerational, community-based Framingham Heart Study, known as the Offspring Study.
Participants in the Offspring Study received a comprehensive check-up, which included a physical exam, lab tests, and detailed pain assessments, between 1990 and 1994.
The participants were divided into three pain groups: widespread pain – defined according to American College of Rheumatology criteria as pain above and below the waist, on both sides of the body, the skull, backbone, and ribs; other pain – classified as pain in one or more joint(s) only; or no pain in any joints.
Information on potentially influential factors was also collected, including evidence of high blood pressure and diabetes; weight; lifestyle factors; employment status; depression scores; history of pain medication; income; marital status; and educational attainment.
Participants were then continuously monitored for the beginnings of cognitive decline and clinical dementia (average of 10 years) or a first stroke (average of 15 years). During the monitoring period, 188 people were diagnosed with some form of dementia, 50 (27%) of whom had widespread pain and 138 (73%) of whom didn’t. 139 people had a stroke, 31 (22%) of whom had widespread pain and 108 (78%) of whom didn’t.
Increased risk of dementia and stroke
After taking account of potentially influential factors, the researchers found that people with widespread pain were 43% more likely to have any type of dementia, 47% more likely to have Alzheimer’s disease, and 29% more likely to have a stroke than those without widespread pain.
When only those aged over 65 were included, these risks were comparable –39% had a heightened risk of all types of dementia; 48% had a heightened risk of Alzheimer’s disease; and 54% had a heightened risk of stroke.
Although the findings of the study are significant, the researchers do recognise several limitations. For example, as the study is observational only, cause cannot be established. They also noted that the actual numbers of dementia and stroke cases were small, while the relationship between pain and cognitive decline is likely to be multifactorial.
The researchers concluded: “These findings provide convincing evidence that [widespread pain] may be a risk factor for all-cause dementia, [Alzheimer’s disease], and stroke. This increased risk is independent of age, sex, multiple sociodemographic factors, and health status and behaviours.”
In conclusion, the researchers determined that widespread pain may directly affect cognitive function, or it may be part of a prodromal phase of dementia and Alzheimer’s disease. They added that wider research is required to investigate these possibilities further.