Chronic Pain Accelerates Brain Aging, Perhaps via Inflammation

A range of conditions produce chronic pain in muscle and skeletal tissue. While conditions such as osteoathritis are comparatively well understood, the etiology of chronic muscular pain disorders such as myofascial pain syndrome is poorly understood and treatment options are consequently limited. Here, researchers analyze available epidemiological data on knee osteoarthritis, and show that it suggests an inflammatory link between chronic pain and an accelerated pace of degenerative brain aging.

Individuals suffering from chronic musculoskeletal pain (CMP) may face a higher high risk of brain aging. CMP is a leading cause of disability, affecting more than 40% of the world's population and impacting patients' cognitive function. Although the exact mechanism is not fully understood, thus hampering prevention and treatment efforts, research indicates that inflammatory markers associated with brain aging are higher in CMP patients, suggesting a link between brain aging and CMP.

Using structural MRI data from over 9,000 individuals, researchers developed a brain age model to compare brain age to chronological age. They found that individuals with knee osteoarthritis, who were identified from both the UK Biobank and additional replication datasets from the local community, experienced more rapid brain aging than healthy individuals. In addition, brain regions responsible for human cognitive function, such as the hippocampus, were found to be associated with such accelerated brain aging.

Moreover, the researchers delved into the genetic landscape and identified the gene SLC39A8 as a shared link between knee osteoarthritis and accelerated brain aging. This gene, which is particularly expressed in microglial cells and astrocytes, underscores the potential role of inflammation and neurodevelopment in the observed phenomena.