PRROPS: Pathways of Risk and Resilience for Overlapping Pain and Sensitization

Chronic pain affects >100 million American adults with estimated costs of up to $1 trillion annually. Older adults are at increased risk of having multiple painful conditions and are living longer with the negative impacts of chronic pain. Chronic pain, regardless of anatomy or diagnosis involved (e.g., back pain, migraine), is the leading cause of disability worldwide. Limited insights into whether common mechanisms underlie all pain conditions, regardless of diagnosis, has contributed to inadequate pain management options, and in turn, to the opioid epidemic. Health care providers who treat one pain condition (e.g., joint pain) typically do not manage symptoms in other parts of the body (e.g., abdominal pain), and patients are often referred from one specialist to another. Studying commonalities of various chronic overlapping pain conditions (COPC) in community-based cohorts unselected for pain conditions can provide novel insights into causes of chronic pain as a disease itself, and into shared risk factors that may be promising targets to help ameliorate chronic pain regardless of diagnosis. Alterations in nociceptive signaling such as pain sensitization assessed by quantitative sensory testing (QST) may commonly underlie chronic pain, but why such alterations occur is not known, and whether such nociceptive signaling changes are heritable is also not known. Beyond nociception, there may be broader nervous system dysfunction underlying chronic pain. Generalized heightened sensitivity to external stimuli (e.g., light, sound) and impaired autonomic nervous system functioning, reflected by diminished heart rate variability (HRV), are associated with chronic pain, but it is unclear if they contribute to COPC, QST-assessed abnormalities, or development of chronic pain. Treatments targeting these potential risk factors could represent new avenues for pain management. Another untapped potential is in understanding whether positive factors such as resilience, sleep quality, and physical activity can be harnessed to alter risk of COPC or QST abnormalities. We propose evaluating COPC in the upcoming study visit of a community-based middle age and older adult cohort unselected for any pain complaints, the 3rd Generation of the Framingham Heart Study (FHS) (N~3374, mean age 60). We aim to understand the relation of multisensory sensitivity, autonomic function, resilience, sleep, and physical activity to COPC, QST-assessed pain processing and evolution of chronic pain over time; and to study heritability of QST abnormalities. Understanding the relation of these novel factors to COPC and QST would spur development of novel pain management approaches for all types of pain regardless of diagnosis involved. We will collect data regarding common chronic pain complaints, QST (to assess pain sensitization), and proposed risk factors, and conduct two follow-up assessments to obtain longitudinal data. We will leverage the ongoing FHS Offspring (2nd Generation) Exam in which we are collecting the same QST measures to assess heritability of pain processing abnormalities. Our work will address several knowledge gaps, and insights gained may facilitate new approaches to relieving chronic pain and its consequences, regardless of underlying diagnosis.