CIRCADIAN CONTROL OF CHRONIC PAIN

Leader(s): Nader Ghasemlou, PhD & Ian Gilron, MD
Institution(s): Queen’s University
Other Members: Luda Diatchenko, PhD (McGill); Elizabeth vandenKerkhof, PhD (Queen’s University); Scott Duggan, MD (Queen’s University), Qingling Duan, PhD (Queen’s University), Brian Kwon, MD (UBC)
Trainee(s): Mitra Knezic (Queen’s), Chloe Nobis (Queen’s), Julia Segal (Queen’s), Kaitlyn Tresidder (Queen’s) 



Why was the study done?
Low back pain is the leading cause of disability worldwide and affects 80% of individuals throughout their lifetimes. In most cases, the pain is acute and individuals recover within weeks. However, a considerable number of individuals develop chronic low back pain where pain persists for more than three months, with inflammation playing a critical role in this response. Previous work suggests that pain fluctuates over the course of the day, where neuropathic pain is most intense at night while inflammatory pain reaches a peak in the morning. Understanding fluctuations in pain intensity is central to a thoughtful clinical pain assessment as these fluctuations may provide clues to the underlying causes and how to better manage pain. There are currently few studies examining how daily changes in the inflammatory response may influence patterns of chronic low back pain. Thus, the goals of our study are to: (1) describe the daily fluctuations in pain in people with chronic low back pain; and (2) identify biomarkers (in the blood) that could explain these fluctuations. 

 

How was the study done?
We are recruiting adults 18 years of age or older who are living with chronic low back pain for at least 3 months, and who have internet access. Individuals are first asked to complete a baseline assessment of their pain before blood is collected in the morning and evening. Following blood sample collection, electronic diaries are completed every morning, afternoon, and evening for one week. These electronic diaries ask participants to rate their pain, mood, and fatigue on a scale of 0-10 to examine the daily fluctuation of each symptom. 

 

What were the study results?
While our study is still ongoing, we have recruited more than 70 patients between the ages of 21-81, with roughly equal numbers of both men and women. Upon completion of our study, we hope to increase our understanding of daily fluctuations in chronic low back pain intensity by exploring how inflammatory factors can influence these pain fluctuations at the molecular level in the blood (biomarkers of pain). These findings may help influence future research and identify new therapeutic strategies to decrease or eliminate fluctuations in pain. As a result, patients may be able to function better throughout their daily activities. 



Recent Updates:

Ms. Lesley Singer, a patient-partner with chronic pain, worked in partnership throughout the development and implementation of this project. Together, we have streamlined data collection methods, identified roadblocks reducing participation, and improved our study design.

Sixty-five patients were recruited, with e-diaries completed and blood samples collected at two times of day.

Last updated: January 2021


Selected Publications:
  • Isolation and RNA purification of macrophages/microglia from the adult mouse spinal cord. Tsatas O, Ghasemlou N. J Immunol Methods. 2020 Feb;477:112678. doi: 10.1016/j.jim.2019.112678.
  • AAAPT Diagnostic Criteria for Acute Knee Arthroplasty Pain. Abdallah FW, Gilron I, Fillingim RB, Tighe P, Parvataneni HK, Ghasemlou N, Sawhney M, McCartney CJL. Pain Med. 2020 Feb 5. pii: pnz355. doi: 10.1093/pm/pnz355.