NCT06973837

Studying the Neurobiological Mechanisms of Non-specific Chronic Low Back Pain and Chronic Insomnia: a Four-group Cross-sectional Study

Unravelling the Neurobiological Mechanisms Underlying the Bidirectional Relationship Between Chronic Sleep Disturbances and Pain Sensitivity in People With Non-specific Chronic Low Back Pain and Chronic Insomnia

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 80 (estimated)
• Sponsor: Vrije Universiteit Brussel · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

This study is a part of a larger project aiming to evaluate the neurobiological mechanisms underlying the relationship between sleep and pain in people with non-specific chronic low back pain. Specifically, this study aims to evaluate the neurobiological mechanisms underlying the relationship between chronic sleep disturbances and pain sensitivity in people with non-specific chronic low back pain and chronic insomnia.

Detailed description

Sleep disturbances, and especially insomnia, reflect one of the most common comorbidities in people with chronic pain, including people with chronic low back pain. Previous research has furthermore demonstrated that a lack of sleep is associated with an increased pain sensitivity. The goal of this study is to evaluate the role of brain neuroinflammation in the relationship between chronic sleep disturbances and both clinical and experimental pain sensitivity in people non-specific chronic low back pain and/or chronic insomnia. A cross-sectional study will be conducted across four age- and sex-matched study groups: healthy controls with good sleep habits (Group 1); people with non-specific chronic low back pain and good sleep habits (Group 2); pain-free individuals with chronic insomnia (Group 3); and people with non-specific chronic low back pain and comorbid chronic insomnia (Group 4). The study will be performed over nine consecutive days. All participants will arrive at the lab at a standardized time, relative to their habitual bedtime, in the afternoon of the first study day. There, they will first fill out a number of baseline questionnaires, after which a battery of quantitative sensory test, utilizing both manual and computerized pressure algometry, will be performed to assess experimental pain sensitivity. After being provided a standardized dinner, the participants will then perform a clinical polysomnography (i.e., sleep study) during an over-night stay at the hospital sleep center (UZ Leuven, Belgium) to acquire data on sleep time, stability, and efficiency, as well as to identify participants with combined sleep-disorder-comorbidity profiles (e.g. insomnia + apnea). Directly upon awakening in the morning of the second day, all participants will first fill in a few additional questionnaires, and then be provided a standardized low-fiber breakfast alongside a bolus of pure fiber. Next, the participants will be escorted to the magnetic resonance imaging facility and perform two blocks of brain scanning separated by an approximate 10-min break. During the first block, magnetic resonance spectroscopy and diffusion-weighted magnetic resonance imaging will be performed to measure markers of neuroinflammation, whereas the second block utilizes functional magnetic resonance imaging during an evoked-low-back-pain task to acquire data on back pain-evoked brain activity. After the two scanning blocks, the second study day ends by the collection of a venous blood sample to assess systemic levels of inflammation (via highly sensitive C-reactive protein) and short chain fatty acids. During the following seven days, all participants will complete a sleep diary once per day, provide momentary ratings of pain, sleepiness, fatigue, and affect eight times per day, and wear an Actigraph at all times (except during heavy water contact). During this seven-day period, the participants will also be instructed to collect a stool sample at a time of their own convenience, but preferably within the first three days, to be used for gut microbiota composition analyses. Continuous dietary intake will therefore also be recorded during the first three days of the seven-day period, while participants who are not able to collect their stool sample during any of these three days will continue to record their dietary intake until a stool sample has been collected.

Conditions

• Chronic Low Back Pain (CLBP)
• Chronic Insomnia
• Neuroinflammation

Interventions

Type	Name	Description
OTHER	Real-life monitoring, experimental pain testing, brain imaging, blood and stool sampling.	See detailed study description and outcome measures.

Timeline

• Start date: 2025-10-03
• Primary completion: 2026-10-01
• Completion: 2026-10-01
• First posted: 2025-05-15
• Last updated: 2025-12-15

Locations

1 site across 1 country: Belgium