Chronic Low Back Pain (Non-specific, Uncomplicated)GLOWNCT07734714
Chronic Low Back Pain Comorbidities: Unravelling Impaired Glucose Metabolism
A study testing Glucose beverage, Isomaltulose beverage and Standardized breakfast in people with Chronic Low Back Pain (Non-specific, Uncomplicated) and Chronic Low Back Pain (CLBP), run by Vrije Universiteit Brussel at 1 site in Belgium.
Trial summary
Chronic low back pain (CLBP) is a global health problem. The first step for developing effective treatments is a better understanding of underlying mechanisms, including its comorbidities. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Chronic Low Back Pain (Non-specific, Uncomplicated), Chronic Low Back Pain (CLBP)
- What is being tested?
- Glucose beverage, Isomaltulose beverage and Standardized breakfast
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 124 participants
- Where
- 1 siteBelgium
- Study dates
- Jul 2026to Apr 2030
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Between 18 and 65 years old
- For patient group: participants must comply to the non-specific CLBP criteria which are low back pain every day for three months or pain for at least half the days in the last six months, without leg pain that exceeds 7 out of 10 on a numeric rating scale and without evidence of specific spinal pathologies.
- For healthy volunteers: pain-free for the entire duration of the study
Who cannot join
- Systemic diseases (e.g., hypertension, cardiovascular disease, chronic gastrointestinal disorder, skin disease, active neuropathic disorder, severe eating disorders, myocardial infarction or cerebrovascular accident in the 6 months prior to the study)
- Current pregnancy or pregnancy in the last year
- Start-up of new medication or (dietary) treatment in the six weeks before the study
- Antibiotic use in the three months prior to the study
- History of bariatric surgery
- Use of analgesics, alcohol, immunosuppressive drugs or smoking 48 hours prior to study participation
- Classified as diabetic according to the American Diabetes criteria: fasting blood glucose ≥ 126 mg/dl, blood HbA1c ≥ 6.5%, or 2-hour PPGR ≥ 200 mg/dl
- Additionally, study participation will be postponed in case the participant donated blood < 8 weeks before baseline and participants will be asked not to donate blood for the duration of the trial.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site
Universitair Ziekenhuis Brussel
Jette, Brussels Capital, 1090
Jinane Ben Amar, PhD student, +32487219246, Jinane.Ben.Amar@vub.be
Joni Michiels, PhD student, +32471103990, Joni.Michiels2@vub.be
About this study
Chronic low back pain (CLBP) is a global health problem. The first step for developing effective treatments is a better understanding of underlying mechanisms, including its comorbidities. Cumulative findings, including breakthrough findings from our own group, point to impaired glucose metabolism as an important CLBP comorbidity. In addition to its metabolic role, the insulin-like growth factor 1 (IGF1)/ growth hormone (GH) axis plays a key role in pain modulation. Therefore, the project aims to examine whether DNA methylation and functional protein levels predicts postprandial glycemic responses to standardized drinks, standardized meals, and real-life meals in patients with CLBP. This will be examined using two (i.e., 1 in CLBP and 1 in healthy controls) double-blind, randomized cross-over experiments (high versus low glycaemic index beverages). After the 14-day experimental phase, all participants will be studied for an additional week to examine whether the experimental findings have ecological validity, i.e., whether they can be confirmed in response to real-life meals in their home environment. Genome-wide changes in DNA methylation will be studied using whole genome bisulfite sequencing and targeted next-generation sequencing. The project allows identification of a biomarker for a potentially very significant CLBP comorbidity, including identifying targetable mechanisms to develop innovative, personalized treatments.
Read the detailed description
With this collaboration between KU Leuven and Vrije Universiteit Brussel, we aim to investigate the role of epigenetic mechanisms in impaired glucose tolerance in patients with CLBP by assessing DNA methylation patterns in genes related to the IGF1/GH-axis. The main objective is to identify whether DNA methylation in these genes predict postprandial glycaemic response (PPGR) to standardized drinks, standardized meals, and real-life meals in patients with CLBP. Secondary objectives are to investigate whether CLBP patients differ from healthy controls in DNA methylation; whether DNA methylation in these genes is associated with serum levels of their functional proteins, pain sensitivity and quality of life in CLBP patients; and whether dietary factors relate to DNA methylation in these genes and impaired glucose metabolism in CLBP patients. We hypothesize that CLBP patients display significantly higher DNA methylation in IGF1/GH-axis genes, accounting for lower serum levels of their proteins, and contributing to impaired glucose metabolism. Moreover, we expect that these epigenetic changes predict PPGR and relate with pain sensitivity and quality of life in patients with CLBP. We will perform a 2-arm, double-blind, randomized, cross-over experiment on 62 patients with CLBP and 62 healthy controls. During the first lab visit, the participants will fill out questionnaires on demographic and medical data, mental health, quality of life and pain, and autonomic nervous system (ANS) function and pain sensitivity will be assessed. Then the participants are randomized (1:1) to one of the interventions. This beverage is either a glucose solution or an isomaltulose solution (high vs low glycaemic index (GI)). For the third visit, they are crossed over to the other beverage. During the second and third visit, identical assessments will be performed. Preprandial assessments include questionnaires on anxiety and pain, blood collection, and ANS measurement. Then the participants consume the standardized drink within 5 minutes and remain seated for 2 hours, after which a postprandial blood collection is done. During the last week of the study the participants will consume a standardized meal (55g of white bread and 50g of dark chocolate) once daily after an overnight fast. For the full duration of the study, glucose levels, nutrition, sleep and physical activity will be measured continuously.
- Being tested
- Glucose beverage, Isomaltulose beverage, Standardized breakfast
- Keywords
- Epigenetic, DNA methylation, Glucose metabolism, IGF1/GH axis, Chronic low back pain, CLBP
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Glucose beverageOther
This beverage is made by dissolving 75 g of glucose in 200 ml of water.
Isomaltulose beverageOther
The isomaltulose beverage consists of 75 g of isomaltulose dissolved in 200 ml of water.
Standardized breakfastOther
During week 3 of the study, all partcipants consume a standardized breakfast after an overnight fast for seven days. This breakfast consists of 55g of white bread and 50g of dark chocolate. The participants are asked not to eat or perform strenuous exercise for up to two hours after consuming the breakfast.
| Study group | Role | What they receive |
|---|---|---|
| Healthy control | Experimental | The healthy controls will undergo the same assessments as the patients with CLBP, namely the high and low glycaemic index beverages. However, the healthy controls do not show signs of chronic low back pain as defined in the protocol. Receives: Other: Glucose beverage; Other: Isomaltulose beverage; Other: Standardized breakfast |
| Patients with CLBP | Experimental | Patients with CLBP will undergo the same assessments as the healthy control group, namely the high and low glycaemic index beverages. CLBP is defined as experiencing low back pain every day for at least 3 months, or every other day for at least 6 months. Receives: Other: Glucose beverage; Other: Isomaltulose beverage; Other: Standardized breakfast |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postprandial glycaemic response (PPGR)
The primary outcome measure is the postprandial glycaemic response (PPGR) following standardized drinks, standardized breakfasts and real-life meals using a continuous glucose monitor.
Measured: During the first and last week of the study, for PPGR to real-life meals and standardized meals respectively, and during the second and third study visit (day 7 and day 14).
Secondary outcomes (15)
DNA methylation of IGF1/GH-axis genes
DNA methylation patterns in specific regions of 4 IGF1/GH-axis genes will be determined by whole genome bisulfite sequencing and targeted next-generation sequencing using Peripheral Blood Mononuclear Cells (PBMCs).
Measured: PBMCs will be isolated after blood collection on day 7 and day 14.
Serum levels of IGF1/GH-axis genes
To assess the effect of differential DNA methylation in the genes of these proteins, we will measure functional protein levels in serum samples using Enzyme-Linked ImmunoSorbent Assays (ELISAs). We expect increased DNA methylation to result in lower serum protein levels.
Measured: Blood collection will be done on day 7 and day 14.
Temperature pain thresholds
Detection and pain thresholds will be determined for both warmth and cold.
Measured: During the first study visit (day 1).
Pressure pain thresholds
Pain thresholds and temporal summation for pressure will be determined.
Measured: During the first study visit (day 1).
36-item Short Form Health Survey (SF-36)
Self-reported quality of life will be assessed through the 36-Item Short Form Health Survey (SF-36). Its score varies between 0 and 100, with higher values representing a better quality of life.
Measured: This questionnaire is completed by the participants at baseline (day 1).
Brief Pain Inventory (BPI)
The BPI will assess the pain sensitivity in the last 24 hours as reported by the participant. Its score ranges from 0 to 10, with higher scores representing increased pain symptoms.
Measured: The BPI is completed during every study visit (day 1, day 7 and day 14).
Central Sensitization Inventory (CSI)
Signs of central sensitization are assessed using a self-reported questionnaire. Its score varies between 0 and 100 with higher scores indicating increased central sensitization and scores of 40 or higher suggesting central sensitization syndrome.
Measured: The CSI is completed during the baseline visit on day 1.
Douleur Neuropathic 4 (DN4)
This assessement consists of 2 self-reported questions and 2 assessments performed by the investigator to test for signs of neuropathic pain. The total score varies between 0 and 10 with higher scores indicating increased neuropathic pain and values of 4 or more suggesting clinically relevant neuropathic pain.
Measured: This assessment will be performed during the baseline visit on day 1.
Pain Catastrophizing Scale (PCS)
As catastrophizing pain can influence pain perception, this will be assessed using a self-reported questionnaire. Its values range between 0 and 52 with higher scores indicating increased catastrophizing and scores of 30 or higher suggesting clinically relevant catastrophizing.
Measured: This assessment will be performed during the baseline visit on day 1.
Pain Vigilance and Awareness Questionnaire (PVAQ)
This self-reported questionnaire assesses pain vigilance and awareness. Its scores range between 0 and 80 with higher scores indicating increased pain vigilance and awareness.
Measured: This assessment will be performed during the baseline visit on day 1.
Widespread Pain Index (WPI)
This self-reported questionnaire assesses the presence and nature of widespread pain. Its scores range between 0 and 19 with higher scores indicating an increased number of painful regions.
Measured: This assessment will be performed during the baseline visit on day 1.
Calorie intake
Calorie intake will be measured in a real-life setting using dietary diaries.
Measured: During the first week, they will complete a 3-day dietary diary with details on the type of food, the amount consumed and the timing of the meals. During the last week, the same diary is filled out for seven days.
Macronutrient intake
Macronutrient intake will be monitored using a dietary diary.
Measured: During the first week, they will complete a 3-day dietary diary with details on the type of food, the amount consumed and the timing of the meals. During the last week, the same diary is filled out for seven days.
Micronutrient intake
Micronutrient intake will be assessed using a dietary diary.
Measured: During the first week, they will complete a 3-day dietary diary with details on the type of food, the amount consumed and the timing of the meals. During the last week, the same diary is filled out for seven days.
Healthy Eating Index (HEI)
Using the dietary diaries, the HEI will be determined to assess how healthy the participants' diet are. Its scores range between 0 and 100 with higher scores indicating a healthier diet.
Measured: During the first week, they will complete a 3-day dietary diary with details on the type of food, the amount consumed and the timing of the meals. During the last week, the same diary is filled out for seven days.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2026
- Study startJul 2026 (estimated)
- Primary completionApr 2030 (estimated)
- Study completionApr 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic Low Back Pain (Non-specific, Uncomplicated)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 124 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vrije Universiteit Brussel
- Sponsor type
- University, hospital or other
- Collaborators
- Universitair Ziekenhuis Brussel, KU Leuven
- Responsible party
- Sponsor
- Investigators
- Jo Nijs, Professor, Principal investigator, Vrije Universiteit Brussel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07734714
- Sponsor's protocol ID
- 25386_GLOW
- Acronym
- GLOW
- Status last verified
- Jun 2026
- First submitted
- 7 Jul 2026
- Last updated
- 29 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided