Gut Microbiota and Bacterial Translocation in Restless Legs Syndrome (RLS-BIOT)

May 17, 2024 updated by: University Hospital, Montpellier

Study of Gut Microbiota and Bacterial Translocation in Patients With Restless Legs Syndrome and Controls

Restless Legs Syndrome (RLS) is a common neurological sensorimotor disorder defined by an urge to move the legs when at rest that increase in the evening and at night. The pathophysiology of RLS remains poorly understood, but brain iron deficiency plays a major role. Iron absorption is an active process located in enterocytes of the proximal bowel, and is inhibited by hepcidin. The gut microbiota plays a central role in intestinal absorption, and in the maturation of the immune system. An imbalance in the microbiota, known as dysbiosis, could lead to a decrease in iron absorption, inflammation of the intestinal epithelium, and an increase in its permeability, thus favoring bacterial translocation and chronic systemic inflammation. Numerous studies showed an association between RLS and gastrointestinal diseases: Irritable bowel syndrome, Crohn's disease, ulcerative colitis, small intestinal bacterial overgrowth. However, no study has examined the gut microbiota in RLS.

The investigators hypothesize that there is an imbalance of gut microbiota in patients with RLS, favoring an increased intestinal permeability and bacterial translocation, leading to chronic inflammation and reduced iron bioavailability.

Study Overview

Detailed Description

Sixty patients with RLS will be included and 60 controls. The patients will be recruited from the active file of the sleep and wake disorders unit.

The control subjects will be recruited from :

  • Patients hospitalized for suspected sleep disorders with normal PSG.
  • The healthy controls of the RLS cognition protocol, ongoing in the department (ID-RCB: 2012-A00581-42, NCT01823354).

The patients will be informed of the study during a medical consultation. The consent of subjects participating in the study will be obtained during the pre-inclusion visit (D-1). The referring physician of the patients with RLS will propose them to participate in the study. After being duly informed of the nature, significance, implications of the study and appropriately documented by one of the investigators, and after sufficient time for reflection, free, informed and written consent will be obtained from all patients.

The control subjects will receive information about the study when they are admitted to hospital for polysomnographic recording, they will sign their consent for. A clinical examination will also be carried out.

Study Type

Observational

Enrollment (Estimated)

120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

      • Montpellier, France, 34295
        • Recruiting
        • Unité des troubles du sommeil et de l'éveil-Centre de référence narcolepsie-Hypersomnie/Département de Neurologie/ Pole neurosciences tête et cou Hôpital Gui De Chauliac

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

60 patients with RLS and 60 controls meeting all criteria, with the aim of having 50 analyzable subjects per group (i.e. with available stool samples).

Description

Inclusion Criteria:

Patient

  • Idiopathic RLS diagnosed according to the 5 clinical criteria established by the IRLSSG (International Restless Legs Syndrome Study Group).
  • Moderate to very severe RLS, IRLSSG questionnaire ≥ 15.
  • Presence of periodic leg movements (PLM) during sleep (PLM index > 15/hour of sleep).
  • Patient never treated or weaned at least 15 days prior to evaluation with dopaminergic agonists, alpha-2delta ligands, opioids or other psychotropic drugs.

Exclusion Criteria:

Patient

  • Presence of digestive, inflammatory, psychiatric or neurological pathologies.
  • C-reactive protein > 10mg/l (marker of acute inflammation)
  • Presence of moderate-to-severe sleep apnea syndrome (apnea-hypopnea index >15/h).
  • History of iron supplementation within 6 months.
  • Use of treatments known to aggravate or cause RLS, such as antidepressants, neuroleptics, antihistamines or lithium.
  • Refusal of consent after information
  • legally protected adult (guardianship, curatorship)
  • Pregnant or breast-feeding women
  • Patient not affiliated to or not benefiting from a social security system.

Inclusion Criteria:

Control

  • Adults without RLS with demographic characteristics similar to patients in terms of age (+- 5 years) and gender

Exclusion Criteria:

Control

  • Presence of gastrointestinal, inflammatory, psychiatric or neurological diseases.
  • C-reactive protein > 10mg/l (marker of acute inflammation).
  • Presence of PLM in sleep (threshold >15 per hour of sleep).
  • Treatment with antidepressants, neuroleptics, antihistamines, lithium, antiepileptics, benzodiazepines, hypnotics, opiates, dopaminergic agonists, levodopa, alpha-2delta ligands.
  • Presence of moderate to severe sleep apnea syndrome (apnea-hypopnea index >15/h)
  • Refusal of consent after information
  • legally protected adult (guardianship, curatorship)
  • Pregnant or breast-feeding woman
  • Participant not affiliated to a social security scheme or not benefiting from such a system.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Control
Polysomnography
approximate volume of 2 ml
1 EDTA tube (7 ml) to test for chronic low-grade inflammation + 1 EDTA tube (7 ml) to test for intestinal inflammation, digestive permeability and microbial translocation
International RLS Study Group Severity Scale, Epworth Sleepiness Scale, Insomnia Severity Index, Beck Depression Inventory-II, Autonomic symtoms scale (SCOPA-AUT)
Patients
Polysomnography
approximate volume of 2 ml
1 EDTA tube (7 ml) to test for chronic low-grade inflammation + 1 EDTA tube (7 ml) to test for intestinal inflammation, digestive permeability and microbial translocation
International RLS Study Group Severity Scale, Epworth Sleepiness Scale, Insomnia Severity Index, Beck Depression Inventory-II, Autonomic symtoms scale (SCOPA-AUT)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Taxonomic composition of gut microbiota
Time Frame: 24 months
Diversity (alpha and beta), abundance, nature and relative quantification of bacterial genera and bacterial taxonomic units (OTUs) present in stool samples identified by metagenomics.
24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ratio between Firmicutes and Bacteroidetes (majority phyla)
Time Frame: 24 months
Richness, diversity and importance of minority phyla in stools, distribution and importance of bacterial genera in patients and controls. The study of the intestinal microbiota will consist of a metabarcoding approach to the V3-V4 regions of the 16S rRNA.
24 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Markers of intestinal inflammation (CD14s, LBP)
Time Frame: 24 months
The study of bacterial translocation will be carried out using the ELISA technique for intestinal inflammation markers.
24 months
Markers of digestive permeability (I-FABP, claudine)
Time Frame: 24 months
The study of bacterial translocation will be carried out using the ELISA technique for markers of membrane permeability.
24 months
Markers of microbial translocation (16S et 18SrDNA)
Time Frame: 24 months
The study of bacterial translocation will be carried out using 16S and 18S qPCR for direct translocation markers.
24 months
Correspondence between bacteria identified by relative quantification of bacterial genera and OTUs present in stools and those detected by qPCR in plasma.
Time Frame: 24 months
Identification of the concordance between bacterial genera identified in plasma and bacterial genera and OTUs present in stools will be done using Spearman's correlation coefficient.
24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: DAUVILLIERS Yves, Pr, Head of Sleep/Wake Unit National reference center for orphan diseases Narcolepsy and hypersomnia

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 9, 2024

Primary Completion (Estimated)

March 29, 2025

Study Completion (Estimated)

September 30, 2025

Study Registration Dates

First Submitted

August 2, 2023

First Submitted That Met QC Criteria

August 2, 2023

First Posted (Actual)

August 14, 2023

Study Record Updates

Last Update Posted (Actual)

May 20, 2024

Last Update Submitted That Met QC Criteria

May 17, 2024

Last Verified

August 1, 2023

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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