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Effects of Vagal Dysfunction on Gastrointestinal and Inflammatory Pathways in HIV

Phase 1
Conditions
HIV
Non-HIV
Vagus Nerve Dysfunction
Interventions
Drug: Placebos
Procedure: non-invasive vagal nerve stimulation
Registration Number
NCT04353778
Lead Sponsor
Icahn School of Medicine at Mount Sinai
Brief Summary

The study team's prior research has shown that dysfunction of a specific nerve, called the vagus nerve, is associated with small intestinal bacterial overgrowth (SIBO), and that SIBO is associated with signs of inflammation in the blood of people living with HIV (PLWH). This research will explore pathways linking vagal dysfunction to inflammation in HIV, focusing on the gastrointestinal tract, and study whether a medication called pyridostigmine and stimulation of the vagus nerve are beneficial therapies.

Detailed Description

Objectives Aim 1: To elucidate mechanisms linking VD, SIBO and chronic inflammation in PLWH. PLWH (N=150) will undergo autonomic function tests (AFTs) for VD, hydrogen/methane breath testing (HBT) for SIBO, Wireless Motility Capsule (WMC, SmartPill) testing for GI transit times and pH measurements, blood draw for quantification of inflammatory mediators, and collection of stool samples and oral swabs for characterization of the GI microbiome.

Hypothesis 1a (primary): The relationship between VD and SIBO in HIV is mediated by prolonged small bowel transit time (SBTT) and hypochlorhydria.

Hypothesis 1b (exploratory): There is an additional pathway linking VD and elevated IL-6 in PLWH which is independent of SIBO and bacterial translocation.

Aim 2: To determine whether the relationship between VD and SIBO is modified by the presence of HIV-infection. HIV-infection results in disruption of the GI mucosal barrier,5 which could make PLWH more vulnerable to adverse GI effects of VD. HIV-uninfected controls (N=100), age and gender matched to the PLWH from Aim 1, will undergo the same assessment as the PLWH. The study team will test for effect modification of the VD-SIBO relationship by HIV status, using logistic regression to examine the interaction between VD and HIV.

Aim 3: To establish vagal pathways as a viable treatment target for individuals with well-controlled HIV. PLWH with VD, SIBO and/or prolonged SBTT (N=96) will be identified from the Aim 1 cohort. The first 86 eligible patients will be randomized to 8 weeks of pyridostigmine versus placebo; the remaining 10 will receive 8 weeks of open-label noninvasive vagal nerve stimulation (nVNS) to assess feasibility. All patients will then be retested (AFTs, HBT, SmartPill, blood draw, stool samples and oral swabs).

Hypothesis 3a (primary): Eight weeks of low-dose pyridostigmine (30mg PO TID) will reduce SIBO as compared to placebo in PLWH. Hypothesis 3b (exploratory): Non-invasive VNS is safe, well tolerated and acceptable to PLWH.

Recruitment & Eligibility

Status
ENROLLING_BY_INVITATION
Sex
All
Target Recruitment
55
Inclusion Criteria

Not provided

Exclusion Criteria
  • Dysphagia to food or pills
  • Known or suspected obstructive disease of the GI tract (e.g. bezoar, strictures, fistulae, physiologic GI obstruction)
  • GI surgery within 3m, Crohn's disease, diverticulitis, any electromechanical medical device (e.g. pacemaker, infusion pump).
  • Contraindication to pyridostigmine (e.g. mechanical intestinal or urinary obstruction, hypersensitivity to pyridostigmine, cardiac arrhythmias, asthma, chronic obstructive pulmonary disease); use of pyridostigmine within the past 6m.
  • History of intracranial aneurysm/hemorrhage, brain tumor, abnormal neck anatomy, or implants or metal hardware near site of stimulation; exposure to VNS within the past 6m.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
PyridostigminePyridostigminePLWH on pyridostigmine 30mg PO TID
PlaceboPlacebosPLWH on placebo
nVNSnon-invasive vagal nerve stimulationPLWH to undergo non-invasive vagal nerve stimulation
Primary Outcome Measures
NameTimeMethod
Small bowel transit time (SBTT)8 weeks

Small bowel transit time (SBTT) measured by wireless motility capsule (wmc, smartpill)

Hydrogen/methane breath testing (hbt)8 weeks

hydrogen/methane breath testing (hbt) to measure small intestinal bacterial overgrowth

IL6 measurement [Time Frame: 5 years]8 weeks
Gastric pH measurement8 weeks

Gastric pH measurement measured by wireless motility capsule (wmc, smartpill)

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Icahn School of Medicine at Mount Sinai

🇺🇸

New York, New York, United States

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