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Chronic Cough and Small Fiber Neuropathy

Not Applicable
Terminated
Conditions
Type 2 Diabetes
Chronic Cough
Interventions
Other: Cough assessment
Other: Neurological tests and cardiovascular tests
Other: Skin biopsy
Registration Number
NCT03787511
Lead Sponsor
University Hospital, Toulouse
Brief Summary

Diabetic patients with and without chronic cough will be included in this study. After giving their informed consent, the patients will perform a spirometry, chest X-ray at the inclusion visit. Cough will be assessed using the cough visual analog scale (VAS) and the Leicester Cough Questionnaire (LCQ). Within 60 days, the patient will perform neurophysiological tests. The neurophysiological assessment will be concluded with a skin biopsy to evaluate small fiber neuropathy. The aim of the study is to compare the proportion of small fiber neuropathy between diabetic patients with chronic cough and those without chronic cough.

Detailed Description

Chronic cough is a very common entity that affects 9.6% people worldwide. Given the high number of patients with refractory cough, the concept of cough hypersensitivity syndrome (CHS) has emerged. In CHS, afferent sensory nerves may exhibit a modification of activation patterns with facilitation of encoding signals in response to irritating stimuli. Similar patterns with neuropathic pain have been described. Small fiber neuropathy has never been assessed in chronic cough. Interestingly, diabetic patients experienced cough more frequently than healthy subject. We hypothesized that small fiber neuropathy may explain chronic cough is more frequent in diabetic patients.

Within 60 days after inclusion, diabetic patients with and without chronic cough will perform neurophysiological tests such as electromyography, thermotest, QSART (Quantitative Sudomotor Axon Reflex Test and Sudoscan), cardio-vascular tests to study the autonomic nervous system. No risks are expecting with these non-invasive tests. A skin biopsy to evaluate small fiber neuropathy will also be performed.After the neurophysiological tests, a consultation will be scheduled at 6 months. A cough VAS and LCQ will be used to assess cough.

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
7
Inclusion Criteria

In diabetic patients with chronic cough:

  • Chronic cough defined by cough for more than 8 weeks.
  • Normal chest X-ray
  • history of type 2 diabetes
  • Age of diabetes onset> 40 years
  • Affiliated or beneficiary person of social security
  • Free, informed and written consent

In diabetic patients without chronic cough

  • History of type 2 diabetes
  • Age of discovery of diabetes> 40 years
  • Affiliated or beneficiary person of social security
  • Free, informed and written consent
Exclusion Criteria
  • Presence of physical signs of peripheral neuropathy
  • Active smoking or smoking cessation within the last 12 months
  • Pregnant or lactating woman
  • History of non-type 2 diabetes (type I, secondary diabetes, monogenic ...)
  • Cancer within the last 5 years (except cutaneous squamous cell carcinoma)
  • History of anti-cancer chemotherapy
  • Suspicion of autoimmune pathology
  • Active neurological pathology
  • Electromyography in favor of large fiber neuropathy
  • Chronic pathology that may interfere with the neurophysiological assessment
  • Patient who were given anticoagulation drug therapy, anti-cholinergic drugs, beta-blocker and impossibility to withdraw the treatment before neurophysiological tests

In diabetic patients without chronic cough, another non-inclusion criteria is acute or chronic cough

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Diabetic patients with chronic coughSkin biopsyDiabetic patients with chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Diabetic patients without chronic coughCough assessmentDiabetic patients without chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Diabetic patients without chronic coughNeurological tests and cardiovascular testsDiabetic patients without chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Diabetic patients with chronic coughCough assessmentDiabetic patients with chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Diabetic patients without chronic coughSkin biopsyDiabetic patients without chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Diabetic patients with chronic coughNeurological tests and cardiovascular testsDiabetic patients with chronic cough defined by cough lasting for more than 8 weeks. Cough assessment, neurological tests and cardiovascular tests and skin biopsy.
Primary Outcome Measures
NameTimeMethod
Proportion of patients with small fiber neuropathy6 month after inclusion visit

The primary endpoint is the proportion of patients with small fiber neuropathy between diabetic patients with chronic cough and those without chronic cough (defined by at least 2 abnormal neurophysiological tests).

Secondary Outcome Measures
NameTimeMethod
values of Leicester Cough Questionnaire (LCQ) in diabetic patients6 month after inclusion visit

estimate the values of Leicester Cough Questionnaire in diabetic patients with and without chronic cough. The Leicester Cough Questionnaire comprises 19 items and takes 5 to 10 minutes to complete. Each item assesses symptoms, or the impact of symptoms, over the last 2 weeks on a seven-point Likert scale. Scores in three domains (physical, psychological and social) are calculated as a mean for each domain (range 1 to 7). A total score (range 3 to 21) is also calculated by adding the domain scores together. Higher scores indicate better quality of life.

values of the DN4 questionnaire in diabetic patients6 month after inclusion visit

estimate the values of the DN4 questionnaire in diabetic patients with and without chronic cough.

It allows to estimate the probability of neuropathic pain in a patient, through 4 questions divided into 10 check items. The practitioner questions or examines the patient and completes the questionnaire himself. He notes a response ("yes", "no") to each item. At the end of the questionnaire, he counts the answers and assigns the note 1 for each "yes", and the score 0 for each "no". The sum obtained gives the score of the patient, scored out of 10.

proportion of patients with abnormal results of laser evoked potentials6 month after inclusion visit

estimate the proportion of patients with abnormal results of laser evoked potentials in each arm (with and without chronic cough)

proportion of patients with pathological results of the sudori-motor response6 month after inclusion visit

estimate the proportion of patients with pathological results of the sudori-motor response in each arm (with and without chronic cough)

proportion of patients with abnormal results of the thermotest6 month after inclusion visit

estimate the proportion of patients with abnormal results of the thermotest in each arm (with and without chronic cough)

proportion of patients with abnormal findings of cutaneous biopsy6 month after inclusion visit

estimate the proportion of patients with abnormal findings of cutaneous biopsy in in each arm (with and without chronic cough)

the proportion of patients with abnormal results of cardiovascular tests6 month after inclusion visit

estimate the proportion of patients with abnormal results of cardiovascular tests assessing the autonomic nervous system in in each arm (with and without chronic cough)

Trial Locations

Locations (1)

Hôpital Larrey

🇫🇷

Toulouse, France

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