Now Available for Public Comment: Notice of Proposed Rulemaking (NPRM) for FDAAA 801 and NIH Draft Reporting Policy for NIH-Funded Trials

Antioxidation Medication for Noise-induced Hearing Loss

This study has been completed.
Sponsor:
Collaborators:
Institute of Occupational Safety and Health, Taiwan
Municipal Hospital of Tainan, Taiwan
Information provided by:
National Taiwan University Hospital
ClinicalTrials.gov Identifier:
NCT00552786
First received: November 1, 2007
Last updated: July 1, 2010
Last verified: November 2009
  Purpose

This study will examine whether oral intake of 1200mg N-Acetylcysteine/day will prevent temporary threshold shift in hearing among workers exposed to noise


Condition Intervention Phase
Hearing Loss
Drug: N-acetylcysteine (NAC)
Drug: glucose
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Antioxidation Medication for Noise-induced Hearing Loss

Resource links provided by NLM:


Further study details as provided by National Taiwan University Hospital:

Primary Outcome Measures:
  • Temporary Threshold Shift Measurement by Pure Tone Audiometry (A Total of Four Hearing Assessments Were Completed for Each Formulation Period on the 1st Day Pre- and Post-shift, and the 14th Day Pre- and Post-shift) [ Time Frame: A total of four hearing assessments were completed for each formulation period on the 1st day pre- and post-shift, and the 14th day pre- and post-shift ] [ Designated as safety issue: No ]
    The hearing threshold level (HL) at high frequency (HF) by pure-tone audiometry (PTA) was defined as the average of HLs at 3k,4k,6kHz for each ear examined. A total of four hearing assessments by PTA were completed for each formulation period on the 1st day pre- and post-shift, and the 14th day pre- and post-shift. The amount of temporary threshold change was calculated by subtracting the pre-shift hearing threshold from the post-shift hearing threshold at each frequency.


Secondary Outcome Measures:
  • Temporary Threshold Changes Measurement by Distortion Product Otoacoustic Emissions (DPOAE) (A Total of Four Hearing Assessments Were Completed for Each Formulation Period on the 1st Day Pre- and Post-shift, and the 14th Day Pre- and Post-shift) [ Time Frame: A total of four hearing assessments were completed for each formulation period on the 1st day pre- and post-shift, and the 14th day pre- and post-shift ] [ Designated as safety issue: No ]
    Distortion product otoacoustic emissions (DPOAE) is an objective measure to assess the cochlear changes. DPOAE response threshold at high frequency (HF) was defined as the average of response levels (dB SPL) at 3k,4k,6kHz for each ear examined. A total of four hearing assessments by DPOAE were completed for each formulation period on the 1st day pre- and post-shift, and the 14th day pre- and post-shift. The amount of DPOAE temporary threshold change was calculated by subtracting the pre-shift DPOAE response threshold from the post-shift DPOAE response threshold at each frequency.


Enrollment: 53
Study Start Date: November 2007
Study Completion Date: March 2008
Primary Completion Date: January 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Acetin Drug: N-acetylcysteine (NAC)
600mg twice daily for 2 weeks
Other Name: acetin (600mg)
Placebo Comparator: Glucose Drug: glucose
1 gm glucose capsule
Other Name: Sugar

Detailed Description:

Both genetic and environmental factors contribute to noise-induced hearing loss (NIHL). The cellular antioxidant system appears to protect cochlear hair cells from oxidative stress due to noise. Previous animal studies showed protective effects of anti-oxidant medicines against NIHL.The objective of this study is to test the hypothesis that preventive medication of antioxidation is related to susceptibility to NIHL.

The 53 noise-exposed workers from steel industries in Taiwan will be recruited, and divided into N-Acetylcysteine (NAC)(Acetine, 1200mg/day) group and placebo one. The duration of medication is 2 weeks initially. After washout for 2 weeks, the kinds of medications in these 2 groups will be crossover and used for 2 weeks. Firstly, questionnaires interview about noise exposure, smoking, alcohol drinking, drug habit history and calculation of Body Mass Index (BMI) will be done. The following methods would be performed individually after medication. With detailed local examination with otoscope, these subjects receive hearing tests by pure-tone audiometry (PTA) and distortion product otoacoustic emissions (DPOAE) before and after their daily works. The possible confounding factors including background noise, solvent, heavy metals, carbon monoxide and temperature in the workplaces will be assessed. The amount of noise exposure is evaluated by personal dosimeter. Early morning, Blood samples will be collected. Deletion polymorphisms in the Glutathione S-transferase (GST)T1 and GSTM1 genes will be determined. Statistical analysis will be performed to evaluate the relation between intake of anti-oxidant medicine and noise-induced temporal threshold shift (TTS).

The expected results of this study are to determine whether anti-oxidant supplements protect workers from noise-induced TTS.

We anticipate that these human studies might help elucidate the relative importance of anti-oxidant enzymes as risk factors for NIHL.

  Eligibility

Ages Eligible for Study:   25 Years to 65 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • workers in steel industry
  • known exposure to noise at work

Exclusion Criteria:

  • ever diagnosed as having diabetes mellitus
  • fasting glucose of 120 or greater
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00552786

Locations
Taiwan
Environmental and Occupational Medicine, National Taiwan University Hospital
Taipei, Taiwan, 100
Sponsors and Collaborators
National Taiwan University Hospital
Institute of Occupational Safety and Health, Taiwan
Municipal Hospital of Tainan, Taiwan
Investigators
Principal Investigator: Yue-Liang L Guo, MD, MPH, PHD National Taiwan University Hospital
Study Director: Tung-Sheng Shih, PHD Institute of Occupational Safety and Health, Taiwan
  More Information

Publications:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Dr. Yue-Liang Guo, National Taiwan University
ClinicalTrials.gov Identifier: NCT00552786     History of Changes
Other Study ID Numbers: 200704018M
Study First Received: November 1, 2007
Results First Received: March 29, 2009
Last Updated: July 1, 2010
Health Authority: Taiwan: Department of Health

Keywords provided by National Taiwan University Hospital:
noise
hearing loss
temporary threshold shift

Additional relevant MeSH terms:
Deafness
Hearing Loss
Hearing Loss, Noise-Induced
Ear Diseases
Hearing Disorders
Hearing Loss, Sensorineural
Nervous System Diseases
Neurologic Manifestations
Otorhinolaryngologic Diseases
Sensation Disorders
Signs and Symptoms
Acetylcysteine
N-monoacetylcystine
Anti-Infective Agents
Antidotes
Antioxidants
Antiviral Agents
Expectorants
Free Radical Scavengers
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents
Respiratory System Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on November 20, 2014