Antioxidation Medication for Noise-induced Hearing Loss
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| Tracking Information | |||||||||
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| First Received Date ICMJE | November 1, 2007 | ||||||||
| Last Updated Date | July 1, 2010 | ||||||||
| Start Date ICMJE | November 2007 | ||||||||
| Primary Completion Date | January 2008 (final data collection date for primary outcome measure) | ||||||||
| Current Primary Outcome Measures ICMJE |
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. |
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| Original Primary Outcome Measures ICMJE |
pure tone audiometry measured temporary threshold shift [ Time Frame: 1 month ] | ||||||||
| Change History | Complete list of historical versions of study NCT00552786 on ClinicalTrials.gov Archive Site | ||||||||
| Current Secondary Outcome Measures ICMJE |
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. |
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| Original Secondary Outcome Measures ICMJE |
Distortion product otoacoustic emissions [ Time Frame: 1 month ] | ||||||||
| Current Other Outcome Measures ICMJE | Not Provided | ||||||||
| Original Other Outcome Measures ICMJE | Not Provided | ||||||||
| Descriptive Information | |||||||||
| Brief Title ICMJE | Antioxidation Medication for Noise-induced Hearing Loss | ||||||||
| Official Title ICMJE | Antioxidation Medication for Noise-induced Hearing Loss | ||||||||
| Brief Summary | This study will examine whether oral intake of 1200mg N-Acetylcysteine/day will prevent temporary threshold shift in hearing among workers exposed to noise |
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| 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. |
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| Study Type ICMJE | Interventional | ||||||||
| Study Phase | Phase 2 | ||||||||
| Study Design ICMJE | Allocation: Randomized Endpoint Classification: Safety/Efficacy Study Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Outcomes Assessor) Primary Purpose: Prevention |
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| Condition ICMJE | Hearing Loss | ||||||||
| Intervention ICMJE |
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| Study Arm (s) |
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| Publications * |
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* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline. |
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| Recruitment Information | |||||||||
| Recruitment Status ICMJE | Completed | ||||||||
| Enrollment ICMJE | 53 | ||||||||
| Completion Date | March 2008 | ||||||||
| Primary Completion Date | January 2008 (final data collection date for primary outcome measure) | ||||||||
| Eligibility Criteria ICMJE | Inclusion Criteria:
Exclusion Criteria:
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| Gender | Male | ||||||||
| Ages | 25 Years to 65 Years | ||||||||
| Accepts Healthy Volunteers | Yes | ||||||||
| Contacts ICMJE | Contact information is only displayed when the study is recruiting subjects | ||||||||
| Location Countries ICMJE | Taiwan | ||||||||
| Administrative Information | |||||||||
| NCT Number ICMJE | NCT00552786 | ||||||||
| Other Study ID Numbers ICMJE | 200704018M | ||||||||
| Has Data Monitoring Committee | No | ||||||||
| Responsible Party | Dr. Yue-Liang Guo, National Taiwan University | ||||||||
| Study Sponsor ICMJE | National Taiwan University Hospital | ||||||||
| Collaborators ICMJE |
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| Investigators ICMJE |
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| Information Provided By | National Taiwan University Hospital | ||||||||
| Verification Date | November 2009 | ||||||||
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ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP |
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