Hearing LossPhase 2NCT00552786
Antioxidation Medication for Noise-induced Hearing Loss
A Phase 2 study testing N-acetylcysteine (NAC) and glucose in people with Hearing Loss, run by National Taiwan University Hospital at 1 site in Taiwan.
Trial 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 Read more about this study
- Who is it for?
- Ages 25 to 65 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Hearing Loss
- What is being tested?
- N-acetylcysteine (NAC) and glucose
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 53 participants
- Where
- 1 siteTaiwan
- Study dates
- Nov 2007to Mar 2008
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 65 years
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- workers in steel industry
- known exposure to noise at work
Who cannot join
- ever diagnosed as having diabetes mellitus
- fasting glucose of 120 or greater
Trial locations and contacts
1 site in 1 country.
Taiwan1 site
Environmental and Occupational Medicine, National Taiwan University Hospital
Taipei, 100
About this study
This study will examine whether oral intake of 1200mg N-Acetylcysteine/day will prevent temporary threshold shift in hearing among workers exposed to noise
Read the 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.
- Conditions
- Hearing Loss
- Being tested
- N-acetylcysteine (NAC), glucose
- Keywords
- noise, hearing loss, temporary threshold shift
- Medical subject headings
- Hearing Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
N-acetylcysteine (NAC)Drug
Also called acetin (600mg)
600mg twice daily for 2 weeks
glucoseDrug
Also called Sugar
1 gm glucose capsule
| Study group | Role | What they receive |
|---|---|---|
| Acetin | Experimental | Not described Receives: Drug: N-acetylcysteine (NAC) |
| Glucose | Placebo comparator | Not described Receives: Drug: glucose |
What is being measured
The primary outcome is the main question the study is designed to answer.
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)
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.
Measured: 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
Secondary outcomes (1)
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)
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.
Measured: 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
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2007 (estimated)
- Study startNov 2007
- Primary completionJan 2008
- Study completionMar 2008
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Hearing LossStudies of the same condition, open and under way.
- More trials run by National Taiwan University HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 53 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Institute of Occupational Safety and Health, Taiwan, Municipal Hospital of Tainan, Taiwan
- Investigators
- Yue-Liang L Guo, MD, MPH, PHD, Principal investigator, National Taiwan University HospitalTung-Sheng Shih, PHD, Study director, Institute of Occupational Safety and Health, Taiwan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00552786
- Sponsor's protocol ID
- 200704018M
- Status last verified
- Nov 2009
- First submitted
- 1 Nov 2007
- Last updated
- 27 Jul 2010
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Coleman JK, Kopke RD, Liu J, Ge X, Harper EA, Jones GE, Cater TL, Jackson RL. Pharmacological rescue of noise induced hearing loss using N-acetylcysteine and acetyl-L-carnitine. Hear Res. 2007 Apr;226(1-2):104-13. doi: 10.1016/j.heares.2006.08.008. Epub 2006 Oct 4.
PubMed 17023129Kopke R, Bielefeld E, Liu J, Zheng J, Jackson R, Henderson D, Coleman JK. Prevention of impulse noise-induced hearing loss with antioxidants. Acta Otolaryngol. 2005 Mar;125(3):235-43. doi: 10.1080/00016480410023038.
PubMed 15966690Duan M, Qiu J, Laurell G, Olofsson A, Counter SA, Borg E. Dose and time-dependent protection of the antioxidant N-L-acetylcysteine against impulse noise trauma. Hear Res. 2004 Jun;192(1-2):1-9. doi: 10.1016/j.heares.2004.02.005.
PubMed 15157958Kopke RD, Jackson RL, Coleman JK, Liu J, Bielefeld EC, Balough BJ. NAC for noise: from the bench top to the clinic. Hear Res. 2007 Apr;226(1-2):114-25. doi: 10.1016/j.heares.2006.10.008. Epub 2006 Dec 20.
PubMed 17184943Lin CY, Wu JL, Shih TS, Tsai PJ, Sun YM, Ma MC, Guo YL. N-Acetyl-cysteine against noise-induced temporary threshold shift in male workers. Hear Res. 2010 Oct 1;269(1-2):42-7. doi: 10.1016/j.heares.2010.07.005. Epub 2010 Jul 16.
PubMed 20638463
Study at a glance
From the registry record, last updated by the sponsor on 27 Jul 2010. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Antioxidation Medication for Noise-induced Hearing Loss
- ClinicalTrials.gov ID
- NCT00552786
- Acronym / sponsor ID
- 200704018M
- Conditions
- Hearing Loss
- Keywords
- noise, hearing loss, temporary threshold shift
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 53 participants (actual)
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Collaborators
- Institute of Occupational Safety and Health, Taiwan, Municipal Hospital of Tainan, Taiwan
- Study start
- Nov 2007
- Primary completion
- Jan 2008 (actual)
- Study completion
- Mar 2008 (actual)
- First posted
- 2 Nov 2007 (estimated)
- Results
- Posted 27 Jul 2010
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will examine whether oral intake of 1200mg N-Acetylcysteine/day will prevent temporary threshold shift in hearing among workers exposed to noise
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Acetin | Experimental | Drug: N-acetylcysteine (NAC) |
| Glucose | Placebo comparator | Drug: glucose |
Who may qualify
- Ages
- 25 to 65 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- workers in steel industry
- known exposure to noise at work
Key exclusion criteria (2 listed)
- ever diagnosed as having diabetes mellitus
- fasting glucose of 120 or greater
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| N-acetylcysteine (NAC)Also: acetin (600mg)600mg twice daily for 2 weeks | Drug | Acetin |
| glucoseAlso: Sugar1 gm glucose capsule | Drug | Glucose |
Primary outcome
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
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.
1 secondary outcome
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
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Jul 2010.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 17023129Coleman JK, Kopke RD, Liu J, Ge X, Harper EA, Jones GE, Cater TL, Jackson RL. Pharmacological rescue of noise induced hearing loss using N-acetylcysteine and acetyl-L-carnitine. Hear Res. 2007 Apr;226(1-2):104-13. doi: 10.1016/j.heares.2006.08.008. Epub 2006 Oct 4.
- Background: PubMed 15966690Kopke R, Bielefeld E, Liu J, Zheng J, Jackson R, Henderson D, Coleman JK. Prevention of impulse noise-induced hearing loss with antioxidants. Acta Otolaryngol. 2005 Mar;125(3):235-43. doi: 10.1080/00016480410023038.
- Background: PubMed 15157958Duan M, Qiu J, Laurell G, Olofsson A, Counter SA, Borg E. Dose and time-dependent protection of the antioxidant N-L-acetylcysteine against impulse noise trauma. Hear Res. 2004 Jun;192(1-2):1-9. doi: 10.1016/j.heares.2004.02.005.
- Background: PubMed 17184943Kopke RD, Jackson RL, Coleman JK, Liu J, Bielefeld EC, Balough BJ. NAC for noise: from the bench top to the clinic. Hear Res. 2007 Apr;226(1-2):114-25. doi: 10.1016/j.heares.2006.10.008. Epub 2006 Dec 20.
- Derived from this study: PubMed 20638463Lin CY, Wu JL, Shih TS, Tsai PJ, Sun YM, Ma MC, Guo YL. N-Acetyl-cysteine against noise-induced temporary threshold shift in male workers. Hear Res. 2010 Oct 1;269(1-2):42-7. doi: 10.1016/j.heares.2010.07.005. Epub 2010 Jul 16.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Yue-Liang L Guo, MD, MPH, PHD principal investigator
National Taiwan University Hospital
Tung-Sheng Shih, PHD study director
Institute of Occupational Safety and Health, Taiwan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing N-acetylcysteine (NAC) and glucose in people with Hearing Loss, run by National Taiwan University Hospital at 1 site in Taiwan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Jul 2010. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Taiwan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Jul 2010). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00552786, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Jul 2010.