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| Name | Class |
|---|---|
| Institute of Occupational Safety and Health, Taiwan | UNKNOWN |
| Municipal Hospital of Tainan, Taiwan | UNKNOWN |
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This study will examine whether oral intake of 1200mg N-Acetylcysteine/day will prevent temporary threshold shift in hearing among workers exposed to noise
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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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Acetin | Experimental |
| |
| Glucose | Placebo Comparator |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| N-acetylcysteine (NAC) | Drug | 600mg twice daily for 2 weeks |
|
|
| Measure | Description | Time Frame |
|---|---|---|
| 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. | 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 |
| Measure | Description | Time Frame |
|---|---|---|
| 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. |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Yue-Liang L Guo, MD, MPH, PHD | National Taiwan University Hospital | Principal Investigator |
| Tung-Sheng Shih, PHD | Institute of Occupational Safety and Health, Taiwan | Study Director |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Environmental and Occupational Medicine, National Taiwan University Hospital | Taipei | 100 | Taiwan |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 17023129 | Background | 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. | |
| 15966690 | Background | Kopke 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. |
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A total of 60 workers voluntarily participated in this study. However, 6 workers had preexisting hearing loss of >50 dBA at high frequency and 1 worker accidentally turned off the noise monitoring device. These 7 participants were excluded from the analysis. The 53 workers who satisfactorily completed the study.
Participants recruited between November 2007 and January 2008.
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| ID | Title | Description |
|---|---|---|
| FG000 | N-acetylcysteine (NAC) First, Then Placebo | Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) in the first intervention period and Placebo (a tablet of identical taste and odor to the NAC agent) in the second intervention period (after washout period). |
| FG001 | Placebo First, Then N-acetylcysteine (NAC) | Placebo in the first intervention period and Formulation NAC in the second intervention period (after washout period). |
| Title | Milestones | Reasons Not Completed | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| First Intervention |
| ||||||||||||||||
| Washout Period of 2 Weeks |
| ||||||||||||||||
| Second Intervention |
|
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| ID | Title | Description |
|---|---|---|
| BG000 | N-acetylcysteine (NAC) First, Then Placebo | Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) in the first intervention period and Placebo (a tablet of identical taste and odor to the NAC agent) in the second intervention period (after washout period). |
| BG001 | Placebo First, Then N-acetylcysteine (NAC) |
| Units | Counts |
|---|---|
| Participants |
|
| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Categorical | Count of Participants |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | 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. | Intent to treat analysis including only participants who had at least one post-baseline assessment. | Posted | Mean | Standard Deviation | decibels | 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 |
|
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | N-acetylcysteine (NAC) | Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) administered in either first intervention period or second intervention period. |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Dr. Yue-Liang Guo | National Taiwan University | +886-2-33228216 | leonguo@ntu.edu.tw |
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| ID | Term |
|---|---|
| D034381 | Hearing Loss |
| ID | Term |
|---|---|
| D006311 | Hearing Disorders |
| D004427 | Ear Diseases |
| D010038 | Otorhinolaryngologic Diseases |
| D012678 | Sensation Disorders |
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| ID | Term |
|---|---|
| D000111 | Acetylcysteine |
| D005947 | Glucose |
| D000073893 | Sugars |
| ID | Term |
|---|---|
| D003545 | Cysteine |
| D000603 | Amino Acids, Sulfur |
| D013457 | Sulfur Compounds |
| D009930 | Organic Chemicals |
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| glucose | Drug | 1 gm glucose capsule |
|
|
| 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 |
| 15157958 | Background | Duan 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. |
| 17184943 | Background | Kopke 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. |
| 20638463 | Derived | Lin 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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| NOT COMPLETED |
|
Placebo in the first intervention period and Formulation NAC in the second intervention period (after washout period). |
| BG002 | Total | Total of all reporting groups |
| Participants |
|
| Age Continuous | Mean | Standard Deviation | years |
|
| Sex: Female, Male | Count of Participants | Participants |
|
| Region of Enrollment | Number | participants |
|
| N-acetylcysteine (NAC) |
Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) administered in either first intervention period or second intervention period. |
| OG001 | Placebo | Placebo administered once daily in either first intervention period or second intervention period. |
|
|
|
| Secondary | 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. | Intent to treat analysis including only participants who had all 4 post-baseline assessments (measurements at beginning of 1st and 2nd intervention periods and end of 1st and 2nd intervention periods). | Posted | Mean | Standard Deviation | decibels (dB SPL) | 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 |
|
|
|
|
| 0 |
| 53 |
| 0 |
| 53 |
| EG001 | Placebo | Placebo administered once daily in either first intervention period or second intervention period. | 0 | 53 | 0 | 53 |
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| D009461 |
| Neurologic Manifestations |
| D009422 | Nervous System Diseases |
| D012816 | Signs and Symptoms |
| D013568 | Pathological Conditions, Signs and Symptoms |
| D000596 |
| Amino Acids |
| D000602 | Amino Acids, Peptides, and Proteins |
| D006601 | Hexoses |
| D009005 | Monosaccharides |
| D002241 | Carbohydrates |