Trial Outcomes & Findings for Antioxidation Medication for Noise-induced Hearing Loss (NCT NCT00552786)
NCT ID: NCT00552786
Last Updated: 2010-07-27
Results Overview
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.
COMPLETED
PHASE2
53 participants
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
2010-07-27
Participant Flow
Participants recruited between November 2007 and January 2008.
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.
Participant milestones
| Measure |
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).
|
Placebo First, Then N-acetylcysteine (NAC)
Placebo in the first intervention period and Formulation NAC in the second intervention period (after washout period).
|
|---|---|---|
|
First Intervention
STARTED
|
25
|
28
|
|
First Intervention
Medication and Hearing Evaluation
|
25
|
28
|
|
First Intervention
COMPLETED
|
25
|
28
|
|
First Intervention
NOT COMPLETED
|
0
|
0
|
|
Washout Period of 2 Weeks
STARTED
|
25
|
28
|
|
Washout Period of 2 Weeks
COMPLETED
|
25
|
28
|
|
Washout Period of 2 Weeks
NOT COMPLETED
|
0
|
0
|
|
Second Intervention
STARTED
|
25
|
28
|
|
Second Intervention
COMPLETED
|
25
|
28
|
|
Second Intervention
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Antioxidation Medication for Noise-induced Hearing Loss
Baseline characteristics by cohort
| Measure |
N-acetylcysteine (NAC) First, Then Placebo
n=25 Participants
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).
|
Placebo First, Then N-acetylcysteine (NAC)
n=28 Participants
Placebo in the first intervention period and Formulation NAC in the second intervention period (after washout period).
|
Total
n=53 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0.0 Participants
n=5 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
25 Participants
n=5 Participants
|
28 Participants
n=7 Participants
|
53.0 Participants
n=5 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0.0 Participants
n=5 Participants
|
|
Age Continuous
|
40.0 years
STANDARD_DEVIATION 11.6 • n=5 Participants
|
42.1 years
STANDARD_DEVIATION 9.6 • n=7 Participants
|
41.1 years
STANDARD_DEVIATION 10.5 • n=5 Participants
|
|
Sex: Female, Male
Female
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0.0 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
25 Participants
n=5 Participants
|
28 Participants
n=7 Participants
|
53.0 Participants
n=5 Participants
|
|
Region of Enrollment
Taiwan
|
25 participants
n=5 Participants
|
28 participants
n=7 Participants
|
53.0 participants
n=5 Participants
|
PRIMARY outcome
Timeframe: 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-shiftPopulation: Intent to treat analysis including only participants who had at least one post-baseline assessment.
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.
Outcome measures
| Measure |
N-acetylcysteine (NAC)
n=53 Participants
Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) administered in either first intervention period or second intervention period.
|
Placebo
n=53 Participants
Placebo administered once daily in either first intervention period or second intervention period.
|
|---|---|---|
|
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)
|
3.4 decibels
Standard Deviation 2.3
|
2.7 decibels
Standard Deviation 2.1
|
SECONDARY outcome
Timeframe: 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-shiftPopulation: 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).
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.
Outcome measures
| Measure |
N-acetylcysteine (NAC)
n=53 Participants
Formulation NAC (1200 mg/day, 14 days) (Actein, Synmosa Corp., Taiwan) administered in either first intervention period or second intervention period.
|
Placebo
n=53 Participants
Placebo administered once daily in either first intervention period or second intervention period.
|
|---|---|---|
|
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)
|
-0.85 decibels (dB SPL)
Standard Deviation 1.1
|
-0.89 decibels (dB SPL)
Standard Deviation 0.9
|
Adverse Events
N-acetylcysteine (NAC)
Placebo
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place