Antioxidation Medication for Noise-induced Hearing Loss

Hearing Loss Clinical Trial

Official title:

Antioxidation Medication for Noise-induced Hearing Loss

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00552786
• Other study ID #: 200704018M
• Status: Completed
• Phase: Phase 2
• First received: November 1, 2007
• Last updated: July 1, 2010
• Start date: November 2007
• Est. completion date: March 2008

Study information

• Verified date: November 2009
• Source: National Taiwan University Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Taiwan: Department of Health
• Study type: Interventional

Clinical 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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 53
• Est. completion date: March 2008
• Est. primary completion date: January 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 25 Years to 65 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Deafness
• Hearing Loss
• Hearing Loss, Noise-Induced

Intervention

Drug:
• N-acetylcysteine (NAC)
600mg twice daily for 2 weeks
• glucose
1 gm glucose capsule

Locations

Country	Name	City	State
Taiwan	Environmental and Occupational Medicine, National Taiwan University Hospital	Taipei

Sponsors (3)

Lead Sponsor	Collaborator
National Taiwan University Hospital	Institute of Occupational Safety and Health, Taiwan, Municipal Hospital of Tainan, Taiwan

Country where clinical trial is conducted

Taiwan, 

References & Publications (4)

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. Epub 2006 Oct 4. — View Citation

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. — View Citation

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. — View Citation

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. Epub 2006 Dec 20. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
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.	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	No
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.	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	No