Clinical trial NCT00808470
Conditions: Noise-Induced Hearing Loss
Keywords: Noise Hearing Loss Tinnitus Antioxidant Vasodilator Beta-Carotene Vitamin C Vitamin E Magnesium
Sponsor: University of Michigan
Start date: 2008-10-01; Completion date: 2013-12-01
Enrollment: 72 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
Noise-induced hearing loss (NIHL) is a significant clinical, social, and economic issue. Studies in animals have allowed us to identify mechanisms contributing to NIHL, including direct mechanical trauma, free radicals formed in association with metabolic stress, and reduced blood flow. A combination of antioxidant vitamins (beta-carotene, and vitamins C and E) and the mineral magnesium (which acts in part as a vasodilator but also as an antioxidant) is highly effective in preventing NIHL in animals. These studies evaluate efficacy of this intervention in humans.

Hypothesis: Treatment with these micronutrients provides safe, effective attenuation of acute hearing changes induced by exposure to real-world sounds producing temporary (non-permanent) or permanent hearing changes induced by exposure to real-world sounds.

Experiment 1: "Digital Audio Player" studies (University of Florida, Gainesville). Prevention of \*temporary\* elevations in hearing thresholds, induced by exposure to moderately loud music, will be measured. Subjects will be 70 young adults with equal numbers of male and female participants.

Detailed description:
This study assessed the potential for prevention of the temporary changes in hearing that can occur after use of a music player device for 4 hours. All participants listened to one of two playlists (pop or rock) set at the same volumes to provide equivalent and consistent exposures across participants. Participants received either a dietary supplement or a placebo once/daily for three days prior to the day of music exposure, and also on the day of music exposure. The fourth and final dose was consumed immediately prior to music listening and consumption was observed by a member of the study team. Changes in hearing were assessed 15-min post-music, and then 1, 2, and 3 hours later, as well as the following day and 1 week later.

Arms: arm 1: Subjects in University of Florida music player study who are assigned to nutrient condition(beta-carotene, vitamins C and E, magnesium). Nutrient tablets are consumed for 4 days. arm 2: Subjects in University of Florida music player study who are assigned to control (placebo) condition. Placebo tablets are consumed for 4 days.
Interventions: intervention 1: beta-carotene, vitamins C and E, magnesium intervention 2: Placebo
Intervention descriptions: intervention 1: 6 mint-flavored tablets per day, taken once daily

total daily dose label claim: micronutrient combination of 500 mg vitamin C (magnesium ascorbate), 315 mg magnesium (magnesium citrate, magnesium ascorbate, magnesium stearate), 267 mg vitamin E (d-α-tocopherol acetate), and 18 mg beta carotene. intervention 2: 6 mint-flavored tablets per day, containing inactive substances including mannitol, peppermint flavor, sucralose, color prep, iron oxide yellow synthetic, stearic acid (vegetable grade), and silicon dioxide colloidal.

Protocol documents: