Since I cannot create threads in the "clinical trial" section, I posted this information in this thread.
The reference of the clinical trial:
https://clinicaltrials.gov/ct2/show/NCT02951715
The results :
https://www.sciencedirect.com/science/article/pii/S2319417018300088
Abstract
Background
Zinc plays a vital antioxidant role in
human metabolism. Recent studies have demonstrated a correlation between
noise-induced hearing loss (NIHL) and oxidative injury; however, no investigation has focused specifically on the subgroup of NIHL associated
tinnitus patients. We aimed to evaluate the effectiveness of zinc
supplementation in treating NIHL associated tinnitus.
Methods
Twenty patients with tinnitus and a typical NIHL
audiogram (38 ears) were included in this study. Another 20
healthy subjects were used as the control group. A full
medical history assessment was performed, and each subject underwent an otoscopic examination, basic audiologic evaluation,
distortion product otoacoustic emissions (DPOAEs), tinnitus-match testing, Tinnitus Handicap Inventory (THI) and
serum zinc level analyses. After 2 months of treatment with zinc, all tests were repeated.
Results
There was a significant difference between pretreatment and post-treatment within the tinnitus group (73.6 vs. 84.6 μg/dl). The pre- and post-treatment difference in serum zinc was significantly higher in the young group (≦50 years) compared to the old group (19.4 ± 11.4 vs. 2.6 ± 9.2 μg/dl, respectively;
p = 0.002). There were no statistically significant differences in
hearing thresholds, speech reception thresholds, or tinnitus frequency and
loudness results before and after treatment. In addition, 17 patients (85%) showed statistically significant improvement of THI-total scores post-treatment, from 38.3 to 30 (
p = 0.024).
Conclusions
Zinc oral supplementation elevated serum zinc levels, especially in younger patients. THI scores improved significantly following zinc treatment in patients with NIHL associated tinnitus. However, no improvements in objective hearing parameters were observed.
Keywords
Noise-induced hearing loss (NIHL)
Tinnitus
Zinc