vitamin-b-12 and Hearing-Loss--Noise-Induced

Occupational noise-induced hearing loss (NIHL) due to industrial, military, and other job -related noise exposure can cause harmful health issues to occupied workers, but may also be potentially preventable. Vitamins/antioxidant have been studied as therapeutic strategies to prevent and/or delay the risks of human diseases as well as NIHL .So, this study was conducted to systematically review the protective effects of vitamins/antioxidants on occupational NIHL.. Online databases including PubMed/Medline, Scopus, Web of Science, EMBASE, Science Direct, and Google Scholar were systematically searched up to 12 January 2021. Based on 6336 potentially relevant records identified through the initial search in the databases, 12 full-text publications were retrieved, one of which can be viewed as two separate trials, because it has studied the effects of two different antioxidants (ginseng and NAC) on NIHL, separately.. A review of the studies shows that vitamin B12, folic acid, and N-acetylcysteine (NAC) have a considerable protective effect on NIHL. However, these protective effects are not yet specified in different frequencies. The findings regarding the protective effects of other antioxidants are inconsistent in this field.. Vitamin B12, folic acid, and NAC may have a protective effect as an antioxidant on reducing occupational hearing loss. For a conclusive evidence of vitamin/antioxidant protective therapies, future studies with precise criteria for noise exposure and similar outcome parameters are required.

Topics: Acetylcysteine; Adult; Antioxidants; Female; Folic Acid; Hearing Loss, Noise-Induced; Humans; Male; Middle Aged; Noise, Occupational; Occupational Diseases; Occupational Exposure; Protective Agents; Vitamin B 12; Vitamins

The aim of this study was to evaluate, in 20 young volunteer subjects, the effects of supra-physiological vitamin B12 administration on noise-induced temporary threshold shift (TTS). All subjects had hearing thresholds within 15 dBHL and type A tympanograms. The subjects were randomly assigned to two different groups. Experimental group subjects received cyanocobalamin, 1 mg daily for 7 days, and 5 mg on the eighth day. Control group subjects received a placebo injection daily for 8 days. The vitamin B12 concentration, hearing thresholds and TTS2 (10 min of exposure, narrowband noise centred at 3 kHz, bandwidth of 775 Hz, 112 dBSPL) were measured before and 8 days after treatment. At the end of treatment, the serum vitamin B12 concentration was significantly increased in the experimental group. After 8 days of treatment, the control group showed the same hearing thresholds and TTS2 degrees. Statistical analysis showed that TTS2 decreased significantly at 3 and 4kHz when cobalamin was used to increase the serum concentration of vitamin B12 to > 2350 pg/ml. In addition, a protective effect at 3 kHz in the experimental group was evident when compared with the placebo group. These results suggest that elevated plasma cyanocobalamin levels may reduce the risk of hearing dysfunction resulting from noise exposure in healthy, young subjects.

Topics: Adult; Analysis of Variance; Audiometry, Pure-Tone; Auditory Threshold; Double-Blind Method; Female; Hearing Loss, Noise-Induced; Humans; Injections, Intramuscular; Male; Noise; Vitamin B 12

Through pure-tone audiometry, we studied the course of hearing recovery in 24 ears of 20 men (ages 18-48 years) who had acute acoustic sensorineural hearing loss (ASHL). All subjects were members of the Japanese Self-Defense Force. The hearing level in 5 ears returned to normal, the hearing level of 13 ears recovered but was not within the normal range, and the hearing level of 6 ears was unchanged. The time from noise exposure to presentation was longer in patients with unchanged hearing than in other patients. Recovery of hearing was poorest at 4,000 Hz, followed by 8,000 and 2,000 Hz. We concluded that hearing in patients with acute ASHL is likely to return to normal when the hearing level at 4,000 Hz recovers gradually; partial recovery of hearing is expected when the hearing level at 4,000 Hz reaches an early plateau.

Topics: Adolescent; Adult; Audiometry, Pure-Tone; Dextrans; Drug Therapy, Combination; Firearms; Follow-Up Studies; Hearing Loss, Noise-Induced; Hearing Loss, Sudden; Humans; Japan; Male; Military Personnel; Occupational Diseases; Prednisolone; Vitamin B 12

The aim of the present study was to determine the levels of homocysteine, folic acid, and Vitamin B12 in subjects with noise-induced hearing loss. Furthermore, possible links between these parameters and noise-induced hearing loss were aimed to be evaluated.. In the present study, blood samples were obtained from all subjects after overnight fasting for biochemical analysis. We examined the levels of homocysteine, Vitamin B12 and folic acid levels in subjects with noise-induced hearing loss. Twenty-eight male patients with noise-induced hearing loss (mean age 37 +/- 5 year) were included in the study group whereas the control group was composed of 32 healthy male volunteers (mean age 36 +/- 4 year).. It was found that homocysteine levels of subjects with noise-induced hearing loss as significantly high compared to healthy controls (P < 0.05). On the other hand, Vitamin B12 and folic acid levels of patients with noise-induced hearing loss were determined to be significantly low compared to the controls (P < 0.05 and < 0.01, respectively).. Our findings indicate that there might be a link between increased homocysteine levels and noise-induced hearing loss. Since increased homocysteine levels cause elevated levels of free radicals in addition to its atherogenic and thrombogenic effects. Further experimental studies are needed to decipher how this relationship is linked.

Topics: Adult; Audiometry, Pure-Tone; Case-Control Studies; Folic Acid; Hearing Loss, Noise-Induced; Homocysteine; Humans; Male; Surveys and Questionnaires; Vitamin B 12

To investigate the levels of vitamin A, E, B12, folic acid in employees with hearing loss due to noise.. Employees in a local hydroelectric powerhouse who suffered from hearing loss due to noise were included in the study. Study and control groups were composed of 28 employees (mean age 37+/-5 years) and 30 voluntary subjects (mean age 36+/-4 years), respectively. All the subjects in patient and control groups were males. Blood samples were obtained from all subjects and vitamin A, E, B12 and folic acid levels were measured.. Level of vitamin B12 was found low in the patient group and normal in the control group and these were found statistically significant (p<0.005). There were no significant differences between vitamin A, E and folic acid levels.. We think that measurement of vitamin B12 in routine control of the people who are working in noisy environment may be useful.

Topics: Adult; Case-Control Studies; Female; Folic Acid; Hearing Loss, Noise-Induced; Humans; Male; Middle Aged; Occupational Diseases; Vitamin A; Vitamin B 12; Vitamin E

Topics: Dextrans; Female; Hearing Loss, Noise-Induced; Humans; Male; Occupational Diseases; Thiamine; Vitamin B 12