ascorbic-acid and Presbycusis

The premise of this study is that the membrane hypothesis of aging, also known as the mitochondrial clock theory of aging, is the basis for presbyacusis. Furthermore, it is proposed that treatment with antioxidants or dietary restriction can attenuate age-related hearing loss. Many studies have demonstrated a reduction in blood flow to specific tissues, including the cochlea, with aging. Hypoperfusion leads to the formation of reactive oxygen metabolites (ROM). ROM are highly toxic molecules that directly affect tissues including inner ear structures. In addition, ROM can damage mitochondrial DNA (mtDNA), resulting in the production of specific mtDNA deletions (mtDNA del4977 [human] or mtDNA del4834 [rat]; also known as the common aging deletion]. Previous corroborating data suggest that the common aging deletion mtDNA4834 may be associated not only with aging but also with presbyacusis, thus further strengthening the basis of the current studies. In this study, experiments provide compelling evidence that long-term treatment with compounds that block or scavenge reactive oxygen metabolites attenuate age-related hearing loss and reduce the impact of associated deleterious changes at the molecular level.. Prospective randomized study.. One hundred thirty rats were randomly assigned to one of six groups with appropriate controls. Animals were divided into the following treatment arms: group 1, 30% caloric restriction; group 2, vitamin E oversupplementation; group 3, vitamin C over-supplementation; group 4, melatonin treatment; group 5, lazaroid treatment; and group 6, placebo. In addition, 10 animals were used to determine the appropriate caloric restriction. All subjects underwent baseline and every-3-month testing until their health failed (range, 18-28 mo; average, 25 mo). This testing included auditory sensitivity studies using auditory brainstem response (ABR) testing, as well as tissue analysis for mtDNA deletions using molecular biological techniques. At the conclusion of the study, animals underwent a final ABR test and were tested for mtDNA deletions in brain and inner ear tissues, and the opposite ear was used for histological analysis.. Results indicated that the 30%-caloric-restricted group maintained the most acute auditory sensitivities, the lowest quantity of mtDNA deletions, and the least amount of outer hair cell loss. The antioxidant-treated subjects had improved auditory sensitivities, and a trend for fewer mtDNA deletions was observed compared with the placebo subjects. The placebo subjects had the poorest auditory sensitivity, the most mtDNA deletions, and the greatest degree of outer hair cell loss.. Intervention designed to reduce reactive oxygen metabolite damage appears to protect against age-related hearing loss specifically and aging in general. This is reflected by an overall reduction in mtDNA deletions. These data also suggest that the common aging deletion appears to be associated with presbyacusis, as demonstrated by an increased frequency of the mtDNA del4834 in the cochleae with the most significant hearing loss. Nutritional and pharmacological strategies may very well provide rational treatment options that would limit the age-associated increase in ROM generation, reduce mtDNA damage, and reduce the degree of hearing loss as the organism advances in age.

Topics: Animals; Antioxidants; Ascorbic Acid; Chromosome Deletion; Diet, Reducing; DNA, Mitochondrial; Energy Intake; Evoked Potentials, Auditory, Brain Stem; Free Radicals; Humans; Melatonin; Presbycusis; Rats; Rats, Inbred F344; Reactive Oxygen Species; Steroids; Vitamin E

There are many well-known aetiological mechanisms of presbyacusis, and free radicals have been shown to play an important role. This study aimed to evaluate the effect of antioxidant agents on the hearing threshold of patients with presbyacusis.. One hundred and twenty individuals were divided into four groups and received one of the following treatment schemes: ginkgo biloba dry extract, α-lipoic acid plus vitamin C, papaverine chlorhydrate plus vitamin E, or placebo. All participants were evaluated at recruitment and after six months, using pure tone audiometry (at isolated and average frequencies), speech recognition threshold and percentage index of speech recognition.. The various treatments had no effect on any of the evaluated measures of hearing, either between groups or over time.. There was no statistically significant change in the hearing threshold after treatment with any of the tested drugs, during the study period.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Auditory Threshold; Double-Blind Method; Female; Ginkgo biloba; Humans; Male; Middle Aged; Papaverine; Phytotherapy; Plant Extracts; Presbycusis; Prospective Studies; Thioctic Acid; Treatment Outcome; Vitamin E

Previous animal studies have shown that vitamins may prevent age-related hearing loss. However, no concrete conclusions have been reached about the association between vitamin intake and presbycusis in humans.. We investigated the association between dietary vitamin intake and hearing thresholds in adults between 50 and 80 y of age by using data from a large population-based survey.. We used data from the 2011 Korea National Health and Nutrition Examination Survey. A pure-tone audiogram and physical examination of the ear were performed, and vitamin intake was calculated by using the 24-h recall method. Data from 1910 participants were analyzed through univariate and multivariate linear regression analyses.. After adjustment for age, sex, smoking, and exposure to occupational and explosive noise, intake of vitamin C correlated with better hearing at midfrequency (2000 and 3000 Hz) (coefficient: -0.012; 95% CI: -0.022, -0.002). Dietary supplement use was positively associated with better hearing at all frequencies. The univariate analysis indicated that dietary intakes of retinol, riboflavin, niacin, and vitamin C were positively correlated with better hearing at most frequencies. In contrast, serum concentrations of vitamin D were associated with worse hearing at mid and high (4000 and 6000 Hz) frequencies.. Dietary intake of vitamin C was associated with better hearing in the older population. Because less than one-half of elderly participants in this study consumed a sufficient amount of vitamins, and vitamin intake decreased with age, we should consider proper diet counseling to prevent hearing decline.

Topics: Aged; Aged, 80 and over; Aging; Ascorbic Acid; Auditory Threshold; Cross-Sectional Studies; Diet; Dietary Supplements; Female; Health Surveys; Humans; Male; Middle Aged; Niacin; Presbycusis; Republic of Korea; Riboflavin; Risk Factors; Sex Factors; Vitamin A; Vitamin D; Vitamins

Low plasma melatonin is significant in the development of high frequency hearing loss (HL) among the elderly.. To determine the correlation between hearing threshold and the plasma melatonin and ascorbic acid (vitamin C).. This was a cross-sectional study involving 126 apparently healthy elderly subjects, 59 males and 67 females, aged >60 years. Subjects underwent pure tone audiometry and plasma melatonin and vitamin C were assayed using high-performance liquid chromatography.. The mean ± SD of plasma melatonin among the subjects with normal hearing (NH) (0-30 dB) and those with HL in the speech frequencies was 18.3 ± 3.6 μg/L and 16.4 ± 4.7 μg/L, respectively. In the high frequencies the values were 17.7 ± 6.2 μg/L and 13.1 ± 6.4 μg/L for NH and HL, respectively. For vitamin C, the mean ± SD among subjects with NH and those with HL in the speech frequencies were 1.2 ± 0.2 μg/L and 1.0 ± 0.1 μg/L, respectively. In the high frequencies, the values were 1.0 ± 0.2 μg/L and 0.9 ± 0.3 μg/L for NH and HL, respectively. Among subjects with high frequency HL, Spearman's correlation revealed significant correlation between increasing hearing threshold and melatonin (correlation coefficient = -0.30, p = 0.01), but not for vitamin C (correlation coefficient = -0.12, p = 0.22). Linear regression, adjusting for age, still revealed significant correlation between the melatonin (correlation coefficient = -0.03, p = 0.00) and hearing threshold in the high frequencies.

Topics: Aged; Aged, 80 and over; Aging; Ascorbic Acid; Auditory Threshold; Cross-Sectional Studies; Female; Free Radical Scavengers; Hearing Loss, High-Frequency; Humans; Male; Melatonin; Middle Aged; Presbycusis

Age-related hearing loss (ARHL) is characterized by gradual, progressive sensorineural hearing loss, which impairs communication, lending to clinical depression and social withdrawal. There are currently no effective treatments for ARHL. The purpose of this study is to evaluate the potential of a combination antioxidant therapy in preventing ARHL.. Randomized controlled trial.. Animal study.. C57BL/6 mice, a recognized animal model of ARHL, were assigned to one of three groups: early treatment (n = 12), late treatment (n = 9), or control group (n = 9). Treatment groups of mice were fed with a combination agent comprising six antioxidant agents that target four sites within the oxidative pathway: L-cysteine-glutathione mixed disulfide, ribose-cysteine, NW-nitro-L-arginine methyl ester, vitamin B12, folate, and ascorbic acid. Auditory brainstem response (ABR) thresholds were recorded at baseline and every three months following initiation of treatment.. Threshold shifts from baseline were decreased in the treatment groups when compared to the control group at all tested frequencies (P < 0.001). The ABR threshold shift at 12 months of age for the control group was 34.7 dB with a 95% confidence interval (CI) of +/-1.6. The mean threshold shifts for the early and late treatment groups were 7.5 dB (+/-0.87, 95% CI) and 9.2 dB (+/-1.6, 95% CI).. Combination antioxidant therapy effectively decreased threshold shifts on ABR within an animal model of ARHL. Combination antioxidant therapy, with further research and investigation, may provide a safe and cost-effective method of preventing presbycusis in the growing elderly population.

Topics: Aging; Animals; Antioxidants; Ascorbic Acid; Auditory Threshold; Cysteine; Disease Models, Animal; Drug Therapy, Combination; Evoked Potentials, Auditory, Brain Stem; Glutathione; Mice; Mice, Inbred C57BL; NG-Nitroarginine Methyl Ester; Presbycusis; Vitamin B Complex

The results of this study suggest that treatment with radical scavengers has the potential to become an effective new therapy for age-related hearing loss.. To assess the efficacy of treatment with radical scavengers for age-related hearing loss.. Rebamipide (300 mg/day), alpha-lipoic acid (60 mg/day), and vitamin C (600 mg/day) were given orally for at least 8 weeks to 46 elderly patients with age-related hearing loss.. Hearing levels after treatment were significantly improved at all frequencies.

Topics: Aged; Aged, 80 and over; Alanine; Ascorbic Acid; Audiometry, Pure-Tone; Drug Therapy, Combination; Ear, Inner; Female; Free Radical Scavengers; Humans; Male; Pilot Projects; Presbycusis; Quinolones; Sensory Thresholds; Thioctic Acid

Using senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize vitamin C (VC), we examined whether modulating VC level affects age-related hearing loss (AHL). KO and wild-type (WT) C57BL/6 mice were given water containing 1.5 g/L VC [VC(+)] or 37.5mg/L VC [VC(-)]. At 10 months of age, KO VC(-) mice showed significant reduction in VC level in the inner ear, plasma, and liver, increase in auditory brainstem response (ABR) thresholds, and decrease in the number of spiral ganglion cells compared to WT VC(-), WT VC(+), and KO VC(+) mice. There were no differences in VC level in the inner ear, ABR thresholds, or the number of spiral ganglion cells among WT VC(-), WT VC(+), and KO VC(+) mice. These findings suggest that VC depletion can accelerate AHL but that supplementing VC may not increase VC level in the inner ear or slow AHL in mice.

Topics: Aging; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Auditory Threshold; Calcium-Binding Proteins; Carboxylic Ester Hydrolases; Intracellular Signaling Peptides and Proteins; Mice; Mice, Knockout; Presbycusis; Spiral Ganglion

The results of this study suggest that treatment with radical scavengers has the potential to become an effective new therapy for presbyacusis.. To assess the efficacy of treatment with the radical scavengers rebamipide and vitamin C for presbyacusis.. Rebamipide (300 mg/day) and vitamin C (600 mg/day) were taken orally for at least 8 weeks by 23 patients with presbyacusis.. Hearing levels after treatment were significantly improved at 125, 250, 500 and 8000 Hz but unchanged at 1000, 2000 and 4000 Hz.

Topics: Aged; Aged, 80 and over; Alanine; Ascorbic Acid; Audiometry; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Follow-Up Studies; Free Radical Scavengers; Humans; Male; Pilot Projects; Presbycusis; Probability; Quinolones; Risk Assessment; Severity of Illness Index; Treatment Outcome

Topics: Aged; Ascorbic Acid; Drug Combinations; Folic Acid; Hearing Disorders; Humans; Minerals; Presbycusis; Procaine; Vitamin B Complex; Vitamins