137 results on '"McMahon CM"'
Search Results
102. Dual sensory impairment in older adults increases the risk of mortality: a population-based study.
- Author
-
Gopinath B, Schneider J, McMahon CM, Burlutsky G, Leeder SR, and Mitchell P
- Subjects
- Age Factors, Aged, Australia epidemiology, Blindness physiopathology, Cohort Studies, Comorbidity, Confidence Intervals, Deafness physiopathology, Female, Humans, Incidence, Male, Middle Aged, Risk Factors, Survival Analysis, Visual Acuity physiology, Blindness mortality, Deafness mortality
- Abstract
Although concurrent vision and hearing loss are common in older adults, population-based data on their relationship with mortality is limited. This cohort study investigated the association between objectively measured dual sensory impairment (DSI) with mortality risk over 10 years. 2812 Blue Mountains Eye Study participants aged 55 years and older at baseline were included for analyses. Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average pure-tone air conduction threshold greater than 25 dB HL (500-4000 Hz, better ear). Ten-year all-cause mortality was confirmed using the Australian National Death Index. After ten years, 64% and 11% of participants with DSI and no sensory loss, respectively, had died. After multivariable adjustment, participants with DSI (presenting visual impairment and hearing impairment) compared to those with no sensory impairment at baseline, had 62% increased risk of all-cause mortality, hazard ratio, HR, 1.62 (95% confidence intervals, CI, 1.16-2.26). This association was more marked in those with both moderate-severe hearing loss (>40 dB HL) and presenting visual impairment, HR 1.84 (95% CI 1.19-2.86). Participants with either presenting visual impairment only or hearing impairment only, did not have an increased risk of mortality, HR 1.05 (95% CI 0.61-1.80) and HR 1.24 (95% CI 0.99-1.54), respectively. Concurrent best-corrected visual impairment and moderate-severe hearing loss was more strongly associated with mortality 10 years later, HR 2.19 (95% CI 1.20-4.03). Objectively measured DSI was an independent predictor of total mortality in older adults. DSI was associated with a risk of death greater than that of either vision loss only or hearing loss alone.
- Published
- 2013
- Full Text
- View/download PDF
103. The need for improved detection and management of adult-onset hearing loss in australia.
- Author
-
McMahon CM, Gopinath B, Schneider J, Reath J, Hickson L, Leeder SR, Mitchell P, and Cowan R
- Abstract
Adult-onset hearing loss is insidious and typically diagnosed and managed several years after onset. Often, this is after the loss having led to multiple negative consequences including effects on employment, depressive symptoms, and increased risk of mortality. In contrast, the use of hearing aids is associated with reduced depression, longer life expectancy, and retention in the workplace. Despite this, several studies indicate high levels of unmet need for hearing health services in older adults and poor use of prescribed hearing aids, often leading to their abandonment. In Australia, the largest component of financial cost of hearing loss (excluding the loss of well-being) is due to lost workplace productivity. Nonetheless, the Australian public health system does not have an effective and sustainable hearing screening strategy to tackle the problem of poor detection of adult-onset hearing loss. Given the increasing prevalence and disease burden of hearing impairment in adults, two key areas are not adequately met in the Australian healthcare system: (1) early identification of persons with chronic hearing impairment; (2) appropriate and targeted referral of these patients to hearing health service providers. This paper reviews the current literature, including population-based data from the Blue Mountains Hearing Study, and suggests different models for early detection of adult-onset hearing loss.
- Published
- 2013
- Full Text
- View/download PDF
104. Hearing-impaired adults are at increased risk of experiencing emotional distress and social engagement restrictions five years later.
- Author
-
Gopinath B, Hickson L, Schneider J, McMahon CM, Burlutsky G, Leeder SR, and Mitchell P
- Subjects
- Aged, Aged, 80 and over, Australia, Cross-Sectional Studies, Female, Health Status, Humans, Male, Middle Aged, Multivariate Analysis, Quality of Life psychology, Retrospective Studies, Risk Factors, Surveys and Questionnaires, Persons With Hearing Impairments psychology, Self Concept, Social Discrimination psychology, Stress, Psychological epidemiology, Stress, Psychological psychology
- Abstract
Background: we aimed to assess both cross-sectional and temporal links between measured hearing impairment and self-perceived hearing handicap, and health outcomes., Methods: in total, 811 Blue Mountains Hearing Study participants (Sydney, Australia) aged ≥55 years were examined twice (1997-99 and 2002-04). Hearing levels were measured with pure-tone audiometry. The shortened version of the hearing handicap inventory (HHIE-S) was administered, scores ≥8 defined hearing handicap., Results: baseline hearing impairment was strongly associated with 7 of the 10 HHIE-S questions, 5 years later. Individuals with and without hearing impairment at baseline reported that they felt embarrassed and/or frustrated by their hearing problem, and that it hampered their personal/social life, multivariable-adjusted OR: 11.5 (CI: 3.5-38.1), OR: 6.3 (CI: 2.5-15.7) and OR: 6.0 (CI: 2.1-17.5), respectively, 5 years later. Hearing-impaired, compared with non-hearing-impaired adults had a significantly higher risk of developing moderate or severe hearing handicap, OR: 3.35 (CI: 1.91-5.90) and OR: 6.60 (CI: 1.45-30.00), respectively. Cross-sectionally (at wave 2), hearing handicap increased the odds of depressive symptoms and low self-rated health by 80 and 46%, respectively., Conclusion: older, hearing-impaired adults were significantly more likely to experience emotional distress and social engagement restrictions (self-perceived hearing handicap) directly due to their hearing impairment.
- Published
- 2012
- Full Text
- View/download PDF
105. Hearing handicap, rather than measured hearing impairment, predicts poorer quality of life over 10 years in older adults.
- Author
-
Gopinath B, Schneider J, Hickson L, McMahon CM, Burlutsky G, Leeder SR, and Mitchell P
- Subjects
- Aged, Audiometry, Pure-Tone, Female, Follow-Up Studies, Health Surveys, Hearing Aids, Hearing Loss diagnosis, Hearing Loss therapy, Humans, Longitudinal Studies, Male, Middle Aged, Prospective Studies, Retrospective Studies, Risk Factors, Self Report, Hearing Loss physiopathology, Quality of Life
- Abstract
Background: We aimed to determine the prospective association between measured hearing impairment, self-reported hearing handicap and hearing aid use with quality of life., Study Design: 829 Blue Mountains Hearing Study participants (≥ 55 years) were examined between 1997-1999 and 2007-2009. The shortened version of the hearing handicap inventory was administered. Hearing levels were measured using pure-tone audiometry. Quality of life was assessed using the 36-Item Short-Form Survey (SF-36); higher scores reflect better quality of life., Results: Hearing impairment at baseline compared with no impairment was associated with lower mean SF-36 mental composite score 10 years later (multivariable-adjusted p=0.03). Physical composite score and mean scores for seven of the eight SF-36 domains after 10-year follow-up were significantly lower among participants who self-reported hearing handicap at baseline. Differences in the adjusted means between participants with and without hearing handicap ranged from 2.7 (physical composite score) to 10.4 units ('role limitations due to physical problems' domain). Individuals who developed incident hearing impairment compared to those who did not, had adjusted mean scores 9.5- and 7.7-units lower in the 'role limitation due to physical problems', and 'bodily pain' domains, respectively, at the 10-year follow-up. Hearing aid users versus non-users at baseline showed a 1.82-point (p=0.03) and 3.32-point (p=0.01) increase in SF-36 mental composite score and mental health domain over the 10-year follow-up, respectively., Conclusion: Older adults with self-perceived hearing handicap constitute a potential risk group for overall deterioration in quality of life, while hearing aid use could help improve the well-being of hearing impaired adults., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
106. Severity of age-related hearing loss is associated with impaired activities of daily living.
- Author
-
Gopinath B, Schneider J, McMahon CM, Teber E, Leeder SR, and Mitchell P
- Subjects
- Acoustic Stimulation, Age Factors, Aged, Aged, 80 and over, Audiometry, Pure-Tone, Auditory Threshold, Correction of Hearing Impairment, Cross-Sectional Studies, Female, Hearing Aids, Humans, Independent Living, Logistic Models, Male, Middle Aged, Multivariate Analysis, New South Wales, Odds Ratio, Presbycusis physiopathology, Presbycusis psychology, Presbycusis rehabilitation, Risk Assessment, Risk Factors, Severity of Illness Index, Surveys and Questionnaires, Activities of Daily Living, Aging, Disability Evaluation, Geriatric Assessment, Persons With Hearing Impairments psychology, Persons With Hearing Impairments rehabilitation, Presbycusis diagnosis
- Abstract
Background: age-related hearing loss is a common chronic condition; hence, it is important to understand its influence on the functional status of older adults. We assessed the association between hearing impairment with activity limitations as assessed by the activities of daily living (ADL) scale., Methods: a total of 1,952 Blue Mountains Hearing Study participants aged ≥60 years had their hearing levels measured using pure-tone audiometry. A survey instrument with questions on functional status as determined by the Older Americans Resources and Services ADL scale was administered., Results: one hundred and sixty-four (10.4%) participants reported ADL difficulty. A higher proportion of hearing impaired than non-impaired adults reported difficulties in performing three out of the seven basic ADL and six out of the seven instrumental ADL tasks. After multivariable adjustment, increased severity of hearing loss was associated with impaired ADL (P(trend )= 0.001). Subjects with moderate to severe hearing loss compared with those without, had a 2.9-fold increased likelihood of reporting difficulty in ADL, multivariate-adjusted odds ratio (OR): 2.87 [95% confidence interval (CI): 1.59-5.19]. Participants aged <75 years with hearing loss compared with those without, had 2-fold higher odds of impaired ADL. Having worn or wearing a hearing aid was also associated with a 2-fold increased likelihood of impaired ADL., Conclusion: functional status as measured by a common ADL scale is diminished in older hearing impaired adults. Our findings suggest that severely diminished hearing could make the difference between independence and the need for formal support services or placement.
- Published
- 2012
- Full Text
- View/download PDF
107. Long-term monaural auditory deprivation and bilateral cochlear implants.
- Author
-
Boisvert I, McMahon CM, and Dowell RC
- Subjects
- Adult, Aged, Aged, 80 and over, Auditory Diseases, Central surgery, Auditory Pathways physiology, Humans, Middle Aged, Retrospective Studies, Speech Perception physiology, Cochlear Implants, Deafness surgery, Hearing Loss, Bilateral surgery
- Abstract
Long-term binaural auditory deprivation is associated with poorer speech recognition outcomes after cochlear implantation, even for postlingual hearing loss. It is, however, unknown to what extent the outcomes of implantation are related to the peripheral changes occurring monaurally or to changes at a higher level in the auditory system related to binaural deafness. This retrospective study aimed to unravel peripheral and central contributions to cochlear implantation outcomes by comparing outcomes obtained in individual ears for adults with long-term monaural auditory deprivation (i.e. unilateral use of hearing aid) who received bilateral cochlear implants. Results showed that similar outcomes can be obtained with the implant placed in the auditory-deprived or in the aided ear. This suggests that the peripheral changes related to monaural auditory deprivation have little effect on outcomes of cochlear implantation.
- Published
- 2012
- Full Text
- View/download PDF
108. Dual sensory impairment in older age.
- Author
-
Schneider JM, Gopinath B, McMahon CM, Leeder SR, Mitchell P, and Wang JJ
- Subjects
- Aged, Cross-Sectional Studies, Databases, Factual, Female, Humans, Research trends, Deaf-Blind Disorders epidemiology
- Abstract
Objective: Hearing and visual impairments are commonly viewed separately in research and service provision, but they often occur together as dual sensory impairment or DSI in older populations. This article examines the frequency and effects of DSI in older age and notes limitations in the evidence., Methods: Search of electronic databases of published papers., Results: DSI diminishes communication and well-being and can cause social isolation, depression, reduced independence, mortality, and cognitive impairment., Discussion: Although intuitively DSI may be expected to have additional impacts over single sensory impairment, research findings are inconclusive. Services and supports required by people with DSI are simply a combination of those required by people with single vision and hearing loss, taking account of the unique communication difficulties posed by DSI.
- Published
- 2011
- Full Text
- View/download PDF
109. Dietary antioxidant intake is associated with the prevalence but not incidence of age-related hearing loss.
- Author
-
Gopinath B, Flood VM, McMahon CM, Burlutsky G, Spankovich C, Hood LJ, and Mitchell P
- Subjects
- Aged, Aging, Antioxidants adverse effects, Antioxidants pharmacology, Australia, Carotenoids pharmacology, Cross-Sectional Studies, Diet Surveys, Female, Follow-Up Studies, Geriatric Assessment, Humans, Incidence, Longitudinal Studies, Male, Middle Aged, Presbycusis epidemiology, Prevalence, Surveys and Questionnaires, Trace Elements pharmacology, Vitamin A adverse effects, Vitamin A pharmacology, Vitamin E adverse effects, Vitamin E pharmacology, Antioxidants therapeutic use, Diet, Dietary Supplements, Hearing drug effects, Presbycusis prevention & control, Vitamin A therapeutic use, Vitamin E therapeutic use
- Abstract
Objectives: Diet is one of the few modifiable risk factors for age-related hearing loss. We aimed to examine the link between dietary and supplement intakes of antioxidants, and both the prevalence and 5-year incidence of measured hearing loss., Design: Cross-sectional and 5-year longitudinal analyses., Setting: Blue Mountains, Sydney, Australia., Participants: 2,956 Blue Mountains Hearing Study participants aged 50+ at baseline, examined during 1997-9 to 2002-4., Measurements: Age-related hearing loss was measured and defined as the pure-tone average of frequencies 0.5, 1.0, 2.0 and 4.0 kHz >25 dB HL. Dietary data were collected in a semi-quantitative food frequency questionnaire, and intakes of α-carotene; β-carotene; β-cryptoxanthin; lutein and zeaxanthin; lycopene; vitamins A, C and E; iron and zinc were calculated., Results: After adjusting for age, sex, smoking, education, occupational noise exposure, family history of hearing loss, history of diagnosed diabetes and stroke, each standard deviation (SD) increase in dietary vitamin E intake was associated with a 14% reduced likelihood of prevalent hearing loss, odds ratio, OR, 0.86 (95% confidence interval, CI, 0.78-0.98). Those in the highest quintile of dietary vitamin A intake had a 47% reduced risk of having moderate or greater hearing loss (>40 dB HL) compared to those in the lowest quintile of intake, multivariable-adjusted OR 0.53 (CI 0.30-0.92), P for trend = 0.04. However, dietary antioxidant intake was not associated with the 5-year incidence of hearing loss., Conclusions: Dietary vitamin A and vitamin E intake were significantly associated with the prevalence of hearing loss. However, dietary antioxidant intake did not increase the risk of incident hearing loss. Further large, prospective studies are warranted to assess these relationships in older adults.
- Published
- 2011
- Full Text
- View/download PDF
110. Relative importance of monaural sound deprivation and bilateral significant hearing loss in predicting cochlear implantation outcomes.
- Author
-
Boisvert I, McMahon CM, Tremblay G, and Lyxell B
- Subjects
- Adult, Aged, Female, Follow-Up Studies, Hearing Loss, Bilateral physiopathology, Hearing Loss, Unilateral physiopathology, Humans, Language Development Disorders diagnosis, Language Development Disorders physiopathology, Language Development Disorders rehabilitation, Male, Middle Aged, Predictive Value of Tests, Retrospective Studies, Speech Perception physiology, Speech Reception Threshold Test, Treatment Outcome, Cochlear Implantation rehabilitation, Hearing Loss, Bilateral diagnosis, Hearing Loss, Bilateral rehabilitation, Hearing Loss, Unilateral diagnosis, Hearing Loss, Unilateral rehabilitation
- Abstract
Objectives: Making evidence-based recommendations to prospective unilateral cochlear implant recipients on the potential benefits of implanting one or the other ear is challenging for cochlear implant teams. This particularly occurs in cases where a hearing aid has only been used in one ear for many years (referred to here as the "hearing ear"), and the contralateral ear has, in essence, been sound-deprived. In such cases, research to date is inconclusive, and little anecdotal evidence exists to inform the debate and support best clinical practice., Design: Retrospective data on speech recognition outcomes of 16 adult participants who received a cochlear implant in an ear deprived of sound for a minimum of 15 yr were analyzed. All subjects were implanted through the Quebec Cochlear Implant Program and were provided with personalized intensive rehabilitation services. Data obtained from clinical records included demographic data and speech recognition scores measured after implantation with the sentences of a multimedia auditory test battery in the auditory-only condition. Speech recognition outcomes were compared with the duration of auditory deprivation in the implanted ear, bilateral significant hearing loss, and auditory stimulation before bilateral significant hearing loss., Results: Using nonparametric correlation analyses, a strong negative correlation was demonstrated between speech recognition scores and the duration of bilateral significant hearing loss and with the duration of auditory stimulation before bilateral significant hearing loss. No significant correlation with the duration of auditory deprivation or with the duration of prior auditory stimulation in the implanted ear was found., Conclusions: These findings suggest that functional outcomes of cochlear implantation for unilateral sound deprivation may be more strongly influenced by central processes than peripheral effects stemming from the deprivation per se. This indicates the relevance of considering the client's history of binaural hearing rather than the hearing in each ear individually when discussing possible outcomes with a cochlear implant.
- Published
- 2011
- Full Text
- View/download PDF
111. Incidence and predictors of hearing aid use and ownership among older adults with hearing loss.
- Author
-
Gopinath B, Schneider J, Hartley D, Teber E, McMahon CM, Leeder SR, and Mitchell P
- Subjects
- Age Distribution, Aged, Aged, 80 and over, Audiometry, Australia, Female, Humans, Interviews as Topic, Male, Middle Aged, Health Knowledge, Attitudes, Practice, Hearing Aids psychology, Hearing Aids statistics & numerical data, Hearing Loss therapy
- Abstract
Purpose: The reasons are not clear as to why people who need hearing aids and possess them do not use them. We aimed to describe the incidence and predictors of hearing aid ownership and use among older adults., Methods: We included 2,015 Blue Mountains Hearing Study participants aged ≥55 years who were examined between 1997 and 1999 and 2002 and 2004. Hearing levels were measured with pure-tone audiometry., Results: The 5-year incidence of hearing aid use and ownership was 8.1% and 8.5%, respectively. Age was associated with incident hearing aid ownership and use, multivariable-adjusted odds ratio (OR) per decade increase in age of 1.79 (95% confidence interval [CI], 1.21-2.64) and of 1.66 (95% CI, 1.15-2.40), respectively. Any level of hearing loss (HL) at baseline predicted a 2.8-fold increased likelihood of using a hearing aid at follow-up. Hearing handicap was associated with 7% increased likelihood of incident aid use. Key reasons provided for not obtaining/using a hearing aid were: not recommended one (8.0%), its high cost (1.7%), and believing that they did not need one (9.0%)., Conclusions: Incident hearing aid ownership and usage was relatively low among hearing impaired adults. Age, question-defined hearing handicap, and measured HL were significant predictors of incident hearing aid use/ownership., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
112. Dietary intake of cholesterol is positively associated and use of cholesterol-lowering medication is negatively associated with prevalent age-related hearing loss.
- Author
-
Gopinath B, Flood VM, Teber E, McMahon CM, and Mitchell P
- Subjects
- Aged, Cohort Studies, Cross-Sectional Studies, Female, Hearing Loss, Sensorineural blood, Hearing Loss, Sensorineural epidemiology, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Lipids blood, Male, Middle Aged, New South Wales epidemiology, Prevalence, Anticholesteremic Agents therapeutic use, Cholesterol, Dietary administration & dosage, Cholesterol, Dietary adverse effects, Hearing Loss, Sensorineural etiology, Hearing Loss, Sensorineural prevention & control
- Abstract
We aimed to assess associations between dietary intake of fats (saturated and monounsaturated fats and cholesterol) and certain food groups (butter, margarine, and nuts) with the prevalence, incidence, and progression of age-related hearing loss. We also aimed to investigate the link between serum lipids and cholesterol-lowering medication (statins) and hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss. Hearing loss was measured in 2956 participants (aged ≥50 y) and was defined as the pure-tone average (PTA) of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level (PTA(0.5-4 kHz)). Dietary data were collected using a semiquantitative FFQ. After multivariable adjustment, the likelihood of prevalent hearing loss increased from the lowest (reference) to the highest quartile of dietary cholesterol intake (P-trend = 0.04). Among persons self-reporting statin use (n = 274), a 48% reduced odds of prevalent hearing loss was observed after multivariable adjustment [OR = 0.52 (95% CI = 0.29-0.93)]. Participants in the second and 3rd quartiles of dietary monounsaturated fat intake compared with those in the first quartile (reference) had a significantly reduced risk of hearing loss progression 5 y later [multivariable-adjusted OR = 0.39 (95% CI = 0.21-0.71)] and [OR = 0.51 (95% CI = 0.29-0.91)], respectively. Our results suggest that a diet high in cholesterol could have adverse influences on hearing, whereas treatment with statins and consumption of monounsaturated fats may have a beneficial influence.
- Published
- 2011
- Full Text
- View/download PDF
113. Five-year incidence and progression of hearing impairment in an older population.
- Author
-
Mitchell P, Gopinath B, Wang JJ, McMahon CM, Schneider J, Rochtchina E, and Leeder SR
- Subjects
- Age Factors, Aged, Australia epidemiology, Cohort Studies, Disease Progression, Female, Hearing Aids statistics & numerical data, Humans, Incidence, Male, Middle Aged, Prevalence, Time Factors, Hearing Loss, Bilateral epidemiology, Hearing Loss, Bilateral physiopathology
- Abstract
Objectives: There are few epidemiological surveys that have examined age-related hearing loss in an older Australian population. This study reports the prevalence, 5-yr incidence, and progression of hearing impairment in a representative sample of older persons., Design: The Blue Mountains Hearing Study (BMHS) is a population-based survey of age-related hearing loss conducted among participants of the Blue Mountains Eye Study cohort. During the period 1997-1999, 2956 had audiometric testing done. Of these, 870 participants without hearing loss and 439 with hearing loss were re-examined from 2002 to 2004., Results: Some degree of hearing loss was present in 33.0% of this population at baseline. Prevalence of hearing loss increased with age, sex-adjusted (odds ratio [OR] 3.5, 95% confidence interval [CI] 3.1-3.9), with men 70% more likely than women to have hearing loss. The 5-yr incidence of hearing impairment was 17.9%. For each decade of age older than 60 yrs, the risk of hearing loss increased threefold, OR 3.9 (CI 2.3-3.8). Gender was not associated with incident hearing loss OR. However, high occupational prestige was associated with decreased incidence of hearing loss OR 0.6 (CI 0.40-0.94). The 5-yr progression of hearing loss defined as a difference in pure-tone average that exceeded 10 dB was relatively high (15.7%). At the baseline hearing study and at the 5-yr follow-up hearing study, 57.4% and 59.7% of hearing impaired subjects, respectively, reported using a hearing aid for a maximum of 5 yrs., Conclusions: Hearing loss was a frequent sensory disability, with one in three persons having a hearing impairment, and of these, almost one in two showing a decline in hearing over a 5-yr period. This information can potentially contribute to the planning and resource investment in auditory rehabilitation services for older Australians.
- Published
- 2011
- Full Text
- View/download PDF
114. Dietary glycemic load is a predictor of age-related hearing loss in older adults.
- Author
-
Gopinath B, Flood VM, McMahon CM, Burlutsky G, Brand-Miller J, and Mitchell P
- Subjects
- Aged, Female, Humans, Male, Multivariate Analysis, Risk Factors, Age Factors, Diet, Glucose administration & dosage, Hearing Loss
- Abstract
Age-related hearing loss is a frequent disability in older adults and nutrition could play a role in the development of this condition. Carbohydrate nutrition [including dietary glycemic index (GI) and load (GL)] may be linked to hearing loss. We aimed to determine the association between carbohydrate nutrition (including mean dietary GI and GL, and the dietary intakes of carbohydrate and sugar), starch, cereal and total fiber, and age-related hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss (1997-1999 to 2002-2004). Hearing loss was measured in 2956 participants (aged ≥50 y) and was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level. Dietary data were collected in a semiquantitative FFQ. A purpose-built database based on Australian GI values was used to calculate the mean GI. A higher mean dietary GI was associated with an increased prevalence of any hearing loss, comparing quintiles 1 (lowest) and 5 (highest), [multivariable-adjusted odds ratio = 1.41 (95% CI = 1.01-1.97)]. Participants in the highest quartile of mean dietary GL intake compared with those in the lowest quartile had a 76% greater risk of developing incident hearing loss (P-trend = 0.04). Higher carbohydrate and sugar intakes were associated with incident hearing loss (P-trend = 0.03 and P-trend = 0.05, respectively). In summary, a high-GL diet was a predictor of incident hearing loss, as was higher intake of total carbohydrate. Hence, high postprandial glycemia might be a potential underlying biological mechanism in the development of age-related hearing loss.
- Published
- 2010
- Full Text
- View/download PDF
115. The association between reduced GFR and hearing loss: a cross-sectional population-based study.
- Author
-
Vilayur E, Gopinath B, Harris DC, Burlutsky G, McMahon CM, and Mitchell P
- Subjects
- Age Distribution, Aged, Audiometry, Pure-Tone, Comorbidity, Confidence Intervals, Cross-Sectional Studies, Female, Follow-Up Studies, Hearing Loss diagnosis, Humans, Kidney Failure, Chronic diagnosis, Male, Middle Aged, Multivariate Analysis, New South Wales epidemiology, Odds Ratio, Prevalence, Risk Assessment, Severity of Illness Index, Sex Distribution, Surveys and Questionnaires, Creatinine blood, Glomerular Filtration Rate, Hearing Loss epidemiology, Kidney Failure, Chronic epidemiology
- Abstract
Background: Chronic kidney disease (CKD) has long been associated with hearing loss in certain syndromes. Reported evidence to date has come from only small observational studies. We present the first community-based study to show an association between nonsyndromal CKD and hearing loss., Study Design: Cross-sectional population-based study to examine the relationship between CKD and age-related hearing loss., Setting & Participants: The Blue Mountains Hearing Study is a survey of age-related hearing loss conducted in 1997-2004; a total of 2,564 participants had audiometric testing and complete renal data., Predictor or Factor: Moderate CKD, defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2)., Outcomes: Bilateral hearing loss, defined as average pure-tone threshold >25 dB for measurements at frequencies of 0.5, 1.0, 2.0, and 4.0 kHz., Measurements: Baseline biochemistry tests, including serum creatinine, were performed. Pure-tone audiometry was performed in sound-treated booths., Results: Moderate CKD was present in 513 of 2,564 participants. Of persons with moderate CKD, 279 (54.4%) had measured hearing loss compared with 581 (28.3%) with eGFR ≥60 mL/min/1.73 m(2). Moderate CKD was independently associated with hearing loss (OR, 1.43; 95% CI, 1.10-1.84; P = 0.006) after adjusting for age; sex; noise exposure; education; diabetes, hypertension, and stroke histories; and smoking. Participants with eGFR <45 mL/min/1.73 m(2) had the highest prevalence of hearing loss (73%) compared with those with eGFR ≥90 mL/min/1.73 m(2) (19%; multivariate adjusted OR, 2.4 [95% CI, 1.3-4.5]). Analyses were repeated after excluding participants reporting furosemide use (a known ototoxic agent); the association between moderate CKD and hearing loss remained significant (multivariate adjusted OR, 1.40 [95% CI, 1.08-1.83]; P = 0.01)., Limitations: The present study is not longitudinal and does not permit causal inference from the observed associations., Conclusions: Moderate CKD per se was associated independently with hearing loss. Recognizing this link could lead to earlier hearing assessment with appropriate interventions to preserve the hearing of patients with CKD., (Copyright © 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
116. Serum homocysteine and folate concentrations are associated with prevalent age-related hearing loss.
- Author
-
Gopinath B, Flood VM, Rochtchina E, McMahon CM, and Mitchell P
- Subjects
- Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Health Surveys, Hearing Loss epidemiology, Humans, Male, Multivariate Analysis, Odds Ratio, Vitamin B 12 blood, Aging, Folic Acid blood, Hearing Loss blood, Homocysteine blood
- Abstract
Elevated total serum homocysteine (tHcy) concentrations associated with vitamin B-12 or folate deficiencies may adversely affect blood flow to the cochlea, leading to age-related hearing loss (presbycusis). However, only 2 small cross-sectional studies have assessed the link between folate, vitamin B-12, or tHcy and presbycusis. We aimed to determine both the cross-sectional and longitudinal association between serum concentrations of folate, vitamin B-12, or tHcy and risk of age-related hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss (1997-1999 to 2002-2004). Presbycusis was measured in 2956 participants (aged >or=50 y) and was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 dB hearing level (HL). Serum concentrations of folate, vitamin B-12, and tHcy were determined from blood samples. Participants with elevated tHcy (>20 micromol/L) concentrations had a 64% increased likelihood of prevalent hearing loss (>25 dB HL) [multivariate-adjusted odds ratio (OR) 1.64; 95% CI, 1.06-2.53]. Low serum folate levels (<11 nmol/L) increased the odds of prevalent mild hearing loss (>25-40 dB HL), multivariate-adjusted [OR 1.37 (CI 1.04-1.81)]. Serum vitamin B-12, however, was not significantly associated with prevalent hearing loss. Serum folate, vitamin B-12, and tHcy concentrations were also not significantly associated with an increased risk of incident hearing loss. Serum concentrations of tHcy and folate were associated with age-related hearing loss cross-sectionally, but no temporal links were observed, which could be due to insufficient study power. Further, large prospective studies will be required in the future to assess these associations.
- Published
- 2010
- Full Text
- View/download PDF
117. Consumption of omega-3 fatty acids and fish and risk of age-related hearing loss.
- Author
-
Gopinath B, Flood VM, Rochtchina E, McMahon CM, and Mitchell P
- Subjects
- Aged, Aged, 80 and over, Animals, Diet Surveys, Female, Fishes, Humans, Male, Middle Aged, Odds Ratio, Risk Factors, Surveys and Questionnaires, Diet, Dietary Fats administration & dosage, Fatty Acids, Omega-3 administration & dosage, Presbycusis prevention & control, Seafood
- Abstract
Background: Identification of modifiable risk factors that could prevent or slow the development of age-related hearing loss (presbycusis) would be valuable. Dietary polyunsaturated fatty acid (PUFA) intake may be related to age-related hearing loss., Objective: We aimed to determine the association between dietary intakes of omega-3 (n-3) PUFAs and fish and the risk of presbycusis., Design: The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss (1997-1999 to 2002-2004). We collected dietary data by using a semiquantitative food-frequency questionnaire and calculated PUFA and fish intakes. In 2956 participants (aged > or =50 y), we measured presbycusis, which we defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 decibels of hearing loss., Results: There was an inverse association between total n-3 PUFA intake and prevalent hearing loss [odds ratio (OR) per SD increase in energy-adjusted n-3 PUFAs: 0.89; 95% CI: 0.81, 0.99]. There was an inverse association between long-chain n-3 PUFAs and incident hearing loss (OR per SD increase in long-chain n-3 PUFAs: 0.76; 95% CI: 0.60, 0.97). Participants who had > or =2 servings of fish/wk compared with participants who had <1 serving of fish/wk had a significantly reduced risk (42%) of developing presbycusis at follow-up (multivariate-adjusted OR: 0.58; 95% CI: 0.35, 0.95). There was an association between consumption of > or =1 to <2 servings/wk of fish and a reduced risk of a progression of hearing loss (OR: 0.53; 95% CI: 0.32, 0.88)., Conclusions: There was an inverse association between higher intakes of long-chain n-3 PUFAs and regular weekly consumption of fish and hearing loss. Dietary intervention with n-3 PUFAs could prevent or delay the development of age-related hearing loss.
- Published
- 2010
- Full Text
- View/download PDF
118. Hearing loss impacts on the use of community and informal supports.
- Author
-
Schneider J, Gopinath B, Karpa MJ, McMahon CM, Rochtchina E, Leeder SR, and Mitchell P
- Subjects
- Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Geriatric Assessment statistics & numerical data, Health Services Needs and Demand, Hearing Loss epidemiology, Humans, Longitudinal Studies, Male, Middle Aged, Severity of Illness Index, Walking statistics & numerical data, Hearing Aids statistics & numerical data, Hearing Loss psychology, Social Support
- Abstract
Objective: the aim of this study is to estimate the cross-sectional and longitudinal impact of hearing loss on use of community support services and reliance on non-spouse family/friends among older people., Methods: Blue Mountains Hearing Study participants (n = 2,956) were assessed for hearing impairment by audiologists in sound-treated booths. Participants were classified as hearing impaired if PTA(0.5-4)( )(kHz) >25 dB HL. Use of services and non-spouse family/friend support was assessed cross-sectionally. Incident use was assessed among survivors at the 5-year follow-up (n = 1,457)., Results: a significant cross-sectional association between hearing loss (>25 dB HL) and use of community support services was observed after adjusting for age, sex, living status, self-rated poor health, self-reported hospital admissions, disability in walking and best-corrected visual impairment [odds ratio (OR) 2.12, 95% confidence interval (CI) 1.15-3.90]. Participants with hearing loss who never used a hearing aid were twice as likely to use formal supports as participants without hearing loss (multivariate-adjusted OR 2.25, 95% CI 1.19-4.24). Hearing loss increased the incident need for non-spouse family/friend support or community services (multivariate-adjusted OR 1.49, 95% CI 1.02-2.18)., Conclusions: after adjusting for confounding factors, hearing impairment negatively impacted on the independence of older persons by increasing reliance on community or family support.
- Published
- 2010
- Full Text
- View/download PDF
119. Incidence, persistence, and progression of tinnitus symptoms in older adults: the Blue Mountains Hearing Study.
- Author
-
Gopinath B, McMahon CM, Rochtchina E, Karpa MJ, and Mitchell P
- Subjects
- Adult, Aged, Aged, 80 and over, Audiometry, Pure-Tone, Auditory Threshold, Australia epidemiology, Chronic Disease, Disease Progression, Evidence-Based Medicine, Female, Follow-Up Studies, Humans, Incidence, Longitudinal Studies, Male, Middle Aged, Risk Factors, Severity of Illness Index, Tinnitus therapy, Young Adult, Health Surveys, Tinnitus epidemiology, Tinnitus physiopathology
- Abstract
Objective: Temporal population-based data on tinnitus are lacking. We used a representative older population-based cohort to establish 5-yr incidence, persistence, and progression of tinnitus symptoms., Design: Two thousand six participants of the Blue Mountains Hearing Study (1997-1999) had complete tinnitus data, and of these, 1214 participants were followed up at 5-yr examinations in 2002-2004. Presence of prolonged tinnitus was assessed by a positive response to a single question administered by an audiologist. Incident tinnitus was defined in participants who were free of tinnitus symptoms at the baseline study in 1997-1999 but who reported tinnitus symptoms at the 5-yr follow-up in 2002-2004. Progression of tinnitus was defined as the increase in annoyance of tinnitus symptoms from baseline to the 5-yr follow-up study. Persistence of tinnitus symptoms was defined as the presence of tinnitus symptoms at both the baseline and follow-up examinations. Hearing impairment was measured as the pure-tone average (PTA) of audiometric hearing thresholds at 500, 1000, 2000, and 4000 Hz (PTA0.5-4 kHz), defining bilateral hearing loss as PTA0.5-4 kHz >25 dB HL., Results: Five-year incidence of tinnitus was 18.0%. A significant age trend was observed for the 5-yr incidence (p = 0.005), with incident tinnitus decreasing with age. Hearing loss increased the risk of developing incident tinnitus, age-sex adjusted odds ratio 2.13 (95% confidence interval, 1.40 to 3.24). Most (55.5%) incident tinnitus cases reported symptoms that were only mildly annoying. Tinnitus at baseline persisted in 81.6% of participants. Of those reporting mildly annoying tinnitus at baseline, 39.6% progressed to moderately annoying and 5.9% to severely annoying tinnitus. At the follow-up, a higher frequency of participants with persistent tinnitus (old cases) reported their symptoms as very/extremely annoying compared with the new (incident) cases of tinnitus (p = 0.01). A high proportion (85.2%) of subjects receiving tinnitus treatment (mainly medications and hearing aid) at baseline still reported tinnitus at 5-yr examinations., Conclusions: Incident tinnitus was frequent, with nearly one in five older adults suffering from this condition after 5 yrs. Tinnitus symptoms persisted in more than three-quarters of the cohort, during the 5 yrs. Longitudinal data are an important contribution to the research evidence base to support timely intervention and effective management of this frequent symptom.
- Published
- 2010
- Full Text
- View/download PDF
120. Optical redox ratio differentiates breast cancer cell lines based on estrogen receptor status.
- Author
-
Ostrander JH, McMahon CM, Lem S, Millon SR, Brown JQ, Seewaldt VL, and Ramanujam N
- Subjects
- Breast Neoplasms drug therapy, Breast Neoplasms genetics, Cell Line, Tumor, Epithelial Cells cytology, Epithelial Cells metabolism, Estradiol analogs & derivatives, Estradiol pharmacology, Estrogen Receptor Modulators pharmacology, Estrogen Receptor alpha biosynthesis, Estrogen Receptor alpha genetics, Female, Flavin-Adenine Dinucleotide metabolism, Fulvestrant, Humans, Mammary Glands, Human cytology, Mammary Glands, Human metabolism, Microscopy, Confocal methods, NAD metabolism, Oxidation-Reduction, RNA, Messenger biosynthesis, RNA, Messenger genetics, Tamoxifen pharmacology, Breast Neoplasms metabolism, Estrogen Receptor alpha metabolism
- Abstract
Autofluorescence spectroscopy is a powerful imaging technique that exploits endogenous fluorophores. The endogenous fluorophores NADH and flavin adenine dinucleotide (FAD) are two of the principal electron donors and acceptors in cellular metabolism, respectively. The optical oxidation-reduction (redox) ratio is a measure of cellular metabolism and can be determined by the ratio of NADH/FAD. We hypothesized that there would be a significant difference in the optical redox ratio of normal mammary epithelial cells compared with breast tumor cell lines and that estrogen receptor (ER)-positive cells would have a higher redox ratio than ER-negative cells. To test our hypothesis, the optical redox ratio was determined by collecting the fluorescence emission for NADH and FAD via confocal microscopy. We observed a statistically significant increase in the optical redox ratio of cancer compared with normal cell lines (P < 0.05). Additionally, we observed a statistically significant increase in the optical redox ratio of ER(+) breast cancer cell lines. The level of ESR1 expression, determined by real-time PCR, directly correlated with the optical redox ratio (Pearson's correlation coefficient = 0.8122, P = 0.0024). Furthermore, treatment with tamoxifen and ICI 182,870 statistically decreased the optical redox ratio of only ER(+) breast cancer cell lines. The results of this study raise the important possibility that fluorescence spectroscopy can be used to identify subtypes of breast cancer based on receptor status, monitor response to therapy, or potentially predict response to therapy. This source of optical contrast could be a potentially useful tool for drug screening in preclinical models., (Copyright 2010 AACR.)
- Published
- 2010
- Full Text
- View/download PDF
121. The effects of smoking and alcohol consumption on age-related hearing loss: the Blue Mountains Hearing Study.
- Author
-
Gopinath B, Flood VM, McMahon CM, Burlutsky G, Smith W, and Mitchell P
- Subjects
- Aged, Cross-Sectional Studies, Female, Humans, Incidence, Male, Middle Aged, New South Wales epidemiology, Noise, Occupational statistics & numerical data, Prevalence, Risk Factors, Alcohol Drinking epidemiology, Hearing Loss, Bilateral epidemiology, Presbycusis epidemiology, Smoking epidemiology, Suburban Population statistics & numerical data
- Abstract
Objectives: We aimed to investigate the temporal association between smoking or alcohol consumption and hearing loss, and to confirm previously published cross-sectional associations., Design: The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss conducted in a defined suburban area, west of Sydney. Hearing loss was measured in 2956 participants (aged 50+ yrs) and was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 dB HL in the better ear (bilateral hearing loss). Alcohol consumption and smoking status were measured using an interviewer-administered questionnaire. Logistic regression was used to obtain odds ratios (OR) with 95% confidence intervals (95% CI) that compared the chances of having hearing loss in participants who did or did not smoke or consume alcohol, after adjusting for other factors previously reported to be associated with hearing loss., Results: The prevalence of hearing loss at baseline was 33.0% (N = 929) and the 5-year incidence of hearing loss was 17.9% (N = 156). Cross-sectional analysis demonstrated a significant protective association between the moderate consumption of alcohol (>1 but < or =2 drinks/day) and hearing function in older adults (compared with nondrinkers), OR 0.75 (95% CI, 0.57 to 0.98). Current smokers not exposed to occupational noise had a significantly higher likelihood of hearing loss after adjusting for multiple variables, OR 1.63 (95% CI, 1.01 to 2.64). A formal likelihood ratio test demonstrated that the interaction between smoking and noise exposure was not significant (p = 0.23). When the joint effects of alcohol consumption and smoking on hearing were explored, there was a trend for alcohol to have a protective relationship with hearing loss in smokers, but this was not statistically significant. However, the 5-year incidence of hearing loss was not predicted by either smoking or alcohol consumption., Conclusions: This study confirms previously reported associations between alcohol consumption or smoking and prevalent hearing loss, but these were not demonstrated in temporal data. Other risk factors could confer greater vulnerability or cause the initial damage to hearing. Future large population-based studies, exploring the influence of other risk factors on the development of age-related hearing loss are warranted.
- Published
- 2010
- Full Text
- View/download PDF
122. Risk factors and impacts of incident tinnitus in older adults.
- Author
-
Gopinath B, McMahon CM, Rochtchina E, Karpa MJ, and Mitchell P
- Subjects
- Aged, Aged, 80 and over, Cohort Studies, Depression epidemiology, Depression etiology, Female, Hearing Loss epidemiology, Humans, Logistic Models, Male, Middle Aged, New South Wales epidemiology, Risk Factors, Sex Factors, Sickness Impact Profile, Tinnitus psychology, Tinnitus epidemiology
- Abstract
Purpose: We used a representative older population-based cohort to establish the predictors and impacts of tinnitus., Methods: A total of 1,214 participants of the Blue Mountains Hearing Study were followed for 5 years (1997-1999 to 2002-2004). The presence of tinnitus was assessed by an audiologist-administered questionnaire. Hearing impairment was defined as the pure tone average (PTA)(0.5-4KHz)>25 dB HL, in the better ear. Quality of life was measured by use of the Short Form 36-item Health Survey (SF-36). Depression was assessed using either the SF-36 (Mental Health Index, subscale) and the Center for Epidemiologic Studies Depression Scale., Results: Symptomatic dizziness and hearing loss were significant risk factors for incident tinnitus, multivariable-adjusted odds ratio, 2.41 (95% confidence interval, 1.62-3.58) and odds ratio 2.31 (95% confidence interval, 1.46-3.66), respectively. Incident tinnitus cases demonstrated significantly lower mean SF-36 scores compared with subjects without tinnitus and were more likely to be depressed as assessed by both the Mental Health Index and Center for Epidemiologic Studies Depression Scale., Conclusions: Incident tinnitus was predicted by two otological risk factors, dizziness and hearing loss. Temporal data documented diminished quality of life and psychological well-being in those subjects experiencing tinnitus. This finding highlights the importance of effective intervention strategies to prevent potentially debilitating morbidity associated with tinnitus., (2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
123. Role of general practitioners in managing age-related hearing loss.
- Author
-
Schneider JM, Gopinath B, McMahon CM, Britt HC, Harrison CM, Usherwood T, Leeder SR, and Mitchell P
- Subjects
- Age Factors, Aged, Australia epidemiology, Confidence Intervals, Cross-Sectional Studies, Data Collection, Female, Health Care Surveys, Health Knowledge, Attitudes, Practice, Hearing Loss, Bilateral diagnosis, Hearing Loss, Bilateral epidemiology, Humans, Male, Middle Aged, Presbycusis diagnosis, Presbycusis epidemiology, Referral and Consultation statistics & numerical data, Clinical Competence, Hearing Loss, Bilateral therapy, Physician's Role, Physicians, Family statistics & numerical data, Presbycusis therapy
- Abstract
Objective: To assess the extent to which general practitioners in Australia are engaged in identifying age-related hearing loss and facilitating its management., Design, Setting and Participants: Cross-sectional analysis of data collected between 1998 and 2000 from the Blue Mountains Hearing Study (BMHS), a representative population-based cohort of people aged >or= 50 years in two postcode areas west of Sydney. Also analysed were data collected between 2003 and 2008 from random samples of Australian GPs who participated in the Bettering the Evaluation and Care of Health (BEACH) study, a national continuous cross-sectional survey of GP activity., Main Outcome Measures: Rate of facilitating management and identification of hearing loss in older patients; content of GP-patient encounters with hearing-impaired people; characteristics of participants seeking help from their GP., Results: Of older people in the BMHS with measured (objective) bilateral hearing loss, about a third reported seeking help from their GP. BEACH survey data showed that only about 3 per 1,000 GP consultations with patients aged >or= 50 years involved management of age-related hearing loss. For every 100 age-related hearing problems managed, GPs undertook 12 procedural treatments, provided 20 referrals to specialists, and made 29 referrals to allied health professionals., Conclusion: In their routine consultations with patients, GPs have opportunities to identify hearing loss and appropriately refer patients to specialists or allied health professionals. Although GPs are responding to patient presentations for hearing loss, referring around 50% of cases, there appear to be relatively few cases in which hearing loss is identified opportunistically. Levels of identification and management of hearing loss by GPs in Australia are relatively low.
- Published
- 2010
- Full Text
- View/download PDF
124. Dizziness and vertigo in an older population: the Blue Mountains prospective cross-sectional study.
- Author
-
Gopinath B, McMahon CM, Rochtchina E, and Mitchell P
- Subjects
- Aged, Audiometry, Pure-Tone, Auditory Threshold physiology, Cross-Sectional Studies, Dizziness diagnosis, Female, Hearing Disorders diagnosis, Hearing Disorders epidemiology, Humans, Incidence, Male, Prevalence, Prospective Studies, Severity of Illness Index, Surveys and Questionnaires, Tinnitus diagnosis, Tinnitus epidemiology, Vertigo diagnosis, Dizziness epidemiology, Vertigo epidemiology
- Abstract
Objectives: We aimed to reassess the prevalence and personal burden of dizziness/vertigo, and to assess the relationship with hearing loss and tinnitus in older adults., Design: Prospective cross-sectional study., Setting: Blue Mountains region, west of Sydney, Australia., Participants: We examined 2751 of 2956 (aged 50+ years) Blue Mountains Hearing Study participants., Main Outcome Measures: Audiologists screened participants for reported dizziness using a single question. Questions from the Dizziness Handicap Inventory were used to assess the impacts of dizziness/vertigo. Hearing impairment was determined as the pure-tone average of audiometric hearing thresholds at 500, 1000, 2000 and 4000 Hz (PTA(0.5-4 KHz)), defining any hearing loss as PTA(0.5-4 KHz) >25 dB HL. Presence of tinnitus was assessed by a positive response to a single question. Quality of life was measured using the Short Form 36-item Health Survey (SF-36). Each SF-36 dimension was scored from 0 (worst possible health state) to 100 (best possible health state)., Results: Prevalences of dizziness/vertigo, vestibular vertigo and non-vestibular vertigo were 36.2%, 10.0% and 14.2%, respectively. Of the dizziness/vertigo reports, 27.7% and 39.3%, respectively, were attributed to vestibular and non-vestibular vertigo. Tinnitus was associated with dizziness, odds ratio, OR, 1.99 (95% confidence interval, CI, 1.68-2.35). However, hearing loss was not associated with dizziness/vertigo. Participants reporting dizziness/vertigo had lower quality of life scores (P < 0.0001). Participants reporting vestibular vertigo were more likely than those with non-vestibular vertigo to report higher DHI scale scores or a greater handicap., Conclusion: Our findings highlight the burden imposed by dizziness, indicating dizziness/vertigo are important public health care issues.
- Published
- 2009
- Full Text
- View/download PDF
125. Depressive symptoms in older adults with hearing impairments: the Blue Mountains Study.
- Author
-
Gopinath B, Wang JJ, Schneider J, Burlutsky G, Snowdon J, McMahon CM, Leeder SR, and Mitchell P
- Subjects
- Aged, Audiometry, Pure-Tone, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, New South Wales epidemiology, Prospective Studies, Psychiatric Status Rating Scales, Risk Factors, Sex Factors, Depression epidemiology, Depression etiology, Hearing Loss complications, Hearing Loss epidemiology
- Published
- 2009
- Full Text
- View/download PDF
126. Relationship of Type 2 diabetes to the prevalence, incidence and progression of age-related hearing loss.
- Author
-
Mitchell P, Gopinath B, McMahon CM, Rochtchina E, Wang JJ, Boyages SC, and Leeder SR
- Subjects
- Age Factors, Aged, Aged, 80 and over, Australia epidemiology, Diabetes Mellitus, Type 2 complications, Disease Progression, Epidemiologic Methods, Female, Humans, Male, Middle Aged, Presbycusis complications, Diabetes Mellitus, Type 2 epidemiology, Presbycusis epidemiology
- Abstract
Aims: Type 2 diabetes and associated microvascular abnormalities are postulated to affect hearing. Our study reports on the relationship between Type 2 diabetes and the prevalence, 5-year incidence and progression of hearing impairment in a representative, older, Australian population., Methods: The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss conducted in a defined suburban area, west of Sydney. Hearing loss was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0 and 4.0 kHz > 25 decibels hearing level (dB HL) in the better ear (bilateral hearing loss). Type 2 diabetes was defined from reported physician-diagnosed diabetes or fasting blood glucose > or = 7.0 mmol/l., Results: Age-related hearing loss was present in 50.0% of diabetic participants (n = 210) compared with 38.2% of non-diabetic participants (n = 1648), odds ratio (OR) 1.55 [95% confidence interval (CI) 1.11-2.17], after adjusting for multiple risk factors. A relationship of diabetes duration with hearing loss was also demonstrated. After 5 years, incident hearing loss occurred in 18.7% of participants with, and 18.0% of those without diabetes, adjusted OR 1.01 (CI 0.54-1.91). Progression of existing hearing loss (> 5 dB HL), however, was significantly greater in participants with newly diagnosed diabetes (69.6%) than in those without diabetes (47.8%) over this period, adjusted OR 2.71 (CI 1.07-6.86)., Conclusions: Type 2 diabetes was associated with prevalent, but not incident hearing loss in this older population. Accelerated hearing loss progression over 5 years was more than doubled in persons newly diagnosed with diabetes. These data explore further reported links between Type 2 diabetes and age-related hearing loss.
- Published
- 2009
- Full Text
- View/download PDF
127. Naturally occurring dominant resistance mutations to hepatitis C virus protease and polymerase inhibitors in treatment-naïve patients.
- Author
-
Kuntzen T, Timm J, Berical A, Lennon N, Berlin AM, Young SK, Lee B, Heckerman D, Carlson J, Reyor LL, Kleyman M, McMahon CM, Birch C, Schulze Zur Wiesch J, Ledlie T, Koehrsen M, Kodira C, Roberts AD, Lauer GM, Rosen HR, Bihl F, Cerny A, Spengler U, Liu Z, Kim AY, Xing Y, Schneidewind A, Madey MA, Fleckenstein JF, Park VM, Galagan JE, Nusbaum C, Walker BD, Lake-Bakaar GV, Daar ES, Jacobson IM, Gomperts ED, Edlin BR, Donfield SM, Chung RT, Talal AH, Marion T, Birren BW, Henn MR, and Allen TM
- Subjects
- Antiviral Agents pharmacology, Carbamates pharmacology, Carbamates therapeutic use, Cohort Studies, Female, Genetic Testing, Hepacivirus genetics, Hepacivirus pathogenicity, Hepatitis C blood, Hepatitis C virology, Humans, Macrocyclic Compounds pharmacology, Macrocyclic Compounds therapeutic use, Male, Oligopeptides pharmacology, Oligopeptides therapeutic use, Phenylthiourea analogs & derivatives, Phenylthiourea pharmacology, Phenylthiourea therapeutic use, Phylogeny, Proline analogs & derivatives, Proline pharmacology, Proline therapeutic use, Quinolines pharmacology, Quinolines therapeutic use, Thiazoles pharmacology, Thiazoles therapeutic use, Viral Load, Viral Nonstructural Proteins antagonists & inhibitors, Antiviral Agents therapeutic use, Drug Resistance, Viral genetics, Hepacivirus enzymology, Hepatitis C drug therapy, Mutation genetics, Protease Inhibitors therapeutic use
- Abstract
Unlabelled: Resistance mutations to hepatitis C virus (HCV) nonstructural protein 3 (NS3) protease inhibitors in <1% of the viral quasispecies may still allow >1000-fold viral load reductions upon treatment, consistent with their reported reduced replicative fitness in vitro. Recently, however, an R155K protease mutation was reported as the dominant quasispecies in a treatment-naïve individual, raising concerns about possible full drug resistance. To investigate the prevalence of dominant resistance mutations against specifically targeted antiviral therapy for HCV (STAT-C) in the population, we analyzed HCV genome sequences from 507 treatment-naïve patients infected with HCV genotype 1 from the United States, Germany, and Switzerland. Phylogenetic sequence analysis and viral load data were used to identify the possible spread of replication-competent, drug-resistant viral strains in the population and to infer the consequences of these mutations upon viral replication in vivo. Mutations described to confer resistance to the protease inhibitors Telaprevir, BILN2061, ITMN-191, SCH6 and Boceprevir; the NS5B polymerase inhibitor AG-021541; and to the NS4A antagonist ACH-806 were observed mostly as sporadic, unrelated cases, at frequencies between 0.3% and 2.8% in the population, including two patients with possible multidrug resistance. Collectively, however, 8.6% of the patients infected with genotype 1a and 1.4% of those infected with genotype 1b carried at least one dominant resistance mutation. Viral loads were high in the majority of these patients, suggesting that drug-resistant viral strains might achieve replication levels comparable to nonresistant viruses in vivo., Conclusion: Naturally occurring dominant STAT-C resistance mutations are common in treatment-naïve patients infected with HCV genotype 1. Their influence on treatment outcome should further be characterized to evaluate possible benefits of drug resistance testing for individual tailoring of drug combinations when treatment options are limited due to previous nonresponse to peginterferon and ribavirin.
- Published
- 2008
- Full Text
- View/download PDF
128. Atorvastatin does not exhibit antiviral activity against HCV at conventional doses: a pilot clinical trial.
- Author
-
O'Leary JG, Chan JL, McMahon CM, and Chung RT
- Subjects
- Adult, Aged, Atorvastatin, Female, Heptanoic Acids pharmacology, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors pharmacology, Male, Middle Aged, Pilot Projects, Pyrroles pharmacology, Hepacivirus drug effects, Hepatitis C, Chronic drug therapy, Heptanoic Acids therapeutic use, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Pyrroles therapeutic use, Virus Replication drug effects
- Abstract
Cholesterol biosynthesis is an integral part of HCV RNA replication. Not only does HCV RNA replicate on lipid rafts, but it also requires cholesterol intermediates to replicate. In addition, it has been shown in vitro that several HMG-CoA reductase inhibitors can decrease HCV RNA replication by > or = 1 log. Therefore, we designed a clinical trial to evaluate the effect of atorvastatin on HCV RNA levels. In this prospective clinical trial, where patients served as their own control, 10 HCV-infected patients who required treatment for high cholesterol were given 20 mg atorvastatin per day. Although serum cholesterol and LDL predictably decreased significantly, there was no statistically significant change in week 4 and week 12 HCV RNA levels compared to pretreatment HCV RNA levels by the paired Student t test. It is unclear whether the addition of an HMG-CoA reductase inhibitor to interferon or a more potent inhibitor of cholesterol biosynthesis may be required to inhibit HCV RNA replication in vivo. In conclusion, atorvastatin, and likely all HMG-CoA reductase inhibitors, does not inhibit HCV RNA replication in vivo at conventional doses.
- Published
- 2007
- Full Text
- View/download PDF
129. K(+) currents produce P(1) in the RW CAP: evidence from DC current bias, K(+) channel blockade and recordings from cochlea and brainstem.
- Author
-
Brown DJ, McMahon CM, and Patuzzi RB
- Subjects
- 4-Aminopyridine pharmacology, Animals, Cochlea physiology, Cochlear Nerve physiology, Electric Stimulation, Electrophysiology, Female, Guinea Pigs, Male, Potassium Channels, Voltage-Gated drug effects, Scala Tympani, Tetraethylammonium pharmacology, Action Potentials physiology, Brain Stem physiology, Cochlear Nucleus physiology, Potassium Channel Blockers pharmacology, Potassium Channels, Voltage-Gated physiology, Round Window, Ear physiology
- Abstract
Tone-burst-evoked compound action potentials (CAP) from the guinea pig round window (RW) are altered by DC current injection through the RW. The CAP waveform consists of a series of interleaved negative and positive peaks (N(1), P(1), N(2), P(2) etc.) of decreasing amplitude. During positive DC current injection (around +50 microA) the positive peaks are depressed substantially and there is an overall negative baseline shift of the waveform following the N(1). Negative current injection (around -50 microA) increased the positive peaks, in particular P(1), and produced an overall positive baseline shift following the N(1) peak. Results support our hypothesis that the first and dominant N(1) peak in the RW CAP is due to depolarising Na(+) currents into the primary afferent dendrites and axons within the cochlea, and that the P(1) potential is largely due to the exit of the hyperpolarising K(+) currents in the same cells. We have reached this conclusion on the basis of the sign and latency of the N(1) and P(1) components at the RW, beneath the myelin layers around the spiral ganglion cells, at the internal auditory meatus (IAM) within the brain case, and on the basis of the differential susceptibility of the various peaks to perfusion of lidocaine in the cochlear nucleus, sectioning of the cochlear nerve at the IAM, application of the K(+) channel blockers 4-amino-pyridine and tetraethylammonium within the cochlea, and DC current biasing at the RW.
- Published
- 2004
- Full Text
- View/download PDF
130. Transient focal cooling at the round window and cochlear nucleus shows round window CAP originates from cochlear neurones alone.
- Author
-
McMahon CM, Brown DJ, and Patuzzi RB
- Subjects
- Acoustic Stimulation, Animals, Cochlea physiology, Cochlear Nerve physiology, Electrophysiology, Guinea Pigs, Action Potentials physiology, Cochlear Nucleus physiology, Cold Temperature, Round Window, Ear physiology
- Abstract
We have measured the compound action potential (CAP) evoked by very brief high-frequency tone-bursts (20 kHz, 1/4 ms) at the round window (RW) and at the surface of the cochlear nucleus (CN) in guinea pigs before, during and after a localised chilling of either the cochlea or CN, with a non-toxic 'freeze spray'. CN chilling almost abolished the negative-going component of the CAP measured in the CN (generated by the CN and here called the cochlear nucleus response or CNR), leaving a positive-going localised response from the cochlear neurones as they leave the internal auditory meatus. Within 3 min, the CNR recovered to control values. During that time, the N(1) component of the RW CAP was slightly increased and the P(1) was larger, even though the CNR was abolished, indicating that the P(1) was not due to electrotonic spread of current from the CN. The N(2) and successive peaks at the RW were also abolished, but returned after 30 s. When the cochlea was chilled, the RW CAP was initially reduced in amplitude, presumably due to a drop in the number of cochlear neurones spiking in response to sound, but recovered within 3 min to be larger than the control waveform, with a more prominent N(1) peak which was delayed slightly, making the CAP more monophasic. At the same time, the CNR was smaller, presumably due to fewer cochlear neurones responding, but overall the CN CAP was altered little in waveshape. These experiments indicate that that RW CAP is generated almost solely by cochlear neurones. We also suggest that some of the changes in the RW CAP during the chills were due to changes in the firing of the lateral olivo-cochlear system of efferent neurons.
- Published
- 2004
- Full Text
- View/download PDF
131. Determinants of the spectrum of the neural electrical activity at the round window: transmitter release and neural depolarisation.
- Author
-
Patuzzi RB, Brown DJ, McMahon CM, and Halliday AF
- Subjects
- Animals, Cochlea physiology, Cochlear Nucleus physiology, Cold Temperature, Electric Stimulation, Electromyography, Electrophysiology, Female, Guinea Pigs, Male, Neck Muscles physiology, Tinnitus diagnosis, Tinnitus physiopathology, Action Potentials physiology, Cochlear Nerve physiology, Round Window, Ear physiology
- Abstract
In this paper we summarise the changes we have observed in the electrical activity at the round window (RW) of guinea pigs during transient cooling of the RW or cochlear nucleus (CN), transient hypoxia, low frequency acoustic biasing, ablation of the CN, and DC current injection into the basal cochlear turn. We have measured the compound action potential (CAP), the spectrum of the average CAP waveform (SAW) evoked by brief tone-bursts, and the spectrum of the neural noise (SNN). We discuss how the changes we have observed can be understood in terms of changes in transmitter release from inner hair cells (that controls stochastic neural firing), or changes in the membrane potential of the primary afferent neurones (that controls the neural firing waveshape and the spectral content of the SAW and SNN). We note that changes in sound intensity produce a simple increase in the stochastic release of transmitter from inner hair cells, without much change in the waveform of the neural response, but manipulations of the auditory brainstem, cooling and current injection all appear to alter neural firing rate and the neural response waveform, producing a baseline shift in the CAP and changes in 1000 Hz peak and low frequency content of the SAW and SNN. We also discuss the use of the CAP, SAW and SNN as an indication of cochlear and auditory brainstem neural activity.
- Published
- 2004
- Full Text
- View/download PDF
132. The origin of the 900 Hz spectral peak in spontaneous and sound-evoked round-window electrical activity.
- Author
-
McMahon CM and Patuzzi RB
- Subjects
- Action Potentials, Anesthetics, Local pharmacology, Animals, Cerebellum physiology, Cochlear Nerve drug effects, Cochlear Nerve physiology, Cochlear Nucleus physiology, Electrophysiology, Guinea Pigs, Hair Cells, Auditory physiology, Lidocaine pharmacology, Oscillometry, Round Window, Ear drug effects, Tetrodotoxin pharmacology, Round Window, Ear physiology, Sound
- Abstract
We have monitored the spectrum of the (spontaneous) neural noise at the round window (RW) and on the surface of the antero-ventral cochlear nucleus (CN) and the dorsal CN (DCN) of anaesthetised guinea pigs. We have also obtained the average gross extracellular waveform evoked by 20 kHz tone-bursts (0.25 ms and 25 ms) at each of these recording sites, and calculated the spectrum of the average waveforms (SAW). With these tone-bursts, only a small population of neurones in the extreme basal turn of the cochlea near the RW electrode responds, presumably with only a single action potential for each 0.25 ms tone-burst. The RW waveforms recorded between 20 dB and 60 dB SPL were very similar, and are therefore presumably a simple estimate of the shape of the contribution of the firing of a single neurone to the gross RW signal (the unitary potential or UP). In normal animals, the SNN and the SAW were remarkably similar, with peaks at 900 Hz and at 2400 Hz, suggesting that they are not due to neural synchronisation (as suggested previously by others), but are due to an oscillatory waveform produced by each single fibre action potential. Abolition of all spike activity by RW tetrodotoxin left a waveform with only a summating potential and a dendritic potential, and no 900 Hz peak in the SAW or SNN, indicating that the spectral peak is due to neural spiking only. Abolition of the CN contribution to the RW waveforms by CN application of lignocaine or sectioning of the cochlear nerve at the internal meatus (by focal aspiration of the DCN and underlying cochlear nerve) showed that the 900 Hz peak was not simply due to the addition of a delayed and inverted CN contribution: mathematical modelling shows that this would produce a broad spectral peak at about 1200 Hz. Moreover, the 900 Hz spectral peak remains after complete abolition of the CN contribution, although reduced in amplitude. This residual 900 Hz peak can be traced to an oscillation in the gross waveform due to the presence of two peaks (P(1)* and N(2)*) which follow the intact N(1) peak. The P(1)* and N(2)* peaks were present at the RW, but not at the cochlear nerve as it exits the internal meatus, suggesting that they were not due to double-spiking of some of the neurones, but were probably due to a sub-threshold electrical resonance in the peripheral dendrites. We have successfully modelled the production of the SNN and the compound action potential and SAW in response to 0.25 ms and 25 ms tone-bursts at 20 kHz by including only a damped 900 Hz resonance in the UP, without refractory effects, preferred intervals or synchronisation in the timing of neural spike generation. Such resonances in other neurones are known to be due to the activation kinetics of the voltage-controlled sodium (Na(+)) channels of these neurones. The presence of such sub-threshold oscillations probably indicates that the peripheral dendrites are devoid of stabilising potassium (K(+)) channels. We also discuss the role of this membrane resonance in generating burst-firing of the cochlear nerve (as with salicylate) and the role of such burst-firing in generating tinnitus.
- Published
- 2002
- Full Text
- View/download PDF
133. The effect of culture growth phase on induction of the heat shock response in Yersinia enterocolitica and Listeria monocytogenes.
- Author
-
McMahon CM, Byrne CM, Sheridan JJ, McDowell DA, Blair IS, and Hegarty T
- Subjects
- Colony Count, Microbial, Culture Media, Hot Temperature, Listeria monocytogenes growth & development, Yersinia enterocolitica growth & development, Heat-Shock Response, Listeria monocytogenes physiology, Yersinia enterocolitica physiology
- Abstract
The effect of culture growth phase on induction of the heat shock response in Yersinia enterocolitica and Listeria monocytogenes, was examined. Exponential or stationary preconditioned cultures were heat shocked and survivor numbers estimated using selective and overlay/resuscitation recovery techniques. The results indicate that prior heat shock induced increased heat resistance in both micro-organisms to higher heat treatments. Heat-shocked cells of each micro-organism were able to survive much longer than non-heat-shocked cells when heated at 55 degrees C. The size of the change in heat resistance between heat-shocked and non-heat-shocked cells was greatest for exponential cultures (X:X). Results indicate that the overall relative thermal resistance of each pathogen was dependent on cell growth phase. Stationary cultures (S:S) were significantly (P < 0.01) more thermotolerant than exponential cultures (X:X) under identical processing conditions. Under most conditions, the use of an overlay/resuscitation recovery medium resulted in higher D-values (P < 0.05) compared with a selective recovery medium.
- Published
- 2000
- Full Text
- View/download PDF
134. Thermal inactivation of Listeria monocytogenes and Yersinia enterocolitica in minced beef under laboratory conditions and in sous-vide prepared minced and solid beef cooked in a commercial retort.
- Author
-
Bolton DJ, McMahon CM, Doherty AM, Sheridan JJ, McDowell DA, Blair IS, and Harrington D
- Subjects
- Animals, Cattle, Heating, Hydrogen-Ion Concentration, Listeria monocytogenes growth & development, Meat microbiology, Yersinia enterocolitica growth & development
- Abstract
D-values were obtained for Listeria monocytogenes and Yersinia enterocolitica at 50, 55 and 60 degrees C in vacuum-packed minced beef samples heated in a laboratory water-bath. The experiment was repeated using vacutainers, which allowed heating of the beef to the desired temperature before inoculation. D-values of between 0.15 and 36.1 min were obtained for L. monocytogenes. Pre-heating the beef samples significantly affected (P < 0.05) the D60 value only. D-values for Y. enterocolitica ranged from 0.55 to 21.2 min and all the D-values were significantly different (P < 0.05) after pre-heating. In general, the D-values obtained for core inoculated solid beef samples were significantly higher (P < 0.05) than those generated in minced beef when heated in a Barriquand Steriflow commercial retort.
- Published
- 2000
- Full Text
- View/download PDF
135. Synergistic effect of heat and sodium lactate on the thermal resistance of Yersinia enterocolitica and Listeria monocytogenes in minced beef.
- Author
-
McMahon CM, Doherty AM, Sheridan JJ, Blair IS, McDowell DA, and Hegarty T
- Subjects
- Listeria monocytogenes drug effects, Yersinia enterocolitica drug effects, Hot Temperature, Listeria monocytogenes physiology, Meat microbiology, Sodium Lactate pharmacology, Yersinia enterocolitica physiology
- Abstract
The effect of sodium lactate (NaL) (0, 2.4 or 4.8%), in heating and recovery media, on Yersinia enterocolitica and Listeria monocytogenes numbers recovered from minced beef heated at 55 degrees C, was examined. Survivors were enumerated on selective media at pH 5.7/7.4 (Y. enterocolitica) or pH 5.7/7.2 (L. monocytogenes). Recovery of the organisms depended on the pH and NaL levels in the recovery medium. The heat resistance of Y. enterocolitica (P < 0.001) and L. monocytogenes (P < 0.01) decreased as the concentration of NaL in the minced beef increased from 0 to 2.4% or 4.8%. The thermal destruction of pathogens in foods processed using mild temperatures may be enhanced by the addition of 2.4% NaL.
- Published
- 1999
- Full Text
- View/download PDF
136. Teaching selected microcomputer skills to retarded students via picture prompts.
- Author
-
Frank AR, Wacker DP, Berg WK, and McMahon CM
- Subjects
- Adolescent, Child, Female, Generalization, Psychological, Humans, Male, Teaching methods, Computers, Cues, Intellectual Disability rehabilitation, Microcomputers
- Abstract
Five retarded students were taught to use picture prompts to help them access and terminate a microcomputer program. Training was provided within a multiple baseline format. Posttesting (picture prompts without feedback), and a return to baseline were later conducted for both the training program and an untrained (generalization) program. The results indicate that the program was successful in teaching the microcomputer skills to the students. In addition, all students were able to maintain their skills over a 7-day interval in which they did not have access to the microcomputer.
- Published
- 1985
- Full Text
- View/download PDF
137. Evaluation of the effectiveness and efficiency of two stimulus prompt strategies with severely handicapped students.
- Author
-
Steege MW, Wacker DP, and McMahon CM
- Subjects
- Adolescent, Child, Follow-Up Studies, Humans, Intelligence, Activities of Daily Living, Behavior Therapy, Education of Intellectually Disabled
- Abstract
In this study we compared the effectiveness and efficiency of two treatment packages that used stimulus prompt sequences and task analyses for teaching community living skills to severely handicapped students. Four severely and multiply handicapped students were trained to perform four tasks: (a) making toast, (b) making popcorn, (c) operating a clothes dryer, and (d) operating a washing machine. Following baseline, each student was exposed to two types of training procedures, each involving a task analysis of the target behavior. Training Procedure 1 (Traditional) utilized a least-to-most restrictive prompt sequence. Training Procedure 2 (Prescriptive) utilized ongoing behavioral assessment data to identify discriminative stimuli. The assessment data were used to prescribe instructional prompts across successive training trials. Performance on the tasks was evaluated within a combination multiple baseline (across subjects) and probe (across tasks) design. Training conditions were counterbalanced across subjects and tasks. Results indicated that both training procedures were equally effective in increasing independent task acquisition for subjects on all tasks; however, the prescriptive procedure was the more efficient procedure.
- Published
- 1987
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.