Measuring taste impairment in epidemiologic studies: the Beaver Dam Offspring Study.

Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.

The use of hearing protection devices by older adults during recreational noise exposure.

A population-based study to assess the use of hearing protection devices by older adults during noisy recreational activities was performed. The population-based Epidemiology of Hearing Loss Study was designed to measure the prevalence of hearing loss in adults residing in Beaver Dam, Wisconsin. The use of hearing protection devices during noisy recreational activities was assessed by performing three examinations over a period of 10 years (1993-1995, no. of participants (n)=3753, aged 48-92 years; 1998-2000, n=2800, aged 53-97 years; 2003-2005, n=2395, aged 58-100 years). The recreational activities included hunting, target shooting, woodworking/carpentry, metalworking, driving loud recreational vehicles, and performing yard work using either power tools or a chain saw. The prevalence of using hearing protection devices during any of these activities increased with time (9.5%, 15.0%, and 19.9% at baseline, 5 years, and 10 years, respectively). However, the use of hearing protection devices remained low for most activities. Those under the age of 65 were twice as likely to use hearing protection devices during noisy activities than were older adults. Men, those with a hearing handicap, and those with significant tinnitus were more likely to use hearing protection devices. Smokers and the less educated were less likely to use hearing protection devices. The results demonstrated that many adults expose themselves to potentially damaging recreational noise, leaving them at risk for hearing loss.

Hearing sensitivity in adults screened for selected risk factors.

As a means of partially distinguishing age effects and other risk factors in presbyacusis, hearing thresholds for 56- to 65-year-old participants screened for exclusion of selected risk factors were compared with thresholds for 48- to 55-year-old participants without the same risk factors. Hearing thresholds for both age groups were also compared with age-appropriate International Standards Organization (ISO) norms. Even after screening participants for exclusion of selected risk factors, differences in hearing sensitivity remained across age groups. Across the male and female groups, thresholds were generally better (lower) for 48 to 55 year olds than for 56 to 65 year olds. ISO norms generally underestimated the degree of hearing loss for participants of comparable age in the present study. The underestimation was small at lower test frequencies, was generally greater for men, and was largest at test frequencies above 2000 Hz.

Association of leisure-time noise exposure and hearing loss.

The purpose of this study was to investigate the association of noisy leisure activities with hearing loss. Participants (n=3571) were examined in a population-based study of age-related hearing loss conducted in Beaver Dam, Wisconsin. Hearing thresholds were determined by audiometry. Hearing loss was defined as the pure-tone average of the frequencies 500, 1,000, 2,000, and 4,000 Hz greater than 25 dB HL in either ear. Information regarding exposure to leisure-time noise was obtained by interview. After adjusting for potential confounders, individuals who engaged in leisure activities with average sound levels greater than 90 dBA were significantly more likely to have a hearing loss than participants who did not engage in noisy leisure activities (OR=1.11, 95 per cent CI=1.01-1.22). Individuals who engaged in woodworking were 30 per cent more likely to have a hearing loss than those who had never done woodworking. There was a 6 per cent increased risk of hearing loss for each 5-year period of participation. Health care professionals should consider counseling their patients who engage in noisy leisure activities about the risk of noise-induced hearing loss.

Diphtheria and hearing loss.

OBJECTIVE: To determine if infectious diseases usually experienced in childhood have an effect on hearing ability later in life. METHODS: The Epidemiology of Hearing Loss Study (N = 3,753) is a population-based study of age-related hearing loss in adults aged 48 to 92 years in Beaver Dam, Wisconsin. As part of this study, infectious disease history was obtained and hearing was tested using pure-tone audiometry. Hearing loss was defined as a pure-tone average of thresholds at 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz greater than 25 decibels hearing level in either ear. RESULTS: After adjusting for confounders, only a history of diphtheria (n = 37) was associated with hearing loss (odds ratio [OR] 2.79; 95% confidence interval [CI] 1.05, 7.36). There was no relationship between hearing loss and history of chickenpox, measles, mumps, pertussis, polio, rheumatic fever, rubella, or scarlet fever. Only two participants with a history of diphtheria and hearing loss reported having a hearing loss before age 20. CONCLUSIONS: Diphtheria in childhood may have consequences for hearing that do not become apparent until later in life. A possible biological mechanism for a diphtheria effect on hearing ability exists: The toxin produced by the Corynebacterium diphtheriae bacteria can cause damage to cranial nerves and therefore may affect the auditory neural pathway. These data may have important implications for areas facing a resurgence of diphtheria cases.

Moderate alcohol consumption and hearing loss: a protective effect.

OBJECTIVE: To determine if moderate alcohol consumption is associated inversely with hearing loss in a large population based study of older adults. DESIGN: Cross-sectional population based cohort study. Data are from the 1993-1995 examinations for the population based Epidemiology of Hearing Loss Study (EHLS) (n = 3571) and the Beaver Dam Eye Study (BDES) (n = 3722). SETTING: Midwestern community of Beaver Dam, Wisconsin. PARTICIPANTS: Residents of Beaver Dam aged 43 to 84 in 1987-1988 were eligible for the BDES (examinations in 1988-1990 and 1993-1995). During 1993-1995, this same cohort was eligible to participate in the baseline examination for the EHLS. MEASUREMENTS: Hearing thresholds were measured by pure tone air and bone conduction audiometry (250-8000 Hz.). History of alcohol consumption in the past year, heavy drinking (ever), medical history, occupation, noise exposure, and other lifestyle factors were ascertained by a questionnaire that was administered as an interview. RESULTS: In multiple logistic regression analyses controlling for potential confounders, moderate alcohol consumption (>140 grams/week) was inversely associated with hearing loss (PTA(.5,1,2,4 > 25 dB HL); odds ratio [OR] = .71, 95% confidence interval [CI] = .52, .97; where PTA is pure tone average). A similar association was found for moderate hearing loss (PTA(.5,1,2,4 > 40 dB HL); OR = 0.49, 95% CI = 0.32, 0.74). Alcohol consumption was associated inversely with the odds of having a low frequency hearing loss (OR = 0.61) or a high frequency hearing loss (OR = 0.60). These findings did not vary significantly by age or gender. There was an increase in the odds of having a high frequency hearing loss (OR = 1.35, 95% CI = 1.04, 1.75), in those with a history of heavy drinking (> or =4 drinks/day). Including cardiovascular disease or its related factors did not significantly attenuate the protective effect. CONCLUSIONS: There is evidence of a modest protective association of alcohol consumption and hearing loss in these cross-sectional data. This finding is in agreement with a small body of evidence suggesting that hearing loss is not an inevitable component of the aging process.

Recreational firearm use and hearing loss.

OBJECTIVE: To assess the relation between recreational firearm use and high-frequency hearing loss in a population of older adults. DESIGN: Cross-sectional, population-based cohort study. SETTING: The midwestern community of Beaver Dam, Wis. PARTICIPANTS: A population-based sample of 3753 participants (83% of those eligible), aged 48 to 92 years, participated in the baseline phase of the Epidemiology of Hearing Loss Study. INTERVENTION: None. MAIN OUTCOME MEASURES: Lifetime and past year self-reported firearm use during target shooting and hunting were assessed by interview. Hearing thresholds were measured by pure-tone audiometry. RESULTS: After age and other factors were adjusted for, men (n = 1538) who had ever regularly engaged in target shooting (odds ratio, 1.57; 95% confidence interval, 1.12-2.19) or who had done so in the past year (odds ratio, 2.00; 95% confidence interval, 1.15-3.46) were more likely to have a marked high-frequency hearing loss than those who had not. Risk of having a marked high-frequency hearing loss increased 7% for every 5 years the men had hunted (odds ratio, 1.07; 95% confidence interval, 1.03-1.12). Thirty-eight percent of the target shooters and 95% of the hunters reported never wearing hearing protection while shooting in the past year. CONCLUSIONS: These results indicate that use of recreational firearms is associated with marked high-frequency hearing loss in men. There is a need for further education of users of recreational firearms regarding the risk of hearing impairment associated with firearm use and the availability and importance of appropriate hearing protection.

Self-reported hearing handicap and audiometric measures in older adults.

As part of an epidemiologic study of hearing disorders in older adults, audiometric thresholds (250-20,000 Hz), word recognition performance (Northwestern University Auditory Test No. 6 word lists in quiet and in competing message), and Hearing Handicap Inventory for the Elderly-Screening (HHIE-S) scores were evaluated for 3178 adults ranging in age from 48 to 92 years. Overall, higher HHIE-S scores were more prevalent for older age groups and for greater degrees of hearing loss. After adjusting for the degree of hearing loss, the probability of reporting a hearing disability (handicap) decreased with age.

Aging and middle ear resonance.

Tympanograms for probes ranging from 250 through 2000 Hz were evaluated for 467 older adults. Measures of middle ear resonant frequency were compared across age groups (48-59, 60-69, 70-79, 80-90 years) and gender. No significant age group trends were observed for middle ear resonant frequency. Middle ear resonant frequencies were significantly higher for older women than for older men, but the differences were small.

Prevalence of hearing loss in older adults in Beaver Dam, Wisconsin. The Epidemiology of Hearing Loss Study.

There are no recent population-based data on the prevalence of hearing loss in older adults using standard audiometric testing. The population-based Epidemiology of Hearing Loss Study was designed to measure the prevalence of hearing loss in adults aged 48-92 years, residing in Beaver Dam, Wisconsin. Hearing thresholds were measured with standardized protocols using pure-tone air- and bone-conduction audiometry in sound-treated booths. The examination also included an otoscopic evaluation, screening tympanogram, and a questionnaire on hearing-related medical history, noise exposure, other potential risk factors, and self-perceived hearing handicap. Of the 4,541 eligible people, 3,753 (82.6%) participated in the hearing study (1993-1995). The average age of participants was 65.8 years, and 57.7% were women. The prevalence of hearing loss was 45.9%. The odds of hearing loss increased with age (odds ratio (OR) = 1.88 for 5 years, 95% confidence interval (CI) 1.80-1.97) and were greater for men than women (OR = 4.42, 95% CI 3.73-5.24). The male excess of hearing loss remained statistically significant after adjusting for age, education, noise exposure, and occupation (OR = 3.65). These results demonstrate that hearing loss is a very common problem affecting older adults. Epidemiologic studies are needed to understand the genetic, environmental, and sex-related determinants of age-related hearing loss and to identify potential intervention strategies.

Aging and high-frequency hearing sensitivity.

As part of a large population-based study of hearing and aging, ultra high-frequency (9-20 kHz) threshold measures are reported for 3396 participants grouped by age (48-59 years, n = 1233; 60-69 years, n = 1031; 70-79 years, n = 851; 80-92 years, n = 281). Ultra high-frequency (UHF) thresholds were higher for older age groups. The percentage of unmeasurable responses also was significantly higher for older age groups and for higher frequencies in the UHF range. The observed age effects remained significant after adjusting for gender. In general, UHF thresholds were significantly higher for men compared to those for women at lower UHF frequencies (9-14 kHz), but were not significantly different by gender for the highest UHF frequencies (16, 18, and 20 kHz). After accounting for hearing loss at traditional audiometric frequencies (250-8000 Hz), the age effect still remained; even for comparable degrees of sensorineural hearing loss, participants in older age groups evidenced higher UHF thresholds.

Accuracy of self-reported hearing loss.

The purpose of this study was to assess the accuracy, in older adults, of questions assessing hearing loss. Study participants (n=3,556), aged 48-92 years, were examined in a population-based study of age-related hearing loss in Beaver Dam, Wisconsin. Self-report data from the ten-question Hearing Handicap Inventory for the Elderly-screening Version (HHIE-S), and four additional questions were compared with hearing loss as measured by pure-tone air conduction audiometry. The single question, 'Do you feel you have a hearing loss?' was the most sensitive question (sensitivity=71 per cent); its overall and gender-specific prevalence estimates were within 3.2 per cent of prevalence measures derived audiometrically, although age-group specific estimates were not as accurate. Using an HHIE-S total score >8 resulted in low sensitivity (34 per cent) and inaccurate prevalence estimates. These results indicate that, for some applications, one simple question may be sufficient for prevalence surveys of hearing loss among older adults.

Low prevalence of hearing aid use among older adults with hearing loss: the Epidemiology of Hearing Loss Study.

OBJECTIVES: To measure the prevalence of hearing aid use among older adults with hearing loss and to identify factors associated with those currently using hearing aids. DESIGN: Population-based cohort study. SETTING: The south-central Wisconsin community of Beaver Dam. PARTICIPANTS: A total of 1629 adults, aged 48 to 92 years, who have hearing loss and are participating in the Epidemiology of Hearing Loss Study and the Beaver Dam Eye Study. MEASUREMENTS: A hearing-related risk factor and medical history questionnaire, the Hearing Handicap Inventory for the Elderly (screening version), screening tympanometry, pure-tone air- and bone-conduction audiometry, and word recognition tests were administered by trained examiners using standard protocols. RESULTS: The prevalence of current hearing aid use among those with a hearing loss (pure-tone average > 25 decibels hearing level over 500, 1000, 2000, and 4000 Hertz, worse ear) was 14.6%. The prevalence was 55% in a subset of the most severely affected participants. In univariate analyses, current hearing aid use was associated with age, severity of loss, word recognition scores, self-reported hearing loss, self-perceived hearing handicap, and history of noise exposure. Factors associated with current hearing aid use in multivariate logistic regression models were age, severity of loss, education, word recognition scores, Hearing Handicap Inventory for the Elderly (screening version) score, and self-report of a hearing loss. CONCLUSIONS: Few older adults with hearing loss are currently utilizing hearing aids. Improved screening and intervention programs to identify older adults who would benefit from amplification are needed to improve hearing-related quality of life for this large segment of the population.

Aging and word recognition in competing message.

As part of an epidemiologic study of hearing disorders in older adults, word recognition performance (NU-6 word lists in quiet and in competing message) was evaluated for 3189 adults grouped by age (48-59 years, n = 1176; 60-69 years, n = 979; 70-79 years, n = 794; 80-92 years, n = 240). Overall, scores for all measures were worse for older age groups and worse for men than for women. Word recognition scores in competing message were poorer than word recognition scores in quiet for all subjects and age groups. Further, differences in scores across age groups and gender were greater for the word recognition test in competing message than for the word recognition test in quiet. Although degree of hearing loss accounted for the largest portion of variation in word recognition scores, the observed age and gender differences remained significant after adjusting for the degree of sensorineural hearing loss.

Cigarette smoking and hearing loss: the epidemiology of hearing loss study.

CONTEXT: Clinical studies have suggested that cigarette smoking may be associated with hearing loss, a common condition affecting older adults. OBJECTIVE: To evaluate the association between smoking and hearing loss. DESIGN: Population-based, cross-sectional study. SETTING: Community of Beaver Dam, Wis. PARTICIPANTS: Adults aged 48 to 92 years. Of 4541 eligible subjects, 3753 (83%) participated in the hearing study. MAIN OUTCOME MEASURES: The examination included otoscopy, screening tympanometry, and pure-tone air-conduction and bone-conduction audiometry. Smoking history was ascertained by self-report. Hearing loss was defined as a pure-tone average (0.5, 1, 2, and 4 kHz) greater than 25-dB hearing level in the worse ear. RESULTS: After adjusting for other factors, current smokers were 1.69 times as likely to have a hearing loss as nonsmokers (95% confidence interval, 1.31-2.17). This relationship remained for those without a history of occupational noise exposure and in analyses excluding those with non-age-related hearing loss. There was weak evidence of a dose-response effect. Nonsmoking participants who lived with a smoker were more likely to have a hearing loss than those who were not exposed to a household member who smoked (odds ratio, 1.94; 95% confidence interval, 1.01-3.74). CONCLUSIONS: These data suggest that environmental exposures may play a role in age-related hearing loss. If longitudinal studies confirm these findings, modification of smoking habits may prevent or delay age-related declines in hearing sensitivity.

Interexaminer reliability of otoscopic signs and tympanometric measures for older adults.

To accurately classify hearing loss and otic disorders among older adults, examiners must be able to consistently assess otoscopic signs and perform middle-ear screening tympanograms. As part of a population-based study of hearing loss in Beaver Dam, Wisconsin, the interexaminer reliability of otoscopic examinations and screening tympanograms was evaluated using 45 replicate examinations. Data from 1941 participants 48 to 91 years of age were used to compare otoscopic and tympanometric results. Overall agreement for nine otoscopic signs ranged from 73 percent (vascularity) to 100 percent (drainage). There were small examiner differences in tympanometric measures of equivalent ear-canal volume (Vea) and tympanogram width. No significant differences were observed for peak compensated static acoustic admittance and tympanogram peak pressure. Our findings suggest that examiners can be trained to consistently and accurately assess otoscopic signs and obtain reliable tympanometric results.

Tympanometric measures in older adults.

Tympanometric measures were obtained in 1240 adults (2147 ears) ranging in age from 48 to 90 years. All subjects reported a negative history of otic disease, passed an otoscopic examination, and did not present a significant air-bone gap based on pure-tone audiometry. Relative to findings for younger adults, tympanometric measures for older adults in the present study showed greater variability, a slightly lower mean peak compensated static acoustic admittance (peak Ytm), and a significantly higher mean equivalent ear-canal volume (Vea). Across age in the present study, Vea tended to decrease with age and tympanogram width (TW) tended to increase with age. Relative to measures for females, males in the present study tended to have higher peak Ytm values, higher Vea values, and slightly lower TW values. Overall, our findings indicate a need to adopt criteria that account for age and gender effects in tympanometry protocols for older adults.

Psychoacoustic tuning curves and averaged electroencephalic responses in a patient with low-frequency sensory-neural hearing loss.

A 10-year-old girl whose bilateral, low-frequency, sensory-neural hearing loss had been noted three years earlier showed a drop in speech discrimination in her left ear with no corresponding decrease in pure-tone sensitivity. Psychoacoustic tuning curves and middle-component averaged electroencephalic responses to tone-pips suggested that damage to the left ear had become greater than indicated by the pure-tone audiogram, accounting for the drop in speech discrimination. This case suggests caution in inferring the magnitude of damage to the peripheral auditory system from tonal thresholds.