Sharon G. Curhan

Change in Prevalence of Hearing Loss in US Adolescents

CONTEXT Hearing loss is common and, in young persons, can compromise social development, communication skills, and educational achievement. OBJECTIVE To examine the current prevalence of hearing loss in US adolescents and determine whether it has changed over time. DESIGN Cross-sectional analyses of US representative demographic and audiometric data from the 1988 through 1994 and 2005 through 2006 time periods. SETTING The Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994, and NHANES 2005-2006. PARTICIPANTS NHANES III examined 2928 participants and NHANES 2005-2006 examined 1771 participants, aged 12 to 19 years. MAIN OUTCOME MEASURES We calculated the prevalence of hearing loss in participants aged 12 to 19 years after accounting for the complex survey design. Audiometrically determined hearing loss was categorized as either unilateral or bilateral for low frequency (0.5, 1, and 2 kHz) or high frequency (3, 4, 6, and 8 kHz), and as slight loss (> 15 to < 25 dB) or mild or greater loss (> or = 25 dB) according to hearing sensitivity in the worse ear. The prevalence of hearing loss from NHANES 2005-2006 was compared with the prevalence from NHANES III (1988-1994). We also examined the cross-sectional relations between several potential risk factors and hearing loss. Logistic regression was used to calculate multivariate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS The prevalence of any hearing loss increased significantly from 14.9% (95% CI, 13.0%-16.9%) in 1988-1994 to 19.5% (95% CI, 15.2%-23.8%) in 2005-2006 (P = .02). In 2005-2006, hearing loss was more commonly unilateral (prevalence, 14.0%; 95% CI, 10.4%-17.6%, vs 11.1%; 95% CI, 9.5%-12.8% in 1988-1994; P = .005) and involved the high frequencies (prevalence, 16.4%; 95% CI, 13.2%-19.7%, vs 12.8%; 95% CI, 11.1%-14.5% in 1988-1994; P = .02). Individuals from families below the federal poverty threshold (prevalence, 23.6%; 95% CI, 18.5%-28.7%) had significantly higher odds of hearing loss (multivariate adjusted OR, 1.60; 95% CI, 1.10-2.32) than those above the threshold (prevalence, 18.4%; 95% CI, 13.6%-23.2%). CONCLUSION The prevalence of hearing loss among a sample of US adolescents aged 12 to 19 years was greater in 2005-2006 compared with 1988-1994.

Heavy Metals Exposure and Hearing Loss in US Adolescents

INTRODUCTION Hearing loss is common and, in young persons, can compromise social development and educational achievement. Exposure to heavy metals has been proposed as an important risk factor for hearing loss. METHODS We evaluated the cross-sectional associations between blood lead, blood mercury, and urinary cadmium and arsenic levels and audiometrically determined hearing loss in participants aged 12 to 19 years in the 2005-2008 National Health and Nutrition Examination Survey after accounting for the complex survey design. There were 2535 individuals available for analysis of blood lead and mercury levels, 878 for urinary cadmium levels, and 875 for urinary arsenic levels. Multivariate logistic regression was used to calculate adjusted odds ratios (ORs) and 95% CIs. RESULTS A blood lead level greater than or equal to 2 μg/dL (to convert to micromoles per liter, multiply by 0.0483) compared with less than 1 μg/dL was associated with increased odds of high-frequency hearing loss (OR, 2.22; 95% CI, 1.39-3.56). Individuals in the highest quartile of urinary cadmium levels had significantly higher odds of low-frequency hearing loss than those in the lowest quartile (OR, 3.08; 95% CI, 1.02-9.25). There was no overall association between quartiles of blood mercury or urinary arsenic levels and hearing loss. CONCLUSION Blood lead levels well below the current recommended action level are associated with substantially increased odds of high-frequency hearing loss.

A prospective study of cardiovascular risk factors and incident hearing loss in men.

Hearing loss is the most common sensory disorder in the United States, affecting more than 36 million people. Cardiovascular risk factors have been associated with the risk of hearing loss in cross‐sectional studies, but prospective data are currently lacking.

Analgesic Use and the Risk of Hearing Loss in Men

BACKGROUND Hearing loss is a common sensory disorder, yet prospective data on potentially modifiable risk factors are limited. Regularly used analgesics, the most commonly used drugs in the US, may be ototoxic and contribute to hearing loss. METHODS We examined the independent association between self-reported professionally diagnosed hearing loss and regular use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and acetaminophen in 26,917 men aged 40-74 years at baseline in 1986. Study participants completed detailed questionnaires at baseline and every 2 years thereafter. Incident cases of new-onset hearing loss were defined as those diagnosed after 1986. Cox proportional hazards multivariate regression was used to adjust for potential confounding factors. RESULTS During 369,079 person-years of follow-up, 3488 incident cases of hearing loss were reported. Regular use of each analgesic was independently associated with an increased risk of hearing loss. Multivariate-adjusted hazard ratios of hearing loss in regular users (2+ times/week) compared with men who used the specified analgesic <2 times/week were 1.12 (95% confidence interval [CI], 1.04-1.20) for aspirin, 1.21 (95% CI, 1.11-1.33) for NSAIDs, and 1.22 (95% CI, 1.07-1.39) for acetaminophen. For NSAIDs and acetaminophen, the risk increased with longer duration of regular use. The magnitude of the association was substantially higher in younger men. For men younger than age 50 years, the hazard ratio for hearing loss was 1.33 for regular aspirin use, 1.61 for NSAIDs, and 1.99 for acetaminophen. CONCLUSIONS Regular use of aspirin, NSAIDs, or acetaminophen increases the risk of hearing loss in men, and the impact is larger on younger individuals.

A prospective study of vitamin intake and the risk of hearing loss in men.

Objective: Hearing loss is the most common sensory disorder in the United States, afflicting more than 36 million people. Higher intakes of vitamins C, E, beta carotene, B12, and folate have been proposed to reduce the risk of hearing loss. Study Design: We prospectively evaluated the association between intake from foods and supplements of vitamins C, E, beta carotene, B12, and folate, and the incidence of hearing loss. Setting: Health Professionals Follow-up Study. Subjects and Methods: A total of 26,273 men aged 40 to 74 years at baseline in 1986. Participants completed questionnaires about lifestyle and medical history every two years and diet every four years. Information on self-reported professionally diagnosed hearing loss and year of diagnosis was obtained from the 2004 questionnaire, and cases were defined as hearing loss diagnosed between 1986 and 2004. Cox proportional hazards multivariate regression was used to adjust for potential confounders. Results: There were 3559 cases of hearing loss identified. Overall, there was no significant association between vitamin intake and risk of hearing loss. Among men aged ≥60 years, total folate intake was associated with a reduced risk of hearing loss; the relative risk for men aged ≥60 years old in the highest quintile compared with the lowest quintile of folate intake was 0.79 (95% confidence interval 0.65-0.96). Conclusions: Higher intake of vitamin C, E, beta carotene, or B12 does not reduce the risk of hearing loss in adult males. Men aged ≥60 years may benefit from higher folate intake to reduce the risk of developing hearing loss.

Prospective Study of Alcohol Use and Hearing Loss in Men

Objective: Hearing loss is a common and disabling sensory disorder, yet prospective data on potentially modifiable risk factors are limited. Previous studies suggest that alcohol consumption may influence the development of hearing loss, yet results have been inconsistent. The purpose of this study was to prospectively examine the relation between alcohol use and hearing loss in men. Design: We examined prospectively the independent association between alcohol intake and self-reported professionally diagnosed hearing loss in 26,809 men aged 40 to 74 yrs at baseline in 1986. Study participants completed detailed questionnaires at baseline and every 2 yrs thereafter. Incident cases of hearing loss were defined as those professionally diagnosed after 1986. Cox proportional hazards multivariate regression was used to adjust for potential confounding factors. Results: During 386,081 person-years of follow-up, 3447 incident cases of hearing loss were reported. Overall, there was no association between level of alcohol intake and risk of hearing loss. Compared with those who did not consume alcohol, the multivariate-adjusted hazard ratios (95% confidence interval) were 1.00 (0.89 to 1.12) for those who consumed 5.0 to 9.9 g/day, 1.08 (0.96 to 1.21) for 10.0 to 14.9 g/day, and 0.98 (0.85 to 1.13) for 30.0 to 49.9 g/day. The results did not differ by age group or folate intake. Among those with lower intake of vitamin B12, however, higher consumption of alcohol, specifically liquor, was associated with an increased risk of hearing loss. Conclusions: Our data suggest that low or moderate alcohol consumption does not influence the risk of hearing loss in older men. A possible relation between vitamin B12 intake, alcohol consumption, and hearing loss merits further investigation.

Diet and Urinary Stone Disease

Diet plays an important role in the development of calcium oxalate kidney stones. Recent studies of the relationship between specific dietary factors and the formation of kidney stones have provided useful information for the management and prevention of this painful and costly condition.

Duration of Analgesic Use and Risk of Hearing Loss in Women

Aspirin, nonsteroidal antiinflammatory drugs (NSAID), and acetaminophen are commonly used. Frequent use of analgesics has been associated with a higher risk of hearing loss. However, the association between duration of analgesic use and the risk of hearing loss is unclear. We investigated the relationship between duration of analgesic use and self-reported hearing loss among 55,850 women in the Nurses’ Health Study. Cox proportional hazards regression was used to adjust for potential confounders. During 873,376 person-years of follow-up (1990–2012), longer durations of NSAID use (for >6 years of use compared with <1 year, multivariable-adjusted relative risk = 1.10, 95% confidence interval: 1.06, 1.15; P for trend < 0.001) and acetaminophen use (for >6 years of use compared with <1 year, multivariable-adjusted relative risk = 1.09, 95% confidence interval: 1.04, 1.14; P for trend < 0.001) were associated with higher risks of hearing loss. Duration of aspirin use was not associated with hearing loss (for >6 years of use compared with <1 year, multivariable-adjusted relative risk = 1.01, 95% confidence interval: 0.97, 1.05; P for trend = 0.35). In this cohort of women, longer durations of NSAID and acetaminophen use were associated with slightly higher risks of hearing loss, but duration of aspirin use was not. Considering the high prevalence of analgesic use, this may be an important modifiable contributor to hearing loss.

Menopause and postmenopausal hormone therapy and risk of hearing loss

Objective: Menopause may be a risk factor for hearing loss, and postmenopausal hormone therapy (HT) has been proposed to slow hearing decline; however, there are no large prospective studies. We prospectively examined the independent relations between menopause and postmenopausal HT and risk of self-reported hearing loss. Methods: Prospective cohort study among 80,972 women in the Nurses’ Health Study II, baseline age 27 to 44 years, followed from 1991 to 2013. Baseline and updated information was obtained from detailed validated biennial questionnaires. Cox proportional-hazards regression models were used to examine independent associations between menopausal status and postmenopausal HT and risk of hearing loss. Results: After 1,410,928 person-years of follow-up, 18,558 cases of hearing loss were reported. There was no significant overall association between menopausal status, natural or surgical, and risk of hearing loss. Older age at natural menopause was associated with higher risk. The multivariable-adjusted relative risk of hearing loss among women who underwent natural menopause at age 50+ years compared with those aged less than 50 years was 1.10 (95% confidence interval [CI] 1.03, 1.17). Among postmenopausal women, oral HT (estrogen therapy or estrogen plus progestogen therapy) was associated with higher risk of hearing loss, and longer duration of use was associated with higher risk (P trend < 0.001). Compared with women who never used HT, the multivariable-adjusted relative risk of hearing loss among women who used oral HT for 5 to 9.9 years was 1.15 (95% CI 1.06, 1.24) and for 10+ years was 1.21 (95% CI 1.07, 1.37). Conclusions: Older age at menopause and longer duration of postmenopausal HT are associated with higher risk of hearing loss.

Epidemiology of Hearing Impairment

Hearing impairment is the most prevalent sensory deficit, affecting approximately 30 million (12.7 %) individuals in the United States in both ears and 48 million (20.3 %) individuals in the United States in at least one ear. Nevertheless, NIH estimates suggest that only 20 % of people who could potentially benefit from a hearing aid seek intervention. Globally, approximately 5.3 % of the world’s population, or 360 million individuals, suffer from hearing impairment that is considered to be disabling by WHO standards. Hearing impairment is a condition that can develop across the life span, and the relations between specific risk factors and hearing impairment may vary with age. The etiology of hearing impairment is complex and multifactorial, representing the cumulative influences of an amalgam of factors, such as aging, genetic, epigenetic, environmental, health comorbidity, diet and lifestyle factors, as well as the complex potential interactions among these factors, that may all contribute to its development. Identification of risk factors for hearing impairment may provide us with a better understanding of the cellular and molecular mechanisms associated with acquired hearing impairment and could aid efforts toward prevention, early detection, and delay of progression. This chapter provides an overview of the epidemiology of hearing impairment in the United States and worldwide, including information on incidence, prevalence, and a discussion of risk factors that have been identified as potential contributors.