Unipolar depressive disorders have been reported¹ as the leading cause and adult-onset hearing impairment (HI) as the second leading cause of years of life lived with disability among adults in high-income countries. Furthermore, depression and HI have been associated^2,3 with personal, societal, and economic burden. However, the relationship between depression and HI has not been reported in a nationally representative sample of US adults. Previous studies^4-8 have been limited primarily to older adults or specific geographically or ethnically distinct populations, and these have shown conflicting results.

Diabetes might affect the vasculature and neural system of the inner ear, leading to hearing impairment. To determine whether hearing impairment is more prevalent among U.S. adults with diabetes. Cross-sectional analysis of nationally representative data. National Health and Nutrition Examination Survey, 1999 to 2004. 5140 noninstitutionalized adults age 20 to 69 years who had audiometric testing. Hearing impairment was assessed from the pure tone average of thresholds over low or mid-frequencies (500, 1000, and 2000 Hz) and high frequencies (3000, 4000, 6000, and 8000 Hz) and was defined as mild or greater severity (pure tone average >25 decibels hearing level [dB HL]) and moderate or greater severity (pure tone average >40 dB HL). Hearing impairment was more prevalent among adults with diabetes. Age-adjusted prevalence of low- or mid-frequency hearing impairment of mild or greater severity in the worse ear was 21.3% (95% CI, 15.0% to 27.5%) among 399 adults with diabetes compared with 9.4% (CI, 8.2% to 10.5%) among 4741 adults without diabetes. Similarly, age-adjusted prevalence of high-frequency hearing impairment of mild or greater severity in the worse ear was 54.1% (CI, 45.9% to 62.3%) among those with diabetes compared with 32.0% (CI, 30.5% to 33.5%) among those without diabetes. The association between diabetes and hearing impairment was independent of known risk factors for hearing impairment, such as noise exposure, ototoxic medication use, and smoking (adjusted odds ratios for low- or mid-frequency and high-frequency hearing impairment were 1.82 [CI, 1.27 to 2.60] and 2.16 [CI, 1.47 to 3.18], respectively). The diagnosis of diabetes was based on self-report. The investigators could not distinguish between type 1 and type 2 diabetes. Noise exposure was based on participant recall. Hearing impairment is common in adults with diabetes, and diabetes seems to be an independent risk factor for the condition.

Since 1959, the United States has conducted examination-based health surveys measuring hearing thresholds in nationally representative samples at specified ages (eg, young children aged 6-11 years, adolescents aged 12-17 or 12-19 years, and adults ≥18 or ≥20 years). Hearing testing in adults has been accomplished in 4 surveys. The 1959-1962 National Health Examination Survey performed air-conduction hearing threshold tests in each ear at 6 frequencies (0.5, 1, 2, 3, 4, and 6 kHz) in adults aged 18 to 74 years. The first National Health and Nutrition Examination Survey (NHANES I) in 1971-1975 tested hearing in each ear at 4 frequencies (0.5, 1, 2, and 4 kHz) in adults aged 25 to 74 years. Since 1999, NHANES has operated continuously in 2-year cycles; during 1999-2004 and 2011-2012, NHANES conducted hearing tests in each ear at 7 frequencies (0.5, 1, 2, 3, 4, 6, and 8 kHz) in adults aged 20 to 69 years. The 1999-2004 data encompassed 3 cycles to accumulate a sufficient sample size since audiometric tests were performed on only half the respondents coming to the mobile examination centers. It was previously reported that high-frequency (3-6 kHz) hearing thresholds for people of specified age and sex groups were better in 1999-2004 than in 1959-1962; most of these differences were statistically significant.¹

Profound bilateral loss of vestibular sensation disables the vestibuloocular and vestibulospinal reflexes that normally maintain stable gaze and posture. Affected individuals experience oscillopsia (illusory movement of the visible world during head movement), chronic disequilibrium, and postural instability that interfere with otherwise routine activities such as walking or driving.^1,2 Although the cause of bilateral vestibular hypofunction (BVH) is frequently unknown, ototoxicity due to gentamicin or other aminoglycosides is the most commonly identified cause of BVH; other causes include Ménière’s disease, labyrinthitis, meningitis, autoimmune disease, and iatrogenic damage due to cochlear implantation or other surgical procedures.^3-5

Information about the prevalence of disorders of the chemical senses has been limited. In the late 1970s, the consensus among experts convened by the National Institutes of Health (NIH) was that more than 2 million adults in the United States had a disorder of smell or taste. A large, nonrandom survey conducted by the National Geographic Society in 1987 found that 1% of their 1.2 million respondents could not smell 3 or more of 6 odorants using a 'scratch and sniff' test. Age was an important factor, with a decline beginning in the second decade of life. No comparable data have been available for taste, although it has been suggested that the sense of taste remains more robust with age. The National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, began collaborating with the National Center for Health Statistics (NCHS) in 1993 to acquire information on the prevalence of smell/taste problems using the Disability Supplement to the National Health Interview Survey (NHIS). This survey was administered to approximately 42,000 randomly‐selected households (representing about 80,000 adults over 18 years of age) in 1994. Adjusted national estimates derived from this survey showed a prevalence of 2.7 million (1.4%) U.S. adults with an olfactory problem. Also, 1.1 million (0.6%) adults reported a gustatory problem. When smell or taste problems were combined, 3.2 million (1.65%) adults indicated a chronic chemosensory problem. The prevalence rates increased exponentially with age. Almost 40% with a chemosensory problem (1.5 million) were 65 years of age or greater. In a multivariate analysis, the individual's overall health status, other sensory impairments, functional limitations (including difficulty standing or bending), depression, phobia, and several other health‐related characteristics were associated with an increase in the rate of chemosensory disorders.

Chemosensory problems challenge health through diminished ability to detect warning odors, consume a healthy diet, and maintain quality of life. We examined the prevalence and associated risk factors of self-reported chemosensory alterations in 3603 community-dwelling adults (aged 40+ years), from the nationally representative, US National Health and Nutrition Examination Survey (NHANES) 2011–2012. In this new NHANES component, technicians surveyed adults in the home about perceived smell and taste problems, distortions, and diminished abilities since age 25 (termed “alterations”), and chemosensory-related health risks and behaviors. The prevalence of self-reported smell alteration was 23%, including phantosmia at 6%; taste was 19%, including dysgeusia at 5%. Prevalence rates increased progressively with age, highest in those aged 80+ years (smell, 32%; taste, 27%). In multivariable logistic regression, controlling for sociodemographics, health behaviors, and chemosensory-related conditions, the strongest independent risk factor for smell alteration was sinonasal symptoms (odds ratio [OR] = 2.06; 95% confidence interval [CI]: 1.63–2.61), followed by heavy drinking, loss of consciousness from head injury, family income ≤110% poverty threshold, and xerostomia. For taste, the strongest risk factor was xerostomia (OR = 2.65; 95% CI: 1.97–3.56), followed by nose/facial injury, lower educational attainment, and fair/poor health. Self-reported chemosensory alterations are prevalent in US adults, supporting increased attention to decreasing their modifiable risks, managing safety/health consequences, and expanding chemosensory screening/testing and treatments.