alOtolaryngology—Head and Neck Surgery 144(1)
Original Research—Sleep Medicine
Association of Obstructive Sleep Apnea and Auditory Dysfunctions in Older Subjects Juen-Haur Hwang, MD, MMS1,2,3, Jin-Cherng Chen, MD1,2, Chuan-Jen Hsu, MD, PhD4, and Tien-Chen Liu, MD, PhD4
No sponsorships or competing interests have been disclosed for this article.
Abstract Objective. Determine the association between obstructive sleep apnea (OSA) and auditory dysfunction in older subjects. Study Design. Cross-sectional study. Setting. Hospital volunteer helpers undergoing questionnaire, morphometry measurement, auditory examinations, and polysomnography between 2008 and 2009. Subjects and Methods. In total, 224 subjects older than 50 years were randomly sampled for above evaluation and testing. The effects of OSA on the peripheral auditory function, represented by averaged pure-tone threshold of low frequencies (PTA-low) and high frequencies (PTA-high), and central auditory function, shown by pitch pattern sequence (PPS scores), were analyzed. Results. The mean ± SD age was 61.2 ± 6.7 years. OSA was confirmed in 6 of 98 women (6.1%) and 28 of 126 men (22.2%). After adjusting for age, gender, and other variables, OSA did not show a significant positive association with PTA-low or PTAhigh for all subjects. Conversely, there was a significant negative association between OSA and PPS scores for all subjects, even after adjusting for age, gender, and other variables. When OSA and central obesity together were taken into account in the multivariate linear regression analysis, OSA still showed significant association with PPS score for all subjects. Conclusion. OSA is independently associated with poorer central auditory function in older subjects.
Otolaryngology– Head and Neck Surgery 144(1) 114–119 © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2011 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0194599810390859 http://otojournal.org
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bstructive sleep apnea (OSA) is a fairly common disorder affecting 24% of male and 9% of female middle-aged adults.1 OSA incidence has been associated with obesity and upper airway obstruction and shown to contribute to several organ system dysfunctions, including hypertension, cardiovascular diseases, stroke, diabetes, and even sexual dysfunction.2,3 Recently, OSA was also found to be associated with several ophthalmic manifestations, erectile dysfunction, nocturia, overactive bladder, and urgency incontinence.4,5 However, to date, there have been no reports on a possible relationship between OSA and age-related hearing impairment (ARHI). ARHI is the most common adult sensory dysfunction.6 The prevalence of hearing loss is reported to be 45.9% in adults aged 48 to 92 years.7 In general, hearing deteriorates more quickly and severely in male than in female subjects and is more pronounced at higher versus lower frequencies of peripheral hearing.8 Also, degeneration of the central auditory system occurs earlier than that of the peripheral hearing organs.9,10 In addition to genetic susceptibility to hearing loss,11,12 several environmental factors, including systemic diseases, noise, tobacco, alcohol, chemical exposure, ototoxic medication, hormonal factors, and socioeconomic status, may also contribute to interindividual variation in the frequency and severity of adult hearing loss.13,14 Recently, our study group found that central obesity was an independent risk factor for peripheral hearing dysfunctions.15 The impact of OSA on auditory functions has only rarely been reported. Hoffstein et al16 found that snoring was not 1
Buddhist Dalin Tzu-Chi General Hospital, Chiayi, Taiwan School of Medicine, Tzu Chi University, Hualien, Taiwan 3 Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan 4 Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan 2
Keywords obstructive sleep apnea, auditory dysfunctions, pure-tone averages, pitch pattern sequence, central obesity Received August 18, 2010; revised October 7, 2010; accepted October 27, 2010.
Corresponding Author: Tien-Chen Liu, MD, PhD, Department of Otolaryngology, National Taiwan University Hospital, No. 7, Chung-Shan S Road, Taipei 100, Taiwan Email:
[email protected]
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Hwang et al associated with ARHI. Conversely, Sardesai et al17 reported that the bed partners of snorers might suffer from unilateral, noise-induced hearing loss but that the snorers themselves did not show evidence of hearing loss. In support of an association, Fisher et al18 reported that patients who developed sudden hearing loss tended to have OSA more frequently than individuals in the study control group. Also, Cao et al19 found that the averaged and high-frequency auditory thresholds in subjects with OSA were degraded as compared to the thresholds of age-matched subjects without OSA. Thus, it seems that OSA, but not snoring, is associated with peripheral hearing loss. However, this putative relationship has not been demonstrated for central auditory function. As mentioned above, obesity itself was associated with ARHI,15 and OSA is more prevalent in obese subjects. Thus, it is reasonable to hypothesize that OSA might contribute to ARHI. However, it remains to be established whether OSA itself is an independent risk factor or just a covariate for ARHI, particularly for central auditory function. Therefore, in the present study, we test the hypothesis that OSA itself is an independent risk factor for reduction in both peripheral and central auditory functions in older adults.
Methods Study Design This was a cross-sectional study on 224 hospital volunteer helpers undergoing sleep, cognitive, health, and habit questionnaires; morphometry measurement; auditory examinations; and/or polysomnography between 2008 and 2009. The study protocol was approved by our hospital institutional review board. Informed consent was obtained for each subject at initial visit.
Inclusion and Exclusion Criteria Age-related hearing impairment was defined as bilateral, symmetric, progressive sensorineural hearing loss. Subjects with some psychiatric or cognitive problems may not be able to follow the instruction of the tests. Also, handedness or professional training (such as musicians) might confound the results of the central auditory function tests. So, we set some criteria for the eligible study population. All adult subjects completed medical, health-related habits, sleep, and cognitive function questionnaires. Otoscopy, tympanogram, and pure-tone audiometric examinations for peripheral hearing threshold were also performed on all eligible subjects. Subjects who were older than 50, were right-handed nonmusicians, had normal or symmetric sensorineural hearing loss (SNHL), and had normal cognitive function were included for this study. In total, 224 subjects participated in this study. All 224 participants were assigned to receive a pitch pattern sequence (PPS) test to evaluate central auditory function. Patients whose questionnaire results suggested the presence of a sleep disorder were confirmed by routine polysomnography. Study exclusion criteria included age younger than 50, poor reading ability, cognitive dysfunction, asymmetric SNHL (defined as 15 dB HL or greater asymmetry at 2 or more
frequencies), pregnancy, women on hormone replacement therapy, and central-type sleep apnea. Subjects with a history of any of the following conditions were also excluded: external or middle ear disease, conductive hearing loss (presenting with air-bone gap in audiogram), high environmental noise exposure or acoustic trauma (presenting with 3- to 6-kHz dip in audiogram), exposure to ototoxic drugs, major neurological or psychiatric disease, brain tumor or vestibular schwannoma, vertigo, liver cirrhosis, chronic kidney disease under peritoneal dialysis or hemodialysis, cancer, head and neck radiation exposure, or history of being a heavy smoker or abuser of either alcohol or controlled substances.
Pure-Tone Audiometry and Pitch Pattern Sequence All auditory testing procedures were conducted in a doublewalled, soundproof booth. Sounds were delivered via earphones (Telephonics Corp, Farmingdale, New York). Six frequencies (250, 500, 1000, 2000, 4000, and 8000 Hz) were tested during a routine, pure-tone audiometric examination (GSI 61 Audiometer, VIASYS Healthcare, Hong-Kong Ltd, Hong Kong). First, the mean threshold of each frequency was calculated for the better ear of each subject. The 250-, 500-, and 1000-Hz thresholds were calculated as the average puretone hearing level of low frequencies (PTA-low) for each subject, whereas 2000-, 4000-, and 8000-Hz thresholds were calculated as the average pure-tone hearing level of high frequencies (PTA-high) for each subject. PPS was used to assess temporal ordering. A set of 50 sequences of 3 tone bursts of different pitches (880 Hz and 1430 Hz) was presented binaurally at a 50-dB sensation level. Subjects were asked to verbally identify the pitch (“low” or “high”) of each stimulus in the sequence. The percentage of correct answers was calculated.20,21
Morphometry, Medical History, and HealthRelated Habits Height, body weight, and waist circumference (WC) were measured. Body mass index was calculated as subject weight in kilograms divided by the square of subject height in meters (kg/m2). WC was measured in a horizontal plane, midway between the inferior margin of the ribs and the superior border of the iliac crest according to the guidelines of the International Diabetes Federation.22 Central obesity in Asians is defined as a WC of >90 cm for males and >80 cm for females.22 Medical history and health data were obtained using a detailed questionnaire. All subjects with systemic diseases were treated according to standard regimens. During the interview, the type, frequency, and duration of cigarette smoking and alcohol consumption were determined from responses to a consumption questionnaire administered to assess participants’ usual consumption over the past decade. Consumption by frequency (cigarettes or drinks per month) plus duration (months) was graded as 1 to 5. Grade 1 was regarded as a nonsmoker or nondrinker, whereas grades 2 to 5 were regarded as a smoker or drinker.
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Otolaryngology–Head and Neck Surgery 144(1)
Table 1. Baseline Characteristics in the Non-OSA and OSA Groups Variables Mean age (SD) Gender, female/male, No. (%) Central obesity, No. (%) CAD, No. (%) HTN, No. (%) DM, No. (%) Dyslipidemia, No. (%) CKD, No. (%) Smoke, No. (%) Alcohol, No. (%) Peripheral auditory function PTA-low (SD) PTA-high (SD) Central auditory function PPS score (SD)
All (N = 224) 61.2 (6.7) 98 (43.8)/126 (56.2)
Non-OSA (n = 190) 61.1 (6.9) 92 (48.4)/98 (51.6)
92 (41.1) 22 (9.8) 66 (29.5) 14 (6.3) 10 (4.5) 2 (0.9) 68 (30.4) 74 (33.0)
OSA (n = 34) 62.2 (5.5) 6 (17.6)/28 (82.4)
78 (41.1) 18 (9.5) 48 (25.3) 14 (7.4) 8 (4.2) 2 (1.1) 48 (25.3) 52 (27.4)
14 (41.2) 4 (11.8) 18 (52.9) 0 (0) 2 (5.9) 0 (0) 20 (58.8) 22 (64.7)
16.8 (7.5) 30.1 (16.6)
16.5 (7.4) 29.1(16.4)
17.1 (7.9) 35.5 (16.3)
74.7 (13.1)
75.2 (13.0)
72.2 (13.3)
P Value .3457 .0009 .9892 .6793 .0011 .1021 .6638 .5479 .0001
