Epidemiology of Age-Related Hearing Loss

University Of Wisconsin-Madison, Madison WI

Investigators

Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): The purpose of this proposed epidemiologic study is to re-examine a large, population-based cohort of older adults to determine the 10-yr incidence and progression of hearing loss and investigate risk factors for age-related changes in hearing. Participants (n=3753) in the baseline examination (1993-95) were 48-92 years of age. They will be reexamined in 2003-2005 using the same standardized protocols for otoscopy, screening tympanometry, audiometry, word recognition tests, and distortion product otoacoustic emissions. A standardized questionnaire about medical history, noise exposure, physical functioning, and health-related quality of life will be completed as an interview. At the five-yr follow-up examination, olfaction testing was added to determine the prevalence of olfactory impairment. The cohort will be re-tested using the same test of olfaction to determine the 5-yr incidence of olfactory impairment. Data on vision impairment, as well as markers of cardiovascular disease risk (C-reactive protein), subclinical peripheral vascular disease (ankle-brachial index), and retinal microvascular changes (arteriolar-venular ratio) will be available from the approved 15-yr follow-up for the Beaver Dam Eye Study. During the proposed grant period, new data will be obtained on the presence and severity of subclinical atherosclerosis. Archived B-mode ultrasound scans of the carotid arteries obtained at the 5-yr examination will be graded for intima-medial thickness, a marker of generalized atherosclerosis. This study will provide important new data about the associations of vascular factors, and other potentially modifiable risk factors, with the incidence and progression of hearing loss in older adults. It will provide the first population-based estimates of the 10-yr incidence and progression of hearing loss and the 5-yr incidence of olfactory impairments. Because of the links with an on-going epidemiologic study of age-related ocular disorders, this study has the opportunity to determine the relative contributions of impairments in three sensory systems, vision, hearing, and smell, to decrements in health-related quality of life and functional disability in older adults. It will provide data important for planning for the health-care needs of older adults and possible targets for intervention strategies to delay or diminish the impact of sensory impairments on quality of life in older adults.