Genetic and environmental effects on hearing acuity and the association between hearing acuity, mobility and falls in older women
Year: 2010
Type: dissertation
Study design: Observational Study
Abstract: The purpose of this study was to examine the contribution of genetic and environmental effects to individual differences in hearing acuity and to explore whether hearing acuity is associated with mobility, postural balance, and falls. This study is part of the Finnish Twin Study on Aging, which comprises 103 monozygotic and 114 dizygotic community-dwelling female twin pairs aged 63-76 years. Hearing acuity was assessed using standardized audiometric methods and a structured questionnaire. Maximal walking speed was measured over 10 meters, walking endurance as the distance covered in 6 minutes and difficulties in walking 2 kilometers according to self-report. Postural balance was indicated as a movement of center of pressure in semi-tandem stance assessed using a force platform. Information on falls was gathered for 12 months of follow-up with a fall calendar. Quantitative genetic modeling showed that genetic effects accounted for over 60% of the total variance in hearing acuity of the better hearing ear at the low, mid and high frequencies, and in speech recognition. The remaining variance was due to environmental effects. Although overall heritability was rather constant across the frequency spectrum, at the low and high frequencies frequency-specific genetic and environmental effects together accounted for the majority of the total variance. Environmental effects were more prominent in the worse hearing ear. Self-reported hearing difficulties were accounted for solely by environmental factors. Hearing impairments were associated with slower maximal walking speed, lower walking endurance and self-reported major difficulties in walking 2 kilometers. Poor hearing also predicted higher risk for new major walking difficulties during three-year follow-up and higher risk for falls, which was partially explained by the poorer hearing participants' poorer postural balance. The results of this study suggest that some people may be genetically predisposed to hearing impairment in old age, hence this finding underlines the need for further genetic studies. Strategies to prevent hearing loss may have wide-ranging influences not only on older people's ability to communicate, but also more widely on functional ability.
Author: Anne Viljanen
Language: English
Subfield: Speech and Hearing
Field: Health Professions
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2177236564