title: Genetic and environmental influences on hearing in older women.
abstract: BACKGROUND
  This study examined the relative contribution of genetic and environmental effects on the air-conducted hearing threshold level (0.5-4 kHz) and speech recognition threshold level of the better ear as well as self-reported hearing in older women.
  
  
  METHODS
  Hearing was measured as a part of the Finnish Twin Study on Aging in 103 monozygotic (MZ) and 114 dizygotic (DZ) female twin pairs aged 63-76 years. Audiometric measured hearing was tested using standardized methods in soundproof conditions. Self-reported hearing was assessed by a structured question. Quantitative genetic modeling was used for data analyses.
  
  
  RESULTS
  No significant differences in age, exposure to noise, hearing-aid use, auditory diseases or accidents, or number of self-reported chronic conditions or prescription medicines were observed between the MZ and DZ twins. A genetic component in common accounted for 75% (95% confidence interval [CI], 67%-81%) of the variance in the better ear's hearing threshold level and 54% (95% CI, 43%-64%) in the better ear's speech recognition threshold level, according to a bivariate genetic analysis. In addition, 10% (95% CI, 4%-15%) of the variance in the better ear's speech recognition threshold level was explained by its specific genetic component.
  
  
  CONCLUSIONS
  Individual differences in audiometrically measured air-conducted hearing threshold level (0.5-4 kHz) and speech recognition threshold level in the better ear were largely accounted for by genetic differences between individuals. In contrast, self-reported hearing appears to be accounted for solely by environmental factors.
authors: Finnish Centre for Interdisciplinary Gerontology, Department of Health Sciences, University of Jyväskylä, Finland. anne.viljanen@sport.jyu.fi
authors: Anne
authors: A
authors: Viljanen
authors: Pertti
authors: P
authors: Era
authors: Jaakko
authors: J
authors: Kaprio
authors: Ilmari
authors: I
authors: Pyykkö
authors: Markku
authors: M
authors: Koskenvuo
authors: Taina
authors: T
authors: Rantanen
mesh_terms: D000368:Aged; D001299:Audiometry; D001309:Auditory Threshold; D015331:Cohort Studies; D004777:Environment; D005260:Female; D006309:Hearing / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007206:Individuality; D008875:Middle Aged; D008957:Models, Genetic; D013067:Speech Perception / Q000502:physiology*; D013069:Speech Reception Threshold Test; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic