Heritability of audiometric shape parameters and familial aggregation of presbycusis in an elderly Flemish population
Faculty of Medicine and Health Sciences
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences . Biomedical Sciences
Hearing research. - Amsterdam
, p. 1-10
University of Antwerp
This study describes the heritability of audiometric shape parameters and the familial aggregation of different types of presbycusis in a healthy, otologically screened population between 50 and 75 years old. About 342 siblings of 64 families (average family-size: 5.3) were recruited through population registries. Audiometric shape was mathematically quantified by objective parameters developed to measure size, slope, concavity, percentage of frequency-dependent and frequency-independent hearing loss and Bulge Depth. The heritability of each parameter was calculated using a variance components model. Logistic regression models were used to estimate the odds ratios (ORs). Estimates of sibling recurrence risk ratios (λs) are also provided. Heritability estimates were generally higher compared to previous studies. ORs and λs for the parameters Total Hearing Loss (size), Uniform Hearing Loss (percentage of frequency-dependent hearing loss) and Bulge Depth suggest a higher heredity for severe types of presbycusis compared to moderate or mild types. Our results suggest that the separation of the parameter Total Hearing Loss into the two parameters Uniform Hearing Loss and Non-uniform Hearing Loss could lead to the discovery of different genetic subtypes of presbycusis. The parameter Bulge Depth, instead of Concavity, seemed to be an important parameter for classifying subjects into susceptible or resistant to societal or intensive environmental exposure.