Grant: Summer Program in Aging

One in every 3 individuals over 65 years of age suffers from hearing difficulty, a rising problem in Canada and worldwide. A person who experiences hearing difficulties may have difficulties communicating with others. As a result, they may suffer from loneliness, depression, and stigmatization. The occurrence of hearing loss is affected by environmental factors such as exposure to noise, ototoxic medications, and diseases. However, hearing difficulty among old people (Age-Related Hearing Loss, ARHL) is also inherited. Unfortunately, the genetic factors contributing to this condition are not very well understood. Our research aims to bridge this knowledge gap and understand the genetic causes of ARHL using state-of-the-art computational analyses. We have obtained genomic and hearing measurement data from 26,622 healthy individuals from the Canadian Longitudinal Study on Aging. Using a mathematical method, we calculated two hearing loss parameters. (i) the sensory parameter, which is attributed to excessive exposure to noise and ear-damaging drugs, and (ii) the metabolic parameter, which is more related to the aging process. We then conducted genomic analyses to identify genetic factors that can increase the probability of experiencing each hearing loss type. We have also performed analyses in males and females separately to determine whether there are any differences. Our primary genetic analyses showed genetic differences leading to the two hearing loss conditions, as well as differences between sex groups. As we expected, we found that metabolic hearing loss was higher for older compared to younger individuals, with no noticeable difference between males and females. In contrast, sensory hearing loss was not found to increase greatly with age, and males showed more sensory hearing loss compared to females.