Grant: Catalyst Grant: Analysis of CLSA Data

Sensory loss and cognitive problems are very common in older adults. Importantly, vision and hearing loss are correlated with cognitive decline, above and beyond what is expected due to aging alone. The reason(s) remain uncertain, and not everyone is affected equally. On average, people with higher levels of sensory loss have a greater likelihood of experiencing cognitive decline, but there are exceptions to the rule. Our research aims to understand if genetic and/or social factors affect the degree to which hearing and vision are associated with cognitive decline. The results may help clarify underlying mechanism(s), and identify individuals with sensory loss who are most at risk, who might be targeted for interventions that aim to slow cognitive declines. First, we will determine if genes that cause both sensory loss and cognitive decline explain the associations. We will investigate the apolipoprotein E gene, since having the epsilon-4 version of the gene is a major risk factor for cognitive decline, and may also increase the risk of hearing and vision loss. Second, we will assess if social isolation affects the association. Social interaction is thought to stimulate the brain and protect it from cognitive decline. Hearing and vision loss, however, may disrupt communication and social participation and lead to isolation and loneliness. If our hypothesis is correct, the association between sensory loss and cognitive decline would be mediated by social isolation. The study will use data from the Canadian Longitudinal Study on Aging, which includes 30,000 participants from across the country who have health measures collected every 3 years. We will have access two sets of data for every participant: Their baseline data (collected in 2012-2015) and their 3-year follow-up data (collected in 2015-2018). Sensory, social and genetic information will be ascertained from the baseline data, and change in cognition will be assessed using data from both time points.