Grant: Project Grant

Cognitive impairment (problems with memory and thinking) is on the rise and so is the proportion of visible minority groups in Canada. Risk factors for cognitive impairment have mostly been studied in Caucasians, with much less research carried out in visible minority groups. This is a problem because some ethnic groups may be at higher risk for cognitive impairment. Furthermore risk factors may differ across ethnic groups. Because visible minorities represent 20% of Canada's population, there is an urgent need to study risk factors for cognitive impairment in these understudied groups. Cardiovascular risk factors, like high blood pressure and obesity, negatively affect the blood vessels of the brain. We call these harmful changes vascular brain injury (VBI). Both cardiovascular risk factors and VBI can lead to cognitive impairment. Interestingly, there are striking differences in the vascular health of Canada's two major visible minority groups: South Asian and Chinese individuals. That is, Canadian South Asians are more prone to cardiovascular risk factors, as reflected by earlier disease onset and more severe risk factors. By contrast, Chinese individuals have less severe cardiovascular risk factors, but are at greater risk for brain hemorrhage (bleeding). An important, but unanswered, question is whether Canadian South Asians and/or Chinese individuals are at heightened risk for cognitive impairment due to cardiovascular conditions and/or VBI. This is the first study to use sophisticated brain imaging and comprehensive cognitive testing to investigate risk factors for cognitive impairment among Canadian ethnic groups. Such knowledge is critical for developing and implementing appropriate prevention and intervention strategies for Canada's diverse communities. Our study will also yield a model for calculating a person's risk of cognitive impairment that takes ethnicity into account. This model could ultimately be used in primary care settings.