Professor Carol Brayne
Carol Braune 教授
The Cognitive Function and Ageing Studies started in the late '80s as a result of the Department of Health and the Medical Research Council in the UK being concerned about the ageing population. They're population-based and they include people in care settings. They use the population registers of primary care, so they're geographically defined, and they are in different parts of the United Kingdom to represent different aspects of exposures to potential risks for dementia. So, for example, in the north of England, where people live for shorter - they have shorter life expectancy and also higher vascular risk, so there's high stroke and so on. In the rural areas, there may be different exposures, such as to pesticides and so on.
Those studies started up and their purpose was to look at the prevalence and incidence of dementia, that is, the proportion of people who have dementia, and also the people who develop dementia over time. That allowed us also to look at risk over time because we measured risk factors at baseline and followed people. We also had a brain donation program which was linked to the study. Twenty years later, we resampled people of the same age, that is 65 and over, in three of the same geographical localities in order to test for cross-generational differences in dementia.
So from the first study, we were able to estimate what numbers of people there were in the United Kingdom who might have dementia at any one time and also what numbers of people would develop dementia in a given time period, and from the second study we were able to say whether dementia itself had changed across time.
The brain donation studies allowed us to look at the underlying neurobiology or neuropathology of dementia in relation to the measures, the in life measurements. So the major findings of the study were the age relationship of dementia, the fact that women are more at risk, that people with higher education are at lower risk, that people with stroke have roughly double the risk, and so on. So these are the sorts of broad findings that we've been able to report.
The brain findings really tested the paradigms that we have of dementia and show that it's more complicated than the simplistic view which is understood by most of the biomedical community, of Alzheimer's disease tau and beta amyloid plaques and tangles always being associated with dementia in life. And we found that that is not the case, that there are protective factors such as education, and the cross-generational aspect of the study showed us that dementia has declined age for age. Prevalence has declined by more than 20%. That means that age for age the risk of having dementia for an individual is substantially lower, particularly in the 75-plus age group. Incidence has also declined by 20% and that is largely accounted for by a large decrease in the incidence in men across the different generations.
Currently CFAS is funded to experiment and to bring a trial into the cohort study, which is an unusual thing to do, so we have done a lot of ethical, legal, social implication work on what it means for cohort participants to be asked whether they'd like to take part in an intervention trial. This trial is a translation of a European prevention trial which is based on internet counselling so that an individual sets their own goals for reduction of their own risk factor profile for dementia and they're supported by a counsellor, and we'll be doing a feasibility study of that in 2018.