Findings from our population studies of older people have provided descriptions to help clinicians and service providers understand prevalence, incidence and expected length of life lived with dementia, including at particular ages and in different settings.
Cognition and ageing studies led by Professor Carol Brayne reveal details about the lives of ordinary people aged over ninety years old, describing their ability to function day to day and their quality of life.
The key studies are:
CFAS – The Cognitive Function and Ageing Studies are large UK-based longitudinal multicentre studies looking at health and cognitive function in older people.
CC75C – The Cambridge City over-75s Cohort Study (CC75C) is a long-term follow-up study of a representative population-based sample of older people which started in 1985 from a survey of over 2,600 men and women aged 75 and above.
CamCan – Cam-CAN is a large-scale collaborative research project, launched in October 2010, with substantial funding from the Biotechnology and Biological Sciences Research Council (BBSRC). The Cam-CAN project is using epidemiological, behavioural, and neuroimaging data to understand how individuals can best retain cognitive abilities into old age.
Read more about Professor Carol Brayne and see her latest publications.
Dementia and cognition
Our dementia and cognition studies have provided
- important evidence on the prediction of risk for development of future dementia, such as the doubling of risk with stroke, and also with poor quality of life
- contributions to large consortia which have highlighted the role of particular patterns of genes to clinically diagnosed Alzheimer’s Disease, including those associated with ageing changes such as inflammation and immune responses
- major impact on thinking about what it is that happens in the brain in the older population leading to the loss of cognitive and mental skills. This is clearly much more complicated than hoped, with research moving from the ‘tombstones’ of the pathologies associated with Alzheimer’s disease to investigation of small proteins, aggregation and their impact on brain cells with potential triggering of harmful cellular responses
- better understanding of the extent to which vascular pathologies are combined with the other neurodegenerative changes, providing a much clearer idea about the mixtures of pathologies that occur within any individual as they (we) age
These neurobiological studies are conducted on our brain collections, from participants and their families who have been so marvellous in supporting our research – Professor Carol Brayne
Our brain-based studies suggest:
- higher education protects from the clinical manifestation of disease
Our tracking of cognition and terminal decline analyses suggest:
- better recovery from impairment with higher education, social class and late life intellectual activity as well as a shorter phase of terminal decline
Our new generation CFA studies describe:
- a drop in the prevalence in dementia (with absolute number estimates in UK therefore remaining stable despite substantial ageing of the population), for which the most likely explanation is higher education and better vascular health.
Healthy ageing, medications and polypharmacy
- We have found polypharmacy to be strongly associated with higher mortality.
- Specific medications can be associated with adverse outcomes. Many of the medications we take reduce the effectiveness of particular proteins involved in memory (anticholinergics). In particular we have investigated the cumulative anticholinergic score of the multiple medications that our older population are now encouraged to take for a variety of conditions.
We have found that the score which indicates a person is taking a lot of anticholinergics is associated with worse cognitive outcomes and higher mortality
Paradoxically we prescribe many medications which may reduce memory to counteract conditions which might also be harmful to cognition, such as hypertension. Those people with Alzheimer’s disease are often prescribed medications which are aimed at boosting acetylcholine through blocking the breakdown of acetylcholine. So there is a strong message here about prescribing for an individual, including assessment of polypharmacy and the nature of the medication for that person.
Screening for Dementia
The population health perspective allows us to consider the potential long term impact of screening of any kind. We have contributed to a range of screening debates and research studies over the years. In the dementia field we have used population data to assess the value of use of particular measures to identify ‘early’ dementia and intermediate conditions such as Mild Cognitive Impairment. This has been explored from a variety of angles, such as how different definitions for dementia work, proportions of the population that develop dementia, and how good the definitions are at identifying people who go on to develop dementia.
We can also assess how new measurements fit in, whether they are likely to identify more accurately those who progress or whether many false positives are likely. These findings have been published in many papers in a range of journals. Overviews and commentaries have been based on these findings and have made major contributions to the current debate on the value of screening for dementia given the current evidence base.
The UK Dementia Platform
The UK Dementias Platform (UKDP) is a radical new approach to dementias research, providing a translation pipeline from basic discovery through to early phase trials. It will combine more than 20 clinical and population cohorts representing 2M participants.
UKDP will create an optimal environment for basic discovery activities relevant to the clinical progression and human impact of dementia. UKDP is intended as a strategic and sustainable resource generating increasing scientific benefit over time, it will also deliver short and medium term benefits through the analysis of existing data, the enrichment of strategically selected cohorts, developing new ways of working with industry, and generating interest and further funding for dementias research generally.
The Institute will be involved in three UKDP work packages including: Biostatistical Methods and Support with MRC Biostatistical Unit (BSU), Ethical Legal and Social Implications (ELSI) with Public Health Genomics Foundation and Brain donation procedures in collaboration with Brains for Dementia Research (BDR) as well as its existing cohort studies: CFAS, CamCAN and EPIC Norfolk.