Factors associated with healthy and pathological ageing in a sample of people over 90 years of age in the city of Madrid

 Progress and results achieved 

The studies carried out so far with long-lived people are relatively scarce and have not yet defined the morphological substratum of the preservation of the physical and cognitive level at advanced ages. MADRID+90 fills this gap. Its mission is to help identify those demographic, clinical, cognitive and functional variables that behave as protective factors associated with healthy aging. Likewise, MADRID+90 will also make it possible to obtain reliable data on the prevalence of cognitively healthy long-lived people with cognitive impairment, as well as to validate a series of assessment instruments in very old people. 

In the first phase, with the collaboration of the Statistics Office of the Madrid City Council, a stratified random sampling has been carried out by census units, from which 692 people over 90 years of age registered in the city of Madrid have been extracted. Subsequently, all these persons have been contacted by postal mail to inform them of the objectives of the study and to indicate that a researcher would come to their home a few days later to check their willingness to participate in the proposed study. If so, the researcher has carried out a face-to-face survey in which demographic, clinical, cognitive and lifestyle-related information is collected. Currently, MADRID+90 is immersed in the collection of information from this first phase. Once this phase has been concluded and the first data have been preliminarily analysed, a subsample of 50 individuals who show a preserved cognitive profile will be invited to carry out an extensive in-person clinical assessment at the CIEN Foundation facilities (PAU Vallecas, Madrid). 

2.1. Objectives, milestones and degree of compliance 

The following table lists the objectives of MADRID+90, briefly summarizes the milestones associated with each of them and quantifies the current degree of compliance. 

2.2. Activities carried out 

The activities carried out in the context of MADRID+90 and associated with each specific objective and each specific milestone are described below. The last column, "Situation", summarises the state of implementation of each activity: 

- Finished: started and finished.

- Started: started but not finished.

- Pending: not yet started.

2.3. Problems and changes in the work plan 

During the execution of the work plan initially planned, a series of incidents occurred to which the research team had to respond in order to meet the objectives of MADRID+90. These incidents, as well as the consequences they have caused and the actions taken to overcome them, are summarised in the following table:

3. Preliminary results 

The main results expected from MADRID+90 include the following points: 

1. Obtaining a representative sample of people over 90 years of age, allowing the generalization of the results obtained. This point is really innovative in comparison with other studies similar to MADRID+90. 

2. Adaptation and validation of a set of cognitive and functional assessment tools (quality of life, dependency, self-perceived health, lifestyles) suitable for use in people over 90 in Spain. These instruments may be applied by telephone or in person, so that they will be useful for application in subsequent epidemiological and clinical studies in this growing segment of the population that usually has disabilities to move to a health center. Its use is also a sign of identity of this project insofar as the telephone scales will allow the remote evaluation of long-lived people in ageing regions, rural and particularly depopulated regions such as the cross-border areas between Spain and Portugal. Characterization from the neuronatomic and functional point of view of a Spanish subsample of cognitively healthy people over 90 to help better understand the physiopathological mechanisms associated with healthy ageing. All this information will be processed and correlated with the cognitive and lifestyle data obtained in this research. Likewise, through the interrelationship with the other two subprojects of PILEP+90, BRAGA+90 and ImageH, it is intended to obtain information not only on those factors that individually characterize long-lived individuals, but also to determine the best combination of all of them by means of data mining techniques. Precisely, the application of such statistical techniques will help researchers discover unintuitive relationships between data. For this purpose, the sample obtained in the context of this research project will be analysed with other similar samples, but from different strata and cultures. In this way, cross validation of all these factors will allow more robust cross-sectional conclusions to be drawn about their involvement in the healthy and pathological ageing process. 

4. Determination of the prevalence figures of dementia in the nonagenarian and centenarian Spanish population. The way of obtaining the sample by random sampling on the census of the city of Madrid will guarantee the generalization of the results. This data is important insofar as, as a consequence of the ageing of the population, a strong increase is expected in the prevalence of dementia and neurodegenerative diseases such as Alzheimer's disease, where age is the most prominent risk factor. MADRID+90 will take advantage of the longitudinal study of the Vallecas Project - a longitudinal research programme for the early detection of Alzheimer's disease developed by the CIEN Foundation - in a complementary and synergistic manner to compare the factors that differentiate the long-lived subjects recruited by this study from those who develop dementia at earlier ages. Complementarity between the two projects may shed light on the best combination of markers that could identify healthy individuals at risk of developing dementia. Even more interesting will be the study of the temporal dynamics in which these markers act on the expression of dementia. All this can help to characterise the early pre-clinical phase of cognitive impairment in order to implement effective preventive and therapeutic measures focused on modifying risk factors and introducing healthy behaviours to fight the disease. The implementation of these programmes will have a direct positive impact on healthy ageing and on the quality of life of individuals and their families. 

Expenditure incurred 

Due to delays beyond our control, which have already been commented on in previous sections and which have caused a delay in the start of the study, only a small part of the MADRID+90 budget has been executed at the present time. Specifically, the concepts that have been implemented are as follows:

However, it is expected that during the month of November MADRID+90 wave 2 will begin and, with it, the largest part of the project will be executed.