Date Published: September 12, 2017
Publisher: BioMed Central
Author(s): Marta Crous-Bou, Carolina Minguillón, Nina Gramunt, José Luis Molinuevo.
Due to the progressive aging of the population, Alzheimer’s disease (AD) is becoming a healthcare burden of epidemic proportions for which there is currently no cure. Disappointing results from clinical trials performed in mild–moderate AD dementia combined with clear epidemiological evidence on AD risk factors are contributing to the development of primary prevention initiatives. In addition, the characterization of the long asymptomatic stage of AD is allowing the development of intervention studies and secondary prevention programmes on asymptomatic at-risk individuals, before substantial irreversible neuronal dysfunction and loss have occurred, an approach that emerges as highly relevant.
The prevalence of dementia worldwide is estimated to be over 45 million people  and is predicted to triple by 2050 as a consequence of increased life expectancy, establishing dementia as one of the biggest global public health challenges. Alzheimer’s disease (AD) is the most common form of dementia and accounts for 60–80% of cases . AD is a progressive neurodegenerative disease, irreversible and disabling, causing a large socioeconomic burden .
New consensus diagnostic criteria for preclinical AD, together with the identification of at-risk individuals through the use of biomarkers that are altered before clinical decline (i.e. amyloid deposition in the brain), are key for identifying at-risk asymptomatic individuals who are ideal candidates to participate in secondary prevention trials. Cerebral Aβ deposition is considered a necessary, but not sufficient, step on the path towards AD development .
Epidemiological evidence of AD risk factors is contributing and encouraging the development of primary prevention initiatives. Current trials and strategies are necessary steps whose results are helping to improve future designs, bringing some post-hoc analysis on the potential benefits of risk factor reduction on disease incidence. Identifying individuals at risk of developing the disease might be the key to success of intervention studies.