Study for Cognitive and Genetic Characterization of a 45-65 Years Old Population

Study Overview
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Brief Summary
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Before Alzheimer's disease (AD) clinical symptoms appear, there is a long period when changes in the brain occur. In this long asymptomatic period or preclinical phase, studies with populations at risk of developing AD have shown cognitive differences compared to control groups without such risk. There is a need for short, sensitive, easily administered, reproducible, non-expensive and independent of socio-demographic influences tests enabling the detection of pre-symptomatic variations in memory, when the memory decline is still within a normal range. Study main hypothesis: When evaluated with high-demanding tests of memory and executive function, the cognitive performance of cognitive healthy people aged between 45 and 65 and, extensively, to a group of up to 75 years, will vary significantly depending on clinical, socio-demographic and genetic features

Detailed Description
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The purpose of Study 45-65 is to assess if: Endogenous factors (clinical history, risk factors, genetic factors APOE4, etc…), exogenous (socio-demographic, ambient and lifestyle variables) and cognitive reserve (including bilingualism) influence cognitive performance. New and/or updated tests translated and validated in Spanish and Catalan when needed, will provide accurate and sensitive measurements of the variability of cognitive performance in this target population, representative of the preclinical phase of Alzheimer's disease. An optional visit is offered to study participants that includes: cerebral magnetic resonance, vascular ultrasound and olfactory testing.

Official Title
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Cross-sectional Study for Cognitive and Genetic Characterization of a 45-65 Years Old Population

Conditions
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Healthy Individuals

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women, aged between 45 and 75 years Spanish and/or Catalan speakers Agreement with the study procedures and tests: Clinical Interview and questionnaires associated to risk factors Cognitive tests Blood sample extraction for DNA analysis Close relative involvement for functional evaluation of the volunteer Signature of informed consent Exclusion Criteria: Cognitive impairment: MMSE <26, o MIS <6, or orientation subtest of the Barcelona Test II <68, o category fluency (animals) <12 Functional status impairment: CDR > 0 Severe auditory and/or visual impairment Neurodevelopmental and/or psychomotor disorder Significant diseases that could currently interfere with cognition: renal failure on hemodialysis, liver cirrhosis, chronic lung disease with oxygen therapy, solid organ transplantation, fibromyalgia, active cancer in treatment or any other disease the investigator considers could affect the participant cognition Major psychiatric disorders (DSM-IV-TR) or diseases that could affect cognitive abilities: major depression, bipolar disorder, schizophrenia and dementia. Neurological disorders: Parkinson's disease, stroke, epilepsy and treatment with frequent seizures (> 1/month) in the past year, multiple sclerosis or other serious neurological disease. Brain injury interfering with cognition: history of head trauma with parenchymal lesion or extraaxial macroscopic large vessel ischemic stroke or hemorrhagic stroke, brain surgery, brain tumors and other causes that can generate acquired brain damage (cerebral chemotherapy or radiotherapy) Family history of Alzheimer's disease with autosomal dominant (3 affected in two different generations) and early onset age (<60 years).

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cognitively normal individuals<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Factors influencing the cognitive performance through demanding tests of episodic memory and executive function | The following tests will be administered: Verbal episodic memory: MBT (Memory Binding Test) WAIS-IV subsets: 1 Perceptual reasoning (Visual Puzzles) 2 Logical reasoning (Matrix Reasoning) 3 Executive attention and working memory (Digit span) 4 Speed of processing (Coding) 5 Abstract verbal reasoning (Similarities) Factors to be considered: Hypertension, diabetes mellitus, and metabolic syndrome APOE4 Cognitive reserve (including bilingualism) Pollution, exposure to toxics, diet | single Visit (up to 3 hours) | 
| Culturally adapted validation in Spanish and Catalan of the MBT and determination of normative data for the population under study. |  | single visit (up to 3 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of the equivalence of the in person and over the phone administration to the close relative of the Clinical Dementia Rating (CDR). |  | single visit/telephone conversation (up to 10 min) | 
| Genetic features of the population | APOE genotyping is being performed | 8 months after study start | 
| Identification of genetic determinants of neuroimaging phenotypes associated to Alzheimer's disease. | Brain MR (magnetic resonance) as well as GWAS (genome-wide association studies) are being performed | 5 years and 8 months after study start | 
| Assessment of the relationship between olfactory and cognitive performance | Olfaction is assessed with the Burghart Medical Technology (Wedel, Germany) kit containing 16 sniffing sticks | 5 years and 8 months after study start | 
| Analysis of the relationship between subclinical atherosclerosis and brain changes, cognitive performance and APOE genotype | Vascular ultrasound of femoral and carotid arteries will be performed | 6 years and 8 months after study start | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Preclinical phase of Alzheimer's disease, Asymptomatic phase of Alzheimer's disease, Cognitive normal, Exogenous factors, Endogenous factors, Episodic memory test, Executive function test, Memory binding test validation into Spanish, Memory binding test validation into Catalan