Retinal Neurodegeneration in Type 2 Diabetes as Biomarker for Alzheimer´s Disease (DIALRET)

April 11, 2017 updated by: Hospital Universitari Vall d'Hebron Research Institute
A clear association between type 2 diabetes (T2D) and Alzheimer's disease (AD) has been reported. This association is independent of vascular impairment, and therefore, it could be attributed to neurodegeneration triggered or accelerated by diabetes itself. At present there are no methods to identify T2D patients at risk for developing AD. The retina shares many features with the brain and, therefore, has been suggested as an easily accessible way of examining pathology in the brain. In fact, many patients with AD present retinal abnormalities. However, the diagnosis of diabetes, a condition frequently associated with retinal neurodegeneration, has not been considered. On this basis, the final aim of this proposal is to identify diabetic patients at risk for developing AD based on the assessment of retinal neurodegeneration by means of non-invasive tests. Specific aims: 1) To compare the prevalence of morphological and functional abnormalities related to retinal neurodegeneration among three groups of T2D patients: patients with AD, patients with Mild Cognitive Impairment (MCI) and patients without AD or MCI. 2) To assess whether the retinal neurodegenerative features are related to severity of AD. 3) To explore whether the combined retinal neurodegeneration in diabetic patients with AD has a different functional and/or morphological pattern in comparison with neurodegeneration secondary to diabetes alone. Methods: Case-control study. Retinal neurodegeneration will be assessed by mutifocal electroretinogram (mfERG) and spectral domain optical coherence tomography (SD-OCT). The potential confounders will be considered in data analyses. Feasibility: A unique multidisciplinary consortium has been created in order to warrant the feasibility of the project Expected impact: This innovative approach will fill a gap that currently exist in the health care system and will reduce the economic burden associated with T2D patients with AD. In addition, this project would be the backbone for future prospective studies.

Study Overview

Status

Completed

Conditions

Detailed Description

A case control study in the recruitment will be carried out from the Diabetes outpatient clinic of a tertiary hospital (HUVH) and from the ACE Foundation. The investigators will include the following groups: 1) Type 2 diabetic patients with AD; B) Type 2 diabetic patients with MCI; 3) Type 2 diabetic patients with normal cognitive status; 4) Non-diabetic patients with AD. The groups will be matched by age (± 5 years), gender, risk factors related to AD (APOE genotype and family history of dementia), diabetes duration and Hba1c (±1%)- the last two criteria apply for the three groups of diabetic patients. Inclusion criteria: Written informed consent obtained from the patient; Age >65years; Diabetes duration>5 years; HbA1c < 10%; No apparent or mild non-proliferative DR according to the International Clinical Diabetic Retinopathy Disease Severity Scale. Exclusion criteria: Patients with other neurodegenerative diseases of the brain or retina (i.e. glaucoma) or cerebrovascular diseases. Sample size calculation: Assuming that diabetic patients will present around 30% of abnormal mfERG implicit time, and considering that this figure will be up 60% in those diabetic patients with AD, the number of patients required in each group would be 25. This calculation has been performed taking into account a 2-side risk level of 0.05 and a statistical power of 80%. However, it should be noted that this estimation has been performed taken into account the variables concerning AD. Therefore, it is foreseeable that more patients will be needed to obtain valid results for MCI. Consequently, the investigators feel it reasonable to extend the sample to 35 subjects per group.

The study will be divided into two stages (as will be further detailed): -Stage I: This will be the first step of the project and type 2 diabetic patients with AD and patients with normal cognitive status will be compared. -Stage II: Type 2 diabetic patients with MCI will be compared with patients with normal cognitive status or AD.

Study Type

Observational

Enrollment (Actual)

126

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Spain
    • Catalunya
      • Barcelona, Catalunya, Spain, 08035
        • Vall d´Hebron Research Institute VHIR

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

65 years and older (Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

We will include the following groups: 1) Type 2 diabetic patients with AD; B) Type 2 diabetic patients with MCI; 3) Type 2 diabetic patients with normal cognitive status; 4) Non-diabetic patients with AD. The groups will be matched by age (± 5 years), gender, risk factors related to AD (APOE genotype and family history of dementia), diabetes duration and Hba1c (±1%)- the last two criteria apply for the three groups of diabetic patients.

Description

Inclusion Criteria:

  • Written informed consent obtained from the patient; Age >65years; Diabetes duration>5 years; HbA1c < 10%; No apparent or mild non-proliferative DR according to the International Clinical Diabetic Retinopathy Disease Severity Scale

Exclusion Criteria:

  • Patients with other neurodegenerative diseases of the brain or retina (i.e. glaucoma) or cerebrovascular diseases.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Control
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
Type 2 diabetic patients with AD
35 patients
Type 2 diabetic patients with MCI
35 patients
Type 2 diabetic patients controls
35 patients
Non-diabetic patients with AD
35 patients

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Retinal neurodegeneration among three groups of type 2 diabetic patients patients with AD, patients with MCI and patients without AD or MCI.
Time Frame: 9 month

-To compare the prevalence of morphological (SD-OCT) and functional abnormalities (mfERG) related to retinal neurodegeneration among three groups of type 2 diabetic patients: patients with AD, patients with MCI and patients without AD or MCI. In addition, a group of non diabetic subjects with AD will also be included.

These groups will be matched by age, gender, duration of diabetes, HbA1C, and genetic risk factors for AD.

  • To assess whether the retinal neurodegenerative features are related to the severity of AD.
  • To explore whether the combined retinal neurodegeneration in diabetic patients with AD has a different functional and/or morphological pattern in comparison with neurodegeneration secondary to diabetes alone.
9 month

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital Universitari Vall d'Hebron Research Institute

Investigators

  • Principal Investigator: Cristina Hernandez, MD, PhD, Vall d´Hebron Research Institute VHIR

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2014

Primary Completion (Actual)

November 1, 2015

Study Completion (Actual)

December 1, 2015

Study Registration Dates

First Submitted

February 5, 2015

First Submitted That Met QC Criteria

February 9, 2015

First Posted (Estimate)

February 10, 2015

Study Record Updates

Last Update Posted (Actual)

April 12, 2017

Last Update Submitted That Met QC Criteria

April 11, 2017

Last Verified

April 1, 2017

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PR(IR)15/2014

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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