Plain English Summary
Background and study aims
Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. Patients with type 2 diabetes have a high risk of cardiovascular (heart) disease and other complications which reduce their quality of life and require high levels of healthcare. The aim of this study is to examine the risk factors for diabetes complications, including biomarkers (molecules that can be measured in blood or tissue) and genetic information.
Who can participate?
Patients with type 2 diabetes in the Netherlands
What does the study involve?
Participants are asked permission to use their medical data for scientific research. The following information is collected: personal information, medication use, physical examination (body measurements, blood pressure, electrocardiography [heart electrical activity], retina [eye] photographs, vibration perception), questionnaires (socio-economic status, lifestyle, [family] history of disease, and well-being), and laboratory measurements. Participants also contribute urine and blood samples and DNA for genetic analysis. National databases like the municipality register are used for mortality (death rate) follow-up.
What are the possible benefits and risks of participating?
There is no direct benefit for the participants. In the future, the study results may lead to improvements in diabetes care. There are no risks of participating.
Where is the study run from?
VU University Medical Center (Netherlands)
When is the study starting and how long is it expected to run for?
November 2006 to January 2050
Who is funding the study?
1. Dutch Ministry of Health, Welfare and Sport (Netherlands)
2. Dutch University Hospitals (Netherlands)
Who is the main contact?
Dr Petra Elders
The Diabetes Pearl: diabetes biobanking in the Netherlands - an observational prospective cohort study
Type 2 diabetes is associated with considerable comorbidity and severe complications, which reduce quality of life of the patients and require high levels of healthcare. The Diabetes Pearl is a large cohort of patients diagnosed with type 2 diabetes, covering different geographical areas in the Netherlands. The aim of this study is to create a research infrastructure that will allow the study of risk factors, including biomarkers and genetic determinants for severe diabetes complications.
Ethics committee of the VU University Medical Center, 09/07/2009, ref: NL27783.029.09
Observational prospective cohort study
Primary study design
Secondary study design
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Type 2 diabetes
Baseline examinations were performed November 2009 - November 2016. To ensure quality of the data collected, standard operation procedures were developed and used in all 8 recruitment centers. From all patients who provide informed consent, the following information is collected: personal information, medication use, physical examination (antropometry, blood pressure, electrocardiography (ECG), retina photographs, ankle-brachial index, peripheral vibration perception), self-report questionnaire (socio-economic status, lifestyle, (family) history of disease, and psychosocial well-being), laboratory measurements (glucose, A1c, lipid profile, kidney function), biobank material (storage of urine and blood samples and isolated DNA). Follow-up of morbidity and mortality is planned through medical care providers and municipal registries. All gathered clinical data and biobank information is uploaded to a database for storage on a national level. Biobanks are maintained locally at all recruitment centers.
Primary outcome measure
Diabetes complications and mortality:
1. Cardio-metabolic risk factors, assessed by anthropometry, blood pressure, ECG, ankle-brachial index, laboratory measurements, and self-report questionnaire at baseline
2. Retinopathy, assessed by retinal photography at baseline
3. Nephropathy, assessed with laboratory measurements at baseline
4. Neuropathy, assessed by peripheral vibration perception at baseline
Follow-up visits have not been planned yet. Follow-up of morbidity and mortality is done through medical care providers and municipal registries.
Secondary outcome measures
Quality of life and physical functioning, assessed by self-reported questionnaire at baseline
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Patients with type 2 diabetes mellitus according to WHO criteria
2. Treated by a Dutch University Clinic, an associated primary care clinic or transmural care system
Target number of participants
Participant exclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
VU University Medical Center
VU Universtity Medical Center
De Boelelaan 1089a
Ministerie van Volksgezondheid, Welzijn en Sport
Dutch Ministry of Health, Welfare and Sport, VWS
Funding Body Type
Funding Body Subtype
Dutch University Hospitals
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The first results are expected in 2017.
IPD sharing plan
Data will not be made available. Proposals for collaborative research can be submitted to Dr Petra Elders.
Intention to publish date
Participant level data
Not expected to be available
Basic results (scientific)
2012 protocol in: https://www.ncbi.nlm.nih.gov/pubmed/23130988