Prevalence of DIAbetic RETinopathy and Impact of Genetic Factors in the Development of Diabetic Retinopathy of Patients With Type 1 and 2 Diabetes Mellitus in SlovaKia (DIARET SK)

September 21, 2016 updated by: Novartis Slovakia, s.r.o.

DIARET SK - Prevalence of Diabetic Retinopathy and Impact of Genetic Factors in the Development of Diabetic Retinopathy of Patients With Type 1 and 2 Diabetes Mellitus in Slovakia

The aim of the study is to find out prevalence and individual stages of Diabetic Retinopathy in patients with type 1 and type 2 DM verified based on complex ophthalmologic measurements in Slovak Republic. The outcome of the project will be epidemiology survey, prevalence of diabetic retinopathy (DR) and diabetic macular edema (DME) in relation to type and duration of diabetes mellitus and risk factors. Project will also identify genetic factors linked with the diseases.

Study Overview

Status

Completed

Intervention / Treatment

Study Type

Observational

Enrollment (Actual)

4011

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Total expected number of patients included in this survey is 5000. With the objective to guarantee non-biased patient selection sample, each screening day the pre-specified sequence of patients (5th, 10th, 15th...) will selected. If the pre-selected patient does not come for visit or does not fulfill the inclusion criteria or does not want to sign the informed consent the next patient is asked to participate in the research. We plan to enroll 4500 patients using this non-biased method.

The weakness of the non-biased random selection is that the less frequent groups of patients will not have enough subjects for the proper statistical analysis. To correct for this effect pool of 500 patients is reserved for special subgroups. Pre-defined subgroups are:

  1. patients with DM duration more 20 years
  2. patients with DM duration less than 5 years already with DR in history All patients from these subgroups will be asked to participate in this project regardless of the pre-specified order.

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Signed informed consent for epidemiological research
  • Signed informed consent for genetic research
  • Patients with DM - type I and II regardless of the DM duration
  • All DM patients must be included regardless of presence of eye complications in patient´s anamnesis or during the examination by the diabetologist Subgroups analysis
  • Patients with DM - type I and II and DM duration ≥ 20 years
  • Patients with DM - type I and II and DM duration < 5 years and DR in history

Exclusion Criteria:

  • Age at the time of inclusion into the <18 years
  • Gestational DM or secondary-induced diabetes
  • Diabetic ketoacidosis or hyperosmolar coma
  • Alcohol abuse or acute alcohol intoxication

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

  • Time Perspectives: Cross-Sectional

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The prevalence of diabetic retinopathy as the proportion of patients with DR (any stage) in a given subgroup according to DM duration
Time Frame: participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
The results will be accompanied by Wald 95% confidence intervals. The combined prevalence results from more subgroups will be evaluated using weighted average using the best available epidemiology data.
participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluate the prevalence and individual stages of Diabetic Retinopathy in patients with type 1 and type 2 DM verified based on complex ophthalmologic measurements
Time Frame: participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
The calculation of prevalence for each stage of DR will be analyzed using the same methods as for the total DR prevalence.
participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
Evaluate the prevalence and individual stages of Diabetic Macular Edema (DME) in patients with type 1 and type 2 DM verified based on complex ophthalmologic measurements
Time Frame: participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
The calculation of prevalence for each stage of DME will be analyzed using the same methods as for the total DR prevalence
participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
Evaluate the impact of risk factors on the prevalence of Diabetic Retinopathy and Diabetic Macular Edema
Time Frame: participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria

The analysis will be realized using multivariate logistics regression. The output of the analysis will be the impact statistical significance of the individual risk factors represented by odds ratio for each risk parameter accompanied with statistical significance and corresponding confidence interval. The risk factors will be at least: age, gender, ethnicity, DM duration since diagnosis, glycemic control and diabetes management based on the average HbA1c of all measurements in the last 12 months, presence of nephropathy, malignancies and BMI.

Age, DM duration since diagnosis, diabetes control based on the average HbA1c of all measurements in the last 12 months and BMI will be assessed as continuous covariates whereas gender, nationality, presence of nephropathy and malignancies will be considered as categorical variables.

participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Epidemiological characteristics of patients with Diabetes Mellitus and with Diabetic Retinopathy in terms of demographic structure, treatment and control of DM and the presence of other microvascular and ophthalmologic complications
Time Frame: participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
The patient characteristics will be described as by standard methods of descriptive statistics - N, %, mean, media, min, max, SD and where necessary accompanied by the histogram or contingence table.
participants screened each working day within 8 working hours during a 6 months period in selected diabetology centers according to protocol criteria
Evaluate the impact of diabetic retinopathy and diabetes mellitus on the Quality Of Life as measured by NEI-VFQ25 questionnaires
Time Frame: participants examined each working day within selected working hours during a 6 months period in selected ophthalmology centers according to protocol criteria
The impact of DR and DME on the quality of life in case of patients with DM will be realized using ANCOVA method where QoL will be evaluated as the continuous variable. The multivariate analysis will include all relevant patient characteristics including visual acuity, age and gender of the patient. These characteristics will serve as covariates to correct for the difference in characteristics of patient with/without DR.
participants examined each working day within selected working hours during a 6 months period in selected ophthalmology centers according to protocol criteria
Investigate DNA polymorphisms and phenotypic features correlating with the development of DR in patients with extreme phenotypes.
Time Frame: DNA analysis during 7 months post study screening period
Genetic analysis is primarily exploratory in nature, does not test the hypothesis previously postulated and formal calculation of sample size can not be determined. In combination with accurately determined ocular and diabetic history is sample size above standard within typical publications of the topic.
DNA analysis during 7 months post study screening period
The analysis of mitochondrial DNA haplotypes in pre-defined patient groups
Time Frame: DNA analysis during 7 months post study screening period
Basic statistical analysis will include binary logistic regression (OR, 95% CI) and Fisher test. This method evaluates the statistical significance for the increase or decrease in the risk of DR for easy single nucleotide polymorphisms (SNPs) in in mitochondrial DNA (mtDNA), their combinations - DNA haplotypes, haplogroups and their clusters and thus identifies possible genetic factors involved in the study disease.
DNA analysis during 7 months post study screening period
The identification of patients with monogenic DM by biomarkers (hsCRP)
Time Frame: DNA analysis during 7 months post study screening period

Calculation of prevalence HNF1A-MODY in a wide Slovak population with diabetes using biomarker hsCRP.

Comparison of the severity of retinopathy in mutation carriers of HNF1A-MODY and type 2 diabetes / type 1 diabetes patients in the specified data set.

DNA analysis during 7 months post study screening period
Identification of patients with extreme phenotypes and family history of DM with eye complications
Time Frame: DNA analysis during 7 months post study screening period
DNA analysis during 7 months post study screening period

Collaborators and Investigators

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

Investigators

  • Study Director: Dagmar Buckova, M.D., Novartis Slovakia
  • Study Director: Peter Carnogursky, MSc., Novartis Slovakia, s.r.o.
  • Study Director: Svetlana Sefcikova, MD, Novartis Slovakia, s.r.o.
  • Study Director: Pavol Tison, MD, Novartis Slovakia, s.r.o.
  • Study Director: Iveta Tvrda, MD, Novartis Slovakia, s.r.o.
  • Study Director: Daniela Gasperikova, MSc., PhD., Novartis Slovakia, s.r.o.
  • Study Director: Ivana Hojsikova, RNDr., Medirex Group Academy
  • Study Director: Ludevit Kadasi, RNDr., DrSc., Comenius University
  • Study Director: Iwar Klimes, Prof., MD, DrSc., Novartis Slovakia, s.r.o.
  • Principal Investigator: Peter Jackuliak, MD, University Hospital Bratislava
  • Principal Investigator: Vladimir Krasnik, MD PhD., University Hospital Bratislava
  • Principal Investigator: Emil Martinka, MD, PhD., National Institute for Endocrinology and Diabetology
  • Principal Investigator: Marian Mokan, Prof. MD DrSc., Jesenius University Martin
  • Principal Investigator: Zuzana Nemethyova, MD, Diabetology Dispensary Bratislava
  • Principal Investigator: Marta Ondrejkova, MD PhD., F.D. Roosevelt Hospital Banska Bystrica
  • Principal Investigator: Jana Stefanickova, MD, University Hospital Bratislava

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

February 1, 2015

Primary Completion (Actual)

November 1, 2015

Study Completion (Actual)

November 1, 2015

Study Registration Dates

First Submitted

September 3, 2014

First Submitted That Met QC Criteria

September 3, 2014

First Posted (Estimate)

September 5, 2014

Study Record Updates

Last Update Posted (Estimate)

September 22, 2016

Last Update Submitted That Met QC Criteria

September 21, 2016

Last Verified

September 1, 2016

More Information

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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