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NCT Number: NCT02232503

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.

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Key information

Conditions

Diabetic Retinopathy Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Diabetic Macular Edema Endocrine System Diseases Eye Diseases Glucose Metabolism Disorders Metabolic Diseases Nutritional and Metabolic Diseases Retinal Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Studied cohort

Genetic

For the purpose of DNA isolation prior to genetic analysis of patients two samples of peripheral blood will be taken; first in the volume of 3.5 ml and second in the volume of 9 ml from each patient included into the study.

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

  2. 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

  3. 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.

Other outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

Sponsors and collaborators

Lead sponsor

Novartis Slovakia, s.r.o.

Industry

Collaborators

  • Comenius University
  • Medirex Group Academy
  • Slovak Technical University

Registry information

Official study title

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

Acronym: DIARET SK

Important dates

Study start
2015
Primary completion
2015
Study completion
2015
First posted
Sep 5, 2014
Registry last updated
Sep 22, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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