Genetic Association of Diabetic Retinopathy-1 (DMR-1)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified December 2011 by Taipei Veterans General Hospital, Taiwan.
Recruitment status was  Recruiting
Sponsor:
Collaborator:
Yen Tjing Ling Medical Foundation
Information provided by (Responsible Party):
vghtpe user, Taipei Veterans General Hospital,Taiwan
ClinicalTrials.gov Identifier:
NCT01298245
First received: February 15, 2011
Last updated: December 5, 2011
Last verified: December 2011
  Purpose

The primary purpose of the study is to investigate allele frequencies of candidate genes in Chinese diabetic patients with or without known diabetic retinopathy. Two hundred Chinese diabetic patients, aged between 20 - 75 years old, who have received ophthalmic fundus examination (either by an ophthalmoscope or fundus camera) within 6 months before the study will be recruited for the study. Each subject will receive anthropometric and blood pressure measurements. Then, fasting blood samples will be taken for the measurements of glucose, HbA1c, lipid profile, and biochemistry. An additional 10 ml blood sample will be taken for DNA extraction from buffy coat. Meanwhile, the participant will receive structural questionnaires for demography, personal history, medical history and concomitant medication. Single nucleotide polymorphisms (SNPs) in candidate genes and in targeted chromosome regions will be genotyped by using the ABI TaqMan assays. The differences in the distribution of genotypes and alleles between the study groups will be analyzed using appropriate statistical methods. Through the study, the investigators hope to build up a platform for future large-scale genetic studies of diabetic retinopathy. The investigators also hope to set up priority of candidate loci for future studies.


Condition
Diabetes
Diabetic Retinopathy

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Genetic Association Studies of Diabetic Retinopathy (1): Vanguard Phase

Resource links provided by NLM:


Further study details as provided by Taipei Veterans General Hospital, Taiwan:

Primary Outcome Measures:
  • The differences in the distribution of candidate genotypes and alleles between the study groups [ Time Frame: 12 months ] [ Designated as safety issue: No ]
    Patients with diabetes who have received ophthalmic fundus examination within 6 months before the study. The eligible participants will be grouped by the results of prior fundus examination: those with known history of diabetic retinopathy; those without known history of diabetic retinopathy.


Secondary Outcome Measures:
  • the frequencies of haplotypes of different single nucleotide polymorphisms [ Time Frame: 12 months ] [ Designated as safety issue: No ]
    We will estimate the frequencies of haplotypes of different single nucleotide polymorphisms, calculate linkage disequilibrium between single nucleotide polymorphisms, and conduct haplotype analysis.


Biospecimen Retention:   Samples With DNA

The participants will receive fasting blood sampling for the measurements of glucose, HbA1c, lipid profile, and biochemistry. An additional 10 ml blood sample will be taken for DNA extraction from buffy coat. Early morning urine samples will also be collected for evaluation of overt proteinuria by a dipstick method.


Estimated Enrollment: 200
Study Start Date: February 2011
Estimated Study Completion Date: December 2012
Estimated Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts
Case: diabetic retinopathy
Patients with diabetes who have received ophthalmic fundus examination within 6 months before the study and those with known positive results of diabetic retinopathy
Control: no diabetic retinopathy
Patients with diabetes who have received ophthalmic fundus examination within 6 months before the study and those without known positive results of diabetic retinopathy

Detailed Description:

Diabetic retinopathy (DR) is one of the most frequent microvascular complications of diabetes (DM). Current guidelines recommend that patients with DM should receive ophthalmic fundus examination annually. DR poses a serious threat to the health of millions patients who have DM. Nowadays, DR has become the leading cause of new cases of visual impairment and blindness among adults.

Genetic factors are likely to account for the susceptibility to DR for the differences in DR incidence between individuals with diabetes. Familial aggregation studies showed that increased risk of severe DR was noted among family members with diabetes with moderate heritability of DR risk. Racial and ethnic differences in the prevalence of DR may also explain some parts of influence of genetic or environmental/cultural risk factors. There were over 30 candidate genes involved in metabolic mechanisms and functional pathways associated with DR. However, consistent associations between candidate genes and DR have yet been identified. The current study is designed to build up a working platform for future large-scale genetic studies of diabetic retinopathy. The investigators also hope to set up priority of candidate loci for future researches.

In the present study, the investigators plan to recruit 200 Chinese patients with DM who have received ophthalmic fundus examination (either by an ophthalmoscope or fundus camera) within 6 months before the study. Each subject will receive anthropometric and blood pressure measurements. Then, fasting blood samples will be taken for the measurements of glucose, HbA1c, lipid profile, and biochemistry. An additional 10 ml blood sample will be taken for DNA extraction from buffy coat. Single nucleotide polymorphisms (SNPs) in candidate genes and in targeted chromosome regions will be genotyped by using the ABI TaqMan assays. The differences in the distribution of genotypes and alleles between the study groups will be analyzed using appropriate statistical methods.

  Eligibility

Ages Eligible for Study:   20 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Patients with DM who have received ophthalmic fundus examination within 6 months before the study, either with or without diabetic retinopathy

Criteria

Inclusion Criteria:

  • Patients with DM, diagnosed by the 2010 American Diabetes Association diagnosis criteria.
  • Men or women.
  • Aged 20 ~ 75 years old (inclusive).
  • Who have received ophthalmic fundus examination within 6 months before the study: either (1)by an ophthalmoscope or fundus camera (results reviewed by a qualified physician), or (2)the ophthalmoscopic examination being performed by an ophthalmologist.
  • Willing to participate in the study by signing an informed consent.

Exclusion Criteria:

  • Women in pregnancy.
  • No document to verify the results of the ophthalmic fundus examination requiring for the inclusion.
  • History of mental incapacity or language barriers that may preclude adequate understanding or cooperation in the study.
  • Current or concomitant illness that would interfere with the subject's ability to perform the study or that would confound the study results, judged by the investigation physicians.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01298245

Contacts
Contact: Chii-Min Hwu, MD 886228757516 chhwu@vghtpe.gov.tw

Locations
Taiwan
Taipei Veterans General Hospital Recruiting
Taipei, Taiwan, 112
Contact: Chii-Min Hwu, MD    8862287516    chhwu@vghtpe.gov.tw   
Sponsors and Collaborators
Taipei Veterans General Hospital, Taiwan
Yen Tjing Ling Medical Foundation
Investigators
Principal Investigator: Chii-Min Hwu, MD Taipei Veterans General Hospital, Taiwan
  More Information

No publications provided

Responsible Party: vghtpe user, Attending physician, Taipei Veterans General Hospital,Taiwan
ClinicalTrials.gov Identifier: NCT01298245     History of Changes
Other Study ID Numbers: 201008023GB, CI-99-1
Study First Received: February 15, 2011
Last Updated: December 5, 2011
Health Authority: Taiwan: Institutional Review Board

Keywords provided by Taipei Veterans General Hospital, Taiwan:
diabetes
diabetic retinopathy
Chinese
gene
associations

Additional relevant MeSH terms:
Diabetic Retinopathy
Retinal Diseases
Cardiovascular Diseases
Diabetes Complications
Diabetes Mellitus
Diabetic Angiopathies
Endocrine System Diseases
Eye Diseases
Vascular Diseases

ClinicalTrials.gov processed this record on October 23, 2014