Genetic Testing for Type 2 Diabetes

April 6, 2015 updated by: US Department of Veterans Affairs

The Impact of Genetic Testing for Type 2 Diabetes on Health Behaviors

In this 6-month randomized, controlled trial, we examined whether providing participants with genetic test results and counseling regarding their risk for type 2 diabetes would motivate them to improve their health behaviors and lose weight to reduce their diabetes risk. We hypothesized that participants who received conventional diabetes counseling plus genetic test results and counseling would have at least 6 lb greater weight loss at 3 months than participants who received conventional diabetes counseling without genetic test results.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

In this 6-month randomized, controlled trial, we evaluated the impact of genetic testing for type 2 diabetes on psychological, health behavior, and clinical outcomes. Eligibility criteria included age 21 to 65 years, overweight or obese (body mass index [BMI] >27 kg/m2), and no prior diagnosis of type 2 diabetes. At baseline, participants (N=601) had conventional risk factors assessed, including demographics, fasting plasma glucose (FPG), and family history. They also provided blood samples for genetic testing of TCF7L2, PPARG, and KCNJ11, three genes that confer elevated risk for development of type 2 diabetes. Participants were then randomized to receive conventional counseling plus control eye disease counseling (CR+EYE) or conventional counseling plus genetic test results (CR+G). Two to four weeks following the baseline visit, when the genetic test results were available, participants returned for a visit with a genetic counselor. All participants received conventional risk counseling based on their lifetime population risk, FPG results, and family history. Next, participants were informed of their randomization assignments; CR+EYE participants received counseling on eye diseases, whereas CR+G participants received genetic counseling. Then perceived risk, affect, self-efficacy, and readiness to change were assessed. All other outcomes were also assessed at 3 and 6 months.

Study Type

Interventional

Enrollment (Actual)

601

Phase

  • Not Applicable

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

  • United States
    • North Carolina
      • Durham, North Carolina, United States, 27705
        • Durham VA Medical Center, Durham, NC

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

21 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • body mass index >27 kg/m2
  • baseline fasting plasma glucose <=125 mg/dL

Exclusion Criteria:

  • prior diagnosis of type 2 diabetes
  • fasting plasma glucose >125 mg/dL on more than one occasion
  • HbA1c > 7%
  • taking diabetes medication
  • actively losing weight
  • enrolled in research study focusing on lifestyle changes
  • unable to provide informed consent or answer survey questions unassisted
  • residing in nursing home or receiving home health care
  • active diagnosis of psychosis or dementia
  • at least one error on 6-item cognitive screener

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

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CR+G
conventional risk counseling (lifetime risk, fasting plasma glucose, and family history) plus genetic testing for type 2 diabetes
Genetic: genetic testing for type 2 diabetes
TCF7L2, PPARG, or KCNJ11
Behavioral: Conventional risk counseling
Risk based on lifetime risk, fasting plasma glucose results, and family history.
Active Comparator: CR+EYE
conventional risk counseling (lifetime risk, fasting plasma glucose, and family history) plus eye disease counseling
Behavioral: Conventional risk counseling
Risk based on lifetime risk, fasting plasma glucose results, and family history.
Behavioral: eye disease counseling
addresses risk for age-related macular degeneration, glaucoma, cataracts

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Weight
Time Frame: 3 months
weight 3 months post-enrollment
3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Insulin Resistance (HOMA2-IR)
Time Frame: 3 months

Calculated using the updated homeostasis model assessment (HOMA) calculator at http://www.dtu.ox.ac.uk/homacalculator/

Higher numbers indicate higher insulin resistance. There are no established cutoffs indicating impaired resistance.
3 months
Perceived Lifetime Risk of Type 2 Diabetes
Time Frame: 3 months
measured on 1-7 scale (definitely will not get diabetes to definitely will get diabetes)
3 months
Daily Caloric Intake
Time Frame: 3 months
Estimated daily caloric intake based on self-reported frequency and amount of intake of specific foods over the past 3 months as assessed by the Block Brief Food Frequency Questionnaire
3 months
Moderate Intensity Physical Activity
Time Frame: 3 months
self-report based on the long version of the International Physical Activity Questionnaire. Moderate physical activity was queried in the domains of work (e.g., carrying light loads), transportation (e.g., bicycling), domestic chores and gardening (e.g., sweeping, raking), and leisure-time (e.g., bicycling, swimming).
3 months

Collaborators and Investigators

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

Sponsor

US Department of Veterans Affairs

Collaborators

Duke University

Investigators

  • Principal Investigator: Corrine I. Voils, PhD, Durham VA Medical Center, Durham, NC

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

August 1, 2010

Primary Completion (Actual)

March 1, 2013

Study Completion (Actual)

March 1, 2013

Study Registration Dates

First Submitted

January 29, 2010

First Submitted That Met QC Criteria

February 1, 2010

First Posted (Estimate)

February 2, 2010

Study Record Updates

Last Update Posted (Estimate)

April 24, 2015

Last Update Submitted That Met QC Criteria

April 6, 2015

Last Verified

April 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IBD 09-039

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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