Effect of Type 2 Diabetes Genetic Risk Information on Health Behaviors and Outcomes (TDE)

One thousand outpatients will be enrolled over two years at two university-affiliated primary care clinics. Patients will be assigned to one of three study arms: those who want genetic testing for diabetes risk will be randomly assigned to either receive the testing in addition to the SRA (SRA+G) or to receive the SRA only (SRA-only). Those who do not wish to have genetic testing will receive the SRA only. All patients will be surveyed at baseline, immediately after going through the SRA (risk-counseling visit; 2-4 weeks after initial visit), at 3 months post risk counseling visit and at 12 months post risk counseling visit. BMI, waist circumference, fasting plasma glucose and insulin will be measured at baseline and 12 months. Surveys will allow us to track patients' emotional responses to diabetes risk information and changing perceptions of personal risk for Type 2 diabetes over time, and to see if these correlate with subsequent diet and exercise behaviors.

We will use a linear model to assess the effects of genetic testing among the three study groups, using HOmeostasis Model Assessment of Insulin Resistance (HOMA-IR) and weight loss as the primary outcomes. We will use generalized linear ordinal regression models to fit the ordinal survey outcomes of risk perceptions to the continuous HOMA-IR and weight outcome variables.