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

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

The primary objective of the study is to assess the clinical utility of a genetic test for Type 2 diabetes risk in combination with standardized risk assessment compared with standardized risk assessment alone, and to measure whether changes in perceived risk following genetic testing for Type 2 diabetes risk are correlated with behavior change and increased concern about risk for Type 2 diabetes.

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.

Inclusion Criteria:

• Are male or female outpatients
• No self-reported history of diabetes
• No self-reported history of prior genetic testing for diabetes
• Not pregnant (self report)
• Are ≥18 and <81 years of age
• Scheduled to receive serum glucose test in participating clinic
• Fasting at time of blood draw (no food or drink - except water - previous 8 hours: self report)
• Able and willing to give legally effective consent
• Able and willing to participate in patient questionnaires
• Ambulatory

Exclusion Criteria:

• Previously or currently taking medications for lowering glucose (i.e., exenatide, pramlintide, metformin, rosiglitazone, pioglitazone, or future diabetes drugs) based on self-report and/or prescreening
• Self-report of current or prior diabetes diagnosis
• Self-reported prior history of genetic testing for diabetes
• Baseline serum glucose test result >125