MINDD 3: Prediabetes and Delay Discounting

The prevention of Type 2 diabetes in an obese person with prediabetes requires developing a healthier lifestyle. The rational approach for someone with prediabetes would be to eat healthier, be more active, lose weight, and manage their comorbidities. However, preliminary research suggests that individuals with Type 2 diabetes discount the future and engage in behaviors that maximize current pleasure and short-term gain; thus, daily choices needed to improve future health are rare in this population. Delay discounting (DD) describes the choice of smaller immediate versus larger delayed rewards. This behavioral process is related to a wide variety of health choices, ranging from preventive health to behavioral and medical regimen adherence, including regimens used for Type 2 diabetes. The investigators believe that DD provides a target for one type of self-regulation that can improve a wide variety of health behaviors and medical adherence.

Research from our laboratories has shown that episodic future thinking (EFT), a form of prospection which reduces the bias towards immediate gratification, activates brain regions involved in planning and prospection such that future rewards have increased value and the extent of delay discounting is reduced. Cueing individuals to think about future events during inter-temporal decision-making reduces the rate of DD, eating in and outside of the laboratory, and smoking behavior. The overarching goal of this research is to use an experimental medicine approach to translate basic research on DD and EFT into clinical interventions to prevent the transition from prediabetes to a diagnosis of Type 2 diabetes.

Inclusion criteria

• Prediabetes: Participants must have a diagnosis of prediabetes within the last 2 years or meet criteria for prediabetes. The American Diabetes Association guidelines defines prediabetes as Fasting Plasma Glucose (FPG) 100-125 mg/dl, 2h glucose 140-199 mg/dl after Oral Glucose Tolerance Test (OGTT), or hemoglobin A1c (HbA1c) approximately 5.7-6.4%.
• Comorbidities: Participants must have a history of comorbid diagnosis such as hypertension and/or hyperlipidemia to participate in the behavioral portion of this study. Hypertension is defined as blood pressure greater than 140/90 on two separate occasions at least one week apart, or medical management for hypertension (i.e. medications including Lisinopril and Diovan). Dyslipidemia is defined by LDL greater than 130 mg/dl, or non-fasting non HDL cholesterol ≥160mg/dL or medical management for dyslipidemia (medications including Niacin, Lovastatin).

Exclusion criteria

• Type 2 Diabetes: Individuals will be excluded if they have Type 2 Diabetes.
• Pregnancy: Women who are pregnant or lactating will be excluded from participation.
• Conditions that affect adherence: Participants should not have a condition that would limit participation which include medical conditions that would affect individuals' ability to use the computer for prolonged period of time; leave the individual unable to ambulate; or current diagnoses of an eating disorder (anorexia, bulimia,), unmanaged psychiatric disorder (depression, anxiety, attention deficit hyperactivity disorder (ADHD), schizophrenia), or an intellectual impairment that would impact study adherence.
• Abnormal glucose related to medications: Participants should not be taking medications that would limit participation and cause abnormal glucose levels (e.g. atypical antipsychotic medications or glucocorticoids) including diabetic drugs such as Metformin.
• Unwilling or unable to eat study food: Participants who are unwilling or not able to eat the study food (a PowerBar) will not be able to take part in this study.

Prior participation in similar studies: Individuals who have recently participated in a laboratory study using similar methods may also be excluded.

• Do not meet discounting criteria: Individuals who do not meet discounting criteria (e.g. nonsystematic discounting) on a delay discounting task may be excluded.