Persons with obesity, prediabetes and type 2 diabetes excessively discount the future in cross sectional studies, and increases in delay discounting (DD) are associated with worsening glycemic control. By implication this worsening glycemic control could be related to the transition from prediabetes to type 2 diabetes. People who are more impulsive and discount the future may demonstrate greater responsivity to food cues, and variability in patterns of eating, which will result in variability in blood glucose. A large body of research shows that variability in blood glucose, as assessed by continuous glucose monitors (CGM), may contribute to risk for diabetes complications. Logically substantial discounting may result in a more variable pattern of eating, which in turn results in variability of blood glucose levels in those with deteriorating beta cell function and insulin resistance. Pilot data from our SOBC grant support a relationship between DD and variability in eating behavior, as well as variability in eating being related to HbA1c values. These results suggest from an experimental medicine approach that reducing DD should reduce variability in behavior by making people less responsive to individual and environmental cues that signal immediate gratification. Episodic future thinking (EFT) has been shown to reduce DD. We propose to study individuals with HbA1c values ranging from normal through prediabetes to type 2 diabetes over a two-week period to establish associations between DD, variability in eating and activity, and glycemia using continuous glucose monitors. We will then randomize these persons to EFT or control conditions for another two weeks. Most importantly for understanding factors related to whether glucose variability exacerbates disease progression in diabetes is that the data from CGM can give information about fasting glucose, variability in glucose and average glucose levels. Based on these methods we plan to two specific aims.
Specific Aim 1 will assess the relationship between DD and variability in eating, activity, and blood glucose levels over a baseline two-week period.
Specific Aim 2 will assess the effects of decreasing DD using EFT on variability in eating, variability in activity, and variability in blood glucose levels over a two-week intervention period. We would follow effects of these short term relationships with a longer term clinical trial to assess effects of EFT on changes in blood glucose variability as well as HbA1c levels.
The proposed research will identify the relationship between delay discounting, eating, activity, and blood glucose variability and assess the effects of modifying delay discounting by episodic future thinking on blood glucose variability. This research will provide a link to why increases in delay discounting may be related to worsening glycemic control, and test the effectiveness of episodic future thinking as a way to reduce variability in behaviors that lead to glucose variability. The findings from this project may help develop novel interventions to treat the public health problems of diabetes and obesity. !
