Information for Medical Providers
This page is for anyone who works with patients who have Type 1 Diabetes
Our team, led by Dr. Rhonda M. Merwin, has been conducting research about Type 1 Diabetes and eating disorders since 2011.
Read more about Dr. Merwin's work, here.
Our current research is the following R21 treatment study, which can be found here at ClinicalTrials.Gov
The purpose of the study is to see if a new treatment for individuals with type 1 diabetes who take less insulin than they need (for weight control or other emotional reasons) is helpful for improving diabetes management. This treatment combines the use of a smartphone application with weekly therapy.
A recent additional grant, obtained from the Duke Department of Psychiatry, is allowing us to expand our research to include the role of the appetite- regulating hormone ghrelin in individuals with and without insulin-witholding behaviors.
The Purpose of this Research
Individuals with type 1 diabetes who take less insulin than is needed are at high risk for diabetes-related medical complications and premature death. Conventional eating disorder (ED) treatments are not as effective for these patients, suggesting that they need a more tailored treatment approach and one that includes intervention at the time and place when they are making decisions about their diabetes self-management (See Background and Significance). The goal of treatment development project is to (1) modify an existing mobile application (app) for EDs (Recovery Record; RR) to address the unique needs of adults with type 1 diabetes (T1D) who underutilize insulin due to eating or weight concerns, and (2) test whether app-supported individual treatment decreases management problems and improves glycemic control. We also gather preliminary data on the impact of the intervention on health care utilization and costs and calculate attrition to assess feasibility. We also explore appetite dysregulation as a factor maintaining aberrant eating (e.g., overeating, binge eating) among T1D patients who restrict insulin.
Our Research Aims
Aim 1. Translate scientific findings on the factors associated with the underuse of insulin into a mobile app that is acceptable to T1D patients with management problems. Over the last several years, we have studied factors associated with insulin omission in the natural environment and conducted focus groups and interviews with patients with type 1 diabetes with a range of eating, weight and shape concerns. In Aim 1, we build T1D-specific content into the existing RR app based on our quantitative data of factors that maintain insulin misuse (R01 DK089329) and subsequent patient-centered qualitative data (See Preliminary Studies). The fully functional version of the modified RR app is then beta tested with 10 T1D patients who omit insulin for weight control. Patients use the app for 14 days and send feedback about user experience via the app. We make final adaptations prior to the start of the treatment trial. Based on our foundational work we do not expect to make substantive changes to app content, but rather more minor modifications to maximize ease of use. [H1] The modified RR app will be acceptable to T1D patients with >90% accessing features of the app on average daily.
Aim 2. Test whether app-supported individual treatment is associated with improved glycemic control, and decreases in diabetes self-management and emergency care utilization. In Aim 2, we recruit twenty-five T1D patients who underutilize insulin complete 3 months of app-supported individual treatment and 6 months of follow-up. Metabolic control is indexed by mean blood glucose (BG) over 3 days of continuous glucose monitoring (CGM) and hemoglobin A1c (HbA1c) at baseline and 3 months, and HbA1c at 6 and 9 months. [H2] Participants will evidence significant decreases in mean BG. [H3] Improvements in glycemic control will correspond with treatment engagement as reflected in frequency of app use from 0-3 months. [H4] Participants will report less frequent T1D mismanagement behavior (e.g., under-dosing of insulin). [H5] Participation in routine medical care will increase [H6] and emergency visits will decrease. [H7] Attrition will be < 20%.
Exploratory Aim: Evaluate plasma concentrations of ghrelin during fasting and after meal ingestion among T1D patients with and without aberrant eating (overeating or binge eating), and examine the relationship between fasting ghrelin and postprandial ghrelin suppression and appetite and eating behavior. Our earlier study (R01 DK089329, PI: Merwin) revealed large differences in susceptibility to hunger between T1D patients with T1D management problems and those without, as well as hunger less tightly synced to declines in BG (Susceptibility to hunger predicted participants’ frequency of binge eating over 72 hours of real-time reporting in the natural environment. Together, these findings suggest that disruptions in appetite regulation may be a factor maintaining eating problems that if addressed could improve the effectiveness of other behavioral interventions.
Twenty T1D patients who participate in Aim 2 will be recruited to complete an assessment of ghrelin levels (fasting and 2-hour postprandial). We will recruit an additional 20 Control participants (T1D patients without aberrant eating) to serve as a comparison. We will examine group differences in ghrelin levels and conduct within-subject comparisons of T1D-ED participants’ ghrelin levels under conditions of adequate administration of short-acting insulin and their typical state of insulin insufficiency. We will also examine the relationship between ghrelin levels and appetite and eating behavior.
[H8] ED Participants will have increased fasting ghrelin levels and blunted ghrelin suppression with a macronutrient load relative to Control Participants.
[H9] Ghrelin levels will correspond to appetite and frequency of uncontrolled eating over the past 7 days.
[H10] ED Participants will report decreased appetite and evidence greater suppression of postprandial ghrelin when they administer short-acting insulin prior to a macronutrient load (relative to when they do not).
Question: "I have patients that I suspect might be under-dosing their insulin, but they don't tell me that. How can I refer them to this study?"
Answer: That's a good question. Many individuals in our studies have told us that is can be very difficult to admit they engage in this behavior to their providers - even to themselves!
Consider saying simply, "I have some information here about a study for people with Type 1 that you might qualify for. Let me give you this information and you look it over*, can I ask one of the research coordinators to call you - just to see if this might be a good match?
That's it. If the person agrees - just pass their name to us and we will contact them!
*We have resources we can provide to you, just contact us!
Question: "Who qualifies for the iOmit study? Who should I refer to you?"
Answer: Adults (between 18-65 years) with Type 1 Diabetes and difficulty with glycemic control may qualify. Participants must be approved for participation by their medical provider, agree to continue care with their medical provider, consent for us to be in contact with their provider and have access to a Smartphone.
The participant also needs to have some type of issue with food/eating that is contributing to the underutilization of insulin and/or poor glycemic control (rather than just practical or logistical issues interfering with management).
Provider Corner
Preliminary findings from our studies here:
Merwin, R. M., Moskovich, A. A., Honeycutt, L. K., Lane, J. D., Feinglos, M., Surwit, R. S., ... & Mooney, J. (2018). Time of Day When Type 1 Diabetes Patients With Eating Disorder Symptoms Most Commonly Restrict Insulin. Psychosomatic medicine, 80(2), 222-229.