Diabetes Prevention Through Genetics, Familial History and Behavior Change

Legacy-DPP: Diabetes Prevention Through Genetics, Familial History and Behavior Change A Family-Enhanced, Genetically-Informed Diabetes Prevention Program

The goal of this clinical trial is to learn if adding a family engagement component to the standard Diabetes Prevention Program (DPP) improves outcomes for adults with prediabetes. It will also learn about the effects of this approach on family members' health.

The main questions it aims to answer are:

• Does adding family health history collection and family participation to the DPP improve session attendance compared to standard DPP?
• Does this family-centered approach lead to greater weight loss and HbA1c (blood sugar) reduction compared to standard DPP?
• Do health improvements extend to participants' family members, and what factors explain differences in family-level outcomes?

Researchers will compare an adapted DPP with a family component to the standard DPP (individual-focused) to see if involving family members improves diabetes prevention outcomes.

Participants will:

• Be assigned to one of two groups: adapted DPP with family sessions, or standard DPP
• If assigned to the adapted DPP, complete a family health history using the CDC's My Family Health Portrait tool and attend 6 additional sessions with family members focused on personalized risk communication
• Attend regular checkups to measure weight and HbA1c at 6 and 12 months
• Have session attendance tracked throughout the program
• Family members of participants may also be asked to complete health assessments to measure any changes in their own health behaviors

Study Overview

• Status: Not yet recruiting
• Conditions: Weight Loss; Prediabetes
• Intervention / Treatment: Behavioral: LEGACY DPP; Behavioral: DPP

Detailed Description

Type 2 diabetes affects 38.4 million U.S. adults, and an additional 97.6 million adults have prediabetes and are at risk of developing the disease. This burden falls disproportionately on racial and ethnic minority families and rural communities.

This clinical trial aims to determine whether embedding family engagement and family health history into the Diabetes Prevention Program (DPP) improves adherence, weight loss, and glycemic outcomes among adults with prediabetes, compared to the standard individual-focused DPP.

Participants will be 200 index participants with prediabetes, along with their family members, recruited from rural and urban sites and stratified by geographic location. Index participants will be block randomized to receive either standard DPP or an adapted version that adds 6 weeks of family health history and genetics education-using the CDC's My Family Health Portrait tool-paired with family participation and skill-building sessions.

All participants will attend regular clinic visits to monitor weight and HbA1c at 6 and 12 months and will have session attendance tracked throughout. Family members will also complete health assessments to measure whether health improvements extend beyond the index participant, and researchers will use the Actor-Partner Interdependence Model to identify factors explaining variation in family-level outcomes.

This is a 2-arm randomized controlled trial comparing standard DPP to a family-adapted DPP incorporating family health history, genetics education, and family skill-building.

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Phase 2; Phase 3

Contacts and Locations

• Study Contact: Name: Tennille Leak-Johnson, PhD; Phone Number: 404-756-5225; Email: tleakjohnson@msm.edu
• Study Contact Backup: Name: Candice L Alick, PhD; Phone Number: 404-752-1009; Email: calick@msm.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age ≥18 years.
• Fasting HbA1c 5.7-6.4% confirmed by CLIA-waived point-of-care testing.
• BMI ≥25 kg/m².
• Able to provide informed consent.
• Has an adult household/family or framily (fictive kin) member willing to enroll as a paired participant.
• Willing to attend in-person sessions

Exclusion Criteria:

• Minors <18 years
• Prior diagnosis of T1 or T2D.
• HbA1c ≥6.5% at screening (Aim 1/2 curriculum eligibility)
• Current glucose-lowering medication use
• Pregnancy
• Physical-activity contraindications
• Individuals unable to speak or understand English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lifestyle Engagement through Genetics and Collaborative familY DPP (LEGACY DPP); Participants will receive the LEGACY DPP intervention	Behavioral: LEGACY DPP; The index partner will participate in an adapted DPP as a dyad with a family member with family health history and family participation and skill building Participants will receive; family health history sessions; core behavioral weight loss group sessions; a family skill building segment covering cohesion and communication during core sessions
Active Comparator: Diabetes Prevention Program (DPP); Participants will receive the DPP intervention	Behavioral: DPP; The index partner will participate in standard DPP Participants will receive - core behavioral weight loss group sessions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent change in body weight	Body weight (kg) expressed as a continuous variable will be collected on a digital scale.	Baseline, 6 months, 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change in Blood Pressure	Blood Pressure measured after 5 minutes of rest and taken in the same position throughout the study.	Baseline, 6 months, 12 months
Change in HbA1c (fasting, CLIA-waived assay)	Blood (~20 mL) will be collected to assess changes in glycosloated hemoglobin	Baseline, 6 months, 12 months
Change in Fasting lipid panel (total cholesterol, HDL, LDL, triglycerides)	Fasting lipid panel will measured to assess changes in total cholesterol, HDL, LDL, and triglycerides.	Baseline, 6 months, 12 months
Change in Skin carotenoids	Skin carotenoids will be assessed using a VeggieMeter as an indicator for fruit and vegetable intake.	Baseline, 6 months, 12 months
Change in Physical activity steps	Steps will be measured using an activity tracker e.g., Fitbit	Baseline, 6 months, 12 months
Change in Self-Regulation of Eating Behaviors	The Eating Behavior Inventory (20 items) measures the adoption of eating behaviors associated with weight loss (e.g., monitoring quantity eaten, frequency of weighing, shopping from a list) to measure self-regulation behaviors. Items are rated on a 5-point frequency scale from "never or hardly ever" to "always or almost always." Scores range from 26 to 130	Baseline, 6 months, 12 months
Change in Self-Efficacy of Eating Behaviors	Measured by survey responses to the Weight Efficacy Lifestyle Questionnaire Short Form (WEL-SF).Scale goes from 0 (not at all confident) to 10 (very confident). Higher scores mean better self efficacy.	Baseline, 6 months, 12 months
Change in Self-Efficacy of Physical Activity	The confidence subscale of the Patient-centered Assessment and Counseling for Exercise Adult Diet and Physical Activity Measure (6 items; ) measures confidence in participating in regular exercise or physical activity in different situations (e.g., "How confident are you that you would participate in regular exercise or physical activity: When I am tired?"). Items rated on a scale from 1 ("not at all confident") to 6 ("extremely confident"). Higher scores show higher self-efficacy.	Baseline, 6 months, 12 months
Change in Social Support for Eating	The Social Support and Eating Habits Survey (10 items) measures social support specific to healthy eating. Subscales assess encouragement for eating behaviors from partners (e.g., "Encouraged me not to eat 'unhealthy food' when I am tempted") and discouragement for eating behaviors from partners (e.g., "Brought home foods I am trying not to eat"). The items are rated on a scale of "none" to "very often." Total scores range from 5 to 50, with higher scores indicating more social support for eating behaviors.	Baseline, 6 months, 12 months
Change in Social Support for Exercise	The exercise participation subscale of the Social Support and Exercise Survey (10 items) measures social support specific to exercise behaviors. The subscale assesses the level of support for exercise from partners. Subscale example items include "Exercised with me" and "Criticized or made fun of me for exercising." Total scores range from 5 to 50, with higher scores indicating more social support for exercise participation behaviors.	Baseline, 6 months, 12 months
Change in Family Communication	Family communication is assessed with the communication subscale of the McMaster Family Assessment Device (6 items). Communication is defined as the exchange of information among family members. Items focused on whether verbal messages were clear and direct for the intended recipient. Responses ranged from "strongly agree" to "strongly disagree." Higher scores represent unhealthy communication.	Baseline, 6 months, 12 months
Change in Family Cohesion	The cohesion subscale (10 items) of the Family Adaptability and Cohesion Evaluation Scale III measures the emotional bonding family members have with one another. Items like "Family members ask each other for help" rated on a 5-point Likert scale from "almost never" to "almost always."	Baseline, 6 months, 12 months
Change in Family Emotional Involvement	The family emotional involvement (7 items) of the Family Emotional Involvement and Criticism Scale rate items on a 5-point Likert scale, as above.	Baseline, 6 months, 12 months
Change in Family Perceived Criticism	The perceived criticism (7 items) subscales of the Family Emotional Involvement and Criticism Scale rate items like on a 5-point Likert scale, as above.	Baseline, 6 months, 12 months
Change in Family Collaborative problem solving	The Family Problem-Solving Communication Index (10 items) was used to measure the specific communication style that families use to manage and solve problems and conflicts in various types of stressful situations. Consisting of 2 subscales, affirmatory communication and incendiary communication, the response options were "false," "mostly false," "mostly true," and "true."	Baseline, 6 months, 12 months

Collaborators and Investigators

• Sponsor: Morehouse School of Medicine
• Investigators: Principal Investigator: Candice L Alick, PhD, Morehouse School of Medicine; Principal Investigator: Tennille Leak-Johnson, PhD, Morehouse School of Medicine

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): January 31, 2031
• Study Completion (Estimated): January 31, 2031

Study Registration Dates

• First Submitted: September 6, 2026
• First Submitted That Met QC Criteria: September 6, 2026
• First Posted (Actual): September 11, 2026

Study Record Updates

• Last Update Posted (Actual): September 11, 2026
• Last Update Submitted That Met QC Criteria: September 6, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Prediabetic State; Rural Health; Family Health; Health Status Disparities; Diabetes Mellitus, Type 2, Prevention and Control
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Body Weight; Body Weight Changes; Glucose Metabolism Disorders; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Weight Loss; Diabetes Mellitus; Prediabetic State
• Other Study ID Numbers: 1R01MD021606 (U.S. NIH Grant/Contract)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No