Couple-Based Lifestyle Intervention to Prevent Type 2 Diabetes

Study Overview
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Brief Summary
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The goal of this randomized pilot clinical trial is to describe the feasibility of a couple-based lifestyle intervention and the study protocol in preparation for a future definitive randomized clinical trial. Participants include individuals at risk for type 2 diabetes and their romantic partners. The main objectives are: To describe the feasibility of the couple-based intervention. To describe the feasibility of the study protocol for use in a definitive trial. Participating couples will be randomized to one of two year-long lifestyle intervention conditions: an individual curriculum or a couple-based curriculum. Participants will complete assessments before and after the year-long intervention, as well as monthly during the intervention. Data will be collected on: feasibility, background, health behaviors, physical and mental health, and relationship functioning.

Detailed Description
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The goal of this randomized pilot clinical trial is to describe the feasibility of a couple-based lifestyle intervention and the study protocol in preparation for a future definitive randomized clinical trial. Participants include individuals at risk for type 2 diabetes and their romantic partners. Prior to all study procedures, eligible participants will be required to complete an informed consent process and electronically sign a consent document. 12 eligible couples will be randomly assigned to either an individual lifestyle intervention (PreventT2) or a couple-based adaptation designed with input from a community advisory board (PreventT2 Together) (1:1). Both curricula have CDC approval for use in the National DPP and are delivered to small groups of participants over the course of 12 months. Across conditions, participants will complete assessments before and after the year-long intervention, as well as monthly during the intervention. Data will be collected on: feasibility, background, health behaviors, physical and mental health, and relationship functioning.

Official Title
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Couple-Based Lifestyle Intervention to Prevent Type 2 Diabetes

Conditions
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PreDiabetes, Prediabetic State, Overweight and Obesity

Intervention / Treatment
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* Behavioral: PreventT2 (Individual intervention)
* Behavioral: PreventT2 Together (Couple-based intervention)


Participation Criteria
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Eligibility Criteria
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Both the target individual (i.e., individual at high risk for type 2 diabetes) and supporting partner (i.e., partner of target individual) must meet eligibility criteria in order for a couple to enroll in the study. Eligibility criteria for target individuals: Eligible for National DPP. A. DPP Inclusion Criteria: 1) BMI of ≥ 25 kg/m2 (≥ 23kg/m2 if Asian) AND 2) High risk for type 2 diabetes, based on 1+ of the following three: CDC/American Diabetes Association Prediabetes Risk Test score ≥ 5 Blood test results indicative of prediabetes in the past year (i.e., fasting blood glucose 100-125 mg/dl; blood glucose of 140-199 mg/dl 2 hours after a 75 g glucose load; OR 6.4% ≥ HbA1c ≥ 5.7%) Previous diagnosis of gestational diabetes (among women) B. DPP Exclusion Criteria: Diagnosis of type 1 diabetes or type 2 diabetes Currently pregnant AND 2. Eligible for Study (Additional Criteria). A. Study Inclusion Criteria: Living together for 1+ year Report being in a romantic relationship Conversational fluency in English Age 18 or older Interested in participating B. Study Exclusion Criteria Diagnosis of another chronic disease (unless stable or with no major events/changes for 3+ months); Current medication for prediabetes or obesity; Current participation in lifestyle intervention for prediabetes or obesity; Past participation in the National DPP; Not comfortable participating in intervention together with partner. Eligibility criteria for supporting partners: A. Study Inclusion Criteria: Partner meets target individual eligibility criteria (per above) Living together for 1+ year Report being in a romantic relationship Conversational fluency in English Age 18 or older Interested in participating B. Study Exclusion Criterion 1) Not comfortable participating in intervention together with partner.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Individual intervention condition<br>PreventT2 individual lifestyle intervention curriculum (2021 revised National DPP curriculum, freely available from the CDC) | Behavioral: PreventT2 (Individual intervention)<br>* PreventT2 will be delivered by a team of trained CDC Lifestyle Coaches to adults at high risk for diabetes. The 2021 version of the curriculum that will be used is freely available from the CDC. The intervention will be delivered in the context of the University of Utah National DPP, which has full recognition from the CDC based on outcome data over the course of a number of years.<br>|
| Experimental: Couple-based intervention condition<br>PreventT2 Together (couple-based adaptation of PreventT2; approved by the CDC in November 2022 as an Alternate Curriculum for use in the National DPP) | Behavioral: PreventT2 Together (Couple-based intervention)<br>* PreventT2 Together will be delivered by a team of trained CDC Lifestyle Coaches to adults at high risk for diabetes and their partners. The curriculum was developed with the input of a community advisory board and was approved by the CDC for use in the National DPP (i.e., meets CDC Diabetes Prevention Recognition Program Standards, including 22+ classes delivered over the course of 12 months and targeting lifestyle changes to prevention type 2 diabetes). In contrast to PreventT2, the intervention includes content specific to couples with prompts encouraging partners to consider and discuss how they can best support one another, information about lifestyle intervention in a relationship context, and examples demonstrating how couples collaborated to make healthy lifestyle changes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Couple-based intervention feasibility | Participants will complete the Theoretical Framework of Acceptability-Based Questionnaire and two open-ended survey items developed by the research team monthly during the intervention and at post-intervention. Participants will also complete a post-intervention qualitative joint couple interview that utilizes a semi-structured couple interview guide. Lifestyle Coaches will also report on attendance, completion of weekly activity logs, and completion of make-up sessions. The team of Lifestyle Coaches delivering PreventT2 Together will also complete open-ended items developed by the research team following each class. Lifestyle Coaches will also complete a measure of barriers to participation and lifestyle change they observed among the participants, as well as several measures based on implementation outcomes (i.e., Acceptability of Intervention Measure, Intervention Appropriateness Measure, Feasibility of Intervention Measure). | 1.5 years | 
| Study protocol feasibility | Participants will report on perceptions of the study protocol in a post-intervention qualitative joint couple interview that utilizes a semi-structured couple interview guide. The guide includes specific prompts focused on recruitment, randomization, and assessments. In addition to these qualitative data collected from participants, data on recruitment feasibility will also be collected with an item on the contact form potential participants complete. Data on assessment feasibility will also be collected based on completion of measures and the length of time participants spend on these measures at each assessment. | 1.5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physical activity. | Assessed pre/post-intervention with the International Physical Activity Questionnaire (IPAQ)-Long and a 7-day accelerometer assessment. Assessed monthly with the IPAQ-7 day. Participants will also self-report minutes of moderate-to-vigorous physical activity over the past week at each attended intervention class. IPAQ questionnaires assess self-reported walking, moderate intensity, and vigorous intensity physical activity as well as overall sedentary time. Accelerometers provide objective assessments of these constructs. | 1.5 years | 
| Diet. | Assessed pre/post-intervention with the Automated Self-Administered 24-hr diet assessment from the NCI (ASA-24). The ASA is a detailed 24-hour recall of food including portion sizes and preparation. Assessed pre/post-intervention and monthly during the intervention with the Rapid Eating Assessment for Participants- Shortened Version (REAP-S), a brief measure of diet quality and content over an average week. | 1.5 years | 
| Sleep. | Assessed pre/post-intervention and monthly with the Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance 8a item scale (SD) and the PROMIS Sleep-Related Impairment 8a item scale (SRI). Participants will also self-report their daily sleep during the 7-day pre/post-intervention accelerometer wear. The SD assesses sleep quality with 8 statements including my sleep was restless, and the SRI assesses the impact of poor sleep and sleepiness on daily behaviors with 8 statements including I had problems during the day because of poor sleep. Item responses on both measures range from 1 (not at all) to 5 (very much). | 1.5 years | 
| BMI | Weight in kilograms and height in meters will be measured pre/post-intervention by Clinical Research Unit staff in order to calculate BMI. | 1.5 years | 
| Waist circumference | Waist circumference in inches will be measured pre/post-intervention by Clinical Research Unit staff. | 1.5 years | 
| Weight | Weight in kilograms will be assessed pre/post-intervention by Clinical Research Unit staff and weight in kilograms will also be collected before each intervention class by Lifestyle Coaches. | 1.5 years | 
| Blood glucose. | Assessed pre/post-intervention by Clinical Research Unit medical staff: fasting blood glucose, HbA1c, 2-hr post glucose load (following 75 g OGTT). | 1.5 years | 
| Anxiety. | Assessed pre/post-intervention and monthly with the PROMIS Anxiety 8a item scale. This 8-item measure includes statements such as I felt fearful. | 1.5 years | 
| Depression. | Assessed pre/post-intervention and monthly with the PROMIS Depression 8a item scale, which includes 8 statements such as I felt worthless. | 1.5 years | 
| Affect. | Participants will complete the Positive and Negative Affective Scale (PANAS) daily during the pre/post-intervention 7-day accelerometer wear. The PANAS assesses positive and negative affect over the last day with 20 items. Participants rate from 1 (very slightly to none at all) to 7 (extremely) the extent to which they experienced each item (e.g., nervous) in the past day. | 1.5 years | 
| Relationship satisfaction. | Assessed pre/post-intervention and monthly with the 16-item Couples Satisfaction Index (CSI), a measure of overall relationship satisfaction. Assessed daily during the pre/post-intervention 7-day accelerometer wear using a brief 4-item version of the CSI. | 1.5 years | 
| Intimacy. | Assessed pre/post-intervention and at months 3, 6, 9 during the intervention, participants will complete the 6-item sexual intimacy subscale of the Personal Assessment for Intimacy in Relationships (PAIR). | 1.5 years | 
| Partner support. | Assessed pre/post-intervention and at months 3, 6, 9 during the intervention, with the Social support and Exercise Survey and the Social Support and Eating Habits Survey. These measures assess the amount of support individuals seeking to exercise regularly perceive from family members and the amount of support individuals seeking to improve their diet receive from family members. Participants will also report on daily emotional and instrumental support during the pre/post-intervention 7-day accelerometer wear. | 1.5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lifestyle Intervention, Prevention, Social Support, Couple Relationships