Diabetes Self-Management program (DSMP) Interventions With and Without HIIT – A Randomized Controlled Trial

Project Description

Objective

The study aims to evaluate between-group changes in accelerometer-derived physical activity and biometric outcomes associated with disease progression among individuals with type 2 diabetes participating in two types of municipal diabetes self-management programs (DSMP) — with and without high-intensity interval training (HIIT) — compared to a control group.

Hypothesis

Participants receiving DSMP + HIIT will demonstrate significant increases in daily physical activity and greater improvements in risk factors for disease progression compared to participants receiving DSMP alone and those allocated to a waiting list control group.

Interventions

• LL (Lev Livet): 9 sessions over 12 weeks. Four initial sessions focus on coping skills across chronic diseases, followed by four diabetes-specific sessions and a follow-up session.
• LLH (Lev Livet + HIIT): LL plus 16 one-hour supervised HIIT sessions.
• Control group: Waiting list control.

For detailed descriptions of the interventions, visit www.steno-aarhus.github.io/living-project.

Trial Sites and Participants

The trial is conducted at selected municipal healthcare centers in:

• Aarhus
• Vejen
• Syddjurs
• Roskilde

Inclusion criteria

• Diagnosed with type 2 diabetes
• Age ≥ 18 years
• Able to speak and understand Danish
• Assessed fit by a healthcare professional to attend Lev Livet

Exclusion criteria

• Contraindications to increased physical activity as assessed by the participant's general practitioner (e.g., unstable angina)

Randomization and Blinding

Trial sites will offer either LL or LLH. Participants are randomized (2:1) to intervention or control using the Research Electronic Data Capture (REDCap) system with a block-randomized schedule (n = 12) prepared by a statistician. Blinding is not possible, as health professionals deliver the interventions.

Outcomes

Primary endpoint

• Time per day spent in moderate-to-vigorous physical activity (MVPA), measured by accelerometer.

Secondary endpoints

• Other physical activity measures (light activity, sedentary time, steps/day, sleep)
• Time spend in different activities (eg. sedentary activity, walking, cycling, running etc)
• HbA1c
• Blood pressure
• Body composition
• BMI
• 30-second sit-to-stand test
• Six-minute walk test

Power Calculation

The sub-study is powered to detect a minimum effect of 5.45 min/day MVPA between LL and LLH groups (n = 32 in each), assuming:

• SD = 7.75 min/day for change in MVPA
• 80% power, α = 0.05
• ICC = 0.01 (cluster effect)
• 10% dropout

The clinically significant threshold is 5 min/day, and previous studies have reported mean changes of ~9 min/day. Given the supervised HIIT dose (≥ 120 min/week), larger effects are anticipated.

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Folder and File Structure

The repository is organized as follows:

• data/
  Manuscript and simulated datasets to ensure that the analysis scripts run as intended.

• doc/
  Notes, drafts, figures, and documentation related to the study.

• R/
  R scripts for data processing and analysis.

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Data Management and Analysis

• All analyses are performed in RStudio.
• Secure data handling is conducted via Midtx.

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Resources

For more information on this project structure, see the prodigenr documentation.