Net-IOB & Exercise Toolkit Pilot Trial: Randomized, Crossover Evaluation of a Behavioral Decision Support Advisor to Improve Glycemic Safety During and After Exercise in Adults With Type 1 Diabetes (NEXT)
Trial Snapshot
- Phase
- Not Applicable
- Status
- Not yet recruiting
- Sponsor
- Stanford University
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Composite Score of Glycemic Safety and Carbohydrate Burden
Study Overview
Brief Summary
This study evaluates a clinician-facing decision-support toolkit designed to assist adults with type 1 diabetes in preparing for moderate-intensity exercise. The netIOB & Exercise Toolkit (NEXT) integrates recent glucose data and insulin delivery history to provide individualized suggestions regarding exercise timing, insulin adjustments, and carbohydrate intake.
Adults with type 1 diabetes will complete three supervised exercise sessions under different pre-exercise guidance approaches:
(A) published consensus-based standard-of-care guidance, (B) usual personal care routines, and (C) guidance informed by the NEXT Toolkit.
A healthy adult control group will complete a single supervised exercise session to provide comparative physiologic data.
Detailed Description
People with type 1 diabetes frequently experience variable glucose responses before, during, and after physical activity, including exercise-associated hypoglycemia and the need for unplanned carbohydrate intake. Although consensus-based recommendations exist to guide exercise preparation, many individuals continue to rely on trial-and-error strategies that can be burdensome or difficult to generalize across activities.
This study evaluates the netIOB & Exercise Toolkit (NEXT), a software-based, clinician-facing decision-support system intended to contextualize exercise preparation using recent continuous glucose monitoring (CGM) data and insulin delivery history. The Toolkit estimates net insulin-on-board relative to an individual's programmed basal insulin profile and presents structured, non-automated suggestions related to exercise timing, insulin target adjustments, and carbohydrate intake. All decisions remain under clinician and participant control.
The primary study population consists of adults with type 1 diabetes who complete three supervised, moderate-intensity exercise sessions in a randomized, three-period crossover design. Each session is conducted under a different pre-exercise strategy: consensus standard-of-care guidance, usual personal care routines, or guidance informed by the NEXT Toolkit. Sessions are separated by washout periods to minimize physiologic carryover, and glycemic, insulin delivery, and behavioral outcomes are assessed during exercise and for up to 48 hours post-exercise.
In addition, a healthy adult control group completes a single supervised exercise session without pre-exercise glucose or insulin management interventions. This group is included to provide comparative physiologic context for exploratory analyses.
Exploratory analyses will examine relationships between pre-exercise net insulin-on-board (netIOB) strata and glycemic, insulin, and treatment outcomes across exercise sessions. These analyses are intended to characterize patterns of response rather than to test formal efficacy hypotheses.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Supportive care
- Masking
- None (open label)
Masking Description
It is not feasible to blind participants or staff to the intervention being applied for each session.
Eligibility Criteria
- Ages
- 18 Years to 60 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- Inclusion Criteria: All Participants (Type 1 Diabetes and Healthy Control Groups)
- Adults between the age of 18-60 years
- Able to perform moderate intensity walking for 60 minutes (target 40-60% age-predicted maximal heart rate).
- Willing and able to comply with study procedures, including supervised exercise visits and device wear
- Able to provide written informed consent
- Inclusion Criteria: Type 1 Diabetes Group Only
- Clinical diagnosis of type 1 diabetes for >1 year, based on the investigator's clinical judgement
- Current use of continuous subcutaneous insulin infusion with Tandem Control-IQ and a compatible continuous glucose monitor (CGM) for >1 month prior to enrollment
- Stable insulin delivery regimen, with no planned changes to insulin pump settings or insulin dosing strategy during the study period
- Consistent CGM use during the month prior to enrollment (>80% data availability)
- Inclusion Criteria: Health Control Group Only
- No diagnosis of diabetes or other disorders of glucose metabolism
- Not using insulin or glucose-lowering medications
Exclusion Criteria
- Exclusion Criteria: All Participants
- Intercurrent illness or medical condition that precludes safe participation in moderate-intensity exercise (e.g., unstable cardiopulmonary disease, uncontrolled arrhythmia, or uncontrolled hypertension), as previously assessed by the participant's primary care physician
- Known coronary artery disease with symptoms limiting moderate physical activity, or history of myocardial infarction, percutaneous coronary intervention, or coronary artery bypass grafting within the past 12 months
- Pregnancy, lactation, or plans to become pregnant during the study period
- Renal insufficiency with estimated GFR <45 mL/min/1.73 m², dialysis dependence, or adrenal insufficiency
- Concurrent participation in another interventional drug or device study within 30 days prior to enrollment
- Inability to comply with study procedures or safety requirements (e.g., inability to achieve target heart-rate zone, attend scheduled visits, or enable required device data access), or otherwise deemed unsuitable by the investigator
- Exclusion Criteria: Type 1 Diabetes Group Only
- Use of non-CSII insulin delivery, including long-acting injectable or inhaled insulin, during the study period
- Use of medications with potential to substantially affect glycemia (e.g., SGLT-2 inhibitors, GLP-1 receptor agonists, or GIP agonists), unless on a stable regimen with no planned changes during the study
- Use of systemic corticosteroids within 4 weeks prior to participation
- History of severe hypoglycemia (requiring third-party assistance) or diabetic ketoacidosis within the prior 6 months
Arms & Interventions
Standard-of-Care (SoC)
Participants follow consensus-based guidance for insulin and carbohydrate adjustments around exercise, as outlined in current international standards. These recommendations are applied by study staff in advance of the exercise session.
Intervention: Continuous Ketone Monitoring (Device)
Usual Care (UC)
Participants use their own strategies for managing insulin and carbohydrate around exercise.
Intervention: Usual Care (UC) (Behavioral)
Usual Care (UC)
Participants use their own strategies for managing insulin and carbohydrate around exercise.
Intervention: Continuous Glucose Monitoring (Device)
Usual Care (UC)
Participants use their own strategies for managing insulin and carbohydrate around exercise.
Intervention: Continuous Ketone Monitoring (Device)
netIOB & Exercise Toolkit (NEXT)
Physicians receive personalized, algorithm-informed recommendations for exercise-related insulin and carbohydrate adjustments. Recommendations are generated using the investigational netIOB & Exercise Toolkit based on CGM data, insulin history, and real-time inputs.
Intervention: netIOB & Exercise Toolkit (NEXT) (Device)
netIOB & Exercise Toolkit (NEXT)
Physicians receive personalized, algorithm-informed recommendations for exercise-related insulin and carbohydrate adjustments. Recommendations are generated using the investigational netIOB & Exercise Toolkit based on CGM data, insulin history, and real-time inputs.
Intervention: Continuous Glucose Monitoring (Device)
netIOB & Exercise Toolkit (NEXT)
Physicians receive personalized, algorithm-informed recommendations for exercise-related insulin and carbohydrate adjustments. Recommendations are generated using the investigational netIOB & Exercise Toolkit based on CGM data, insulin history, and real-time inputs.
Intervention: Continuous Ketone Monitoring (Device)
Healthy Control
Adults without diabetes complete one supervised moderate-intensity exercise session for physiologic comparison.
Intervention: Continuous Glucose Monitoring (Device)
Healthy Control
Adults without diabetes complete one supervised moderate-intensity exercise session for physiologic comparison.
Intervention: Continuous Ketone Monitoring (Device)
Standard-of-Care (SoC)
Participants follow consensus-based guidance for insulin and carbohydrate adjustments around exercise, as outlined in current international standards. These recommendations are applied by study staff in advance of the exercise session.
Intervention: Continuous Glucose Monitoring (Device)
Standard-of-Care (SoC)
Participants follow consensus-based guidance for insulin and carbohydrate adjustments around exercise, as outlined in current international standards. These recommendations are applied by study staff in advance of the exercise session.
Intervention: Standard-of-Care Guidance (SoC) (Behavioral)
Outcomes
Primary Outcomes
Composite Score of Glycemic Safety and Carbohydrate Burden
Time Frame: Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).
This composite outcome reflects glycemic risk during exercise and the subsequent post-exercise monitoring period. The score is based on a Magni risk-derived metric computed from continuous glucose monitoring (CGM) data, with the glycemic effects of rescue carbohydrate treatments removed to isolate underlying glycemic risk. Each evaluated timepoint is given a score ranging from 0 to 100, where lower scores indicate lower glycemic risk and higher scores indicate higher glycemic risk. Scores across the defined observation windows are summarized across intervention conditions.
Secondary Outcomes
- Baseline and Peak Ketone Levels(Baseline (immediately prior to exercise) and Exercise (0 to 90 minutes from exercise).)
- Ketone Exposure (AUC) During and After Exercise(Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise) per visit.)
- Percent-Based Continuous Glucose Monitor Metrics(Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).)
- Glucose Concentration and Variability Metrics from Continuous Glucose Monitor(Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).)
- Frequency of Hypoglycemic Events(Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise); total of 7.5 hours per visit (3 visits).)
- Glucose Nadir Value(Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise); total of 7.5 hours per visit (3 visits).)
- Time to First Hypoglycemic Event(Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise); total of 7.5 hours per visit (3 visits).)
- Carbohydrate Consumption for Hypoglycemia Prevention/Treatment(Exercise (0 to 90 minutes); total of 1.5 hours per visit (3 visits).)
- Total and Programmed Insulin Delivery(Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).)
- Frequency of User-Initiated Pump Adjustments(Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).)
- Duration of User-Initiated Pump Adjustments(Baseline (1 hour pre-exercise), Exercise (0 to 90 minutes), Early Post-Exercise (0 to 6 hours after exercise), Mid Post-Exercise (6 to 24 hours after exercise), Late Post-Exercise (24 to 48 hours after exercise); total of 50.5 hours per visit (3 visits).)
Investigators
Rayhan A. Lal
Assistant Professor of Medicine & Pediatrics
Stanford University
Study Sites (1)
Identifiers
- NCT ID
- NCT07226583
- Other Study IDs
- 82224, 2407-07175
Dates
- First Submitted
- (11 months ago)
- First Posted
- (10 months ago)
- Primary Completion
- (in 4 months)
- Study Completion
- (in 4 months)
- Last Verified
- (2 months ago)
- Last updated
- (last month)
Regulatory & Sharing
- FDA Regulated Drug
- No
- FDA Regulated Device
- Yes
- IPD Sharing Plan
- Yes
- Continuous glucose monitoring (CGM) metrics from the Dexcom G7 (e.g., time in range, time below/above range, mean glucose, glucose variability)
- Carbohydrate treatment data (timing, amount, type)
- Insulin delivery data (e.g., pump settings, suspensions, automated adjustments)
- Demographic information (e.g., age range, sex, diabetes duration)
- Direct identifiers (e.g., names, exact dates of birth, addresses)
- Free-text responses or notes containing potentially identifiable information
- Any raw data not essential to the reported outcomes or secondary analyses
- Has Results
- No
De-identified individual participant-level data will be shared, including:
IPD that will not be shared includes: