CompletedNot Applicable

Effects of Pre-Exercise Basal Insulin Manipulation on Glucose Dynamics in Females vs. Males With Type 1 Diabetes

Israel18 participantsStarted 2023-10-20

Plain-language summary

The Purpose of the Study The purpose of this study is to compare how blood sugar levels change during exercise in men and women with type 1 diabetes (T1D). Researchers want to understand if biological sex affects the risk of low blood sugar (hypoglycemia) during physical activity. Additionally, the study examines whether reducing the background (basal) insulin dose before exercise is effective at keeping blood sugar stable. Study Population The study includes active adults (men and women) aged 18-45 who have lived with type 1 diabetes for at least 18 months and use an insulin pump. What Happens During the Study Participants complete three laboratory visits: Visit 1: A fitness test on a treadmill to measure the participant's aerobic capacity. Visits 2 \& 3: Two 60-minute moderate-intensity exercise sessions on a treadmill. In one session, participants reduce their basal insulin by 50% starting 90-120 minutes before exercising. In the other session, they maintain their usual insulin dose. Researchers measure blood sugar every 10 minutes during exercise and collect blood samples before and after the sessions to monitor hormone levels. Study Design This is a randomized crossover study, meaning every participant performs both exercise strategies in a random order to serve as their own control.

Who can participate

Age range

18 Years – 45 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Adults aged 18 to 45 years. * Diagnosis of Type 1 Diabetes (T1D) for at least 18 months. * Current use of an insulin pump (Continuous Subcutaneous Insulin Infusion - CSII) for diabetes management. * Regular physical activity level, defined as at least 150 minutes of aerobic exercise per week across three or more sessions for at least 4 weeks prior to the study. * Ability to perform 60 minutes of continuous treadmill running. * Aerobic fitness level (VO2peak) of ≥ 30 mL·kg-¹·min-¹ for females or ≥ 32 mL·kg-¹·min-¹ for males. Exclusion Criteria: * Most recent HbA1c \> 9.9% (85 mmol/mol). * C-peptide levels ≥ 0.7 nmol/L. * Presence of significant diabetes complications (e.g., proliferative retinopathy, nephropathy, or symptomatic neuropathy). * Use of concomitant medications affecting glucose metabolism other than insulin (e.g., steroids, SGLT2 inhibitors, GLP-1 receptor agonists, or non-selective beta-blockers). * History of hypoglycemia unawareness. * Occurrence of severe hypoglycemia resulting in seizure, coma, or hospitalization within the 6 months prior to recruitment. * Adherence to a low-carbohydrate or ketogenic diet (\<30 g of carbohydrates per day). * Current engagement in shift work. * For female participants: presence of primary or secondary amenorrhea (cessation of menstruation for \>12 months). * Uncontrolled hypertension (Systolic BP \> 200 mmHg or Diastolic BP \> 110 mmHg). * Known cardiovascular disease or significant cardiovascular risk…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Mean Rate of Capillary Blood Glucose (CBG) Decline

Timeframe: During the 60-minute exercise session.

Trial details

NCT IDNCT07550608

SponsorNaama Constantini

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2025-07-01

View on ClinicalTrials.gov More Type 1 Diabetes trials