NCT07550608Completed
Effects of Pre-Exercise Basal Insulin Manipulation on Glucose Dynamics in Females vs. Males With Type 1 Diabetes
Effects of Pre-Exercise Basal Insulin Manipulation on Glucose Dynamics in Females vs. Males With Type 1 Diabetes: A Cross-Over Study
Source: ClinicalTrials.gov · Last updated 30 Apr 2026
Brief summary (registry, in English)
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.
- Status (registry)
- Completed
- Study type
- Interventional
- Enrollment
- 18 (actual)
- First submitted
- 19 Apr 2026
- Start date
- 20 Oct 2023
- Primary completion date
- 1 Jul 2025
- Lead sponsor
- Naama Constantini
- Diseases
- Type 1 diabetes
- NCT number
- NCT07550608
What you commit to
- Study type: Interventional
- Participants enrolled: 18
- From 20 Oct 2023 to the primary completion date, 1 Jul 2025
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Occurrence of severe hypoglycemia resulting in seizure, coma, or hospitalization within the 6 months prior to recruitment.
Other illness
- Presence of significant diabetes complications (e.g., proliferative retinopathy, nephropathy, or symptomatic neuropathy).
- History of hypoglycemia unawareness.
- Uncontrolled hypertension (Systolic BP \> 200 mmHg or Diastolic BP \> 110 mmHg).
- Known cardiovascular disease or significant cardiovascular risk factors (e.g., ischemic heart disease).
Lab values
- Most recent HbA1c \> 9.9% (85 mmol/mol).
- Use of concomitant medications affecting glucose metabolism other than insulin (e.g., steroids, SGLT2 inhibitors, GLP-1 receptor agonists, or non-selective beta-blockers).
Other
- C-peptide levels ≥ 0.7 nmol/L.
- 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).
Who the study is looking for
- 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.
Age in the registry: 18 years to 45 years · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Sylvan Adams Sport Institute, Tel Aviv University Coordinator of this site? Confirm its status | Tel Aviv | Israel | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.