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

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.

NCT Number	NCT07550608
Lead Sponsor	Naama Constantini
Conditions	Type 1 Diabetes
Enrollment	18 participants
Start Date	2023-10-20
Primary Completion	2025-07-01 (estimated)
Study Completion	2025-07-01 (estimated)
Updated on ClinicalTrials.gov	2026-04-30