Effects of Long Duration Cycling in People With Type 1 Diabetes
Trial ID: NCT07286019
Status: ACTIVE_NOT_RECRUITING
Study type: INTERVENTIONAL
Phase: NA
Start date: 2025-11-22
Completion date: 2025-12
Sponsor: Universitat de Girona
Collaborators: University Hospital of Girona Dr. Josep Trueta
Conditions: Type 1 Diabetes (T1D)
Interventions: Prolonged moderate-intensity cycling session
Locations: Modeling & Intelligent Control Engineering Laboraotry (Universitat de Girona)
Countries: Spain
Enrollment: 29
Age range: 18 Years - 60 Years
Sex: ALL

Summary:
The goal of this interventional study is to build a high quality, real world multimodal dataset that combines continuous glucose monitoring (CGM), wearable and fitness data, performance metrics, and saliva and urine omics collected during a prolonged, moderate intensity outdoor gravel-cycling session in adults with type 1 diabetes (T1D).

The main questions it aims to answer are:

* Can we collect and synchronize comprehensive CGM, physiological, performance, and omics data around a single cycling session to enable further artificial intelligence (AI) model development?
* What molecular changes in saliva and urine occur during exercise, and how do they relate to glycemic outcomes?

Participants will:

* Complete a supervised \~75 km gravel-cycling route at their own pace under real-world conditions, without protocolized therapy adjustments.
* Wear a Dexcom G7 starting \~4 days before the ride and continue through the sensor lifespan to capture CGM data.
* Provide saliva and urine immediately before and after the ride for epigenomic and proteomic analyses.

This study will generate an integrated resource that supports the development and validation of AI models for predicting glucose responses to exercise in T1D and will help guide future studies on how prolonged exercise affects glucose control.

Eligibility criteria:
Inclusion Criteria:

* Type 1 diabetes for \> 5 years.
* Age between 18-60 years.
* HbA1c ≤ 8.5%.
* Body mass index between 18 and 30 kg/m².
* Physically active (≥ 4 hours/week of exercise).
* Laboratory data and EKG without alterations of the last 12 months.
* Valid Type 2 sports medical examination, which includes a monitored stress test with continuous ECG and blood pressure monitoring, as well as an official medical certificate confirming fitness to participate in this study.
* Experience using CGM sensors and be used to self-monitor blood glucose and carbohydrate counting.

Exclusion Criteria:

* Unable to ride gravel bikes.
* Unable to use clipless pedals.
* Pregnancy and breastfeeding.
* Hypoglycemia unawareness (Clarke Test \> 3).
* Severe hypoglycemia in the previous 6 monhts.
* Progressive fatal disease.
* History of drug or alcohol abuse.
* Impaired liver function.
* Clinically relevant microvascular complications (macroalbuminuria, pre-proliferative and proliferative retinopathy), cardiovascular, hepatic, neurological, endocrine or other systemic disease, apart from T1D.
* Mental conditions that prevent the subject from understanding the nature, purpose and possible consequences of the study.
* Using an experimental drug or device during the prior 30 days.

Inclusion (healthy control group): adults 18-60 years without diabetes and physically active (≥ 4 hours/week of exercise) who can provide pre/post saliva and uringe samples for omics analyses.

Outcomes:
Proportion of participants with a complete multimodal dataset collected