Cardiopulmonary Fitness and Health-Related Quality of Life in Children and Adolescents With Type 1 Diabetes (FIT-T1D)

Children and adolescents with type 1 diabetes (T1D) are at risk of a sedentary lifestyle, as this chronic disease may lead patients into a vicious cycle of deconditioning, resulting in reduced physical activity levels and increased cardiovascular risk.

Our previous studies have demonstrated impaired exercise capacity and reduced quality of life, associated with physical deconditioning and increased sedentary behavior in children and adolescents with other chronic diseases.

This study aims to evaluate cardiopulmonary fitness, physical activity and health-related quality of life in children with type 1 diabetes aged 6 - 17 years and to compare these outcomes with healthy peers. We also aim to evaluate the parameters associated with cardiopulmonary fitness in this population.

Primary outcome: The primary outcome will be the VO2max, assessed by a standardized CPET on cycloergometer. These results will be expressed in Z-score, using contemporary Z-score values in pediatric population.

Secondary Outcomes :

• Others functional parameters of the CPET will be analyzed (maximum heart rate, ventilatory anaerobic threshold, ventilatory efficiency, oxygen pulse, maximal power, respiratory exchange ratio, respiratory reserve) which enable a precise understanding of adaptations and potential limiting factors.
• Health Related Quality of Life will be assessed using valeted scores in the pediatric population (PedsQL and PedsQL proxy)
• Muscular strength of superior limbs will be measured using a hand dynamometer (Jamar Handgrip). Muscular strength of inferior limbs will be measured using the Easyforce dynamometer. These values will be compared to references values published in pediatric population.
• Level of Physical Activity will be assessed with two different tools. Measurement of the Metabolic Equivalent of Task (MET), a validated method for measuring physical activity intensity and energy expenditure will be assessed using an activity monitor (ActiGraph 3GTX®) worn for 7 days. Patients will fill a physical activity and sedentarily related score (CAPAS-Q). The two dimensions (physical activities and sedentary behaviors) appear to correlate with accelerometry measurements.
• An information sheet filled by patients will permit us to collect diabetes treatment's modality, sociodemographic factors and to assess diabetes control (HbA1c, TIR, variability of glycemia, time in hypoglycemia)

Based on our previous similar work and studies that have measured VO2max in young diabetics, we expect to observe a difference of 3.5mL/kg/min between the cohort's VO2max and our published reference values (mean sex-adjusted norm 43.5±7.5 mL/ kg/min). With an α-risk of 5%, power of 90% and 10% missing data on the primary endpoint, we plan to include a total of 214 subjects, including 107 patients and 107 controls.

Control population has already been recruited and studied in one of our previous studies from 2021 to 2023 assessing the same outcomes.

Inclusion criteria

• Patient aged from 6 to 17 years with a type 1 diabetes (diagnosed at least 1 month before)

Exclusion criteria

• Patient with a congenital heart disease or any significative comorbidity that could reduce functional capacities
• Patient with a contraindication to the CPET