Relationship between Participant-Reported Outcomes, Residual Beta Cell Function, and Metabolic Parameters in Youth with Newly Diagnosed Type 1 Diabetes

Introduction

Type 1 diabetes (T1D) is a chronic autoimmune condition characterized by the destruction of insulin-producing beta cells in the pancreas, leading to lifelong insulin deficiency. It primarily affects children and adolescents, and preserving residual beta cell function shortly after diagnosis is associated with better metabolic control and reduced risk of complications. Clinical trials aiming to preserve this function often use participant-reported outcome measures (PROMs) to assess quality of life and psychological well-being. However, how these PROMs evolve soon after diagnosis and how they relate to residual beta cell function and objective metabolic parameters remain unclear.

Study Objectives

This study aimed to investigate the relationship between PROMs—specifically, the Pediatric Quality of Life Inventory diabetes module (PedsQL) and the Hypoglycemia Fear Survey (HFS)—and residual beta cell function measured by C-peptide secretion, glycemic control (HbA1c), and continuous glucose monitoring (CGM) parameters in youth newly diagnosed with type 1 diabetes. Importantly, it assessed both child/adolescent self-reports and parent reports to capture differing perspectives.

Methods

The data were derived from two clinical trials: CLOuD and USTEKID. The CLOuD trial involved 97 youth aged 10-18 years comparing hybrid closed-loop insulin delivery systems (HCL) and multiple daily injections (MDI), while the USTEKID trial involved 72 participants comparing ustekinumab immunotherapy to placebo. Repeated PROMs assessments were collected over 48 months post-diagnosis, alongside measurements of stimulated C-peptide (reflecting beta cell function), HbA1c, and CGM data.

Participant-Reported Outcomes

PedsQL evaluates diabetes-specific quality of life, while HFS assesses fear of hypoglycemia. Scores exhibited substantial inter-individual variability but remained relatively stable within individuals during the 48-month follow-up period. Baseline PROM scores strongly predicted later scores, indicating that psychological and quality of life aspects are established early after diagnosis. Children/adolescents reported better quality of life on the PedsQL than their parents did, whereas parents reported greater fear of hypoglycemia on the HFS than their children.

Associations with Metabolic Parameters

Meta-analyses showed modest but statistically significant associations between better glycemic control (lower HbA1c) and higher PedsQL scores, suggesting better perceived quality of life with improved glucose management. Similarly, greater time in range (TIR), a CGM metric indicating glucose levels within target range, correlated with better PedsQL scores but not significantly with HFS scores.

Beta cell function, assessed via stimulated C-peptide testing, correlated strongly with improved glycemic control (lower HbA1c) and higher TIR. Although there was a trend suggesting higher beta cell function might be linked to somewhat better quality of life and less fear of hypoglycemia, these associations did not reach statistical significance.

No significant changes in PROMs were observed between intervention groups (ustekinumab or hybrid closed-loop insulin delivery) and controls, highlighting the complexity of improving quality of life and psychological outcomes in the early disease stage.

Interpretation and Clinical Implications

This study underscores several important points:

1. Psychological and quality of life measures in newly diagnosed youth with T1D are fairly stable over the first four years post-diagnosis.
2. Participants’ and parents’ perceptions differ, with children often perceiving better quality of life but parents experiencing greater fear related to hypoglycemia.
3. Objective metabolic indicators such as HbA1c and CGM metrics relate modestly to participant-reported quality of life, implying that improved glucose control benefits perceived well-being.
4. Residual beta cell function shows stronger correlation with these metabolic parameters but weaker and non-significant links to quality of life and hypoglycemia fear.
5. Current PROMs may only partially reflect the clinical advantages of preserved beta cell function or advanced therapies.

Consequently, future clinical trials should develop and employ psychometric tools tailored specifically for young people using modern diabetes technologies and receiving disease-modifying therapies, enabling more precise evaluation of meaningful patient-centered outcomes.

Conclusions

Overall, quality of life and hypoglycemia fear remain relatively stable in youth within the first 48 months following type 1 diabetes diagnosis. These measures are modestly associated with glycemic control but less so with residual beta cell function. This suggests that while maintaining beta cell function is crucial for metabolic benefits, its impact on patient and family-reported outcomes is more subtle and may require more sensitive assessment tools to detect. Future research should focus on refining PROMs for contemporary clinical trials to capture the real-world benefits of beta cell preservation and innovative treatments for young people with type 1 diabetes.