P-222: Glycemic outcomes in cystic fibrosis–related diabetes in youth: discordance between HbA1c and CGM metrics and limited evidence on diabetes technologies — a systematic review
W Roesler-Wilhelm, L Coimbra, M Zorron, A Chobot, T Jeronimo dos SantosAbstract
Introduction
Cystic fibrosis–related diabetes (CFRD) is the most common endocrine complication of cystic fibrosis. In the era of CFTR modulators and advanced diabetes technologies, their impact on glycemic outcomes in youth remains unclear.
Objectives
To systematically synthesize glycemic outcomes in youth with CFRD, focusing on the effects of CFTR modulators and diabetes technologies.
Methods
This systematic review followed PRISMA guidance and was registered in PROSPERO (CRD420251268343). PubMed, Embase, Scopus, Web of Science, and CENTRAL were searched (January 2000–November 2025). Eligible studies included individuals <30 years with CFRD reporting any glycemic outcomes. Studies were classified as CORE 1 (strict pediatric CFRD criteria) or CORE 2 (supportive evidence from mixed-age populations).
Results
Of 1,920 records identified, 1,609 were screened after duplicate removal. Full-text assessment of 25 studies resulted in 10 included studies (table 1). Evidence was derived mainly from small observational cohorts with substantial heterogeneity. Across CORE 1 studies, CFTR modulators showed heterogeneous effects on HbA1c. CGM data were scarce and inconsistently reported, limiting the ability to detect true effects. Among studies reporting CGM outcomes, metrics were generally unchanged, including stable variability, suggesting a discordance between HbA1c and real-time glycemic patterns. Evidence on diabetes technologies in CFRD populations <30 years was limited. Mixed-age cohorts demonstrated improvements with automated insulin delivery (TIR:∼60%→76%; CV: ∼39%→30%).
Conclusions
Evidence on glycemic outcomes in youth with CFRD is limited, with only a small number of pediatric-focused studies and scarce CGM data. Available findings suggest variable changes in HbA1c and insufficient evidence to determine the impact of CFTR modulators on real-time glycemic patterns, highlighting evidence gaps and the need for pediatric-focused studies.