Management of Cystic Fibrosis-Related Diabetes in Denmark—A Population-Based, Cross-Sectional Study

Background: Cystic fibrosis-related diabetes (CFRD) is the most common comorbidity in cystic fibrosis (CF). After the introduction of modulator therapy, extended life expectancy and altered nutritional status may have changed the landscape of CFRD. This study aimed to evaluate the current CFRD management in Denmark. Methods: In a nationwide, cross-sectional study, we included all individuals in Denmark diagnosed with CFRD, defined by insulin use, ≥2 abnormal OGTTs (2-h glucose ≥11.1 mmol/L), or elevated HbA1c (>48 mmol/mol). The cohort was identified using the Danish CF Registry, including all CF cases in Denmark. Health records were reviewed to validate diagnoses and extract data on treatment regimens and glycemic control. Results: We identified 151 people with CFRD, with a prevalence of 40% in adults with CF and 1% in adolescents. Among them, 7% used insulin pumps, 41% used basal-bolus treatment, 11% used only basal or mixed insulin, 6% used only bolus insulin, 33% did not use insulin or oral antidiabetics, and 2% used combinations or had missing data on treatment regimen. Median HbA1c was 48 mmol/mol, with 10% having HbA1c ≥ 70 mmol/mol. Continuous glucose monitoring (CGM) users (44%) had a median time in range of 70% and median time below range of 1%. No cases of severe hypoglycemia were recorded in the year before data collection. Conclusions: In the Danish CFRD cohort glycemic control was generally good, although some remained severely dysregulated. While insulin remains the only antidiabetic treatment, the role of oral antidiabetics is likely to expand in the post-modulator era.