TOPLINE:

Continuous glucose monitoring (CGM)-derived metrics reliably identified cystic fibrosis-related diabetes in patients with cystic fibrosis. Additionally, a novel way of analysing CGM data called glucodensity, which shows how often glucose levels fall into different ranges, worked better than A1c and standard CGM measures in detecting early cystic fibrosis-related diabetes.

METHODOLOGY:

• Researchers in Spain conducted a prospective observational study among 38 participants with cystic fibrosis (mean age, 33.6 years; 36.8% women) to determine whether A1c, standard CGM metrics, and glucodensities can distinguish participants with and without cystic fibrosis-related diabetes.
• Participants underwent a standardised oral glucose tolerance test (OGTT) within the previous 6 months; baseline A1c levels were also measured.
• They wore a FreeStyle Libre 2 CGM sensor for 14 days and were instructed to scan at least every 8 hours; only sensors with a wear time of more than 70% were included in the final analysis.
• Participants also completed a short quality-of-life questionnaire addressing their preferences for cystic fibrosis-related diabetes screening methods, including the OGTT and other procedures.

TAKEAWAY:

• All participants expressed a preference for blood test screening methods over OGTTs, and most of them said that they would accept wearing a CGM sensor if glucose abnormalities were detected.
• For CGM metrics, time above 180 mg/dL for more than 6% of wear time had a sensitivity of 93% in detecting cystic fibrosis-related diabetes (P = .042), and time above 140 mg/dL for more than 20% of wear time had a specificity of 90% (P = .032); both metrics outperformed A1c in distinguishing participants with and without cystic fibrosis-related diabetes.
• Glucodensities showed improved diagnostic performance for cystic fibrosis-related diabetes, with an area under the curve of 0.903 and both sensitivity and specificity above 85%.

IN PRACTICE:

"The results of this study strongly support the need for further research, with large prospective studies, to define the optimal cut-off point of CGM metrics and/or glucodensities for the screening and diagnosis of CFRD [cystic fibrosis-related diabetes]. Nevertheless, because of its accuracy and acceptability among people with CF, CGM may eventually become a new standard in CFRD diagnosis," the authors of the study wrote.

SOURCE:

This study was led by Irene Aguilera García, University Hospital La Paz (HULP), Madrid, Spain. It was published online on October 19, 2025, in Diabetes Research and Clinical Practice.

LIMITATIONS:

This study was limited by its observational design, single-centre experience, and small sample size. The CGM sensor was not blinded, which may have influenced patients' behaviour and glucose levels. Additionally, no standardised approach exists for evaluating CGM results to diagnose diabetes.

DISCLOSURES:

This study did not receive any specific funding. The authors declared having no competing financial interests or personal relationships that might have influenced the results.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.