MON-574 - Continuous Glucose Monitoring Improves Glycaemic Control and Quality of Life in Patients with Cystic Fibrosis-Related Diabetes

Background:
Cystic fibrosis-related diabetes (CFRD) is the commonest non-pulmonary complication, affecting up to half of adults with cystic fibrosis. It is associated with reduced lung function, more chest infections, poorer nutrition, and increased mortality. Fingerprick glucose testing adds substantial treatment burden to patients with CFRD and many have difficulty monitoring their glucose levels multiple times daily as recommended. Insufficient glucose monitoring limits a patient’s and clinician’s ability to safely titrate insulin therapy. Several studies have demonstrated benefit of continuous glucose monitoring (CGM) on glycaemic control in CFRD but most have been limited to small retrospective studies and have used less sensitive glycaemic outcome measures such as HbA1c.

Methods:
We performed a prospective paired trial in adults with insulin-requiring CFRD comparing routine care to CGM use on glycaemic control and diabetes-related quality of life (QOL). All participants had a two week blinded CGM applied to determine baseline glycaemia and then underwent a control period of routine care for thirteen weeks followed by an intervention period of thirteen weeks of CGM use. All participants had two weeks of CGM data collected at the end of each period. Glycaemic control was assessed using CGM metrics including time in range (TIR), time above range (TAR), hypoglycaemic time, and glucose variability, as well as HbA1c. QOL was assessed using the Problem Areas in Diabetes (PAID-20) scale.

Results:
Twenty-one participants were recruited between April 2024–November 2025. Fourteen participants completed the trial. Median age was 35 years and 43% were male. 85% were on modulator therapy and 14% were post lung transplant. Median duration of diabetes was 11.5 years. Median baseline HbA1c, TIR and TAR were 6.9%, 69% and 27.5% respectively. Median baseline PAID score was 28.1. Following the intervention, TIR improved significantly to 76.5% (p=0.018). HbA1c improved from 6.9% at baseline and 6.8% after control to 6.6% after CGM (p=0.035), whereas TAR was lower after CGM (21%) than baseline (27.5%) but not control (25%, overall p=0.041). Median PAID score improved significantly to 11.3 (p=0.018). There were no significant differences in hypoglycaemic time, glucose variability, BMI, or total daily insulin dose.

Conclusions:
These data suggest benefit in offering CGM to all individuals with insulin-requiring CFRD to improve both glycaemic control and QOL. These results support the ongoing advocacy to achieve subsidised access to CGM for those living with CFRD.

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