Many individuals with cystic fibrosis related diabetes (CFRD) have difficulty monitoring glucose levels with finger-prick testing. Use of continuous glucose monitoring (CGM) has removed the need for finger-prick testing and been shown to reduce HbA1c in type 1 diabetes. Data is lacking in CFRD.
We performed a prospective single-arm trial of 3 months CGM (Libre2) use in individuals with CFRD using insulin, to assess the impact of CGM on glycaemic control and quality of life. All outcomes were assessed at baseline, 3 and 6 months. Glycaemic control was assessed by comparison of the glycated haemoglobin (HbA1c) and the time in range, time in very low range and glucose variability. Quality of life (QOL) was assessed by Problem Areas in Diabetes (PAID).
A total of 19 subjects with CFRD, on insulin therapy, were recruited. Of these, 58% were on modulator therapy and 37% post lung transplant. Median duration of diabetes was 13 years. Metformin was prescribed to 26% of the participants, and 16% prescribed a GLP-1 agonist.
Median baseline HbA1c was 8.7% (IQR:8–10.55), decreasing to 7.8% (IQR:7.3 – 8.3) (p=0.018) at completion of intervention. Decreasing further to median 7.3% (IQR: 6.9 – 8.3) at 3 months post completion. Median baseline PAID score was 29 (IQR:16.0 – 48.5), decreasing to 14.5 (IQR: 10.5 – 19.75) (p=0.02) at completion of intervention. At 3 months post completion median increased to 17 (IQR 10 – 22). Time in range in the first 2 weeks of CGM use 42%, (IQR:25.5-54.5) was not different to the last fortnight 61%, (IQR:26.5 – 74), p=0.16). There was no increase in the time spent <3.0mmol/L before and after sensor use (0% vs 0.3% p=0.50).
The use of CGM improved glycaemic control without increase in hypoglycaemia, and improved QOL in CFRD. Benefits were maintained at 3 months post CGM intervention.