ESPE Abstracts

Introduction: Continuous-glucose monitoring (CGM) is becoming a useful tool to evaluate glucose profiles in real-life conditions and to detect glucose abnormalities undetected by OGTT in CF patients.

Objectives: • Evaluation of OGTT and CGM results longitudinally • Evaluation of BMI z-score and %FEV1 changes in relation to OGTT and CGM results. • Analysis of 6 proposed criteria to classify glucose abnormalities by CGM results.

Patients and Methods: Prospective longitudinal and cross-sectional study. Patients with genetically-confirmed CF >10 years old, visited between November/2012 and November/2019. Fifty patients (28 female), age: 13.79 ± 2.43 years. Patients receiving insulin, lung transplant; or treatment with corticosteroids, GH and/or immunosuppressants or having disease exacerbation in the previous 4 weeks were excluded. OGTT and GCM performed yearly. BMI and %FEV1 assessed at the time of testing (±2 months) and at the previous year (±2 months). OGTT classifies patients into normal glucose tolerance (NGT), abnormal glucose tolerance (AGT) or CFRD. After OGTT, CGM (IproTm²) was carried out for 6 days with regular exercise and diet. Comparison, by ROC curve, of sensitivity and specificity of the proposed criteria to classify glucose abnormalities by CGM results. Statistical analysis performed with SPSS v.24 program.

Results: Cross-sectional study: 26% homozygous and 50% heterozygous for F508del mutation. 80% pancreatic insufficiency.-OGTT: 28 patients (56%) NGT, 19 (38%) AGT and 3 (6%) CFRD.-CGM: One patient (2%) with NGT and 11 (22%) with AGT had glucose peaks >200mg/dlTo classify glucose abnormalities by CGM the following criteria were chosen (Specificity: 71.43%, Sensitivity: 86.36%), AGT: glucose between 140-199 mg/dl ≥ 4.5% of monitoring time or one peak of glucose ≥200mg/dl; CFRD: ≥2 glucose peaks ≥200mg/dl on different days.Prospective study: in 21 patients at least 2 pairs of tests (CGM and OGTT) were performed (second test age: 15.33 ±2.38 years) and in 12 of them (third test age: 16.01 ±1.71 years) 3 pairs of tests.

Conclusions: • CGM is a useful method to evaluate glucose abnormalities in CF patients. • Criteria to diagnose glucose abnormalities using CGM are proposed. • CGM is more sensitive than OGTT in detecting glucose abnormalities that are related with lung function variations and predicting future nutritional changes (decreased BMI).