Impact of continuous glucose monitoring in youth with type 1 diabetes aged 15-21 years

Background People with type 1 diabetes (T1D) aged <21 years are eligible for subsidised continuous glucose monitoring (CGM) products under the Australian National Diabetes Services Scheme. There are few real-world published studies to evaluate the benefits of CGM in young adults. Aims To perform a real-world observation study among youth with T1D to evaluate CGM use and benefits of CGM. Methods Patients at the Westmead Hospital Young Adult Diabetes Clinic aged 15-21 years who commenced CGM before July 2018 were followed for 6 months post commencement of CGM. Differences in HbA1c and glucose metrics at baseline and follow up are compared between those commencing CGM and those that did not. Results Forty-four (38%) of 115 eligible patients commenced CGM. Demographic characteristics and baseline HbA1c did not differ significantly between those started on CGM and those that did not. At 6 months, 18 (41%) of 44 patients still used CGM, with discomfort and inconvenience the most common reasons for dropout. In CGM continuers, at 6 months compared with baseline, there was no change in HbA1c (8.2% vs 8.0%; P = 0.8), coefficient of variation of glucose (38% vs 39%; P = 0.5) or percentage time in range (52% vs 58%; P = 0.3). Six-month follow-up HbA1c in CGM non-users deteriorated significantly compared with users. Mean hypoglycaemia fear scores (worry scale) were significantly decreased from baseline at 6 months (33 vs 18; P < 0.01). Conclusion There are high rates of discontinuation in CGM use among youth with T1D. At 6 months of CGM use, there was no significant change in glycaemic control, although HbA1c in non-users deteriorated significantly. Worry of hypoglycaemia was significantly decreased among those who continued CGM.