Glycemic and Psychosocial Outcomes of Advanced Hybrid Closed Loop Therapy in Youth With High HbA1c: A Randomized Clinical Trial

OBJECTIVE To determine the efficacy of advanced hybrid closed loop (AHCL) therapy in a high-risk cohort of youth on continuous subcutaneous insulin infusion (CSII) ± continuous glucose monitoring (CGM) with suboptimal glycemia. RESEARCH DESIGN AND METHODS In a 6-month multicenter clinical trial, youth with type 1 diabetes with mean and most recent HbA1c > 8.5% (65 mmol/mol) were randomly assigned 1:1 to AHCL or treatment as usual (CSII ± CGM). The primary outcome was the 24-week between-group difference in HbA1c. Secondary outcomes included CGM metrics from masked CGM and psychological measures (youth-reported problem areas in diabetes [PAID], quality of life, anxiety, depression, and hypoglycemia fear) assessed using validated questionnaires. RESULTS A total of 42 participants were randomized (mean [SD] age 16.2 [2.5] years, HbA1c 9.8 [1.1]% or 84 [12] mmol/mol, PAID score 50.3 [19.8]). At study end, the mean (SD) HbA1c was 8.8 (1.1)% or 73 (12) mmol/mol with AHCL and 9.9 (1.2)% or 85 (13.1) mmol/mol with CSII ± CGM, with mean adjusted group difference of −0.77% (95% CI −1.45 to −0.09) or −8.4 mmol/mol (−15.8 to −1.0); P = 0.027. AHCL increased time in range 70–180 mg/dL (difference 19.1%; 95% CI 11.1 to 27.1), reduced time >180 mg/dL (difference −17.7%; 95% CI −26.6 to −8.8), with no increase in time spent <70 mg/dL (difference −0.8%; 95% CI −2.7 to 0.6). There was no evidence for difference in psychosocial outcomes between the two groups at study end. CONCLUSIONS AHCL should be encouraged in youth with suboptimal glycemia, as AHCL improves glycemia. However, psychological support remains vital, as technology alone may not be able to reduce the burden of diabetes care in this subgroup.