Initiation of intermittently-scanned continuous glucose monitoring is associated with reduced hospitalization for acute diabetes events and cardiovascular complications in adults with type 1 diabetesRunning title: Reduced type 1 diabetes complications using CGM

Objective We assessed the impact of intermittently-scanned continuous glucose monitoring (isCGM), compared to blood glucose monitoring (BGM), on rates of hospitalization for metabolic and vascular complications of diabetes, and on HbA1c levels for adults with type 1 diabetes. Research design and methods This retrospective study, using data from the Swedish National Diabetes Register (NDR) and the Swedish National Patient Register (NPR), comprises adults with type 1 diabetes and an isCGM initiation date after 01/06/2017 and matched controls using BGM. Hospital admission rates were calculated per 100 person-years of follow up. Results We identified 11,822 adults with type 1 diabetes and an isCGM index date after 01/06/2017 and HbA1c baseline values 3-8 months prior to index date. Compared to 3,007 BGM controls, isCGM users had significantly lower relative risk (RR; 95% CI) of hospitalization for hypoglycaemia (RR=0.32; 0.14, 0.74), diabetic ketoacidosis (DKA, RR=0.55; 0.35, 0.87), stroke (RR=0.48; 0.37, 0.64), acute myocardial infarction (RR=0.64; 0.46, 0.91), atrial fibrillation (RR=0.59; 0.38, 0.94), heart failure (RR=0.25; 0.16, 0.39), peripheral vascular disease (RR=0.21; 0.07, 0.62), kidney disease (RR=0.48; 0.35, 0.66) or hospitalization for any reason (RR=0.32; 0.29, 0.35). Compared to BGM controls, change in mean HbA1c for isCGM users was ‑0.30% (‑3.3 mmol/mol) at 6 months and ‑0.24% (‑2.6 mmol/mol) at 24 months (both p<0.001). Conclusions This study shows that adults in Sweden with type 1 diabetes who initiate isCGM have significantly reduced hospitalization rates for acute diabetes events, kidney disease and cardiovascular complications, along with improved glucose control, compared to BGM controls.