Continuous glucose monitoring versus blood glucose monitoring for risk of severe hypoglycaemia and diabetic ketoacidosis in children, adolescents, and young adults with type 1 diabetes: a population-based study

Background The effect of continuous glucose monitoring on the risk of severe hypoglycaemia and ketoacidosis in patients with diabetes is unclear. We investigated whether rates of acute diabetes complications are lower with continuous glucose monitoring, compared with blood glucose monitoring, and which metrics predict its risk in young patients with type 1 diabetes. Methods In this population-based cohort study, patients were identified from 511 diabetes centres across Austria, Germany, Luxembourg, and Switzerland participating in the Diabetes Prospective Follow-up initiative. We included people with type 1 diabetes aged 1 center dot 5-25 center dot 0 years, with a diabetes duration of more than 1 year, who had been treated between Jan 1, 2014, and June 30, 2021, and had an observation time of longer than 120 days in the most recent treatment year. Severe hypoglycaemia and ketoacidosis rates during the most recent treatment year were examined in people using continuous glucose monitoring and in those using blood glucose monitoring. Adjustments of statistical models included age, sex, diabetes duration, migration background, insulin therapy (pump or injections), and treatment period. Rates of severe hypoglycaemia and diabetic ketoacidosis were evaluated by several continuous glucose monitoring metrics, including percentage of time below target glucose range (<3 center dot 9 mmol/L), glycaemic variability (measured as the coefficient of variation), and mean sensor glucose. Findings Of 32 117 people with type 1 diabetes (median age 16 center dot 8 years [IQR 13 center dot 3-18 center dot 1], 17 056 [53 center dot 1%] males), 10 883 used continuous glucose monitoring (median 289 days per year), and 21 234 used blood glucose monitoring. People using continuous glucose monitoring had lower rates of severe hypoglycaemia than those using blood glucose monitoring (6 center dot 74 [95% CI 5 center dot 90-7 center dot 69] per 100 patient-years vs 8 center dot 84 [8 center dot 09-9 center dot 66] per 100 patient-years; incidence rate ratio 0 center dot 76 [95% CI 0 center dot 64-0 center dot 91]; p=0 center dot 0017) and diabetic ketoacidosis (3 center dot 72 [3 center dot 32-4 center dot 18] per 100 patient-years vs 7 center dot 29 [6 center dot 83-7 center dot 78] per 100 patient-years; 0 center dot 51 [0 center dot 44-0 center dot 59]; p<0 center dot 0001). Severe hypoglycaemia rates increased with percentage of time below target glucose range (incidence rate ratio 1 center dot 69 [95% CI 1 center dot 18-2 center dot 43]; p=0 center dot 0024, for 4 center dot 0-7 center dot 9% vs <4 center dot 0% and 2 center dot 38 [1 center dot 51-3 center dot 76]; p<0 center dot 0001, for =8 center dot 0% vs <4 center dot 0%) and glycaemic variability (coefficient of variation =36% vs <36%; incidence rate ratio 1 center dot 52 [95% CI 1 center dot 06-2 center dot 17]; p=0 center dot 022). Diabetic ketoacidosis rates increased with mean sensor glucose (incidence rate ratio 1 center dot 77 [95% CI 0 center dot 89-3 center dot 51], p=0 center dot 13, for 8 center dot 3-9 center dot 9 mmol/L vs <8 center dot 3 mmol/L; 3 center dot 56 [1 center dot 83-6 center dot 93], p<0 center dot 0001, for 10 center dot 0-11 center dot 6 mmol/L vs <8 center dot 3 mmol/L; and 8 center dot 66 [4 center dot 48-16 center dot 75], p<0 center dot 0001, for =11 center dot 7 mmol/L vs <8 center dot 3 mmol/L). Interpretation These findings provide evidence that continuous glucose monitoring can reduce severe hypoglycaemia and ketoacidosis risk in young people with type 1 diabetes on insulin therapy. Continuous glucose monitoring metrics might help to identify those at risk for acute diabetes complications.

Automated summary

Continuous glucose monitoring can reduce the risk of severe hypoglycemia and ketoacidosis in young patients with type 1 diabetes on insulin therapy. The use of continuous glucose monitoring metrics can help identify individuals at risk for acute diabetes complications.