Effect of Continuous Glucose Monitoring on Glycemic Control in Adolescents and Young Adults With Type 1 Diabetes

Abstract

; for the CGM Intervention in Teens and Young Adults with T1D (CITY) Study Group IMPORTANCE Adolescents and young adults with type 1 diabetes exhibit the worst glycemic control among individuals with type 1 diabetes across the lifespan. Although continuous glucose monitoring (CGM) has been shown to improve glycemic control in adults, its benefit in adolescents and young adults has not been demonstrated. OBJECTIVE To determine the effect of CGM on glycemic control in adolescents and young adults with type 1 diabetes. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial conducted between January 2018 and May 2019 at 14 endocrinology practices in the US including 153 individuals aged 14 to 24 years with type 1 diabetes and screening hemoglobin A 1c (HbA 1c) of 7.5% to 10.9%. INTERVENTIONS Participants were randomized 1:1 to undergo CGM (CGM group; n = 74) or usual care using a blood glucose meter for glucose monitoring (blood glucose monitoring [BGM] group; n = 79). MAIN OUTCOMES AND MEASURES The primary outcome was change in HbA 1c from baseline to 26 weeks. There were 20 secondary outcomes, including additional HbA 1c outcomes, CGM glucose metrics, and patient-reported outcomes with adjustment for multiple comparisons to control for the false discovery rate. RESULTS Among the 153 participants (mean [SD] age, 17 [3] years; 76 [50%] were female; mean [SD] diabetes duration, 9 [5] years), 142 (93%) completed the study. In the CGM group, 68% of participants used CGM at least 5 days per week in month 6. Mean HbA 1c was 8.9% at baseline and 8.5% at 26 weeks in the CGM group and 8.9% at both baseline and 26 weeks in the BGM group (adjusted between-group difference, −0.37% [95% CI, −0.66% to −0.08%]; P = .01). Of 20 prespecified secondary outcomes, there were statistically significant differences in 3 of 7 binary HbA 1c outcomes, 8 of 9 CGM metrics, and 1 of 4 patient-reported outcomes. The most commonly reported adverse events in the CGM and BGM groups were severe hypoglycemia (3 participants with an event in the CGM group and 2 in the BGM group), hyperglycemia/ketosis (1 participant with an event in CGM group and 4 in the BGM group), and diabetic ketoacidosis (3 participants with an event in the CGM group and 1 in the BGM group). CONCLUSIONS AND RELEVANCE Among adolescents and young adults with type 1 diabetes, continuous glucose monitoring compared with standard blood glucose monitoring resulted in a small but statistically significant improvement in glycemic control over 26 weeks. Further research is needed to understand the clinical importance of the findings.

Self‐management among pre‐teen and adolescent diabetes device users

“…Results of previous research on the benefits of CGM for adolescents has been mixed. In a recent randomized controlled trial, a significant reduction in HbA1c by 0.37% was found among adolescents with the use of adjunctive CGM 40 . In prior research, when data from children and adolescents were analyzed together with a larger adult population, CGM use was associated with reduction in HbA1c 11,41,42 .…”

“…In a recent randomized controlled trial, a significant reduction in HbA1c by 0.37% was found among adolescents with the use of adjunctive CGM. 40 In prior research, when data from children and adolescents were analyzed together with a larger adult population, CGM use was associated with reduction in HbA1c. 11,41,42 Our findings showing a negative association between SMBG and bolus frequency and HbA1c are supported by several studies examining insulin pump self-management in this population.…”

Glycemic Improvement Using Continuous Glucose Monitoring by Baseline Time in Range: Subgroup Analyses from the DIAMOND Type 1 Diabetes Study

“…S everal studies have shown use of continuous glucose monitors (CGMs) can improve glycemic control and reduce hypoglycemia for participants with type 1 diabetes (T1D). [1][2][3] The DIAMOND T1D trial found that participants randomized to receive a real-time continuous glucose monitor (rtCGM) had a 0.6% greater reduction in mean hemoglobin A1c (HbA1c) and spent an additional 77 min per day in range 70-180 mg/dL compared with participants in selfmonitoring of blood glucose (SMBG) group. 4 Beyond the finding of a clinically relevant overall benefit of rtCGMs, it is important to assess improvement at an individual level to identify individuals who can potentially benefit the most from rtCGM use.…”

Continuous Glucose Monitoring in Adolescent, Young Adult, and Older Patients With Type 1 Diabetes

“…In this issue of JAMA, 2 clinical trials provide important data on the efficacy of CGM in these high-risk populations with type 1 diabetes. 5,6 The periods of adolescence and young adulthood (13-24 y) are distinctive developmental stages marked by transition of disease self-management tasks from family to self in the midst of tumultuous change in an individual's social, geographic, financial, and health care situations. 7 As a result, adolescents and young adults exhibit the highest hemoglobin A 1c (HbA 1c ) levels and rates of hospitalization of all age groups with type 1 diabetes.…”