Continuous Glucose Monitoring vs Conventional Therapy for Glycemic Control in Adults With Type 1 Diabetes Treated With Multiple Daily Insulin Injections

Abstract

IMPORTANCEThe majority of individuals with type 1 diabetes do not meet recommended glycemic targets.OBJECTIVE To evaluate the effects of continuous glucose monitoring in adults with type 1 diabetes treated with multiple daily insulin injections. DESIGN, SETTING, AND PARTICIPANTSOpen-label crossover randomized clinical trial conducted in 15 diabetes outpatient clinics in Sweden between February 24, 2014, and June 1, 2016 that included 161 individuals with type 1 diabetes and hemoglobin A 1c (HbA 1c ) of at least 7.5% (58 mmol/mol) treated with multiple daily insulin injections.INTERVENTIONS Participants were randomized to receive treatment using a continuous glucose monitoring system or conventional treatment for 26 weeks, separated by a washout period of 17 weeks. MAIN OUTCOMES AND MEASURESDifference in HbA 1c between weeks 26 and 69 for the 2 treatments. Adverse events including severe hypoglycemia were also studied. RESULTS Among 161 randomized participants, mean age was 43.7 years, 45.3% were women, and mean HbA 1c was 8.6% (70 mmol/mol). A total of 142 participants had follow-up data in both treatment periods. Mean HbA 1c was 7.92% (63 mmol/mol) during continuous glucose monitoring use and 8.35% (68 mmol/mol) during conventional treatment (mean difference, −0.43% [95% CI, −0.57% to −0.29%] or −4.7 [−6.3 to −3.1 mmol/mol]; P < .001). Of 19 secondary end points comprising psychosocial and various glycemic measures, 6 met the hierarchical testing criteria of statistical significance, favoring continuous glucose monitoring compared with conventional treatment. Five patients in the conventional treatment group and 1 patient in the continuous glucose monitoring group had severe hypoglycemia. During washout when patients used conventional therapy, 7 patients had severe hypoglycemia.CONCLUSIONS AND RELEVANCE Among patients with inadequately controlled type 1 diabetes treated with multiple daily insulin injections, the use of continuous glucose monitoring compared with conventional treatment for 26 weeks resulted in lower HbA 1c . Further research is needed to assess clinical outcomes and longer-term adverse effects.

Clinical Implications of Accuracy Measurements of Continuous Glucose Sensors

“…The Diamond trial 32 demonstrated a significantly greater (0.6%) decrease in HbA1c and time in hypoglycemia (43 vs. 80 min/day) with the use of CGM plus individualized insulin dosing recommendations. The 1-year duration GOLD trial 33 used a crossover design and demonstrated slightly lower (0.43%) HbA1c levels with CGM and significant education. This effect disappeared in subjects using CGM <70% of the time.…”

Continuous Glucose Monitoring with Multiple Daily Insulin Treatment: Outcome Studies

“…From a baseline HbA1c of 8.6%, the mean HbA1c during CGM use was 7.92%, and during conventional treatment was 8.35%, mean difference -0.43% (95% CI -0.57% to -0.29%, P < 0.001). 43 Time spent in hypoglycemia was 2.79% during the CGM period and 4.79% during conventional therapy. 43 Notably, significant improvement was noted in subjective wellbeing and treatment satisfaction, and hypoglycemia confidence improved during the CGM treatment period in GOLD.…”

“…43 Time spent in hypoglycemia was 2.79% during the CGM period and 4.79% during conventional therapy. 43 Notably, significant improvement was noted in subjective wellbeing and treatment satisfaction, and hypoglycemia confidence improved during the CGM treatment period in GOLD. 43 The conclusions drawn from these studies were summarized by Davidson 44 As the prevalence of type 1 diabetes increases, clinicians and healthcare systems will be challenged to find better management strategies that are patient centric, and that reduce both the acute and chronic risks of the disease.…”

“…Conventional Therapy for Glycemic Control in Adults with Type 1 Diabetes Treated with Multiple Daily Injections) randomized clinical trials specifically targeted MDI-treated patients to evaluate the added benefit of CGM in addition to SMBG versus SMBG alone. 42,43 Both studies used the DexCom G4 Platinum CGM system. In DIAMOND, 152 participants, mean age 48, mean baseline HbA1c 8.6%, were randomized to CGM plus SMBG or SMBG alone for 24 weeks.…”

“…42 The GOLD trial used a crossover design with half of the 161 randomized participants using CGM for 6 months in addition to SMBG, followed by a 4-month washout period, then 6 months of usual care with SMBG alone, whereas the other half of the participants performed SMBG for the initial 6 months, and washout period followed by 6 months of CGM. 43 Followup data were available for 142 participants, who wore the CGM between 86.5% and 91.9% of the time assigned. From a baseline HbA1c of 8.6%, the mean HbA1c during CGM use was 7.92%, and during conventional treatment was 8.35%, mean difference -0.43% (95% CI -0.57% to -0.29%, P < 0.001).…”