Dongyuan Xing

Continuous glucose monitoring and intensive treatment of type 1 diabetes

BACKGROUND The value of continuous glucose monitoring in the management of type 1 diabetes mellitus has not been determined. METHODS In a multicenter clinical trial, we randomly assigned 322 adults and children who were already receiving intensive therapy for type 1 diabetes to a group with continuous glucose monitoring or to a control group performing home monitoring with a blood glucose meter. All the patients were stratified into three groups according to age and had a glycated hemoglobin level of 7.0 to 10.0%. The primary outcome was the change in the glycated hemoglobin level at 26 weeks. RESULTS The changes in glycated hemoglobin levels in the two study groups varied markedly according to age group (P=0.003), with a significant difference among patients 25 years of age or older that favored the continuous-monitoring group (mean difference in change, -0.53%; 95% confidence interval [CI], -0.71 to -0.35; P<0.001). The between-group difference was not significant among those who were 15 to 24 years of age (mean difference, 0.08; 95% CI, -0.17 to 0.33; P=0.52) or among those who were 8 to 14 years of age (mean difference, -0.13; 95% CI, -0.38 to 0.11; P=0.29). Secondary glycated hemoglobin outcomes were better in the continuous-monitoring group than in the control group among the oldest and youngest patients but not among those who were 15 to 24 years of age. The use of continuous glucose monitoring averaged 6.0 or more days per week for 83% of patients 25 years of age or older, 30% of those 15 to 24 years of age, and 50% of those 8 to 14 years of age. The rate of severe hypoglycemia was low and did not differ between the two study groups; however, the trial was not powered to detect such a difference. CONCLUSIONS Continuous glucose monitoring can be associated with improved glycemic control in adults with type 1 diabetes. Further work is needed to identify barriers to effectiveness of continuous monitoring in children and adolescents. (ClinicalTrials.gov number, NCT00406133.)

The effect of continuous glucose monitoring in well-controlled type 1 diabetes.

OBJECTIVE The potential benefits of continuous glucose monitoring (CGM) in the management of adults and children with well-controlled type 1 diabetes have not been examined. RESEARCH DESIGN AND METHODS A total of 129 adults and children with intensively treated type 1 diabetes (age range 8–69 years) and A1C <7.0% were randomly assigned to either continuous or standard glucose monitoring for 26 weeks. The main study outcomes were time with glucose level ≤70 mg/dl, A1C level, and severe hypoglycemic events. RESULTS At 26 weeks, biochemical hypoglycemia (≤70 mg/dl) was less frequent in the CGM group than in the control group (median 54 vs. 91 min/day), but the difference was not statistically significant (P = 0.16). Median time with a glucose level ≤60 mg/dl was 18 versus 35 min/day, respectively (P = 0.05). Time out of range (≤70 or >180 mg/dl) was significantly lower in the CGM group than in the control group (377 vs. 491 min/day, P = 0.003). There was a significant treatment group difference favoring the CGM group in mean A1C at 26 weeks adjusted for baseline (P < 0.001). One or more severe hypoglycemic events occurred in 10 and 11% of the two groups, respectively (P = 1.0). Four outcome measures combining A1C and hypoglycemia data favored the CGM group in comparison with the control group (P < 0.001, 0.007, 0.005, and 0.003). CONCLUSIONS Most outcomes, including those combining A1C and hypoglycemia, favored the CGM group. The weight of evidence suggests that CGM is beneficial for individuals with type 1 diabetes who have already achieved excellent control with A1C <7.0%.

Overnight closed loop insulin delivery (artificial pancreas) in adults with type 1 diabetes: crossover randomised controlled studies

Objective To compare the safety and efficacy of overnight closed loop delivery of insulin (artificial pancreas) with conventional insulin pump therapy in adults with type 1 diabetes. Design Two sequential, open label, randomised controlled crossover, single centre studies. Setting Clinical research facility. Participants 24 adults (10 men, 14 women) with type 1 diabetes, aged 18-65, who had used insulin pump therapy for at least three months: 12 were tested after consuming a medium sized meal and the other 12 after consuming a larger meal accompanied by alcohol. Intervention During overnight closed loop delivery, sensor measurements of glucose were fed into a computer algorithm, which advised on insulin pump infusion rates at 15 minute intervals. During control nights, conventional insulin pump settings were applied. One study compared closed loop delivery of insulin with conventional pump therapy after a medium sized evening meal (60 g of carbohydrates) at 1900, depicting the scenario of “eating in.” The other study was carried out after a later large evening meal (100 g of carbohydrates) at 2030, accompanied by white wine (0.75 g/kg ethanol) and depicted the scenario of “eating out.” Main outcome measures The primary outcome was the time plasma glucose levels were in target (3.91-8.0 mmol/L) during closed loop delivery and a comparable control period. Secondary outcomes included pooled data analysis and time plasma glucose levels were below target (≤3.9 mmol/L). Results For the eating in scenario, overnight closed loop delivery of insulin increased the time plasma glucose levels were in target by a median 15% (interquartile range 3-35%), P=0.002. For the eating out scenario, closed loop delivery increased the time plasma glucose levels were in target by a median 28% (2-39%), P=0.01. Analysis of pooled data showed that the overall time plasma glucose was in target increased by a median 22% (3-37%) with closed loop delivery (P<0.001). Closed loop delivery reduced overnight time spent hypoglycaemic (plasma glucose ≤3.9 mmol/L) by a median 3% (0-20%), P=0.04, and eliminated plasma glucose concentrations below 3.0 mmol/L after midnight. Conclusion These two small crossover trials suggest that closed loop delivery of insulin may improve overnight control of glucose levels and reduce the risk of nocturnal hypoglycaemia in adults with type 1 diabetes. Trial registration ClinicalTrials.gov NCT00910767 and NCT00944619.

Factors predictive of use and of benefit from continuous glucose monitoring in type 1 diabetes.

OBJECTIVE To evaluate factors associated with successful use of continuous glucose monitoring (CGM) among participants with intensively treated type 1 diabetes in the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Randomized Clinical Trial. RESEARCH DESIGN AND METHODS The 232 participants randomly assigned to the CGM group (165 with baseline A1C ≥7.0% and 67 with A1C <7.0%) were asked to use CGM on a daily basis. The associations of baseline factors and early CGM use with CGM use ≥6 days/week in the 6th month and with change in A1C from baseline to 6 months were evaluated in regression models. RESULTS The only baseline factors found to be associated with greater CGM use in month 6 were age ≥25 years (P < 0.001) and more frequent self-reported prestudy blood glucose meter measurements per day (P < 0.001). CGM use and the percentage of CGM glucose values between 71 and 180 mg/dl during the 1st month were predictive of CGM use in month 6 (P < 0.001 and P = 0.002, respectively). More frequent CGM use was associated with a greater reduction in A1C from baseline to 6 months (P < 0.001), a finding present in all age-groups. CONCLUSIONS After 6 months, near-daily CGM use is more frequent in intensively treated adults with type 1 diabetes than in children and adolescents, although in all age-groups near-daily CGM use is associated with a similar reduction in A1C. Frequency of blood glucose meter monitoring and initial CGM use may help predict the likelihood of long-term CGM benefit in intensively treated patients with type 1 diabetes of all ages.

Severe hypoglycemia and diabetic ketoacidosis in adults with type 1 diabetes: results from the T1D Exchange clinic registry.

CONTEXT Few studies have assessed factors associated with severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) in adults with type 1 diabetes (T1D). OBJECTIVE Our objective was to determine frequency of and factors associated with the occurrence of SH and DKA in adults with T1D. DESIGN AND SETTING We conducted a cross-sectional analysis from the T1D Exchange clinic registry at 70 U.S. endocrinology centers. PATIENTS Analysis included 7012 participants in the T1D Exchange clinic registry aged 26 to 93 years old with T1D for ≥2 years. RESULTS Higher frequencies of SH and DKA were associated with lower socioeconomic status (P < .001). SH was strongly associated with diabetes duration (P < .001), with 18.6% of those with diabetes ≥40 years having an event in the past 12 months. SH frequency was lowest in those with hemoglobin A1c (HbA1c) levels of 7.0% (53 mmol/mol) to 7.5% (58 mmol/mol), being higher in those with HbA1c levels <7.0% (<53 mmol/mol) or >7.5% (>58 mmol/mol). DKA frequency increased with higher HbA1c levels (P < .001), with 21.0% of those with HbA1c ≥10.0% (≥86 mmol/mol) having an event in the past 12 months. CONCLUSIONS SH and DKA are more common in those with lower socioeconomic status. DKA, most common in those with HbA1c ≥10.0% (≥86 mmol/mol), should be largely preventable. In contrast, SH, most frequent with diabetes ≥40 years duration, cannot be abolished given the limitation of current therapies. To reduce SH in adults with longstanding diabetes, consideration should be given to modifying HbA1c goals, particularly in patients with very low HbA1c levels.

A Randomized Clinical Trial to Assess the Efficacy and Safety of Real-Time Continuous Glucose Monitoring in the Management of Type 1 Diabetes in Young Children Aged 4 to <10 Years

OBJECTIVE Continuous glucose monitoring (CGM) has been demonstrated to improve glycemic control in adults with type 1 diabetes but less so in children. We designed a study to assess CGM benefit in young children aged 4 to 9 years with type 1 diabetes. RESEARCH DESIGN AND METHODS After a run-in phase, 146 children with type 1 diabetes (mean age 7.5 ± 1.7 years, 64% on pumps, median diabetes duration 3.5 years) were randomly assigned to CGM or to usual care. The primary outcome was reduction in HbA1c at 26 weeks by ≥0.5% without the occurrence of severe hypoglycemia. RESULTS The primary outcome was achieved by 19% in the CGM group and 28% in the control group (P = 0.17). Mean change in HbA1c was −0.1% in each group (P = 0.79). Severe hypoglycemia rates were similarly low in both groups. CGM wear decreased over time, with only 41% averaging at least 6 days/week at 26 weeks. There was no correlation between CGM use and change in HbA1c (rs = −0.09, P = 0.44). CGM wear was well tolerated, and parental satisfaction with CGM was high. However, parental fear of hypoglycemia was not reduced. CONCLUSIONS CGM in 4- to 9-year-olds did not improve glycemic control despite a high degree of parental satisfaction with CGM. We postulate that this finding may be related in part to limited use of the CGM glucose data in day-to-day management and to an unremitting fear of hypoglycemia. Overcoming the barriers that prevent integration of these critical glucose data into day-to-day management remains a challenge.

Comparison of fingerstick hemoglobin A1c levels assayed by DCA 2000 with the DCCT/EDIC central laboratory assay: results of a Diabetes Research in Children Network (DirecNet) Study.

Abstract:  Background:  The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) high‐performance liquid chromatography (HPLC) method for measuring hemoglobin A1c (HbA1c) serves as a reference standard against which other assays are compared. The DCA 2000® + Analyzer (Bayer Inc., Tarrytown, NY, USA), which uses an immunoassay, is a very popular device for measuring HbA1c levels in pediatric diabetes practices.

Sustained benefit of continuous glucose monitoring on A1C, glucose profiles, and hypoglycemia in adults with type 1 diabetes

OBJECTIVE To evaluate long-term effects of continuous glucose monitoring (CGM) in intensively treated adults with type 1 diabetes. RESEARCH DESIGN AND METHODS We studied 83 of 86 individuals ≥25 years of age with type 1 diabetes who used CGM as part of a 6-month randomized clinical trial in a subsequent 6-month extension study. RESULTS After 12 months, median CGM use was 6.8 days per week. Mean change in A1C level from baseline to 12 months was −0.4 ± 0.6% (P < 0.001) in subjects with baseline A1C ≥7.0%. A1C remained stable at 6.4% in those with baseline A1C <7.0%. The incidence rate of severe hypoglycemia was 21.8 and 7.1 events per 100 person-years in the first and last 6 months, respectively. Time per day with glucose levels in the range of 71–180 mg/dl increased significantly (P = 0.02) from baseline to 12 months. CONCLUSIONS In intensively treated adults with type 1 diabetes, CGM use and benefit can be sustained for 12 months.

Severe hypoglycemia and diabetic ketoacidosis among youth with type 1 diabetes in the T1D Exchange clinic registry

Severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) are common serious acute complications of type 1 diabetes (T1D). The aim of this study was to determine the frequency of SH and DKA and identify factors related to their occurrence in the T1D Exchange pediatric and young adult cohort.

Continuous Glucose Monitoring in Youth with Type 1 Diabetes: 12-Month Follow-Up of the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Randomized Trial

BACKGROUND The use of continuous glucose monitoring (CGM) in the pediatric population is not well characterized. We have evaluated the use of CGM over a 12-month interval in youth with type 1 diabetes (TID) and have provided a description of CGM use. METHODS Eighty subjects 8-17 years old with T1D and baseline hemoglobin A1c (HbA1c) >or=7.0% used CGM as part of a 6-month randomized trial and subsequent 6-month extension study. Outcomes included frequency of CGM use, HbA1c levels, rate of severe hypoglycemia, and a CGM satisfaction scale. RESULTS Seventy-six (95%) of 80 subjects were using CGM after 6 months (median use = 5.5 days/week) compared with 67 (84%) after 12 months (median use = 4.0 days/week). The 17 subjects using CGM >or=6 days/week in month 12 had substantially greater improvement from baseline in HbA1c than did the 63 subjects using CGM <6 days/week in month 12 (mean change - 0.8 +/- 0.6% vs. +0.1 +/- 0.7%, P < 0.001). They also reported greater satisfaction with use of CGM (P = 0.001). The incidence of severe hypoglycemic events was low during the 12 months of the study irrespective of the amount of CGM use. CONCLUSIONS In youth with T1D, frequency of use decreases over time. Individuals who use CGM on a near-daily basis can have substantial improvement in glycemic control.