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Diabetes Research in Children Network (DirecNet) Study Group

Publications and source records attributed to Diabetes Research in Children Network (DirecNet) Study Group.

10 recordsLinked to original sources
PubMed2006

Psychological aspects of continuous glucose monitoring in pediatric type 1 diabetes.

Clinical use of near-continuous glucose monitors (CGMs) could have substantial impact on family management of pediatric type 1 diabetes and could generate both beneficial and adverse psychological reactions. In addition to glycemic benefits, CGM could possibly yield educational and motivational benefits. Conversely, CGM may also lead to information overload and increased treatment burden. Further, patients and families with certain affective, behavioral, and cognitive characteristics might derive greater benefit from CGM use. As information about these processes could facilitate optimal clinical use of CGM, the Diabetes Research in Children Network (DirecNet) included measurement of selected psychological variables in a recent randomized trial of the GlucoWatch G2 Biographer (GW2B, Cyngus, Inc., Redwood City, CA, USA). A multicenter sample of 200 youths with type 1 diabetes was randomized to 6 months of either continued usual care (UC) using a conventional home glucose meter for diabetes or supplementation of standard care with use of the GW2B. Diabetes treatment adherence, diabetes-specific quality of life, and diabetes-related anxiety were measured at baseline and at the end of the study. Satisfaction with use of the GW2B was measured at the end of the study. The results indicated neither adverse nor beneficial psychological effects of CGM use. More frequent GW2B use over the 6-month study was found among youths whose parents reported higher scores for treatment adherence and diabetes-related quality of life at baseline. The study illustrates the empiric assessment of the psychological context of CGM use and establishes methods that are applicable to new CGM devices as they emerge.

Adolescent↗
PubMed2006

Prevention of hypoglycemia during exercise in children with type 1 diabetes by suspending basal insulin.

OBJECTIVE: Strategies for preventing hypoglycemia during exercise in children with type 1 diabetes have not been well studied. The Diabetes Research in Children Network (DirecNet) Study Group conducted a study to determine whether stopping basal insulin could reduce the frequency of hypoglycemia occurring during exercise. RESEARCH DESIGN AND METHODS: Using a randomized crossover design, 49 children 8-17 years of age with type 1 diabetes on insulin pump therapy were studied during structured exercise sessions on 2 days. On day 1, basal insulin was stopped during exercise, and on day 2 it was continued. Each exercise session, performed from approximately 4:00-5:00 p.m., consisted of four 15-min treadmill cycles at a target heart rate of 140 bpm (interspersed with three 5-min rest breaks over 75 min), followed by a 45-min observation period. Frequently sampled glucose concentrations (measured in the DirecNet Central Laboratory) were measured before, during, and after the exercise. RESULTS: Hypoglycemia (< or = 70 mg/dl) during exercise occurred less frequently when the basal insulin was discontinued than when it was continued (16 vs. 43%; P = 0.003). Hyperglycemia (increase from baseline of > or = 20% to > or = 200 mg/dl) 45 min after the completion of exercise was more frequent without basal insulin (27 vs. 4%; P = 0.002). There were no cases of abnormal blood ketone levels. CONCLUSIONS: Discontinuing basal insulin during exercise is an effective strategy for reducing hypoglycemia in children with type 1 diabetes, but the risk of hyperglycemia is increased.

Adolescent↗
PubMed2006

The effects of aerobic exercise on glucose and counterregulatory hormone concentrations in children with type 1 diabetes.

OBJECTIVE: To examine the acute glucose-lowering effects of aerobic exercise in children and adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS: Fifty children and adolescents with type 1 diabetes (ages 10 to <18 years) were studied during exercise. The 75-min exercise session consisted of four 15-min periods of walking on a treadmill to a target heart rate of 140 bpm and three 5-min rest periods. Blood glucose and plasma glucagon, cortisol, growth hormone, and norepinephrine concentrations were measured before, during, and after exercise. RESULTS: In most subjects (83%), plasma glucose concentration dropped at least 25% from baseline, and 15 (30%) subjects became hypoglycemic (< or = 60 mg/dl) or were treated for low glucose either during or immediately following the exercise session. The incidence of hypoglycemia and/or treatment for low glucose varied significantly by baseline glucose, occurring in 86 vs. 13 vs. 6% of subjects with baseline values <120, 120-180, and >180 mg/dl, respectively (P < 0.001). Exercise-induced increases in growth hormone and norepinephrine concentrations were marginally higher in subjects whose glucose dropped < or = 70 mg/dl. Treatment of hypoglycemia with 15 g of oral glucose resulted in only about a 20-mg/dl rise in glucose concentrations. CONCLUSIONS: In youth with type 1 diabetes, prolonged moderate aerobic exercise results in a consistent reduction in plasma glucose and the frequent occurrence of hypoglycemia when preexercise glucose concentrations are <120 mg/dl. Moreover, treatment with 15 g of oral glucose is often insufficient to reliably treat hypoglycemia during exercise in these youngsters.

Adolescent↗
PubMed2005

Accuracy of the modified Continuous Glucose Monitoring System (CGMS) sensor in an outpatient setting: results from a diabetes research in children network (DirecNet) study.

OBJECTIVE: We previously reported the results of an inpatient accuracy study in children with type 1 diabetes using the Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA). During the course of that study, a new process was implemented for manufacturing the CGMS sensor. Accuracy from the resulting modified sensor used by only 14 children was significantly better than the original version [median relative absolute difference (RAD), 11% vs. 19%; P < 0.001]. Baseline data from a subsequent outpatient study provide an opportunity to further assess the accuracy of the modified sensor in a much larger sample of children with type 1 diabetes. RESEARCH DESIGN AND METHODS: As part of a randomized trial to assess the utility of the GlucoWatch G2 Biographer (Cygnus, Inc., Redwood City, CA), 200 children with type 1 diabetes were instructed to wear a CGMS for 48-72 h in an outpatient setting at baseline. Glucose measurements from a OneTouch UltraSmart (Lifescan, Inc., Milpitas, CA) home glucose meter were downloaded and used as reference values to calculate accuracy measures. RESULTS: The overall median RAD was 12%. Accuracy was better during hyperglycemia than during hypoglycemia (median RAD, 10% vs. 20%; P < 0.001) and on optimal versus non-optimal days but did not vary significantly by the number of calibrations entered. CONCLUSIONS: These data confirm the improved accuracy previously reported for the modified version of the CGMS sensor.

Blood Glucose↗
PubMed2005

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.

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. OBJECTIVE: To determine how HbA1c values measured with the DCA 2000 in a multisite, pediatric diabetes clinic setting compare with corresponding HbA1c values measured in the DCCT/EDIC laboratory. DESIGN/METHODS: To examine this question, the Diabetes Research in Children Network (DirecNet) used the DCA 2000 in five clinical centers to measure baseline HbA1c levels in 200 youth with type 1 diabetes mellitus (T1DM) (aged 12.5 +/- 2.8 yr) who were participating in an outpatient clinical trial. At the same visit, an additional blood sample was obtained, refrigerated, and shipped to the DCCT/EDIC central laboratory for determination of HbA1c values. RESULTS: The central laboratory HbA1c value averaged 8.0 +/- 0.9% (mean +/- SD), with a median (25th and 75th quartiles) of 7.8% (7.3 and 8.5%, respectively). The DCA 2000 HbA1c values were strongly correlated (r = 0.94, p < 0.001), but significantly higher than DCCT/EDIC central laboratory values with a mean difference of +0.2% (95% confidence interval +0.14 to 0.23%, p < 0.001). There was some variation in the differences between DCA 2000 and central laboratory values at the five clinical centers (p < 0.001) with mean differences ranging between 0.0 and 0.3%, but differences between the two methods did not vary significantly by age or gender. CONCLUSION: Measurements of HbA1c by the DCA 2000 compare favorably with the DCCT/EDIC central laboratory method, albeit with slightly higher values.

Adolescent↗
PubMed2005

Youth and parent satisfaction with clinical use of the GlucoWatch G2 Biographer in the management of pediatric type 1 diabetes.

OBJECTIVE: A continuous glucose monitor satisfaction scale (CGM-SAT) was evaluated during a 6-month randomized controlled trial of the GlucoWatch G2 Biographer (GW2B) in youths with type 1 diabetes. RESEARCH DESIGN AND METHODS: At the end of the 6-month trial, 97 parents and 66 older children who had been randomized to the GW2B group completed the CGM-SAT, which assesses satisfaction on 37 items using a five-point Likert scale. Descriptive analysis, calculation of several reliability estimates, and assessment of concurrent validity were performed. RESULTS: The CGM-SAT demonstrated high internal reliability (Cronbach's alpha = 0.95 for parents and 0.94 for youths aged > or = 11 years), split-half reliability (rho = 0.91 for parents and 0.93 for youths), and parent-adolescent agreement (rho = 0.68, P < 0.001). Convergent validity was supported by marginally significant associations with treatment adherence and frequency of GW2B use. CGM-SAT scores did not correlate significantly with changes in treatment adherence, quality of life, or diabetes-related anxiety from baseline to 6 months. Mean scores on CGM-SAT items indicated that 81% of parental responses and 73% of youths' responses were less favorable than "neutral." Descriptive analysis indicated the GW2B requires substantial improvement before it can achieve widespread clinical utility and acceptance. CONCLUSIONS: The results supported the psychometric properties of the CGM-SAT. The CGM-SAT warrants further research use and cross-validation with other continuous glucose monitors. This study provides a benchmark for comparison with new glucose sensors.

Adolescent↗
PubMed2004

GlucoWatch G2 Biographer alarm reliability during hypoglycemia in children.

BACKGROUND: The GlucoWatch G2 Biographer (GW2B) (Cygnus, Inc., Redwood City, CA) provides near-continuous monitoring of glucose values in near real time. This device is equipped with two types of alarms to detect hypoglycemia. The hypoglycemia alarm is triggered when the current glucose measurement falls below the level set by the user. The "down alert" alarm is triggered when extrapolation of the current glucose trend anticipates hypoglycemia to occur within the next 20 min. METHODS: We used data from an inpatient accuracy study to assess the performance of these alarms. During a 24-h clinical research center stay, 89 children and adolescents with Type 1 diabetes mellitus (3.5-17.7 years old) wore 174 GW2B devices and had frequent serum glucose determinations during the day and night. RESULTS: Sensitivity to detect hypoglycemia (reference glucose < or = 60 mg/dL) during an insulin-induced hypoglycemia test was 24% with the hypoglycemia alarm alone and 88% when combined with the down alert alarm. Overnight sensitivity from 11 p.m. to 6 a.m. was 23% with the hypoglycemia alarm alone and 77% when combined with the down alert alarm. For 16% of hypoglycemia alarms, the reference glucose was above 70 mg/dL for 30 min before and after the time of the alarm. For the two alarm types combined, the corresponding false-positive rate increased to 62%. CONCLUSIONS: The down alert alarm substantially improves the sensitivity of the GW2B to detect hypoglycemia at the price of a large increase in the false alarm rate. The utility of these alarms in the day-to-day management of children with diabetes remains to be determined.

Adolescent↗
PubMed2004

Accuracy of the GlucoWatch G2 Biographer and the continuous glucose monitoring system during hypoglycemia: experience of the Diabetes Research in Children Network.

OBJECTIVE: The goal of this study was to assess the accuracy of the GlucoWatch G2 Biographer (GW2B) and the continuous glucose monitoring system (CGMS) during hypoglycemia in children and adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS: During a 24-h clinical research center stay, 91 children and adolescents with type 1 diabetes (aged 3.5-17.7 years) wore one or two CGMSs, and 89 of these subjects wore one or two GW2Bs. Frequent serum glucose determinations were made during the day, overnight, and during insulin-induced hypoglycemia resulting in 192 GW2B reference pairs and 401 CGMS reference pairs during hypoglycemia (reference glucose < or =60 mg/dl). RESULTS: During hypoglycemia, the median absolute difference between the 192 GW2B reference glucose pairs was 26 mg/dl and between the 401 CGMS reference glucose pairs was 19 mg/dl with 31 and 42%, respectively, of the sensor values within 15 mg/dl of the reference glucose. Sensitivity to detect hypoglycemia when the GW2B alarm level was set to 60 mg/dl was 23% with a false-alarm rate of 51%. Analyses suggested that modified CGMS sensors that became available in November 2002 might be more accurate than the original CGMS sensors (median absolute difference 15 vs. 20 mg/dl). CONCLUSIONS: These data show that the GW2B and the CGMS do not reliably detect hypoglycemia. Both of these devices perform better at higher glucose levels, suggesting they may be more useful in reducing HbA1c levels than in detecting hypoglycemia.

Adolescent↗