Glycemic Patterns Detected by Continuous Subcutaneous Glucose Sensing in Children and Adolescents With Type 1 Diabetes Mellitus Treated by Multiple Daily Injections vs Continuous Subcutaneous Insulin Infusion

Continuous subcutaneous insulin infusion versus multiple daily injections in children and young people at diagnosis of type 1 diabetes: the SCIPI RCT

BACKGROUND

The risk of developing long-term complications of type 1 diabetes (T1D) is related to glycaemic control and is reduced by the use of intensive insulin treatment regimens: multiple daily injections (MDI) (≥ 4) and continuous subcutaneous insulin infusion (CSII). Despite a lack of evidence that the more expensive treatment with CSII is superior to MDI, both treatments are used widely within the NHS.

OBJECTIVES

(1) To compare glycaemic control during treatment with CSII and MDI and (2) to determine safety and cost-effectiveness of the treatment, and quality of life (QoL) of the patients.

DESIGN

A pragmatic, open-label randomised controlled trial with an internal pilot and 12-month follow-up with 1 : 1 web-based block randomisation stratified by age and centre.

SETTING

Fifteen diabetes clinics in hospitals in England and Wales.

PARTICIPANTS

Patients aged 7 months to 15 years.

INTERVENTIONS

Continuous subsutaneous insulin infusion or MDI initiated within 14 days of diagnosis of T1D.

DATA SOURCES

Data were collected at baseline and at 3, 6, 9 and 12 months using paper forms and were entered centrally. Data from glucometers and CSII were downloaded. The Health Utilities Index Mark 2 was completed at each visit and the Pediatric Quality of Life Inventory (PedsQL, diabetes module) was completed at 6 and 12 months. Costs were estimated from hospital patient administration system data.

OUTCOMES

The primary outcome was glycosylated haemoglobin (HbA_1c) concentration at 12 months. The secondary outcomes were (1) HbA_1c concentrations of < 48 mmol/mol, (2) severe hypoglycaemia, (3) diabetic ketoacidosis (DKA), (4) T1D- or treatment-related adverse events (AEs), (5) change in body mass index and height standard deviation score, (6) insulin requirements, (7) QoL and (8) partial remission rate. The economic outcome was the incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

A total of 293 participants, with a median age of 9.8 years (minimum 0.7 years, maximum 16 years), were randomised (CSII, n = 149; MDI, n = 144) between May 2011 and January 2015. Primary outcome data were available for 97% of participants (CSII, n = 143; MDI, n = 142). At 12 months, age-adjusted least mean squares HbA_1c concentrations were comparable between groups: CSII, 60.9 mmol/mol [95% confidence interval (CI) 58.5 to 63.3 mmol/mol]; MDI, 58.5 mmol/mol (95% CI 56.1 to 60.9 mmol/mol); and the difference of CSII - MDI, 2.4 mmol/mol (95% CI -0.4 to 5.3 mmol/mol). For HbA_1c concentrations of < 48 mmol/mol (CSII, 22/143 participants; MDI, 29/142 participants), the relative risk was 0.75 (95% CI 0.46 to 1.25), and for partial remission rates (CSII, 21/86 participants; MDI, 21/64), the relative risk was 0.74 (95% CI 0.45 to 1.24). The incidences of severe hypoglycaemia (CSII, 6/144; MDI, 2/149 participants) and DKA (CSII, 2/144 participants; MDI, 0/149 participants) were low. In total, 68 AEs (14 serious) were reported during CSII treatment and 25 AEs (eight serious) were reported during MDI treatment. Growth outcomes did not differ. The reported insulin use was higher with CSII (mean difference 0.1 unit/kg/day, 95% CI 0.0 to 0.2 unit/kg/day; p = 0.01). QoL was slightly higher for those randomised to CSII. From a NHS perspective, CSII was more expensive than MDI mean total cost (£1863, 95% CI £1620 to £2137) with no additional QALY gains (-0.006 QALYs, 95% CI -0.031 to 0.018 QALYs).

LIMITATIONS

Generalisability beyond 12 months is uncertain.

CONCLUSIONS

No clinical benefit of CSII over MDI was identified. CSII is not a cost-effective treatment in patients representative of the study population.

FUTURE WORK

Longer-term follow-up is required to determine if clinical outcomes diverge after 1 year. A qualitative exploration of patient and professional experiences of MDI and CSII should be considered.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN29255275 and EudraCT 2010-023792-25.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 42. See the NIHR Journals Library website for further project information. The cost of insulin pumps and consumables supplied by F. Hoffman-La Roche AG (Basel, Switzerland) for the purpose of the study were subject to a 25% discount on standard NHS costs.

Efficacy and Safety of Continuous Subcutaneous Insulin Infusion vs. Multiple Daily Injections on Type 1 Diabetes Children: A Meta-Analysis of Randomized Control Trials

OBJECTIVE

This meta-analysis was performed to evaluate the efficacy and safety of continuous subcutaneous insulin infusion (CSII) vs. multiple daily injections (MDI) in children with type 1 diabetes.

METHODS

A literature search was conducted on databases including PubMed and Embase up to June 2017. The pooled weighted mean difference or risk ratio as well as 95% confidence intervals were calculated using RevMan 5.3 software.

RESULTS

Eight studies involving 310 children with type 1 diabetes were included. Results showed that HbA1c (%) was significantly lower (p=0.007) after CSII compared with MDI in children with type 1 diabetes. In addition, there was no significant difference between groups in HbA1c (%) change, total daily insulin doses, change of total daily insulin doses and incidence of ketoacidosis and severe hypoglycemia. However, subgroup analyses indicated that age, treatment duration and study design were influenced the efficacy of CSII and MDI in children with type 1 diabetes.

CONCLUSION

CSII is associated with lower HbA1c levels in children with type 1 diabetes but appears to have no effect on insulin requirement or incidence of ketoacidosis and severe hypoglycemia.

Continuous subcutaneous insulin infusion versus multiple daily injections in individuals with type 1 diabetes: a systematic review and meta-analysis

The relative efficacy of continuous subcutaneous insulin infusion and multiple daily injections in individuals with type 1 diabetes is unclear. We sought to synthesize the existing evidence about the effect of continuous subcutaneous insulin infusion on glycosylated hemoglobin, hypoglycemic events, and time spent in hypoglycemia compared to multiple daily injections. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, and Scopus from January 2008 through November 2015 for randomized controlled trials that enrolled children or adults with type 1 diabetes. Trials identified in a previous systematic review and published prior to 2008 were also included. We included 25 randomized controlled trials at moderate risk of bias. Meta-analysis showed a significant reduction in glycosylated hemoglobin in patients treated with continuous subcutaneous insulin infusion compared to multiple daily injections (mean difference 0.37; 95 % confidence interval, 0.24-0.51). This effect was demonstrated in both children and adults. There was no significant difference in minor or severe hypoglycemic events. Continuous subcutaneous insulin infusion was associated with lower incidence of nocturnal hypoglycemia. There was no significant difference in the time spent in hypoglycemia. In children and adults with type 1 diabetes and compared to multiple daily injections, continuous subcutaneous insulin infusion is associated with a modest reduction in glycosylated hemoglobin. There was no difference in severe or minor hypoglycemia, but likely a lower incidence of nocturnal hypoglycemia with continuous subcutaneous insulin infusion.

Study protocol for a randomised controlled trial of insulin delivery by continuous subcutaneous infusion compared to multiple daily injections

Background

Intensive insulin therapy with continuous subcutaneous insulin infusion (CSII) devices or multiple daily injections (MDI) reduces the risk of long-term vascular complications of type I diabetes (TID). Both treatments are used routinely, but there is little evidence to demonstrate superiority of either treatment. If CSII treatment reduces the risk of long-term complications or is associated with an improved quality of life (QoL), the additional cost of this therapy may be compensated for by a reduction in long-term health expenditure. If there is no demonstrable difference between treatments, health-care resources may be better invested elsewhere. This study aims to address this gap in knowledge.

Methods/design

This is a pragmatic, randomised controlled trial (RCT). Fifteen centres, selected to represent a population with a broad demographic, will recruit 316 patients, newly diagnosed with TID, aged between 7 months and 15 years. Exclusion criteria include additional pathologies or treatments likely to affect glycaemic control and a first-degree relative with TID. Randomisation to CSII or MDI is stratified for age, gender and recruiting centre. The randomised treatment starts within 15 days of diagnosis. Patients will be trained to adjust their insulin dose according to carbohydrate intake and blood glucose level.

Study visits coincide with routine clinic appointments at 3, 6, 9 and 12 months when data relating to routine clinical assessments, adverse events and concomitant medications are collected. Health utilities questionnaires are completed at each visit and a diabetes-specific QoL questionnaire (PedsQL) at diagnosis, 6 and 12 months.

The primary outcome is glycaemic control (HbA1c) at 12 months. Secondary outcome measures include QoL, insulin use, growth and weight gain, adverse events and a health economics appraisal.

Discussion

This is the first adequately powered RCT comparing CSII and MDI in a non-selected population, treated according to standard practice guidelines. It will produce data that are meaningful to individual patients and local and national policymakers.

Trial registration

The study was registered with the European Clinical Trials Database on 4 November 2010, reference 2010-023792-25.

Continuous glucose monitoring in insulin-treated patients in non-ICU settings

Inpatient hyperglycemia, in patients with and without a history of diabetes, is associated with increased risk of complications, mortality, and longer hospital stay in medicine and surgical patients. Bedside capillary point of care testing is widely recommended as the preferred method for glucose monitoring and for guiding glycemic management of individual patients; however, the accuracy of most handheld glucose meters is far from optimal. Recent studies in the hospital setting have reported that the use of continuous glucose monitoring (CGM) can provide real-time information about glucose concentration, direction, and rate of change over a period of several days. Because it provides glucose values every 5-10 minutes 24 hours a day, CGM may have an advantage over point of care testing with respect to reducing the incidence of severe hypoglycemia in acute care. Real-time CGM technology may facilitate glycemic control and to reduce hypoglycemia in insulin-treated patients. Recent guidelines, however, have recommended deferring the use of CGM in the adult hospital setting until further data on accuracy and safety become available. In this study, we review the advantages and disadvantages of the use of real-time CGM in the management of dysglycemia in the hospital setting.

Evaluation of the utility of a glycemic pattern identification system

BACKGROUND

With the increasing prevalence of systems allowing automated, real-time transmission of blood glucose data there is a need for pattern recognition techniques that can inform of deleterious patterns in glycemic control when people test. We evaluated the utility of pattern identification with a novel pattern identification system named Vigilant™ and compared it to standard pattern identification methods in diabetes.

METHOD

To characterize the importance of an identified pattern we evaluated the relative risk of future hypoglycemic and hyperglycemic events in diurnal periods following identification of a pattern in a data set of 536 patients with diabetes. We evaluated events 2 days, 7 days, 30 days, and 61-90 days from pattern identification, across diabetes types and cohorts of glycemic control, and also compared the system to 6 pattern identification methods consisting of deleterious event counts and percentages over 5-, 14-, and 30-day windows.

RESULTS

Episodes of hypoglycemia, hyperglycemia, severe hypoglycemia, and severe hyperglycemia were 120%, 46%, 123%, and 76% more likely after pattern identification, respectively, compared to periods when no pattern was identified. The system was also significantly more predictive of deleterious events than other pattern identification methods evaluated, and was persistently predictive up to 3 months after pattern identification.

CONCLUSIONS

The system identified patterns that are significantly predictive of deleterious glycemic events, and more so relative to many pattern identification methods used in diabetes management today. Further study will inform how improved pattern identification can lead to improved glycemic control.

Variability of glucose-lowering effect as a limiting factor in optimizing basal insulin therapy: a review

Lowering blood glucose with insulin therapy towards beneficial target levels while also avoiding hypoglycaemia is a challenging task. An important confounding factor, which might be under-appreciated in this scenario, is that of variable glucose readings causing difficulties with dose adjustment. Furthermore, this glucose variability is, to some extent, a reflection of variability in the glucose-lowering action of the insulin therapy itself. Not only is glucose variability a major confounding factor in disease management but it is possibly also of direct prognostic consequence and is increasingly recognized as an informative measurement in diabetes management. The scope for insulin-induced glucose variability is particularly great with basal insulins because of their prolonged absorption from high-dose depots. Pharmacodynamic (PD) variability manifests as both fluctuations in the level of glucose-lowering effect over time, and as inconsistencies in the response from one injection to another. Well-controlled pharmacokinetic (PK)/PD studies using repeated isoglycaemic clamp methodology clearly how that many injected basal insulin products have high variable absorption with correspondingly variable action. Incomplete resuspension and precipitation appear to be important issues with regard to unpredictability in this action, while an inadequate duration of action relative to the dosing interval results in a fluctuating action profile. There are some ultra-long-acting basal insulins with novel protraction mechanisms currently in clinical development for which clamp studies show markedly improved PK/PD profiles.

Comparative analysis of the efficacy of continuous glucose monitoring and self-monitoring of blood glucose in type 1 diabetes mellitus

BACKGROUND

Self-monitoring of blood glucose (SMBG) and continuous glucose monitoring (CGM) have been proven effective in improving hemoglobin A1c (HbA1c) and in reducing hypoglycemia in patients with type 1 diabetes mellitus (T1DM). It is not clear, however, if CGM provides further efficacy and safety benefits beyond SMBG in the management of T1DM.

METHODS

MEDLINE (1966-November 2009), COCHRANE REGISTRY (all years), and EMBASE (1980-November 2009), and article bibliographies were searched for randomized controlled trials (RCTs) investigating the use of CGM in patients with T1DM, with clinical outcomes, including HbA1c and hypoglycemia and/or hyperglycemia.

RESULTS

Fourteen RCTs met eligibility criteria [n = 1188 patients, 97.4% with T1DM, age 29.0 ± 14.3 years, diabetes duration 11.7 ± 7.0 years, and baseline HbA1c 8.3 ± 0.8% (mean ± standard deviation)]. Compared with SMBG, the use of CGM was associated with a greater reduction in HbA1c [-0.3% (confidence interval: 0.4, -0.2), p < .0001]. The number of hypoglycemic events was not significantly different between the CGM and SMBG groups (0.52 ± 0.52 versus 0.52 ± 0.63 events/day, p = .5), but duration of hypoglycemia was shorter for the CGM group (75 ± 39 versus 89 ± 19 min/day), with an incremental reduction of hypoglycemia duration of -15.2 min/day, p < .0001. Continuous glucose monitoring also resulted in a shorter duration of hyperglycemia than SMBG (172 ± 125 versus 217 ± 152 min/day, p = .04).

CONCLUSIONS

The use of CGM is associated with improvement in metabolic control in T1DM, with significant short- and long-term reductions in HbA1c and reduction in the duration of periods of hypoglycemia and hyperglycemia versus SMBG.

A prototype of a new noninvasive device to detect nocturnal hypoglycemia in adolescents with type 1 diabetes--a pilot study

BACKGROUND

Severe hypoglycemic events are a major consequence of tight diabetes control. Continuous glucose monitoring systems (CGMSs) were recently introduced in order to minimize the risk of hypoglycemia. However, the present CGMSs are invasive and costly and have been recently demonstrated to be intolerant for most children and adolescents. Hence there is a need for a simple, noninvasive, convenient, and inexpensive device to detect hypoglycemic events. The Gili Medical Hypoglycemia Non Invasive Monitoring System (GMHNIMS) (Gili Medical Ltd., Migdal HaEmek, Israel) has been currently developed for these purposes.

SUBJECTS AND METHODS

Ten patients 14-18 years old with type 1 diabetes for at least 1 year participated in a pilot study that was held at the Meyer Children's Hospital, Rambam Medical Center, Haifa, Israel. All patients were either treated by insulin pump or by multiple daily injections. The GMHNIMS was connected to the study subjects during three consecutive nights in an inpatient setting while they received their usual insulin regimen. The system is composed of four sensors (heart rate, perspiration, skin temperature, and tremor) that detect physiologic changes during hypoglycemia. In addition, each patient was connected to a real-time CGMS for 3 nights. When a hypoglycemic event was suspected clinically by the patient, a bedside capillary glucose was checked by a glucometer.

RESULTS

The system was found to be convenient without any disturbances to sleep quality. The sensitivity of the GMHNIMS for detection of true hypoglycemic events was 100% with specificity of 85.7%.

CONCLUSIONS

The new device showed high detection rates of nocturnal hypoglycemic events with an acceptable degree of false-positive readings. Being inexpensive and noninvasive, this device has the potential for routine use in insulin-treated patients.

Impact of insulin pumps on glycaemic control in a pump-naïve paediatric regional population

AIM

To examine the clinical impact of insulin-pump therapy for children with type 1 diabetes mellitus (T1DM) in a regional paediatric service, Auckland, New Zealand.

METHODS

Retrospective analysis of children with T1DM from the Starship paediatric diabetes database who started on insulin-pump therapy from 2002 to 2008 compared with the whole T1DM population and with an equal number of non-pump patients matched by age, sex, ethnicity and duration of diabetes.

RESULTS

From 621 subjects with 6680 clinic visits, 75 children were treated with insulin-pump therapy for more than 12 months. Transitioning to insulin-pump treatment was associated with an improvement in HbA1c compared with baseline (-0.3%/year, P < 0.001) for up to 3 years. In contrast, despite similar deprivation scores, non-pump controls showed a continuing trend to higher HbA1C values (+0.2%/year, P < 0.01). The risk of severe hypoglycaemia fell after pump start (from 27 (0-223) to 5 (0-0.91) events/100 patient years) with no change in non-pump controls; the rate of diabetic ketoacidosis remained low in both groups.

CONCLUSIONS

In a pump-naïve regional paediatric population, insulin-pump therapy for T1DM was safe and effective, and associated with sustained improvements in HbA1c and lower risk of hypoglycaemia.

Hypoglycemia in critically ill children

BACKGROUND

The practice of glycemic control with intravenous insulin in critically ill patients has brought clinical focus on understanding the effects of hypoglycemia, especially in children. Very little is published on the impact of hypoglycemia in this population. We aimed to review the existing literature on hypoglycemia in critically ill neonates and children.

METHODS

We performed a systematic review of the literature up to August 2011 using PubMed, Ovid MEDLINE and ISI Web of Science using the search terms "hypoglycemia or hypoglyc*" and "critical care or intensive care or critical illness". Articles were limited to "all child (0-18 years old)" and "English".

RESULTS

A total of 513 articles were identified and 132 were included for review. Hypoglycemia is a significant concern among pediatric and neonatal intensivists. Its definition is complicated by the use of a biochemical measure (i.e., blood glucose) for a pathophysiologic problem (i.e., neuroglycopenia). Based on associated outcomes, we suggest defining hypoglycemia as <40-45 mg/dl in neonates and <60-65 mg/dl in children. Below the suggested threshold values, hypoglycemia is associated with worse neurological outcomes, increased intensive care unit stay, and increased mortality. Disruptions in carbohydrate metabolism increase the risk of hypoglycemia incritically ill children. Prevention of hypoglycemia, especially in the setting of intravenous insulin use, will be best accomplished by the combination of accurate measuring techniques, frequent or continuous glucose monitoring, and computerized insulin titration protocols.

CONCLUSION

Studies on hypoglycemia in critically ill children have focused on spontaneous hypoglycemia. With the current practice of maintaining blood glucose within a narrow range with intravenous insulin, the risk factors and outcomes associated with insulin-induced hypoglycemia should be rigorously studied to prevent hypoglycemia and potentially improve outcomes of critically ill children.

The effect of socioeconomic deprivation on efficacy of continuous subcutaneous insulin infusion: a retrospective paediatric case-controlled survey

We aimed to retrospectively evaluate the efficacy of continuous subcutaneous insulin infusion (CSII) therapy in relation to social deprivation in an urban paediatric type 1 diabetic population. Data were compared between 51 children on CSII therapy (mean age 11.2 years and duration of follow-up 1.9 years) and matched controls on multiple daily injection (MDI) therapy. Social deprivation was measured using the UK Office of National Statistics 2007 Index of Multiple Deprivation. Using linear mixed modelling analysis, lower HbA1c levels at 24 months were associated with CSII not MDI therapy (P = 0.02), after adjustment for known variables. Children with the least educated parents showed a rise in HbA1c levels from baseline on MDI therapy (least versus most educated tertile; HbA1c change +0.5% [95% confidence interval -0.1 to 1.1] versus 0% [-0.8 to 0.8]), whereas this was not observed in CSII therapy (least versus most educated tertile; HbA1c change -0.3% [-0.7 to +0.1] versus -0.2% [-0.7 to +0.3], P value for ANCOVA = 0.02, after adjusting for income and employment).

CONCLUSION

Parental educational deprivation was associated with a failure of MDI but not CSII therapy. These outcomes need confirmation by larger studies.

Benefits of blinded continuous glucose monitoring during a randomized clinical trial

BACKGROUND

Real-time, personal continuous glucose monitoring (CGM) is a validated technology that can help patients improve glycemic control. Blinded CGM is a promising technology for obtaining retrospective data in clinical research where the quantity and quality of blood glucose information is important. This study was designed to investigate the use of novel procedures to enhance data capture from blinded CGM.

METHODS

Following a 4-week run-in, 46 patients with type 1 diabetes were randomized to one of two prandial insulins for a 12-week treatment period, after which they were crossed over to the alternate treatment for 12 weeks. Continuous glucose monitoring was implemented at the end of run-in (practice only) and during the last 2 weeks of each treatment period. Eighty percent of 288 possible daily glucose values were required for at least three days. Continuous glucose monitoring was extended for an additional week if these criteria were not met, and patients were allowed to insert sensors at home when necessary. Continuous glucose monitoring results were compared to reference eight-point self-monitoring of blood glucose (SMBG).

RESULTS

Higher than expected sensor failure rate was approximately 25%. During run-in, 12 of 45 attempted profiles failed adequacy criteria. However, treatment periods had only 1 of 82 attempted profiles considered inadequate (6 cases required an additional week of CGM). Using SMBG as reference, 93.7% of 777 CGM values were in Clarke error grid zones A+B.

CONCLUSIONS

With appropriate training, adequate practice, and opportunity to repeat blinded CGM as needed, nearly 100% of attempted profiles can be obtained successfully.

The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults

This article reviews the evidence and nutrition practice recommendations from the American Dietetic Association's nutrition practice guidelines for type 1 and type 2 diabetes in adults. The research literature was reviewed to answer nutrition practice questions and resulted in 29 recommendations. Here, we present the recommendations and provide a comprehensive and systematic review of the evidence associated with their development. Major nutrition therapy factors reviewed are carbohydrate (intake, sucrose, non-nutritive sweeteners, glycemic index, and fiber), protein intake, cardiovascular disease, and weight management. Contributing factors to nutrition therapy reviewed are physical activity and glucose monitoring. Based on individualized nutrition therapy client/patient goals and lifestyle changes the client/patient is willing and able to make, registered dietitians can select appropriate interventions based on key recommendations that include consistency in day-to-day carbohydrate intake, adjusting insulin doses to match carbohydrate intake, substitution of sucrose-containing foods, usual protein intake, cardioprotective nutrition interventions, weight management strategies, regular physical activity, and use of self-monitored blood glucose data. The evidence is strong that medical nutrition therapy provided by registered dietitians is an effective and essential therapy in the management of diabetes.

The Correlation and Accuracy of Glucose Levels between Interstitial Fluid and Venous Plasma by Continuous Glucose Monitoring System

Background

Clinical experience with the continuous glucose monitoring systems (CGMS) is limited in Korea. The objective of this study is to evaluate the accuracy of the CGMS and the correlation between interstitial fluid and venous plasma glucose level in Korean healthy male subjects.

Methods

Thirty-two subjects were served with glucose solution contained same amount of test food's carbohydrate and test foods after separate overnight fasts. CGMS was performed over 3 days during hopitalization for each subjects. Venous plasma glucose measurements were carried out during 4 hours (0, 0.25, 0.5, 0.75, 1, 2, 4 hours) just before and after glucose solution and test food load. The performance of the CGMS was evaluated by comparing its readings to those obtained at the same time by the hexokinase method using the auto biochemistry machine (Hitachi 7600-110). Also, correlations between glucose recorded with CGMS and venous plasma glucose value were examined.

Results

CGMS slightly underestimated the glucose value as compared with the venous plasma glucose level (16.3 ± 22.2 mg/dL). Correlation between CGMS and venous plasma glucose values throughout sensor lifetime is 0.73 (regression analysis: slope = 1.08, intercept = 8.38 mg/dL). Sensor sensitivity can deteriorate over time, with correlations between venous blood glucose and CGMS values dropping from 0.77 during 1st day to 0.65 during 2nd and 3rd day.

Conclusion

The accuracy of data provided by CGMS may be less than expected. CGMS sensor sensitivity is decreased with the passage of time. But, from this study, CGMS can be used for glucose variability tendency monitoring conveniently to the Korean.

Patients' evaluation of nocturnal hypoglycaemia with GlucoDay continuous glucose monitoring in paediatric patients

A study was conducted to evaluate the accuracy of GlucoDay (A. Menarini Diagnostics) during 48 h of continuous glucose monitoring (CGMS) in type 1 diabetic adolescents and use this novel approach to assess otherwise ignored nocturnal hypoglycaemias, in relationship to intermediate-acting insulin administration timing. Twenty type 1 diabetic adolescents with poor metabolic control were selected from our out-patient department. Equal doses of intermediate insulin were administered at 19:00 and at 22:00 of the first and second night of the study, respectively. Correlation coefficient between GlucoDay and standard glucometer was 0.94; 98.3% of data fall in the A + B area of Error Grid Analysis and 1.7% in the D area. The mean error was 13.9% overall and 16.4% with blood glucose values (BGV) <75 mg/dl. The accuracy, ±15 mg/dl, was 82% for BGV <75 mg/dl and 74% for BGV >75 mg/dl. The CGMS discovered nocturnal hypoglycaemia (NH) in 12/18 patients, but no severe hypoglycaemia. During the first night, 8 asymptomatic NH episodes were found with BGV <60 mg/dl and 12 with BGV <80. During the second night, 4 asymptomatic NH episodes with BGV <60 mg/dl and 5 with BGV <80 were found. Furthermore, during the second night, the mean duration of BGV <126 mg/dl was lower than in the first night. GlucoDay is a reliable device for CGMS in paediatric patients and able to determine asymptomatic NH. Bedtime insulin injections provided safer glycaemic profiles and a lower percentage of hypoglycaemic events, representing a safer insulin administration scheme.

Predictors of glycaemic control in patients with Type 1 diabetes commencing continuous subcutaneous insulin infusion therapy

AIMS

To identify variables that predict glycaemic control in Type 1 diabetic patients switched to a continuous subcutaneous insulin infusion (CSII) regimen, in order to improve patient selection for this treatment.

METHODS

The notes of 421 Type 1 diabetic patients aged 2.6-39.8 years (median 19.4) who initiated CSII treatment in 1998-2007 and used it for > or = 1 year were reviewed. Details about their background and disease-related and treatment-related variables were recorded. At pump initiation, the mean age was 15.9 +/- 7.2 years, mean diabetes duration 6.4 +/- 5.8 years. Mean time of CSII use was 4.1 +/- 2.1 years. Good glycaemic control was defined by glycated haemoglobin (HbA(1c)) stratified by age (American Diabetes Association target levels). Improvement in glycaemic control was defined as a reduction of > or = 0.5% in HbA(1c) from baseline. The change in the rate of severe hypoglycaemic or diabetic ketoacidosis events was also determined.

RESULTS

There was a significant sustained decrease in HbA(1c) with CSII for an average of 6 years, without increased rates of hypoglycaemia. Achievement of target HbA(1c) was significantly associated with the following parameters at pump initiation: lower HbA(1c) (P < 0.001), younger age (< 12 years), shorter diabetes duration (P < 0.001) and more frequent daily self blood glucose monitoring (SBGM) (P < 0.01). Improved glycaemic control was associated with longer CSII use (P = 0.032) and higher HbA(1c) at CSII initiation (P < 0.001).

CONCLUSIONS

Switching patients to CSII resulted in sustained decrease in HbA(1c) and improved glycaemic control in patients with high HbA(1c). Young age, frequent SBGM and lower HbA(1c) at pump initiation were identified as predictors of achieving glycaemic targets with CSII.

Continuous subcutaneous insulin infusion (CSII) versus multiple insulin injections for type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes is a metabolic disorder resulting from a defect in insulin secretion. Onset of type 1 diabetes mellitus may occur at any age and it is one of the most common chronic diseases of childhood and adolescence. Since there are no interventions known to prevent onset, it is vital that effective treatment regimes are available. Glycaemic control is maintained by replacement of insulin and may be in the form of 'conventional' insulin therapy (multiple injections per day) or continuous subcutaneous insulin infusion (CSII).

OBJECTIVES

To assess the effects of CSII compared to multiple insulin injections (MI) in people with type 1 diabetes mellitus.

SEARCH STRATEGY

Studies were obtained from electronic searches of The Cochrane Library, MEDLINE, EMBASE and CINAHL.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials comparing CSII with three or more insulin injections per day (MI) in people with type 1 diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted characteristics of included studies. Authors contacted study investigators to obtain missing information. Generic inverse variance meta-analyses using a random-effects model were performed.

MAIN RESULTS

Twenty three studies randomised 976 participants with type 1 diabetes to either intervention. There was a statistically significant difference in glycosylated haemoglobin A1c (HbA1c) favouring CSII (weighted mean difference -0.3% (95% confidence interval -0.1 to -0.4). There were no obvious differences between the interventions for non-severe hypoglycaemia, but severe hypoglycaemia appeared to be reduced in those using CSII. Quality of life measures suggest that CSII is preferred over MI. No significant difference was found for weight. Adverse events were not well reported, no information is available on mortality, morbidity and costs.

AUTHORS' CONCLUSIONS

There is some evidence to suggest that CSII may be better than MI for glycaemic control in people with type 1 diabetes. Non-severe hypoglycaemic events do not appear to be reduced with CSII. There is insufficient evidence regarding adverse events, mortality, morbidity and costs.

Clinical review: Hypoglycemia with intensive insulin therapy: a systematic review and meta-analyses of randomized trials of continuous subcutaneous insulin infusion versus multiple daily injections

CONTEXT

Hypoglycemia limits the efficacy of intensive insulin therapy. The extent to which continuous insulin infusion (CSII) overcomes this limitation is unclear.

OBJECTIVE

The aim was to summarize evidence on the effect of CSII and multiple daily injections (MDIs) on glycemic control and hypoglycemia.

DATA SOURCES

We searched electronic databases between 2002 and March 2008.

STUDY SELECTION

We selected published randomized trials of CSII vs. MDI.

DATA EXTRACTION

Reviewers working in duplicate and independently extracted study characteristics and quality and differences in glycosylated hemoglobin (HbA1c) and hypoglycemic events.

DATA SYNTHESIS

We found 15 eligible randomized trials of moderate quality, with elevated baseline and end-of-study HbA1c levels. Patients with type 1 diabetes using CSII had slightly lower HbA1c [random-effects weighted mean difference, -0.2%; 95% confidence interval (CI), -0.3, -0.1, compared with MDI], with no significant difference in severe (pooled odds ratio, 0.48; 95% CI, 0.23, 1.00) or nocturnal hypoglycemia (pooled odds ratio 0.82, 95% CI 0.33, 2.03). Adolescents and adults with type 1 diabetes enrolled in crossover trials had nonsignificantly fewer minor hypoglycemia episodes per patient per week (-0.08; 95% CI, -0.21, 0.06) with CSII than MDI; children enrolled in parallel trials had significantly more episodes (0.68; 95% CI, 0.16, 1.20; P(interaction) = 0.03). Outcomes were not different in patients with type 2 diabetes.

CONCLUSIONS

Contemporary evidence indicates that compared to MDI, CSII slightly reduced HbA1c in adults with type 1 diabetes, with unclear impact on hypoglycemia. In type 2 diabetes, CSII and MDI had similar outcomes. The effect in patients with hypoglycemia unawareness or recurrent severe hypoglycemia remains unclear because of lack of data.

Children and adolescents on intensive insulin therapy maintain postprandial glycaemic control without precise carbohydrate counting

AIMS

Carbohydrate (CHO) quantification is used to adjust pre-meal insulin in intensive insulin regimens. However, the precision in CHO quantification required to maintain postprandial glycaemic control is unknown. We determined the effect of a +/-10-g variation in CHO amount, with an individually calculated insulin dose for 60 g CHO, on postprandial glycaemic control.

METHODS

Thirty-one children and adolescents (age range 9.5-16.8 years), 17 using continuous subcutaneous insulin infusion (CSII) and 14 using multiple daily injections (MDI), participated. Each subject consumed test lunches of equal macronutrient content, differing only in carbohydrate quantity (50, 60, 70 g CHO), in random order on three consecutive days. For each participant, the insulin dose was the same for each meal, based on their usual insulin : CHO ratio for 60 g CHO. Activity was standardized. Continuous glucose monitoring was used.

RESULTS

The CSII and MDI subjects demonstrated no difference in postprandial blood glucose levels (BGLs) for comparable carbohydrate loads (P > 0.05). The 10-g variations in CHO quantity resulted in no differences in BGLs or area under the glucose curves for 2.5 h (P > 0.05). Hypoglycaemic episodes were not significantly different (P = 0.32). The 70-g meal produced higher glucose excursions after 2.5 h, with a maximum difference of 1.9 mmol/l at 3 h (P = 0.01), but the BGLs remained within international postprandial targets.

CONCLUSIONS

In patients using intensive insulin therapy, an individually calculated insulin dose for 60 g of carbohydrate maintains postprandial BGLs for meals containing between 50 and 70 g of carbohydrate. A single mealtime insulin dose will cover a range in carbohydrate amounts without deterioration in postprandial control.

Continuous subcutaneous insulin infusion vs. multiple daily injections in children with type 1 diabetes: a systematic review and meta-analysis of randomized control trials

OBJECTIVE

To investigate potential effects of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) on glycemic control in children with type 1 diabetes mellitus (T1DM).

STUDY DESIGN

Meta-analysis and systematic review of randomized control studies (RCTs). The electronic databases MEDLINE, Cochrane Library, and EMBASE were searched through October 2007.

RESULTS

Six RCTs involving 165 participants with T1DM met our predefined inclusion criteria. Combined data from all trials showed that the CSII group compared with the MDI group experienced a significant reduction in the level of glycosylated hemoglobin. The pooled weighted mean difference (WMD) was -0.24% [95% confidence interval (95% CI) -0.41 to -0.07, p < 0.001] with a fixed model and remained significant in the random effect model. This effect was reached by slightly decreasing insulin requirement [three RCTs, n = 74, WMD -0.22 IU/kg/d (95% CI -0.31 to -0.14, p < 0.001)]. No differences in the incidences of ketoacidosis and severe hypoglycemic events were found.

CONCLUSIONS

In short-term insulin therapy, CSII compared with MDI is a more effective form of metabolic control and allows reducing the daily insulin requirement. Yet, no conclusions have been made so far whether this effect holds in later years. These results should be approached with caution because of the methodological limitations of the analyzed studies.

Continuous subcutaneous insulin infusion (CSII) 30 years later: still the best option for insulin therapy

Thirty years after its introduction, the use of continuous subcutaneous insulin infusion (CSII) keeps increasing, especially among children and adolescents. The technique, when used properly, is safe and effective.Compared with traditional NPH-based multiple daily injections (MDI), CSII provides a small but clinically important reduction of HbA(1c) levels, diminishes blood glucose variability, decreases severe hypoglycaemic episodes and offers a better way to cope with the dawn phenomenon.Insulin analogues have improved the treatment of diabetes, eroding part of the place previously occupied by CSII, but CSII still remains the first option for patients experiencing severe hypoglycaemic episodes, high HbA(1c) values or marked glucose variability while being treated with optimized MDI. Furthermore CSII is better than MDI considering the effects on quality of life and the possibility to adjust insulin administration according to physical activity or food intake.CSII may be limited by cost. Present estimates suggest that CSII may be cost-effective just for patients experiencing a marked improvement in HbA(1c) or a decrease in severe hypoglycaemic episodes, but the effects on quality of life are difficult to measure.CSII does not merely imply wearing an external device; it requires a multidisciplinary team, intensive patient education and continuous follow up.

Continuous glucose monitoring: a review of biochemical perspectives and clinical use in type 1 diabetes

Self-monitoring of blood glucose is a fundamental part of diabetes management. It is mandatory for tight glucose control. For the past 30 years, intermittent measurement of capillary blood glucose has been the method of choice for self-monitoring. The main disadvantage of such measurements is that they provide isolated glucose values which do not reflect variations occurring throughout the day and night. Hence systems monitoring blood glucose concentrations on a "continuous basis" have been developed. In clinical studies, different devices were shown to provide useful information on glycemic excursions in people with diabetes with sufficient accuracy. Thus, in clinical practice, this approach has also been shown to help in the medical management leading to a reduction in glycated hemoglobin and glycemic variability. However, because of lack of experience, this technology has yet to replace standard capillary blood glucose monitoring. In this paper, we review the biochemical perspectives of continuous glucose monitoring and its clinical use in type 1 diabetes.

Effects of pulsatile subcutaneous injections of insulin lispro on plasma insulin concentration levels

BACKGROUND

Most insulin pumps used for the treatment of diabetes perform subcutaneous insulin injections by pulses. The purpose of this work is to analyze the effects of pulsatile injections of modern insulins on plasma insulin levels compared with a continuous insulin infusion.

METHOD

We simulate pulsatile implementations of a basal rate profile over a day on a type 1 diabetes mellitus patient using insulin lispro. Pulse periods were varied between 1 and 60 min, and random pump errors were included, modeled as white noise, 1/f noise, or 1/f(2) noise with relative standard deviations up to 10% of the pump output.

RESULTS

Oscillations in plasma insulin caused by the pulsatile injections were not significant with respect to the global variations for pulse periods below 15 min. This cutoff period was found to be robust to random pump errors with standard deviations up to 10% of the pump output and hence solely determined by the insulin kinetics. Additionally, we showed that the pulse period achieving the best implementation of a continuous profile is an increasing function of the error variance for a given type of noise.

CONCLUSIONS

Our findings support that continuous insulin infusion can be implemented by a pulsatile injection of insulin as infrequent as a pulse every 15 min without significant effects on plasma insulin levels. If clinically confirmed, this result would have important consequences on the design and in silico testing of automated insulin treatment strategies, as increased delivery intervals imply higher accuracy of insulin delivery and facilitated implementations of closed-loop control algorithms.

A review of current evidence with continuous glucose monitoring in patients with diabetes

Devices that measure glucose on a near-continuous basis may provide a better insight into glycemic profiles, allowing patients with diabetes to make therapeutic adjustments to improve metabolic control, thereby reducing the risk of diabetic complications. Motivated and technologically adept patients with brittle diabetes, hypoglycemia unawareness, diabetic pregnancy, or who use pumps might benefit.Current evidence of continuous glucose monitoring (CGM) on health outcome in patients with diabetes is critically reviewed. No data are available on chronic complications or mortality. Therefore, surrogate endpoints need to be investigated, particularly HbA1c, number of hypo- and hyperglycemic episodes, time within normal, high, or low glucose concentrations, glycemic variability, and quality of life.Randomized controlled trials (RCTs) using CGM in a retrospective way did not show metabolic improvement. In contrast, most RCTs applying real-time CGM showed a decrease in HbA1c, reduced glycemic variability, and a diminished number and length of hypo- and hyperglycemic events. Using accurate, real-time CGM devices improves quality of life by reducing the fear of unexpected hypoglycemic events. These beneficial effects were observed despite the fact that in most studies no clear treatment algorithm based on CGM results was provided to the patients. However, most trials were too short in duration, with a variable use of CGM, and were performed in small study samples.In conclusion, real-time CGM systems can improve metabolic control, reduce hypoglycemic episodes, and improve quality of life. Whether this holds true for longer time periods and in the majority of patients remains to be proven. In the long term, CGM might help to reduce chronic diabetes complications and perhaps also mortality, thereby reducing health care costs.

Continuous glucose monitoring in insulin pump treated children

INTRODUCTION

Insulin pump therapy aims to improve glycemic control and decrease the risk of hypoglycemia in type 1 diabetes.

OBJECTIVE

To evaluate interstitial glucose levels and the frequency, duration and symptoms of hypo- and hyperglycemia through the use of a continuous glucose monitoring system (GGMS) in children and adolescents with insulin pump-treated type 1 diabetes, and to determine whether this monitoring method is well tolerated by these patients.

PATIENTS AND METHOD

Thirteen patients (4 boys) with insulin pump-treated type 1 diabetes mellitus were monitored. Age was 10.6±3.5 (range, 3.2-13.6) years, diabetes duration was 5.0±3.2 years, pump therapy duration was 12.0±4.6 months, insulin dose was 0.99 ± 0.19 U/kg/day, and last hemoglobin A1c level was 7.1% ± 0.8%. The Minimed CGMS was used for 72 hours.

RESULTS

A 3-year-old preschool child did not tolerate the CGMS. Interstitial glucose concentration was 187±40 mg/dl. Hypoglycemia (below 70mg/dl) accounted for 3.6% ± 5.6% of total time, while hyperglycemia (above 180 mg/dl) occurred 47.3% ± 17.4% of the time. No asymptomatic hypoglycemia episodes were detected.

CONCLUSIONS

Insulin pump-treated children and adolescents showed an irregular interstitial glucose level and did not achieve normoglycemia. In our patients, adrenergic symptoms of hypoglycemia were preserved and the CGMS was generally well tolerated.

The role of new technologies in treating children and adolescents with type 1 diabetes mellitus

Given the physiological and psychological impact of type 1 diabetes in children and adolescents, these patients present special challenges to pediatric health care providers. The goals of intensive management of diabetes have been clearly established since the publication of the Diabetes Control and Complication Trial (DCCT) in 1993, which demonstrated that tight metabolic control achieved with intensive insulin therapy is superior to conventional treatment in reducing the risk of long-term microvascular complications. Thus, current recommendations mandate that youth with type 1 diabetes should aim to achieve metabolic control as close to normal as possible. However, strict glycemic control is hard to achieve requiring frequent blood glucose measurements and several insulin injections per day, and in addition is associated with an increased risk of severe hypoglycemia. Recurrent episodes of hypoglycemia, especially at young ages, may cause adverse effects on neurocognitive function, may lead to hypoglycemia unawareness, and may be associated with significant emotional morbidity for the child and parents. Since the discovery of insulin in 1921 there has been constant progress in the way patients with type 1 diabetes are treated. The introduction of recombinant insulin and insulin analogs as well as new insulin delivery systems and glucose monitoring devices enhanced the ability of both patients and medical teams to better define the therapeutic goals and to develop more effective therapeutic strategies. Recent advances in devices for insulin administration and glucose monitoring and the introduction of telemedicine are having a profound effect on the lives of youth with type 1 diabetes. This review focuses on the new technologies which have been developed for treating children and adolescents with type 1 diabetes.

Nocturnal hypoglycaemias in type 1 diabetic patients: what can we learn with continuous glucose monitoring?

AIM

In type 1 diabetic patients (T1DM), nocturnal hypoglycaemias (NH) are a serious complication of T1DM treatment; self-monitoring of blood glucose (SMBG) is recommended to detect them. However, the majority of NH remains undetected on an occasional SMBG done during the night. An alternative strategy is the Continuous glucose monitoring (CGMS), which retrospectively shows the glycaemic profile. The aims of this retrospective study were to evaluate the true incidence of NH in T1DM, the best SMBG time to predict NH, the relationship between morning hyperglycaemia and NH (Somogyi phenomenon) and the utility of CGMS to reduce NH.

METHODS

Eighty-eight T1DM who underwent a CGMS exam were included. Indications for CGMS evaluation, hypoglycaemias and correlation with morning hyperglycaemias were recorded. The efficiency of CGMS to reduce the suspected NH was evaluated after 6-9 months.

RESULTS

The prevalence of NH was 67% (32% of them unsuspected). A measured hypoglycaemia at bedtime (22-24 h) had a sensitivity of 37% to detect NH (OR=2.37, P=0.001), while a single measure < or =4 mmol/l at 3-hour had a sensitivity of 43% (OR=4.60, P<0.001). NH were not associated with morning hyperglycaemias but with morning hypoglycaemias (OR=3.95, P<0.001). After 6-9 months, suspicions of NH decreased from 60 to 14% (P<0.001).

CONCLUSION

NH were highly prevalent and often undetected. SMBG at bedtime, which detected hypoglycaemia had sensitivity almost equal to that of 3-hour and should be preferred because it is easier to perform. Somogyi phenomenon was not observed. CGMS is useful to reduce the risk of NH in 75% of patients.

Treatment with insulin glargine reduces asymptomatic hypoglycemia detected by continuous subcutaneous glucose monitoring in children and adolescents with type 1 diabetes

OBJECTIVE

Unsatisfactory basal insulin substitution may lead to asymptomatic hypoglycemia in children and adolescents with type 1 diabetes (T1D). To investigate the effects of multiple daily injections before and after changing to insulin glargine (IG), continuous glucose monitoring system (CGMS) data were used to analyze glycemic control and hypoglycemic episodes during the two different therapy regimens.

METHODS

Basal insulin therapy was changed to one daily injection of IG in 30 pediatric patients with T1D (14 boys and 16 girls; age 4.5-18.3 yr, median 14.2 yr; diabetes duration 0.5-15.6 yr, median 4.6 yr) having elevated fasting glucose or recurrent hypoglycemia despite treatment with multiple injection therapy (basal insulin: two to four injections of neutral protamine Hagedorn (NPH) and/or zinc lente insulin). Ambulatory CGMS was applied before and 6-8 wk after treatment change. Frequency of hypoglycemic and hyperglycemic episodes, glucose area under the curve (AUC), and time below 60 mg/dL and above 180 mg/dL, respectively, were calculated from CGMS data during the day (8:00-22:00 hours) and at night (22:00-8:00 hours).

RESULTS

Nocturnal hypoglycemia was detected by CGMS in 20 patients before and in 12 patients after the change to IG (p = .039), whereas both, the number of nocturnal and diurnal hypoglycemic episodes, decreased not significantly from 41 to 36 (p = .758) and 48 to 28 (p = .055), respectively. AUC and time below 60 mg/dL as well as hemoglobin A1c (HbA1c) were not significantly different before and after the change to IG.

CONCLUSION

Under treatment with IG, asymptomatic hypoglycemia was reduced without increase of HbA1c.

Using continuous glucose monitoring to measure the frequency of low glucose values when using biphasic insulin aspart 30 compared with biphasic human insulin 30: a double-blind crossover study in individuals with type 2 diabetes

OBJECTIVE

Rapid-acting insulin analogs in basal-bolus regimens can reduce nocturnal hypoglycemia, so it is conceivable that twice-daily biphasic insulin analogs might reduce hypoglycemia in patients with insulin-treated type 2 diabetes. We used a continuous glucose monitoring system (CGMS) and self-reported episodes to investigate differences in the frequency of low glucose values in patients with type 2 diabetes, using either biphasic insulin aspart 30 (BIAsp 30) or biphasic human insulin 30 (BHI 30).

RESEARCH DESIGN AND METHODS

This was a double-blind, two-period, crossover trial involving 160 subjects. After 8 weeks' run-in, subjects were randomized to the first of two 16-week treatment periods.

RESULTS

No differences in overall incidence of low interstitial glucose (IG) were found. Twenty-four-hour plots of CGMS showed low IG was more frequent at night than during the day and was unrecognized by patients. At night, subjects spent significantly less time (percentage of total CGMS recorded) with IG <3.5 and <2.5 mmol/l during BIAsp 30 than during BHI 30 treatment, respectively (<3.5 mmol/l: 6.36 vs. 7.93% [mean], 0.67 vs. 2.43% [median], P = 0.018; <2.5 mmol/l: 2.35 vs. 2.86% [mean], 0 vs. 0% [median], P = 0.0467). No treatment difference in A1C was observed.

CONCLUSIONS

Overall rates of low glucose over 24 h were not different but were twice as frequent at night than during the day in individuals with type 2 diabetes. Compared with BHI 30, BIAsp 30 was associated with similar low IG readings over 24 h but with fewer nocturnal episodes and less self-reported nocturnal hypoglycemia.

A pilot trial in pediatrics with the sensor-augmented pump: combining real-time continuous glucose monitoring with the insulin pump

Real-time continuous glucose monitoring and the insulin pump have been combined into the Sensor-Augmented Pump system (Medtronic MiniMed, Northridge, CA). This short-term pilot trial demonstrated that pediatric subjects with type I diabetes improved mean hemoglobin A1c (A1c) and glucose levels and reduced hypoglycemia and hyperglycemia using the Sensor-Augmented Pump system.

Closing the loop: combining insulin pumps and glucose sensors in children with type 1 diabetes mellitus

Tight glycemic control of diabetic patients is associated with a reduction in the risk of microvascular and macrovascular complications, yet with elevated risk of severe episodes of hypoglycemia. The goal of "closing the loop" is to develop an autonomous insulin delivery system attached to a device capable of continuous glucose sensing, thus mimicking the islet beta cells activity and its capability of maintaining normal blood glucose levels and freeing the patient from the need of constant calculations of daily insulin and carbohydrates. The closed loop will protect patients from experiencing glucose excursions, including life-threatening events of hypoglycemia, thus improving glycemic control, reducing the fear from hypoglycemia and improving patients' quality of life. This review focuses on the steps towards closing the loop in the attempts to develop an artificial pancreas and on recent ongoing research and future directions in this field.

Cost-effectiveness of continuous subcutaneous insulin infusion (CSII) in children: illusion or delusion?

Cost-effectiveness of continuous subcutaneous insulin infusion (CSII) in children is reviewed in the context of possible improvement of percentage of hemoglobin A1c (HbA1c) and of other clinical benefits over multiple daily injections (MDI). Cost-effectiveness depends on clinical efficacy but reported clinical efficacy parameters may overlook definite benefits perceived by children and parents using CSII. There are few detailed reports on cost comparisons between CSII and MDI in adults, even less in children or adolescents. Review of direct extra costs for CSII over conventional treatment, including MDI, suggest that these may double, 5000-6000 EUR vs. 3000 EUR per patient year. An example is given of how to calculate direct cost differences, showing local differences. Randomized comparisons between CSII and MDI in childhood and adolescence show few marked clinical effects, but non-randomized comparisons favor CSII. Quality of life parameters fall short in any such comparison in children and adolescents alike. The reasons for the apparent discrepancy between non-randomized childhood studies and the randomized prospective ones are given. There is a dire need for better parameters to assess the well-being of diabetic children treated by CSII or MDI. Only then is it warranted to estimate the cost-effectiveness of CSII vs. MDI in childhood and adolescence.

Continuous glucose monitoring-guided insulin adjustment in children and adolescents on near-physiological insulin regimens: a randomized controlled trial

OBJECTIVE

This randomized controlled trial assesses the effect on glycemic control of continuous glucose monitoring system (CGMS)-guided insulin therapy adjustment in young people with type 1 diabetes on intensive diabetes treatment regimens with continuous subcutaneous insulin infusion (CSII) or glargine.

RESEARCH DESIGN AND METHODS

Pediatric subjects were recruited if they had an HbA(1c) (A1C) <10% and had been on CSII or glargine for at least 3 months. Thirty-six subjects were randomized to insulin adjustment on the basis of 72 h of CGMS every 3 weeks or intermittent self-monitoring of blood glucose (SMBG) for 3 months. A1C and fructosamine were measured at baseline and 6 and 12 weeks. Follow-up A1C was measured at 6 months. Mean baseline A1C was 8.2% (n = 19) in the CGMS group and 7.9% (n = 17) in the control group.

RESULTS

There was a significant improvement in A1C from baseline values in both groups, but there was no difference in the degree of improvement in A1C at 12 weeks between the CGMS (-0.4% [95% CI -0.7 to -0.1]) and the control group (-0.4% [-0.8 to 0.2]). In the CGMS group, improved A1C was at the cost of increased duration of hypoglycemia.

CONCLUSIONS

CGMS is no more useful than intermittent fingerstick SMBG and frequent review in improving diabetes control in reasonably well-controlled patients on near-physiological insulin regimens when used in an outpatient clinic setting.

Acute effects of hyperglycaemia in children with type 1 diabetes mellitus: the patient's perspective

INTRODUCTION

This study presents the results of a systematic examination of how parents and patients perceive the effects of acute hyperglycaemia on mood and on intellectual and fine-motor performance.

METHODS

A random sample of parents and children with type 1 diabetes mellitus (n = 380) were asked via questionnaire about their perception of the effects of hyperglycaemia.

RESULTS

Answers were received from 368 children and parents (97%); mean age was 12.5 years (range 3.7 to 19.8 years). Blood glucose levels between 15-18 mmol/l were reported by 68% to affect thinking performance, by 75% to affect mood and emotions and by 53% to affect coordination. The symptoms most commonly associated with hyperglycaemia were (in decreasing order): irritable (64%), short-tempered (60%), moody (56%), unreasonable (43%), aggressive (37%), hyperactive (31%), sad/depressed (27%) confused (23%), clumsy (18%). Homework was thought to be affected by hyperglycaemia in 36%, sport in 25%, play activity in 32%. Higher mean HbA1c since diagnosis was associated with higher reporting of effects on feeling/mood (p <0.001). Parents were especially concerned about the effects of hyperglycaemia on school and social interaction.

CONCLUSIONS

The effects of hyperglycaemia on immediate performance are of concern to children and parents. Hyperglycaemia (15-18 mmol/l) is reported to influence emotion and behaviour more than intellectual and fine-motor performance. This may contribute to the adverse psychological consequences of type 1 diabetes mellitus in children.

Insulin pump therapy in youth with type 1 diabetes: a retrospective paired study

OBJECTIVE

To compare by age and glycemic control continuous subcutaneous insulin infusion with multiple daily injections in youth with type 1 diabetes.

METHODS

The files of 279 patients who had type 1 diabetes and switched from multiple daily injections to continuous subcutaneous insulin infusion between 1998 and 2003 were reviewed for glycemic control, body mass index standard deviation score, and adverse events. Patients were divided by age as follows: 23 prepubertal (median age: 5.4; range: 1.6-8.6 years), 127 adolescent (median age: 13.7; range 9-17 years), and 129 young adult (median age: 22.8; range: 17-40 years). The data were compared between the 12 months of multiple daily injections that preceded continuous subcutaneous insulin infusion and the period after the start of continuous subcutaneous insulin infusion for the whole cohort and by age group.

RESULTS

A significant decrease in hemoglobin A1c was demonstrated after the start of continuous subcutaneous insulin infusion use for the entire cohort (-0.51%) and for the prepubertal (-0.48%), adolescent (-0.26%), and young adult (-0.76%) groups. There was a significant interaction between the change in hemoglobin A1c level and hemoglobin A1c value at initiation of pump therapy (-1.7% for patients with hemoglobin A1c > or = 10%; 0.2% for patients with hemoglobin A1c < or = 7%). The rate of severe hypoglycemic episodes decreased significantly in the adolescent group, from 36.5 to 11.1 events per 100 patient-years, and in the young adult group, from 58.1 to 23.3. There was no significant change in the rate of diabetic ketoacidosis between the 2 periods. The young adults showed a significant decrease in body mass index standard deviation scores (-0.08 +/- 0.37).

CONCLUSIONS

Continuous subcutaneous insulin infusion improves glycemic control in youth with type 1 diabetes, especially in those with a history of poor glycemic control. This improvement is associated with a decrease in the rate of severe hypoglycemia in the absence of weight gain.

Continuous subcutaneous glucose monitoring in children with type 1 diabetes mellitus: a single-blind, randomized, controlled trial

BACKGROUND

Tight glycemic control delays the long-term complications of type 1 diabetes mellitus (T1DM) but increases the risk for hypoglycemia. The continuous glucose-monitoring system (CGMS) provides blood glucose (BG) readings every 5 min, and its accuracy and reliability has been established in adults. However, there are limited data on its efficacy and safety in children. The purpose of this study was to determine if CGMS use improves metabolic control in children with T1DM.

METHODS

Twenty-seven children (12 male) with T1DM participated in this single-blind, randomized, controlled trial. Participants (age: 11.4 +/- 3.7 (mean +/- SD) yr, range: 7-17 yr) were randomized to an intervention group (n = 18) or a control group (n = 9). Both groups wore the CGMS for 72-h periods at 0, 2, and 4 months. Adjustments in therapy for the intervention group were based on both CGMS and self-monitoring of BG (SMBG) data, while only SMBG data were used for the control group. Hemoglobin A1c (HbA1c) was determined at 0, 2, 4, and 6 months. The change in HbA1c from 0 to 6 months (HbA1c(Delta1-4)) and mean daily area under the CGMS curve for glucose <70 mg/dL area under the curve (AUC(<70)) were compared between groups.

RESULTS

At study entry, HbA1c levels were similar in the intervention and control groups (8.4 +/- 0.98 and 8.8 +/- 0.86%, respectively; p = 0.12) but were significantly lower in the intervention group compared with the control group at study completion (7.8 +/- 0.88 and 8.6 +/- 0.95%, respectively; p = 0.02). The decrease in HbA1c of 0.61 +/- 0.68% in the intervention group was statistically significant (p = 0.03), whereas the decrease in HbA1c of 0.28 +/- 0.78% in the control group was not. Nonetheless, the differences in HbA1c(Delta1-4) between groups did not reach statistical significance (p = 0.13). There was no statistically significant difference in AUC(<70) between study groups (p = 0.18).

CONCLUSION

CGMS use may improve metabolic control in children with T1DM without increasing the risk for hypoglycemia.

Brain glucose concentrations in healthy humans subjected to recurrent hypoglycemia

Mechanisms responsible for hypoglycemia unawareness remain unknown. Previously, we found that patients with type 1 diabetes and hypoglycemia unawareness had increased brain glucose concentrations as measured by (1)H-magnetic resonance spectroscopy (MRS) compared with controls measured under the same metabolic condition, suggesting that an alteration in brain glucose transport and/or metabolism may play a role in the pathogenesis of hypoglycemia unawareness. To determine whether the brain glucose concentration is altered in normal subjects subjected to recurrent hypoglycemia, we compared the brain glucose concentrations measured in healthy subjects after three episodes of hypoglycemia to blunt the counterregulatory response over 24 hr and compared this value with that measured at a time remote from the antecedent hypoglycemia protocol. Sixteen subjects (9 M/7 F, age 36 +/- 10 years, mean +/- SD) underwent three hypoglycemic clamps for 30 min at 8 AM (0 hr), 5 PM (9 hr), and 7 AM (24 hr). After the third hypoglycemic clamp, subjects underwent a hyperglycemic clamp during which brain glucose concentration was measured by MRS at 4 T. Brain glucose concentration after repeated hypoglycemia was not different from the brain glucose concentration measured in the same subjects during a control study (5.1 +/- 0.8 vs. 4.5 +/- 0.5 mumol/g wet weight, respectively, P = 0.05). These observations suggest that brain glucose transport or metabolism is not altered following short episodes of recurrent hypoglycemia in healthy human volunteers.

Monitoring Exercise-Induced Changes in Glycemic Control in Type 2 Diabetes

PURPOSE

The present study determined the efficacy of the Continuous Glucose Monitoring System (CGMS) during moderate exercise and monitored the changes in whole-day glucose profiles using the CGMS in individuals with and without type 2 diabetes.

METHODS

Six, obese, diet-treated individuals with and four age-matched individuals without type 2 diabetes were monitored using the CGMS for 3 d. Subjects cycled at 90% of a predetermined lactate threshold for 1 h at approximately 09:00 h on day 2, during which venous blood was sampled at 10-min intervals and immediately analyzed for glucose concentrations.

RESULTS

Venous blood glucose and CGMS values declined during exercise in the diabetes (P < 0.001) but not the control group (P = 0.085). The CGMS overestimated blood glucose in the control (P = 0.003) and the diabetes (P = 0.045) groups during exercise. The number of data points outside of the 95% confidence intervals was <5% in both groups, showing that there is a statistically acceptable level of agreement between venous blood glucose and CGMS values during exercise. Moderate exercise improved whole-day average glucose concentrations (P = 0.007) and whole-day area under the glucose curve (P = 0.016) values (AUCglu), and the time spent within +/-10% of fasting venous glucose (FVG) increased in the diabetes group (P = 0.021). No such effects were seen in the control group.

CONCLUSION

Using continuous glucose monitoring we were able to demonstrate that a period of moderate exercise improved whole-day glycemic control in obese individuals with type 2 diabetes. The CGMS should only be used as an adjunct and not as an alternative to frequent blood glucose sampling when examining the changes in glucose values during exercise in individuals with and without type 2 diabetes.

A cross-sectional international survey of continuous subcutaneous insulin infusion in 377 children and adolescents with type 1 diabetes mellitus from 10 countries

OBJECTIVE

To document current practices using continuous subcutaneous insulin infusion (CSII) by downloading electronically the 90-d pump data held within the pump memory and relating that to clinical data from children and adolescents in different pediatric diabetes centers from Europe and Israel.

METHODS

Data of patients (1-18 yr) treated with CSII in 23 centers from nine European countries and Israel were recorded with the encapture software (PEC International, Frankfurt, Germany). The number of patients who participated was 377 (48% female; mean diabetes duration +/- SD: 6.8 +/- 3.7 yr; age: 12.9 +/- 3.8 yr, preschool n = 33; prepubertal n = 95; adolescent n = 249; CSII duration: 1.6 +/- 1.2 yr; local HbA1c: 8.1 +/- 1.2%).

RESULTS

The total insulin dose was lower than previously reported for injection therapy (0.79 +/- 0.20 U/kg/d). Covariance coefficient of daily total insulin was high in all age groups (adolescents 19 +/- 9%, prepubertal 18 +/- 8 and preschool 17 +/- 8). The distribution of basal insulin infusion rates over 24 hr (48 +/- 12% of total dose) varied significantly between centers and age groups. The number of boluses per day (7 +/- 3) was not significantly different between the age groups (average daily bolus amount: 0.42 +/- 0.16 U/kg). The rate of severe hypoglycemia (coma/convulsions) was 12.4 episodes per 100 patient-years and the number of diabetes-related hospital days was 124 per 100 patient-years.

DISCUSSION

Pediatric CSII patients show a high variability in their insulin therapy. This relates both to age-dependent differences in the distribution of basal insulin as to the age-independent day-to-day variation in prandial insulin.

Hypoglycemia: a complication of diabetes therapy in children

The experience of hypoglycemia is probably the most feared and hated consequence of life with type 1 diabetes among pediatric patients and their parents. Although transient detrimental effects are clearly disturbing and may have severe results, there is surprisingly little evidence of long-term CNS damage, even after multiple hypoglycemic episodes, except in rare instances. Despite the latter evidence, we advocate that every treatment regimen be designed to prevent hypoglycemia without inducing unacceptable hyperglycemia and increasing the risk of micro- and macrovascular complications.