Incidence and predictive criteria of nocturnal hypoglycemia in young children with insulin-dependent diabetes mellitus

The Advanced Diabetes Technologies for Reduction of the Frequency of Hypoglycemia and Minimizing the Occurrence of Severe Hypoglycemia in Children and Adolescents with Type 1 Diabetes

Hypoglycemia is an often-observed acute complication in the management of children and adolescents with type 1 diabetes. It causes inappropriate glycemic outcomes and may impair the quality of life in the patients. Severe hypoglycemia with cognitive impairment, such as a convulsion and coma, is a lethal condition and is associated with later-onset cognitive impairment and brain-structural abnormalities, especially in young children. Therefore, reducing the frequency of hypoglycemia and minimizing the occurrence of severe hypoglycemia are critical issues in the management of children and adolescents with type 1 diabetes. Advanced diabetes technologies, including continuous glucose monitoring and sensor-augmented insulin pumps with low-glucose suspension systems, can reduce the frequency of hypoglycemia and the occurrence of severe hypoglycemia without aggravating glycemic control. The hybrid closed-loop system, an automated insulin delivery system, must be the most promising means to achieve appropriate glycemic control with preventing severe hypoglycemia. The use of these advanced diabetes technologies could improve glycemic outcomes and the quality of life in children and adolescents with type 1 diabetes.

Significance of the CGM metric of time in range in children and adolescents with type 1 diabetes

Continuous glucose monitoring (CGM) has been widely used in children and adolescents as well as adults with type 1 diabetes. CGM metrics include three key measurements of target glucose: time in range (TIR: 70-180 mg/dL), time below range (TBR: <70 mg/dL), and time above range (TAR: >180 mg/dL). The primary goal of optimal glycemic control is to increase TIR to more than 70%, while simultaneously reducing TBR to less than 4%, while minimizing severe hypoglycemia to less than 1%, as proposed by the Advanced Technologies and Treatments for Diabetes (ATTD) panel. However, several studies have indicated that the TIR goal is quite difficult to achieve in pediatric patients who have remarkable interindividual and day-to-day glycemic variation due to their irregular lifestyles. Previous studies have demonstrated that patients without an automated insulin delivery system are unlikely to attain the recommended glycemic goals. On the other hand, reduction of hypoglycemia, particularly minimizing severe hypoglycemia, is a critical issue in the effective management of children with type 1 diabetes. Frequent episodes of severe hypoglycemia and hypoglycemia can cause lasting neurological damage. Accordingly, we propose reducing the TBR to less than 5%, rather than just targeting the TIR to more than 70%. In CGM metrics this should be the cardinal glycemic goal for pediatric patients who are either being treated with multiple daily injections of insulin or a conventional insulin pump, but who are not using an automated insulin delivery system.

Significance of "Time below Range" as a Glycemic Marker Derived from Continuous Glucose Monitoring in Japanese Children and Adolescents with Type 1 Diabetes

INTRODUCTION

We evaluated the frequencies of various glycemic markers derived from continuous glucose monitoring in Japanese children and adolescents with type 1 diabetes and assessed the significance of hypoglycemia duration.

METHODS

We enrolled 85 children and adolescents (36 boys and 49 girls) with type 1 diabetes who used FreeStyle® Libre in the present study. Frequencies of blood glucose levels as time within target range (TIR; 70-180 mg/dL), time below target range (TBR; <70 mg/dL), time below extreme hypoglycemia range (TBER; <54 mg/dL), and time above range (TAR; >180 mg/dL) were assessed during a 3-month study period. Furthermore, we evaluated the intraday frequencies of TBR and TBER.

RESULTS

The mean frequencies of TIR, TBR, and TAR were 52.7 ± 11.3%, 10.8 ± 5.4%, and 36.5 ± 10.8%, respectively, whereas the mean frequency of TBER was 1.1 ± 0.9% (0-3.0%); there was no clinical episode of severe hypoglycemia. The mean frequency of TBR was significantly greater in 0-6 h (16.9 ± 5.2%) than in 6-12 h (7.8 ± 2.9%) and 18-24 h (6.8 ± 4.8%; p < 0.01) time zones, respectively.

DISCUSSION/CONCLUSION

We found similar TIR and comparatively higher TBR frequencies, particularly during sleep, than those that were previously reported. Possible reasons for the higher frequency of TBR include differences in the quality of insulin treatment and diabetes care between the present study and the European studies. The utilization of advanced technologies, such as a predictive low-glucose suspend-function pump or closed-loop therapy, can reduce the frequency of TBR, with a consequent increase in TIR frequency and comprehensive improvement in glycemic control.

Sleep and Night-time Caregiving in Parents of Children and Adolescents with Type 1 Diabetes Mellitus - A Qualitative Study

BACKGROUND

Type 1 diabetes mellitus (T1DM) is a common chronic illness of childhood, with parents assuming considerable responsibility for night-time diabetes caregiving. This qualitative study explored diabetes-related factors affecting, and solutions proposed to improve, parental sleep.

PARTICIPANTS

10 mothers and 10 fathers of children ≤18 years of age with T1DM in Otago, New Zealand.

METHODS

Semi-structured individual interviews were audio-recorded, transcribed, and systematically coded for themes. Parents completed the Pittsburgh Sleep Quality Index (PSQI) and habitual sleep of parents and children were assessed via 7-day actigraphy.

RESULTS

Parents (n = 20) and their children with T1DM (n = 16) were aged between 32 and 54 years, and 1 and 17 years, respectively. PSQI revealed poor quality sleep in 13/20 parents. A range of diabetes-related factors, including glucose monitoring and fear of hypoglycemia, contributed to parental sleep disturbance, including awakenings and the perception of "sleeping lightly". Two distinct time periods resulted in greater sleep disturbance, notably, following T1DM diagnosis and when transitioning to using a new diabetes technology. Factors influencing maternal and paternal sleep were similar, but, generally, mothers described greater night-time care burden and sleep disturbance. While the use of diabetes technologies was generally advocated to improve parental sleep and the provision of nocturnal T1DM care, they were also perceived to potentially contribute to parental sleep disturbance.

CONCLUSIONS

Pediatric diabetes care teams should be aware of diabetes-related factors potentially affecting parental sleep, the mixed impacts of diabetes technologies, and consider tailored parental support and education to reduce the burden of nocturnal care.

Prediction of Nocturnal Hypoglycemia in Adults with Type 1 Diabetes under Multiple Daily Injections Using Continuous Glucose Monitoring and Physical Activity Monitor

(1) Background: nocturnal hypoglycemia (NH) is one of the most challenging side effects of multiple doses of insulin (MDI) therapy in type 1 diabetes (T1D). This work aimed to investigate the feasibility of a machine-learning-based prediction model to anticipate NH in T1D patients on MDI. (2) Methods: ten T1D adults were studied during 12 weeks. Information regarding T1D management, continuous glucose monitoring (CGM), and from a physical activity tracker were obtained under free-living conditions at home. Supervised machine-learning algorithms were applied to the data, and prediction models were created to forecast the occurrence of NH. Individualized prediction models were generated using multilayer perceptron (MLP) and a support vector machine (SVM). (3) Results: population outcomes indicated that more than 70% of the NH may be avoided with the proposed methodology. The predictions performed by the SVM achieved the best population outcomes, with a sensitivity and specificity of 78.75% and 82.15%, respectively. (4) Conclusions: our study supports the feasibility of using ML techniques to address the prediction of nocturnal hypoglycemia in the daily life of patients with T1D on MDI, using CGM and a physical activity tracker.

Development and Validation of the Parent-Preschoolers Diabetes Adjustment Scale (PP-DAS)

OBJECTIVE

This article extends work on a social-ecological model of caregiver adjustment and describes the: (a) development and (b) validation of the Parent-Preschoolers Diabetes Adjustment Scale (PP-DAS), a broad measure of caregiver adjustment.

METHODS

Participants were caregivers (nstudy1 = 51; nstudy2 = 177) of very young children (<6 years old) with Type 1 diabetes (T1D). In study 1, researchers and stakeholders collaborated to develop 92 items using the 5 domains of a social-ecological model of caregiver adjustment to the challenges of raising a very young child with T1D, and parents and researchers provided feedback on these items. In study 2, confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were used to examine the factor structure of the PP-DAS. Reliability and validity were also examined.

RESULTS

After review by parents and researchers, 52 items were removed resulting in the 40-item version used in study 2. The CFA demonstrated poor fit with the five proposed domains of the social-ecological model, so an EFA was conducted and supported a different five-factor solution. Twenty items were removed due to low factor loadings or communalities, resulting in a final 20-item measure. The PP-DAS demonstrated adequate internal consistency (α's = .73-.84), convergent validity with parent psychological functioning and self-efficacy in T1D management, and criterion validity with hemoglobin A1c and adherence.

CONCLUSIONS

The PP-DAS is a valid and reliable measure of adjustment in caregivers of very young children with T1D. The PP-DAS may help identify caregivers who are having adjustment difficulties and would benefit from additional support.

A Novel CGM Metric-Gradient and Combining Mean Sensor Glucose Enable to Improve the Prediction of Nocturnal Hypoglycemic Events in Patients with Diabetes

Nocturnal hypoglycemia is a serious complication of insulin-treated diabetes, and it is often asymptomatic. A novel CGM metric-gradient was proposed in this paper, and a method of combining mean sensor glucose (MSG) and gradient was presented for the prediction of nocturnal hypoglycemia. For this purpose, the data from continuous glucose monitoring (CGM) encompassing 1,921 patients with diabetes were analyzed, and a total of 302 nocturnal hypoglycemic events were recorded. The MSG and gradient values were calculated, respectively, and then combined as a new metric (i.e., MSG+gradient). In addition, the prediction was conducted by four algorithms, namely, logistic regression, support vector machine, random forest, and long short-term memory. The results revealed that the gradient of CGM showed a downward trend before hypoglycemic events happened. Additionally, the results indicated that the specificity and sensitivity based on the proposed method were better than the conventional metrics of low blood glucose index (LBGI), coefficient of variation (CV), mean absolute glucose (MAG), lability index (LI), etc., and the complex metrics of MSG+LBGI, MSG+CV, MSG+MAG, and MSG+LI, etc. Specifically, the specificity and sensitivity were greater than 96.07% and 96.03% at the prediction horizon of 15 minutes and greater than 87.79% and 90.07% at the prediction horizon of 30 minutes when the proposed method was adopted to predict nocturnal hypoglycemic events in the aforementioned four algorithms. Therefore, the proposed method of combining MSG and gradient may enable to improve the prediction of nocturnal hypoglycemic events. Future studies are warranted to confirm the validity of this metric.

Severe Hypoglycemia: Is It Still a Threat for Children and Adolescents With Type 1 Diabetes?

Severe hypoglycemia is defined as a condition with serious cognitive dysfunction, such as a convulsion and coma, requiring external help from other persons. This condition is still lethal and is reported to be the cause of death in 4-10% in children and adolescents with type 1 diabetes. The incidence of severe hypoglycemia in the pediatric population was previously reported as high as more than 50-100 patient-years; however, there was a decline in the frequency of severe hypoglycemia during the past decades, and relationship with glycemic control became weaker than previously reported. A lot of studies have shown the neurological sequelae with severe hypoglycemia as cognitive dysfunction and abnormalities in brain structure. This serious condition also provides negative psychosocial outcomes and undesirable compensatory behaviors. Various possible factors, such as younger age, recurrent hypoglycemia, nocturnal hypoglycemia, and impaired awareness of hypoglycemia, are possible risk factors for developing severe hypoglycemia. A low HbA_1c level is not a predictable value for severe hypoglycemia. Prevention of severe hypoglycemia remains one of the most critical issues in the management of pediatric patients with type 1 diabetes. Advanced technologies, such as continuous glucose monitoring (CGM), intermittently scanned CGM, and sensor-augmented pump therapy with low-glucose suspend system, potentially minimize the occurrence of severe hypoglycemia without worsening overall glycemic control. Hybrid closed-loop system must be the most promising tool for achieving optimal glycemic control with preventing the occurrence of severe hypoglycemia in pediatric patients with type 1 diabetes.

Novel ambulatory glucose-sensing technology improves hypoglycemia detection and patient monitoring adherence in children and adolescents with type 1 diabetes

Purpose

Glucose monitoring [GM] is a mainstay of diabetes control and management. Improving glycemic control is essential to prevent microvascular complications. However, adherence to GM can be a challenge in children and adolescents. Detecting hypoglycemia is essential for its prevention and treatment. We aim to study the impact of the flash ambulatory glucose monitoring in detecting hypoglycemia and enhancing adherence in children and adolescents with type 1 diabetes.

Methods

The study is prospective involving 3 hospital visits. Children and adolescents with diabetes were enrolled in the study which involved a period on conventional glucose self-monitoring [glucometers] followed by a similar period of monitoring using the flash glucose monitoring device (FreeStyle Libre). Frequency of GM, duration and frequency of hypoglycemia were compared on conventional and the flash monitoring.

Results

75 subjects were studied. Age mean (range) was 11.9 years (2-19). Significant difference was seen in hypoglycemia detection between both testing devices. 68 (94%) and 65 (90%) patients detected nocturnal and diurnal hypoglycemia respectively on Flash monitoring compared to 12 (16.6%) and 30 (41%) on glucometer testing (p < 0.00). Mean (range) duration of hypoglycemia was 95 min (15-330). Statistically-significant difference was found between the frequency of GM on glucometer testing compared with Flash monitoring (2.87 and 11.6/day) (p < 0.001).

Conclusions

Flash monitoring is a useful tool to improve adherence to GM and detecting hypoglycemia [diurnal and nocturnal] in children and adolescents with type 1 diabetes.

The risks of nocturnal hypoglycaemia in insulin-treated diabetes

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia.

Challenges of Diabetes Management in Toddlers

Toddlers with type 1 diabetes have distinctive combination of challenges to their families and healthcare providers. A major factor is the difficulty in achieving metabolic control without risking hypoglycemia. The rising incidence of type 1 diabetes in toddlers increases the magnitude of the problem and creates a greater need for providing specialized service to cater for this age group's unique need. Type 1 has a specific disease nature in younger children and its clinical presentation mimics common childhood diseases. Symptoms and signs in the newly presented toddler with diabetes might be unspecific causing diagnosis to be missed or delayed. With the low cognitive ability and immature communication, toddlers might not be able to express their ill-feeling resulting from hypoglycemia or hyperglycemia. Hypoglycemia fear is common, which aggravates stress and reduces adherence to strict metabolic control. Nocturnal hypoglycemia is more common in toddlers and can be undiagnosed unless continuous glucose monitoring is used. Insulin administration and adjustment can be challenging due to pain, fear, refusal, and frequent intercurrent illness. Glucose monitoring is crucial. However, it can be distressing to the child and difficult to adhere to due to commitment or financial reasons. Insulin pump therapy is proven to be an effective and a safe method of treatment for toddlers, but it requires intensive training, resources, and long-term support. Provision of multidisciplinary team with special expertise in managing toddlers with diabetes is essential. Providing more physiological insulin regimes and customized technology is required to improve treatment compliance and diabetes control.

Glucose sensing in the peritoneal space offers faster kinetics than sensing in the subcutaneous space

The paramount goal in the treatment of type 1 diabetes is the maintenance of normoglycemia. Continuous glucose monitoring (CGM) technologies enable frequent sensing of glucose to inform exogenous insulin delivery timing and dosages. The most commonly available CGMs are limited by the physiology of the subcutaneous space in which they reside. The very same advantages of this minimally invasive approach are disadvantages with respect to speed. Because subcutaneous blood flow is sensitive to local fluctuations (e.g., temperature, mechanical pressure), subcutaneous sensing can be slow and variable. We propose the use of a more central, physiologically stable body space for CGM: the intraperitoneal space. We compared the temporal response characteristics of simultaneously placed subcutaneous and intraperitoneal sensors during intravenous glucose tolerance tests in eight swine. Using compartmental modeling based on simultaneous intravenous sensing, blood draws, and intraarterial sensing, we found that intraperitoneal kinetics were more than twice as fast as subcutaneous kinetics (mean time constant of 5.6 min for intraperitoneal vs. 12.4 min for subcutaneous). Combined with the known faster kinetics of intraperitoneal insulin delivery over subcutaneous delivery, our findings suggest that artificial pancreas technologies may be optimized by sensing glucose and delivering insulin in the intraperitoneal space.

Glycemic extremes in youth with T1DM: the structural and functional integrity of the developing brain

The adult brain accounts for a disproportionally large percentage of the body’s total energy consumption (1). However, during brain development,energy demand is even higher, reaching the adult rate by age 2 and increasing to nearly twice the adult rate by age 10, followed by gradual reduction toward adult levels in the next decade (1,2). The dramatic changes in brain metabolism occurring over the first two decades of life coincide with the initial proliferation and then pruning of synapses to adult levels.The brain derives its energy almost exclusively from glucose and is largely driven by neuronal signaling, biosynthesis, and neuroprotection (3–6).Glucose homeostasis in the body is tightly regulated by a series of hormones and physiologic responses. As a result, hypoglycemia and hyperglycemia are rare occurrences in normal individuals, but they occur commonly inpatients with type 1 diabetes mellitus (T1DM) due to a dysfunction of peripheral glucose-insulin-glucagon responses and non-physiologic doses of exogenous insulin, which imperfectly mimic normal physiology. These extremes can occur more frequently in children and adolescents with T1DM due to the inadequacies of insulin replacement therapy, events leading to the diagnosis [prolonged untreated hyperglycemia and diabetic ketoacidosis (DKA)], and to behavioral factors interfering with optimal treatment. When faced with fluctuations in glucose supply the metabolism of the body and brain change dramatically, largely to conserve resources and, at a cost to other organs, to preserve brain function (7). However,if the normal physiological mechanisms that prevent these severe glucose fluctuations and maintain homeostasis are impaired, neuronal function and potentially viability can be affected (8–11).

Hypoglycaemia, fear of hypoglycaemia and quality of life in children with Type 1 diabetes and their parents

AIM

To evaluate the association between fear of hypoglycaemia, episodes of hypoglycaemia and quality of life in children with Type 1 diabetes and their parents.

METHODS

This was a cross-sectional, population-based study of 325 children with Type 1 diabetes and their parents. The children were aged 2-18 years. A total of 325 parents of the patients aged 2-18 years and 196 of the patients themselves (aged 8-18 years) completed questionnaires including the PedsQL Diabetes Module, the Hypoglycaemia Fear Survey and Clarke's hypoglycaemia awareness questionnaire. Data were compared with HbA1c results and the history of severe hypoglycaemia episodes.

RESULTS

Parents with the highest levels of fear of hypoglycaemia reported that their children had a reduced quality of life (P < 0.001). Similarly children with the greatest fear also reported a reduced quality of life (P < 0.001); however a history of severe hypoglycaemia was not associated with the child's quality of life as perceived by the child or parent. Episodes of severe hypoglycaemia were associated with an increased fear of hypoglycaemia for the parents (P = 0.004) but not the children. Children in the highest fear quartile also had a higher HbA(1c) concentration compared with those in the lowest fear quartile [increase in HbA(1c) 7 mmol/mol (0.6%), P < 0.01].

CONCLUSIONS

Fear of hypoglycaemia and not episodes of hypoglycaemia per se is associated with increased psychological burden for children with Type 1 diabetes. Interventions to reduce fear of hypoglycaemia in these families may improve their quality of life.

Susceptibility of interstitial continuous glucose monitor performance to sleeping position

BACKGROUND

Developing a round-the-clock artificial pancreas requires accurate and stable continuous glucose monitoring. The most widely used continuous glucose monitors (CGMs) are percutaneous, with the sensor residing in the interstitial space. Inaccuracies in percutaneous CGM readings during periods of lying on the devices (e.g., in various sleeping positions) have been anecdotally reported but not systematically studied.

METHODS

In order to assess the impact of sleep and sleep position on CGM performance, we conducted a study in human subjects in which we measured the variability of interstitial CGM data at night as a function of sleeping position. Commercially available sensors were placed for 4 days in the abdominal subcutaneous tissue in healthy, nondiabetic volunteers (four sensors per person, two per side). Nocturnal sleeping position was determined from video recordings and correlated to sensor data.

RESULTS

We observed that, although the median of the four sensor readings was typically 70-110 mg/dl during sleep, individual sensors intermittently exhibited aberrant glucose readings (&gt;25 mg/dl away from median) and that these aberrant readings were strongly correlated with subjects lying on the sensors. We expected and observed that most of these aberrant sleep-position-related CGM readings were sudden decreases in reported glucose values, presumably due to local blood-flow decreases caused by tissue compression. Curiously, in rare cases, the aberrant CGM readings were elevated values.

CONCLUSIONS

These findings highlight limitations in our understanding of interstitial fluid physiology in the subcutaneous space and have significant implications for the utilization of sensors in the construction of an artificial pancreas.

Closed-loop artificial pancreas: current studies and promise for the future

PURPOSE OF REVIEW

The availability of glucose sensors and insulin pumps has enabled the development of devices and software to partially or completely automate insulin delivery. Over the last 2 years, the number of centers developing and evaluating such systems, as well as the number of reports of these studies in the literature, have expanded dramatically. The purpose of this review is to highlight the progress along multiple fronts to develop automated systems to improve control of type 1 diabetes.

RECENT FINDINGS

Multiple approaches, including automated suspension for actual or impending hypoglycemia, automated augmentation for hyperglycemia, as well as hybrid and full closed-loop control, are in parallel development. So far, early hypoglycemia prevention studies and small inpatient feasibility studies have demonstrated the potential for reducing hypoglycemia and improving overall diabetes control.

SUMMARY

Current sensors, pumps, and control algorithms show promise for use in a closed-loop system but have been limited to inpatient studies. The next phase of development should focus on their evaluation in controlled short-term outpatient safety and efficacy trials.

Hypoglycemia does not change the threshold for arousal from sleep in adolescents with type 1 diabetes

BACKGROUND

Nocturnal hypoglycemia is a significant problem for children and adolescents with type 1 diabetes. The counterregulatory hormone response to hypoglycemia is blunted in both patients with type 1 diabetes and healthy subjects during sleep. It is not known whether the threshold for arousal from sleep is also modified by hypoglycemia. To address this question we compared the acoustic arousal threshold from sleep during hypoglycemia and euglycemia in adolescents with type 1 diabetes.

METHODS

Adolescents with type 1 diabetes were studied on two occasions: under hypoglycemic and euglycemic conditions. During the hypoglycemia night, subjects underwent a hyperinsulinemic hypoglycemic clamp with nadir glucose level of 2.8 mmol/L. Hypoglycemia was initiated during stage 2 sleep and maintained during slow-wave sleep. During the euglycemia night, blood glucose was maintained at 5.5 mmol/L using the same clamp technique. The acoustic arousal threshold was determined during the first cycle of slow-wave sleep.

RESULTS

Seven subjects (mean±SE, 14.2±0.8 years old, mean glycosylated hemoglobin 8.1±0.3%, duration of diagnosis 2.5±0.5 years) completed both study nights. Arousal was only noted during acoustic testing and did not occur during hypoglycemia alone. The acoustic arousal threshold during slow-wave sleep was similar under both conditions: 79±8 dB during euglycemia and 71±6 dB (P=0.353) during hypoglycemia.

CONCLUSION

In adolescents with type 1 diabetes, hypoglycemia does not impair arousal from slow-wave sleep induced by an external auditory stimulus.

Treatment of severe diabetic hypoglycemia with glucagon: an underutilized therapeutic approach

Tight glycemic control is important in reducing and delaying vascular complications in type 1 and 2 diabetes patients; however, the benefits achieved through strict metabolic control are counterbalanced by an increased risk of hypoglycemia. Glucagon is an effective therapy for treating severe hypoglycemia. Available as an emergency kit, glucagon is an essential tool for rapid response, but remains underappreciated and underused. This article reviews the role of glucagon in treating severe hypoglycemia and discusses the need for better education on glucagon for people with diabetes and their caregivers in order to alleviate fears of hypoglycemia and of administering glucagon in the event of an emergency.

Manual closed-loop insulin delivery in children and adolescents with type 1 diabetes: a phase 2 randomised crossover trial

BACKGROUND

Closed-loop systems link continuous glucose measurements to insulin delivery. We aimed to establish whether closed-loop insulin delivery could control overnight blood glucose in young people.

METHODS

We undertook three randomised crossover studies in 19 patients aged 5-18 years with type 1 diabetes of duration 6.4 years (SD 4.0). We compared standard continuous subcutaneous insulin infusion and closed-loop delivery (n=13; APCam01); closed-loop delivery after rapidly and slowly absorbed meals (n=7; APCam02); and closed-loop delivery and standard treatment after exercise (n=10; APCam03). Allocation was by computer-generated random code. Participants were masked to plasma and sensor glucose. In APCam01, investigators were masked to plasma glucose. During closed-loop nights, glucose measurements were fed every 15 min into a control algorithm calculating rate of insulin infusion, and a nurse adjusted the insulin pump. During control nights, patients' standard pump settings were applied. Primary outcomes were time for which plasma glucose concentration was 3.91-8.00 mmol/L or 3.90 mmol/L or lower. Analysis was per protocol. This trial is registered, number ISRCTN18155883.

FINDINGS

17 patients were studied for 33 closed-loop and 21 continuous infusion nights. Primary outcomes did not differ significantly between treatment groups in APCam01 (12 analysed; target range, median 52% [IQR 43-83] closed loop vs 39% [15-51] standard treatment, p=0.06;

INTERPRETATION

Closed-loop systems could reduce risk of nocturnal hypoglycaemia in children and adolescents with type 1 diabetes.

FUNDING

Juvenile Diabetes Research Foundation; European Foundation for Study of Diabetes; Medical Research Council Centre for Obesity and Related Metabolic Diseases; National Institute for Health Research Cambridge Biomedical Research Centre.

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Key Words Collapse

MESH Headings

• Adolescent
• Algorithms
• Biosensing Techniques
• Blood Glucose/metabolism
• Child
• Child, Preschool
• Cross-Over Studies
• Diabetes Mellitus, Type 1/blood
• Diabetes Mellitus, Type 1/drug therapy
• Female
• Humans
• Hypoglycemic Agents/administration & dosage
• Infusions, Subcutaneous
• Insulin/administration & dosage
• Insulin/blood
• Insulin Infusion Systems
• Male
• Treatment Outcome

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Grants

• G0600717 Medical Research Council

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Affiliation(s)

Roman Hovorka Department of Paediatrics, University of Cambridge, Cambridge, UK.
Janet M Allen
Daniela Elleri
Ludovic J Chassin
Julie Harris
Dongyuan Xing
Craig Kollman
Tomas Hovorka
Anne Mette F Larsen
Marianna Nodale
Alessandra De Palma
Malgorzata E Wilinska
Carlo L Acerini
David B Dunger

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Clinical evaluation of a noninvasive alarm system for nocturnal hypoglycemia

BACKGROUND

The aim of this study was to evaluate the performance of a prototype noninvasive alarm system (HypoMon) for the detection of nocturnal hypoglycemia. A prospective cohort study evaluated an alarm system that included a sensor belt, a radio frequency transmitter for chest belt signals, and a receiver. The receiver incorporated integrated "real-time" algorithms designed to recognize hypoglycemia "signatures" in the physiological parameters monitored by the sensor belt.

METHODS

Fifty-two children and young adults with type 1 diabetes mellitus (T1DM) participated in this blinded, prospective, in-clinic, overnight study. Participants had a mean age of 16 years (standard deviation 2.1, range 12-20 years) and were asked to follow their normal meal and insulin routines for the day of the study. Participants had physiological parameters monitored overnight by a single HypoMon system. Their BG levels were also monitored overnight at regular intervals via an intravenous cannula and read on two independent Yellow Springs Instruments analyzers. Hypoglycemia was not induced by any manipulations of diabetes management, rather the subjects were monitored overnight for "natural" occurrences of hypoglycemia. Performance analyses included comparing HypoMon system alarm times with allowed time windows associated with each hypoglycemic event.

RESULTS

The primary recognition algorithm in the prototype alarm system performed at a level consistent with expectations based on prior user surveys. The HypoMon system correctly recognized 8 out of the 11 naturally occurring overnight hypoglycemic events and falsely alarmed on 13 out of the remaining 41 normal nights [sensitivity 73% (8/11), specificity 68% (28/41), positive predictive value 38%,negative predictive value 90%].

CONCLUSION

The prototype HypoMon shows potential as an adjunct method for noninvasive overnight monitoring for hypoglycemia events in young people with T1DM.

Continuous glucose monitoring in youth with type 1 diabetes

Continuous glucose monitoring (CGM) is becoming increasingly popular and represents the third era of diabetes management. Currently available CGM devices have been studied in youth with type 1 diabetes and show similar accuracy across all age groups. Tolerability of these devices relates to alarm settings, sensor skin irritation, and durability of the device. Youth will be most successful on a CGM regimen if they have a personal investment in wearing the CGM device and have a stable support system for their diabetes care. Data indicate that glycemic control improves the most in youth who wear CGM devices >or=5 days per week, allowing for the ability to make more insulin dose changes. CGM has proven useful in alerting youth to hypoglycemia and may be a valuable tool with exercise. Further studies are needed to assess the utility of CGM for prevention of severe hypoglycemic events and increasing time spent in euglycemia. Fear of hypoglycemia may be ameliorated with CGM use; however, the potential for increased stress in families with continuous feedback must also be considered. In the future, CGM use in youth may couple with insulin pump technology to create a "closed-loop" system in which the CGM device will direct insulin administration without user input.

Prevalence of structural central nervous system abnormalities in early-onset type 1 diabetes mellitus

OBJECTIVE

To characterize the effects of severe hypoglycemia on the developing brain in children with early-onset type 1 diabetes mellitus (T1DM).

STUDY DESIGN

Children diagnosed with T1DM before age 6 years were studied. Those with prospectively monitored severe hypoglycemia (coma/seizure; n = 32) were compared with age-matched peers (n = 30) with no history of such events using magnetic resonance imaging. Glycemic control (evaluated based on glycated hemoglobin [HbA(lc)] level), episodes of diabetic ketoacidosis (DKA), and clinical variables were monitored continuously since diagnosis in all subjects.

RESULTS

Mean HbA(lc) from diagnosis and the duration of T1DM were similar in those with and without a history of severe hypoglycemia (9.0% +/- 0.9% vs 8.8% +/- 0.9%; 7.2 +/- 2.7 years vs 6.7 +/- 2.3 years). A high prevalence of central nervous system (CNS) structural abnormalities was detected (29%), and mesial temporal sclerosis (MTS) was detected in 16% of the total sample (n = 62). The presence of MTS was not associated with a history of severe hypoglycemia or DKA. Analysis of brain matter volumes suggested relatively less gray matter density in those subjects with a history of severe hypoglycemia.

CONCLUSIONS

Early age of onset of T1DM per se is associated with a high incidence of CNS abnormalities, particularly MTS, suggesting hippocampal damage. Early-onset severe hypoglycemia may have an effect on gray matter volume.

Real-time continuous glucose monitoring in the clinical setting: the good, the bad, and the practical

Real-time continuous glucose monitoring (RT-CGM) is the latest technological breakthrough in diabetes care. Despite its limitations of lag time between sensor and blood glucose, the need for calibration, false detection of and failure to detect hypoglycemia, and mild discomfort or skin irritation reported in some users, RT-CGM is a highly beneficial tool that can be used to detect nocturnal or unrecognized hypoglycemia and glycemic variability. This, in turn, can lead to better treatment decisions, which may improve metabolic control and decrease the incidence and progression of diabetes complications. The RT-CGM devices are fairly accurate and easy to use. It is not difficult to establish a clinical RT-CGM program in the office. However, it requires persistence and an understanding of the patient's perspective of using RT-CGM so it can be presented and taught appropriately. This article discusses the benefits and limitations of RT-CGM and establishment of a RT-CGM program in the clinical setting.

High volume-low intensity exercise camp and glycemic control in diabetic children

AIM

To evaluate the effects of the designed regime encompassing high volume-low intensity physical activity programme on glycemic control in diabetic children, 20 subjects (age 12.81 +/- 2.14) spent 2 weeks in a controlled environment of a summer camp.

METHODS

An exercise physiologist and a kinesiology specialist programme and conducted the three exercise sessions a day. Total daily caloric intake was controlled and the blood glucose was monitored four times a day with special concern for hypoglycaemia episodes. Short and long-term effects (HbA1c) of the summer camp were evaluated 10 days and 2 months following programme completion. The insulin dosage was not lowered at the beginning of the camp for everyone, but it was individually modified according to the blood glucose monitoring.

RESULTS

Initial HbA1c was 8.28 +/- 1.3% and decreased to 7.92 +/- 1.42% measured 10 days after the camp (P = 0.023) while the number of children with the satisfactory HbA1c level lower than 7.5% doubled. HbA1c increased again 2 months following the camp. The average blood glucose concentrations decreased in the last days of the camp when compared with the first day in three out of four daily measurements (P < 0.05). There were only two clinically manifested hypoglycaemia episodes recorded.

CONCLUSION

With a low rate of hypoglycaemia crisis and better glycemic control the proposed programme was found to be satisfactory but the downside was that the duration of the effects was too short. With no participation in organised exercise programmes and with absence of controlled nutrition, the beneficial effects of the camp disappeared within 2 months after the camp.

Hypoglycemia in type 1 diabetes: a still unresolved problem in the era of insulin analogs and pump therapy

The Diabetes Control and Complications Trial demonstrated that in patients with type 1 diabetes, tight metabolic control achieved with intensive insulin therapy can reduce the risk of long-term microvascular complications. However, strict glycemic control carries an increased risk of severe hypoglycemia. Recurrent episodes of hypoglycemia, especially at young ages, can lead to hypoglycemia unawareness, exert adverse effects on neurocognitive function, and cause significant emotional morbidity in the child and parents. Although the introduction of the new insulin analogs in diabetes therapy and the use of continuous subcutaneous insulin infusion raised hopes for a solution to this problem, these modalities have not been associated with the expected reduction in hypoglycemic episodes. The findings suggest that the prevention of hypoglycemia in patients with type 1 diabetes lies in biologically controlled insulin secretion, as in islet transplantation, or the development of an autonomous closed-loop system that efficiently mimics the action of the pancreatic beta-cells and maintains blood glucose levels within the desired range.

The Medtronic Minimed Gold continuous glucose monitoring system: an effective means to discover hypo- and hyperglycemia in children under 7 years of age

BACKGROUND

The glycemic patterns of children less than 7 years with type 1 diabetes have not been well studied using continuous glucose monitoring. Our goal was to assess the incidence of hypoglycemia as well as postprandial glycemic patterns in this age group utilizing continuous glucose monitoring.

METHODS

Nineteen children used the Medtronic MiniMed (Northridge, CA) CGMS System Gold on three to seven occasions over approximately 6 months.

RESULTS

Nineteen children (nine girls and 10 boys; mean age 4.8 +/- 1.4 years, range 1.6-6.8 years) used the CGMS 102 times, providing 434 days of data; 79% of days were optimal based on CGMS Solutions software version 3.0. Mild hypoglycemia (glucose <or=70 mg/dL) was noted during 28% of 323 nights. When compared to paired meter blood glucose values, the false-positive rate was 16% for mild and 55% for severe sensor hypoglycemia. The mean peak glucose during the 3 h following breakfast (247 +/- 64 mg/dL) was higher than following lunch (199 +/- 67 mg/dL) or dinner (194 +/- 63 mg/dL). The rate of glucose rise to peak was >or=2 mg/dL/min following 50% of breakfasts. Children with hemoglobin A1c levels >or=8% had higher postprandial glucose concentrations. There was no significant advantage of continuous subcutaneous insulin infusion therapy over multiple daily injection therapy in decreasing postprandial hyperglycemia.

CONCLUSIONS

CGMS tracings from young children with diabetes demonstrate frequent mild nocturnal hypoglycemia and significant postprandial hyperglycemia, with a rapid rise in glucose following the meal. The most rapid rate of rise and the most severe postprandial hyperglycemia occurred after breakfast.

What is the frequency of symptomatic mild hypoglycemia in type 1 diabetes in the young?: assessment by novel mobile phone technology and computer-based interviewing

BACKGROUND

The prevalence of mild hypoglycemia is difficult to document, particularly, in young people with diabetes. The usual method is to ask for subject recall using written 'diaries'.

OBJECTIVE

In 2004, we investigated if new technology could be used to ascertain an accurate prevalence of mild hypoglycemia, particularly self-treated. We compared the use of 'text messaging' and computer-based interviewing with the standard diary method.

PARTICIPANTS

Thirty-seven participants, aged 7-18 yr, with type 1 diabetes (T1D) for >1-yr duration.

METHOD

Open comparison of three systems to collect the data on frequency of hypos (all severity): diary, mobile phone and computer-based interview (CBI), with qualitative analysis of patient feedback.

RESULTS

One hundred thirty-two hypos were found over 705 recorded days. All were graded mild or moderate and none severe. Calculated frequency was 5.2 hypos per month: 13.6% subjects had no recorded episode, 36.4% had 1-4, 31.8% 5-9 and 18.2% >10. Mean blood glucose level at the onset of hypoglycemia was 3.0 mmol/L (1.0-5.2). Response rate of occurrence of hypoglycemic episode recorded by three systems is as follows - diary: 24 (65%) of the 37 subjects reported episodes, mobile: 18 (95%) of 19 subjects and CBI: 16 (89%) of 18 subjects. Sixty-five percent of subjects preferred the mobile and 54% of subjects preferred CBI compared with the diary. Fifty-five percent and 30.8% of subjects found the mobile and the CBI, respectively, easiest to fit into their everyday life.

CONCLUSIONS

Mobile phone text messaging and CBI are alternatives to written diaries as methods of data collection. Each has its own strengths and weaknesses, but both have the advantage of daily reminders, rapid response and quick data analysis. Using this technology, it was found that the frequency of hypoglycemia was higher (>3 times) than that previously recognized.

Unrecognised hypoglycaemia in children and adolescents with type 1 diabetes using the continuous glucose monitoring system: prevalence and contributors

AIM

To determine prevalence of hypoglycaemia, and contributing factors, in children with type 1 diabetes, using the Medtronic MiniMed continuous glucose monitoring system (CGMS).

METHODS

Fifty-one children and adolescents with diabetes were studied with the CGMS. The studies were analysed for frequency and duration of hypoglycaemia (below 3.5 and 2.5 mmol/L). Contributing clinical factors were determined. Occurrence of nocturnal hypoglycaemia was related to bedtime and fasting home glucose recording.

RESULTS

Hypoglycaemia was common, with 1 (0-4.2) (median (range)) episode per patient per 24 hours, and 0.33 (0-2) episodes per patient per night. Nocturnal episodes were longer than daytime episodes [97.5 (5-720) versus 35 (5-295) minutes for episodes below 3.5 mmol/L, P < 0.001; and 75 (10-640) versus 25 (5-200) minutes for episodes below 2.5 mmol/L, P < 0.001], and less likely to be recognised by the subject (P < 0.001 for episodes below both 3.5 and 2.5 mmol/L). Nocturnal hypoglycaemia was more common with a bedtime glucose recording <6 mmol/L, but also occurred frequently in subjects with glucose recordings >10 mmol/L. No bedtime glucose value reduced the risk of nocturnal hypoglycaemia to <10%.

CONCLUSION

Hypoglycaemia, assessed using the CGMS, is common in children with type 1 diabetes and can be prolonged (although is predominantly mild). Bedtime home glucose recordings are poorly predictive of hypoglycaemia during the following night. Continuous glucose monitoring has proven very useful in management of individual patients, particularly adolescents experiencing difficulties with adherence to diabetes management.

Contemporary Australian outcomes in childhood and adolescent type 1 diabetes: 10 years post the Diabetes Control and Complications Trial

The reporting of the results of the Diabetes Control and Complications Trial in 1993 has led to a major reappraisal of management practices and outcomes in type 1 diabetes in children and adolescents. A considerable body of outcome data has been generated from Australia in this post-Diabetes Control and Complications Trial era relating to incidence, metabolic control, growth, hypoglycaemia, microvascular and macrovascular complications, cognition, behaviour and quality of life. These data are important in planning future management strategies and resource allocation and as a basis for future research.

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.

Use of insulin glargine in children under age 6 with type 1 diabetes

AIM

Children under 6 yr have the highest incidence of severe hypoglycemia (SH) and the greatest likelihood of brain damage from SH. The purpose of this study is to evaluate the use of insulin glargine (Lantus in children under age 6 with type 1 diabetes (T1D).

METHODS

The electronic medical records were reviewed for patients under age 6 during the first 6 months of insulin glargine therapy and compared with age, sex, and duration of diabetes for matched control patients on neutral protamine Hagedorn (NPH) insulin. Data from 128 subjects (32 male pairs and 32 female pairs) were collected relating to the incidence of severe and non-severe hypoglycemic events, hemoglobin A1c (HbA1c) values, body mass index (BMI), and daily insulin dose. Additionally, parents were asked to complete a diabetes Quality of Life (QoL) survey.

RESULTS

In the 6 months before the study period, the glargine group had 16 SH events compared with three in the 6 months post-glargine. The comparison (NPH) group had seven and six SH events in their respective 6-month periods. Nighttime SH events in the glargine group decreased from 12 prestudy events to one during the study period. The average daily insulin dose in the glargine group was higher than that in the NPH group (0.8+/- 0.2 vs. 0.7+/- 0.2 U/kg/day; p=0.03). The HbA1c values, BMI, and QoL responses were not significantly different between the two groups.

CONCLUSIONS

SH was decreased, particularly at night (from 12 episodes to one), after the introduction of glargine in young children with T1D.

Hypoglycemia, hypoglycemia unawareness and counterregulation in children and adolescents with type 1 diabetes mellitus

Three clinical phenomena have been defined in the last decade in patients with diabetes mellitus as a dangerous iatrogenic sequel of hypoglycemia. These are hypoglycemia unawareness, defective glucose counterregulation and a lowered hypoglycemic threshold for hypoglycemic symptoms. Former mild hypoglycemia episodes cause a decrease and a delay in the protective hormonal counterregulatory response and warning symptoms in subsequent episodes, and in the absence of these, risk of severe hypoglycemia increases considerably. It has been demonstrated that when protection is provided against hypoglycemia with strict monitoring programs designed to avoid even mild hypoglycemia episodes, blunted autonomic symptoms and counterregulatory hormonal responses are rectified. Therefore, the best course of action in the treatment of pediatric diabetes mellitus is frequent blood sugar measurements, flexible multiple dose insulin regimens facilitating insulin dose adjustments as required, and a diet. In order to implement this, it is essential to organize an intensive training program with the patient and family, and to provide psychological support and close coordination with the diabetes treatment team.

A randomized multicenter trial comparing the GlucoWatch Biographer with standard glucose monitoring in children with type 1 diabetes

OBJECTIVE

This study assesses whether use of the GlucoWatch G2 Biographer (GW2B) in addition to standard glucose monitoring lowers HbA(1c) and reduces hypoglycemia compared with standard glucose monitoring alone.

RESEARCH DESIGN AND METHODS

In all, 200 subjects aged 7 to <18 years with type 1 diabetes were randomly assigned at five centers to standard glucose monitoring (usual care) or standard glucose monitoring plus GW2B use for 6 months. Study outcomes included HbA(1c) values obtained at 6 months and occurrence of severe hypoglycemia.

RESULTS

The mean HbA(1c) at baseline was 8.0% in both groups; at 6 months, HbA(1c) was 7.9% in the usual care group and 8.1% in the GW2B group (95% CI for mean reduction in the GW2B group compared with the usual care group -0.4 to 0.1%; P = 0.15). A decrease in HbA(1c) of > or =0.5% was achieved in 21% of the usual care group and 28% of the GW2B group (P = 0.29). Severe hypoglycemia events occurred in 7% of the GW2B group and in 2% of the usual care group (P = 0.10). In the GW2B group, sensor use declined throughout the study from a mean value of 2.1 times/week in the 1st month to 1.5 times/week in the 6th month. Reasons given for declining use included skin irritation (76%), frequent skips (56%), excessive alarms (47%), and inaccurate readings (33%).

CONCLUSIONS

Use of the GW2B in addition to standard glucose monitoring did not improve glycemic control or reduce the frequency of severe hypoglycemia. Skin reactions and other problems led to decreasing sensor use over time.

Past 10-year status of insulin therapy for preschool-age Japanese children with type 1 diabetes

The aim of this study was to evaluate the past 10-year status of insulin therapy for preschool-age children with type 1 diabetes in Japan. One-hundred and forty-two patients who had been diagnosed at less than 5 years of age within the past 10 years (1993-2002) at 36 hospitals were registered in this study on April 2003. The methods of daily insulin therapy and episodes of severe hypoglycemia during the preschool period were investigated. Eighty-six (60.6%) children were treated with a pen-type device and 56 (39.4%) were treated with a syringe-type device. The once-a-day insulin regimen was used for 2, a twice-a-day regimen for 104, a three-times-a-day for 28 and a four-times-a-day for 8. Episodes of severe hypoglycemia were recorded in nearly half of the subjects, and one-fourth of the subjects had repeated episodes. One hundred and eleven of their parents were questioned regarding the degree of psychosocial stress experienced during the care of their children. Most parents worried about the glycosylated hemoglobin value at each hospital visit. They were next very afraid of nocturnal severe hypoglycemia, independent of any actual experience. These results suggest that although insulin therapy can involve various methods, the important point is to simultaneously provide good glycemic control and prevent severe hypoglycemia, especially during this age.

Severe hypoglycaemia, metabolic control and diabetes management in children with type 1 diabetes in the decade after the Diabetes Control and Complications Trial -- a large-scale multicentre study

Hypoglycaemia is frequently the limiting factor in achieving optimal glycaemic control. Therefore, insulin therapy, the incidence of hypoglycaemia, and glycaemic control were investigated in 6309 unselected children with type 1 diabetes in a large-scale multicentre study. Using standardised computer-based documentation, the incidence of severe hypoglycaemia, HbA1( c) levels, insulin regimen, diabetes duration, and the number of patients attending a treatment centre were investigated for the age groups 0-<5 years ( n =782), 5-<7 years ( n =1053), and 7-<9 years ( n =4474). The average HbA1( c) level was 7.6% (no significant difference between age groups). Young children had more severe hypoglycaemic events (31.2/100 patient years) as compared to older children (19.7; 21.7/100 patient years, P <0.05) independent of the treatment regimen. Our data suggest that diabetes centres treating less than 50 patients per year have a higher incidence of hypoglycaemia in 0-<5-year-old children (43.0/100 patient years) as compared to larger centres (24.1/100 patient years; P <0.0001). Significant predictors of hypoglycaemia were younger age ( P <0.0001), longer diabetes duration ( P <0.0001), higher insulin dose/kg per day ( P <0.0001), injection regimen ( P <0.0005), and centre experience ( P <0.05).

CONCLUSION

Despite modern treatment, young children have an elevated risk for developing severe hypoglycaemia compared to older children, especially when treated at smaller diabetes centres. The therapeutic goal of carefully regulating metabolic control without developing hypoglycaemia has still not been achieved. Further advances in diabetic treatment may result from giving more attention to hypoglycaemia in young children.

Continuous glucose monitoring and the reality of metabolic control in preschool children with type 1 diabetes

OBJECTIVE

To determine using the MiniMed continuous glucose monitoring system (CGMS) 1) whether twice-daily insulin injection therapy achieves adequate control in preschool children with type 1 diabetes and 2) whether the CGMS is more informative than self-monitoring of blood glucose (SMBG) regarding glucose control and well tolerated by preschool children and their families.

RESEARCH DESIGN AND METHODS

Ten children <6 years of age with type 1 diabetes were monitored twice using the CGMS. The distribution of glucose values was analyzed, particularly the frequency, duration, and distribution of hypoglycemia. We analyzed the accuracy of the CGMS in detecting hypoglycemia as well as the clinical relevance of the difference between CGMS and SMBG values.

RESULTS

Although hypoglycemia was more frequent during the night (0.8 nighttime episodes . subject(-1) . 24 h(-1) vs. 0.3 daytime episodes . subject(-1) . 24 h(-1)), the difference did not reach statistical significance (P=0.07). However, nighttime episodes lasted longer than daytime episodes (1.2 vs. 0.2 h . subject(-1) . 24 h(-1), P=0.006). Hypoglycemia accounted for 7% and normoglycemia for 24%, while hyperglycemia occurred 64% of the time, with postprandial hyperglycemia being an almost universal feature (94 +/- 7% of all postmeal values). The CGMS correlated well with SMBG without significant clinical discrepancy. The CGMS sensitivity to detect hypoglycemia was 70% with a specificity of 99%; however, the CGMS detected twice as many total episodes as SMBG (82 vs. 40).

CONCLUSIONS

Twice-daily insulin injection rarely achieves control in preschool children with type 1 diabetes. The CGMS is well tolerated by patients and has the advantage of revealing daily glucose trends missed by SMBG.

Special management of insulin lispro in continuous subcutaneous insulin infusion in young diabetic children: a randomized cross-over study

OBJECTIVE

To compare the safety, efficacy and management of insulin lispro (LP) with regular human insulin (RH) in young diabetic children treated with continuous subcutaneous insulin infusion (CSII).

STUDY DESIGN

27 very young diabetic children (age 4.6 +/- 2.2 years) treated with CSII participated in an open-label, randomized cross-over multicenter study comparing 2 periods of 16 weeks of CSII with LP or RH.

RESULTS

Mean daily basal rate was significantly higher during the LP period (p = 0.04). No differences were seen in changes in HbA1c levels, number of hypoglycemic events, cutaneous infections and catheter occlusions. There was no significant difference between the two treatments for preprandial and postprandial glucose values, although prandial glucose excursions tended to be lower with LP (significant at dinner, p = 0.01). Mean blood glucose levels were significantly higher at 0.00 and 3.00 a.m. during LP therapy (p < 0.05). No episode of ketoacidosis occurred during LP treatment. More parents indicated that LP made their own and the child's daily life easier (p = 0.02) and preferred LP (p = 0.01).

CONCLUSIONS

LP in CSII therapy in children is safe, as effective as RH, improved postprandial excursions, met the needs of young children in their daily life well, and gained their parents' satisfaction and preference. However, a shorter duration of LP resulted in hyperglycemia during the first part of the night, which must be compensated for by increasing nocturnal basal rates during this time.

Continuous glucose monitoring in children with type 1 diabetes: before and after insulin pump therapy

OBJECTIVE

The aim of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes mellitus (T1DM) is to mimic as closely as possible the normal physiologic pattern seen in individuals without diabetes. This study was undertaken to determine the specific areas of improved glycemic control in subjects after initiation of insulin pump therapy and times where further improvement is needed.

RESEARCH DESIGN AND METHODS

Eight patients with T1DM (age 7.5-17 yr) wore the Continuous Glucose Monitoring System (CGMS) (Medtronic MiniMed, Northridge, CA, USA) for 3 d before and 3 months after initiation of insulin pump therapy. The CGMS, which measures inter- stitial glucose concentrations every 5 min for a 72-h period, was used to evaluate glucose profiles. Patients entered 4-5 fingerstick blood glucose measurements daily into the sensor for calibration. Detailed logs of food intake, exercise, and hypoglycemic symptoms were also recorded.

RESULTS

Hemoglobin A1c (HbA1C) was reduced (p < 0.007) following 3 months of insulin pump therapy. Post-CSII continuous glucose profiles demonstrated an overall improvement in hourly mean glucose over a 24-h period (p < 0.001) as well as a reduction in the area under the curve for glucose (27 +/- 4 prepump vs. 8.6 +/- 1.4 mg/dL/d postpump, p < 0.004). This improvement was a result of an attenuation of the maximal postprandial glycemic excursions. Postbreakfast 349 +/- 24 vs. 267 +/- 16 mg/dL, p < 0.003; lunch 340 +/- 16 vs. 217 +/- 20 mg/dL, p < 0.003. Postdinner average similarly decreased after 3 months of CSII by 22%, p < 0.04.

CONCLUSIONS

Pump therapy specifically improved the postprandial glucose excursions in children.

Hypoglycemia in children with type 1 diabetes: current issues and controversies

Hypoglycemia is a common complication of insulin therapy, particularly in the young. For children and adolescents with diabetes, the risk of hypoglycemia may not only prevent optimal glycemic control but can also add significantly to the psychosocial burden of the disease. Recently, surveys employing prospective monitoring techniques have allowed more precise information to be gained about rates of hypoglycemia, its clinical associations, and the impact of new therapies and technologies. A number of reports have estimated rates of hypoglycemic comas and convulsions to be approximately 20 events per 100 patient years in children on current conventional therapy. There is evidence that the introduction of new analog short- and longer-acting insulins and the more widespread use of continuous subcutaneous infusion therapies may allow improvements in glycemic control to occur without the usual increased rate of severe hypoglycemic episodes. The use of glucose sensor technology has brought into focus the widespread occurrence of asymptomatic hypoglycemia. Asymptomatic hypoglycemia has long been recognized, particularly at night, when the combination of excessive insulin action and suppressed counter-regulatory hormone responses put children at special risk of hypoglycemia. Hypoglycemia unawareness is common in the young and is associated with an increased risk of severe hypoglycemia. Whether episodes of severe hypoglycemia have long-term consequences is controversial. Early studies suggesting that the developing brain is sensitive to permanent neurological damage as a result of hypoglycemia have not been confirmed in more recent reports. Many studies have not found convincing evidence of neurological sequelae of the hypoglycemic events that are an inevitable complication of insulin therapy. The question, however, remains under active investigation. Continued prospective monitoring of hypoglycemia rates and consequences has become an essential component of diabetes management.