Insulin doses before and one year after pump start: children have a reversed dawn phenomenon

During an 18-month course of automated insulin delivery treatment, children aged 2 to 6 years achieve and maintain a higher time in tight range

AIMS

To investigate whether the positive effects on glycaemic outcomes of 3-month automated insulin delivery (AID) achieved in 2- to 6-year-old children endure over an extended duration and how AID treatment affects time in tight range (TITR), defined as 3.9-7.8 mmol/L.

RESEARCH DESIGN AND METHODS

We analysed 18 months of follow-up data from a non-randomized, prospective, single-arm clinical trial (n = 35) conducted between 2021 and 2023. The main outcome measures were changes in time in range (TIR), glycated haemoglobin (HbA1c), time above range (TAR), TITR, and mean sensor glucose (SG) value during follow-up visits (at 0, 6, 12 and 18 months). The MiniMed 780G AID system in SmartGuard Mode was used for 18 months. Parental diabetes distress was evaluated at 3 and 18 months with the validated Problem Areas in Diabetes-Parent, revised (PAID-PR) survey.

RESULTS

Between 0 and 6 months, TIR and TITR increased, and HbA1c, mean SG value and TAR decreased significantly (p < 0.001); the favourable effect persisted through 18 months of follow-up. Between 3 and 18 months, PAID-PR score declined significantly (0 months: mean score 37.5; 3 months: mean score 28.6 [p = 0.06]; 18 months: mean score 24.6 [p < 0.001]).

CONCLUSIONS

Treatment with AID significantly increased TITR and TIR in young children. The positive effect of AID on glycaemic control observed after 6 months persisted throughout the 18 months of follow-up. Similarly, parental diabetes distress remained reduced during 18 months follow-up. These findings are reassuring and suggest that AID treatment improves glycaemic control and reduces parental diabetes distress in young children over an extended 18-month follow-up.

Insulin Requirements for Basal and Auto-Correction Insulin Delivery in Advanced Hybrid Closed-Loop System: 4193 Days' Real-World Data of Children in Two Different Age Groups

BACKGROUND

The insulin requirements of people with type 1 diabetes (T1D) can vary throughout the day due to factors such as biorhythm, exercise, and food intake. The MiniMed 780G system delivers micro boluses to adjust basal insulin and delivers auto-correction boluses to meet insulin needs when micro bolus increases are insufficient. Through analysis of MiniMed 780G data, this study investigates the variations in insulin requirements throughout the day.

METHODS

4193 days' pump and continuous glucose monitoring (CGM) data of 34 children using MiniMed 780G were collected from Medtronic CareLink. Micro and auto-correction boluses were analyzed on an hourly basis for two age groups: below nine years old and above nine years old. Glycemic metrics were analyzed based on International CGM consensus.

RESULTS

The mean age was 12.3 years and mean duration of diabetes was 6.1 years. The mean time in range (TIR) and glucose management indicator (GMI) were 80.5% and 6.6%, respectively. The micro bolus (basal) ratio between 05.00 and 07.00 was significantly higher than the ratio between 10.00 and 03.00 (P < .01), whereas micro bolus was significantly lower between 19.00 and 21.00 than those between 00.00 and 10.00 (P < .001). The auto-correction ratio between 21.00 and 00.00 was significantly higher than those between 03.00-17.00 (P < .001) and 19.00-21.00 (P = .008), whereas auto-correction was significantly lower between 07.00 and 10.00 than those between 10.00 and 03.00 (P < .001). The micro bolus ratio was significantly higher in children below nine years old than in children above nine years old between 21.00-00.00 (P = .026) and 00.00-03.00 (P = .003).

CONCLUSION

The basal insulin need follows a diurnal pattern with two significantly different periods-high between 00.00 and 10.00 and low between 10.00 and 00.00. The auto-correction rates are low between 05.00 and 10.00 and show an increasing pattern peaking between 21.00 and 00.00. These findings are compatible with the dawn and reverse dawn phenomena.

MiniMed 780G™ in 2- to 6-Year-Old Children: Safety and Clinical Outcomes After the First 12 Weeks

Objective: The safety and impact of the advanced hybrid closed-loop (AHCL) system on glycemic outcome in 2- to 6-year-old children with type 1 diabetes and the diabetes distress of caregivers were evaluated. Research Design and Methods: This was an open-label prospective study (n = 35) with historical controls matched by treatment unit, diabetes duration, age, gender, and baseline treatment modality. The inclusion criteria were (1) type 1 diabetes diagnosis >6 months, (2) total daily dose of insulin ≥8 U/day, (3) HbA1c <10% (85 mmol/mol), and (4) capability to use insulin pump and continuous glucose monitoring. The MiniMed 780G™ AHCL in SmartGuard™ Mode was used for 12 weeks. Parental diabetes distress was evaluated with a validated Problem Areas In Diabetes-Parent, revised (PAID-PR) survey. Results: No events of diabetic ketoacidosis or severe hypoglycemia occurred. Between 0 and 12 weeks, HbA1c (mean change = -2.7 mmol/mol [standard deviation 5.7], P = 0.010), mean sensor glucose value (SG) (-0.8 mmol/L [1.0], P < 0.001), and time above range (TAR) (-8.6% [9.5], P < 0.001) decreased and time in range (TIR) (8.3% [9.3], P < 0.001) increased significantly, whereas no significant change in time below range (TBR) was observed. At the same time, PAID-PR score decreased from 37.5 (18.2) to 27.5 (14.8) (P = 0.006). Conclusions: MiniMed 780G™ AHCL is a safe system and 12-week use was associated with improvements in glycemic control in 2- to 6-year-old children with type 1 diabetes. In addition, AHCL is associated with a reduction in parental diabetes distress after 12-week use. ClinicalTrials.gov registration number: NCT04949022.

Insulin pumps in children - a systematic review

BACKGROUND

Insulin pump therapy is a real breakthrough in managing diabetes Mellitus, particularly in children. It can deliver a tiny amount of insulin and decreases the need for frequent needle injections. It also helps to maintain adequate and optimal glycemic control to reduce the risk of metabolic derangements in different tissues. Children are suitable candidates for pump therapy as they need a more freestyle and proper metabolic control to ensure adequate growth and development. Therefore, children and their caregivers should have proper education and training and understand the proper use of insulin pumps to achieve successful pump therapy. The pump therapy continuously improves to enhance its performance and increase its simulation of the human pancreas. Nonetheless, there is yet a long way to reach the desired goal.

AIM

To review discusses the history of pump development, its indications, types, proper use, special conditions that may enface the children and their families while using the pump, its general care, and its advantages and disadvantages.

METHODS

We conducted comprehensive literature searches of electronic databases until June 30, 2022, related to pump therapy in children and published in the English language.

RESULTS

We included 118 articles concerned with insulin pumps, 61 were reviews, systemic reviews, and meta-analyses, 47 were primary research studies with strong design, and ten were guidelines.

CONCLUSION

The insulin pump provides fewer needles and can provide very tiny insulin doses, a convenient and more flexible way to modify the needed insulin physiologically, like the human pancreas, and can offer adequate and optimal glycemic control to reduce the risk of metabolic derangements in different tissues.

Initial Basal and Bolus Rates and Basal Rate Variability During Pump Treatment in Children and Adolescents

OBJECTIVE

Pump-treated children with type 1 diabetes (T1DM) have widely differing basal insulin (BI) infusion profiles for specific periods of the day. The pattern of BI requirements depends on the timing and magnitude of cortisol and growth hormone secretion within each age group. In adolescents and young adults, a decreased insulin sensitivity is seen, particularly in the early morning (dawn phenomenon) and to a lesser extent, in the late afternoon (dusk phenomenon). Different approaches exist for the inititation of basal rates. However, there is a lack of evidence-based recommendation, especially in young children. Usually the basal rates are set equally throughout day and night or the day is divided into tertiles. The aim of this study was to analyze the change of the initial, equally distributed, BI rates over the first year of standard insulin pump therapy.

METHODS

A total of 154 patients with T1DM, aged between 0 and <21 years at diagnosis, from a single center were documented. Patients were divided into five age groups according to age at pump initiation: group 1, <5 years (n=36); group 2, 5-8 years (n=20); group 3, 8-15 years (n=74); group 4, 15-18 years, (n=19); and group 5, >18 years, (n=5). Distribution of hourly basal rates at the initiation of the pump and at the end of first year were evaluated.

RESULTS

Median (range) age and diabetes duration was 14.46 (1.91-26.15) and 7.89 (1.16-17.15) years, respectively. Forty-four percent were male, 56% were female. Mean total insulin dose/kg in the whole cohort at the initiation and after one year of pump therapy was 0.86±0.23 U/kg and 0.78±0.19 U/kg, respectively and differed significantly between each age group (p<0.001; p<0.001). Mean daily basal rate/kg showed significant differences between the five groups (p<0.001). Circadian distribution of BI differed markedly among the five age groups.

CONCLUSION

At the initiation of insulin pump therapy, circadian profiles by age group should be taken into account in pediatric patients to optimize basal rate faster and more easily.

In Silico Trials of an Open-Source Android-Based Artificial Pancreas: A New Paradigm to Test Safety and Efficacy of Do-It-Yourself Systems

Objective: Safety data on Do-It-Yourself Artificial Pancreas Systems are missing. The most widespread in Europe is the AndroidAPS implementation of the OpenAPS algorithm. We used the UVA/Padova Type 1 Diabetes Simulator to in silico test safety and efficacy of this algorithm in different scenarios. Methods: We tested five configurations of the AndroidAPS algorithm differing in aggressiveness and patient's interaction with the system. All configurations were tested with insulin sensitivity variation of ±30%. The most promising configurations were tested in real-life scenarios: over- and underestimated bolus by 50%, bolus delivered 15 min before meal, and late bolus delivered 15 min after meal. Continuous Glucose Monitoring (CGM) time in ranges (TIRs) metrics were used to assess the glycemic control. Results: In silico testing showed that open-source closed-loop system AndroidAPS works effectively and safely. The best results were reached if AndroidAPS algorithm worked with microboluses and when half of calculated bolus was issued (mean glycemia 131 mg/dL, SD 27 mg/dL, TIR 91%, time between 54 and 70 mg/dL <1%, and low blood glucose index even <1). The meal bolus over- and underestimation as well as late bolus did not affect the TIR and, importantly, the time between 54 and 70 mg/dL. Conclusion: In silico testing proved that AndroidAPS implementation of the OpenAPS algorithm is safe and effective, and it showed a great potential to be tested in prospective home setting study.

Prospective evaluation of insulin-to-carbohydrate ratio in children and adolescents with type 1 diabetes using multiple daily injection therapy

AIM

Assessment of insulin-to-carbohydrate ratio (ICR) in children and adolescents with type 1 diabetes mellitus (T1DM) using multiple daily injection (MDI) therapy.

METHODS

This prospective observational study was conducted over a 2-year period at Sohag University Hospital, Egypt. Children and adolescents aged 4 to 17 years, diagnosed with T1DM for at least 1 year, with fasting serum C-peptide levels <0.24 ng/dL and whose parents accepted to shift their management to flexible MDI using carbohydrate counting, were included. Participants were initially hospitalized for estimation of ICR and insulin doses, then followed-up monthly for further adjustments. Insulin doses, ICR, and glycemic control parameters were assessed after 3 months.

RESULTS

The study included 201 participants, 110 (54.7%) of them were males. The median age was 9.5 years (interquartile range: 7-12.5 years). Bolus insulin requirements estimated by the 500 rule were significantly lower than the actual doses used by the study participants for all meals (P < .001). Bolus insulin requirement for morning meal was significantly higher compared to other meals (P < .001). Linear regression analyses between ICR for different meals and the reciprocal of total daily dose (TDD) in 96 participants with optimum glycemic control revealed that ICR could be calculated as 301 to 309/TDD for morning meal (R² = 0.97, P < .001), 317 to 331/TDD for afternoon meal (R² = 0.96, P < .001), and 362 to 376/TDD for evening meal (R² = 0.98, P < .001).

CONCLUSIONS

Bolus insulin requirements showed diurnal variation. Using 301 to 309/TDD, 317 to 331/TDD, and 362 to 376/TDD formulas would be more appropriate than the 500 rule for initial estimation of ICR for morning, afternoon, and evening meals, respectively.

A Retrospective Review of the Clinical Characteristics and Blood Glucose Data from Cellnovo System Users using Data Collected from the Cellnovo Online Platform

Technological advances have led to innovative insulin delivery systems for patients with type 1 diabetes mellitus. In particular, the combination of miniature engineering and software algorithms contained in continuous subcutaneous insulin infusion (CSII) system pumps provide the user and the healthcare practitioner with an opportunity to review and adjust blood glucose (BG) levels according to system feedback, and to modify or programme their regimen according to their needs. While CSII pumps record a number of data parameters such as BG level, carbohydrate intake, activity and insulin delivered, these data are generally ‘locked in’ and can only be accessed by uploading to a cloud-based system, thus information is not contemporaneous. The Cellnovo Diabetes Management System (Cellnovo, Bridgend, UK) allows data to be transmitted securely and wirelessly in real time to a secure server, which is then retrieved by an online platform, the Cellnovo Online platform, enabling continuous access by the user and by clinicians. In this article, the authors describe a retrospective review of the patient data automatically uploaded to the Cellnovo Online platform. Baseline clinical and demographic characteristics collected at the start of pump therapy are shown for all patients, and BG data from a sub-cohort of patients who have been using the system for at least 6 months and who take and record an average of three BG level tests per day are presented to demonstrate glycaemic data over time.

20 Years of insulin lispro in pediatric type 1 diabetes: a review of available evidence

BACKGROUND

Insulin lispro, the first rapid-acting insulin analog, was developed 20 years ago and has been studied in multiple situations and various populations.

OBJECTIVE

To review the literature on the use of insulin lispro in children, adolescents, and young adults.

PATIENTS

Children, adolescents, and young adults with type-1-diabetes.

METHODS

One hundred and twenty-two relevant publications, identified by a systematic (MEDLINE) and manual literature search, were reviewed.

RESULTS

Multiple daily injection (MDI) treatment with insulin lispro or other rapid-acting insulins, mainly using neutral protamine Hagedorn (NPH) insulin as the basal component, was associated with reduced postprandial glucose excursions, similar or improved HbA1c levels, and similar or reduced risks of severe hypoglycemia when compared with regular human insulin across all age-groups. Continuous subcutaneous insulin infusion (CSII)-treatment with insulin lispro also showed similar or improved glycemic control vs. MDI- or other CSII-regimens across all age-groups, without increasing the rate of severe hypoglycemia. The other two more recently developed rapid-acting insulins (aspart, glulisine) demonstrated non-inferiority to lispro on HbA1c. Long-term observational studies and real-life experience indicate that the increasing use of optimized MDI- and CSII-regimens with insulin lispro was associated with improvements in overall glycemic control.

CONCLUSIONS

For almost 20 years, rapid-acting insulins, in particular insulin lispro as the first-in-class, have contributed to broadening the treatment options for the unique needs of pediatric patients with type-1-diabetes across all age-groups, and have enabled more physiological insulin administration. Now widely used, they have allowed pediatric patients to safely reach better glycemic control, with more flexibility in their daily lives.

Bolus Calculator Settings in Well-Controlled Prepubertal Children Using Insulin Pumps Are Characterized by Low Insulin to Carbohydrate Ratios and Short Duration of Insulin Action Time

BACKGROUND

The "500 rule" has been used extensively to find the insulin to carbohydrate ratio (ICR) for carbohydrate counting (CC). Duration of insulin action (DIA) is often recommended to be set to 4 hours. Data are lacking on validating these routines in young children.

METHODS

ICR was calculated by dividing carbohydrate grams by insulin units. Insulin sensitivity factor (ISF) was defined by the 100 rule (100 divided by total daily insulin dose [TDD]). DIA was set to 3 hours. ICR, ISF, and DIA were adjusted continuously. Data for this retrospective analysis were taken from pump downloads at a routine visit. ICR and ISF were recalculated to rules (ICR/ISF multiplied by TDD).

RESULTS

A total of 21 prepubertal children aged 7.0 ± 2.3 (mean ± SD), range 2-10 years, with diabetes duration 3.0 ± 1.9, range 0.5-7.7 years, used the pump bolus calculator for CC. HbA1c IFCC (NGSP) was 53 ± 6 mmol/mol (7.0 ± 0.5%). None had experienced severe hypoglycemia (unconsciousness/seizures) since diabetes diagnosis. TDD was 0.7 ± 0.1 U/kg/24 h (range 0.5-1.0), and the percentage basal insulin 38 ± 11%. Median breakfast rule was 211 (Q, quartiles 162;310), and for other meals 434 (Q 301;496). Median ISF rule was 113 (Q 100;128) in the morning, and 120 (Q 104;134) during the rest of the day. DIA was 2.6 ± 0.5 h (range 2-3) and target BG 5.3 ± 0.4 mmol/l (range 5.0-6.0).

CONCLUSIONS

Prepubertal children seem to need more bolus insulin for meals than calculated from the 500 rule, especially at breakfast, but less insulin for corrections than calculated from the 100 rule. Two to 3 hours seems to be the appropriate range for DIA in this age group.

Continuous Subcutaneous Insulin Infusion in Children: A Pilot Study Validating a Protocol to Avoid Hypoglycemia at Initiation

BACKGROUND

The occurrence of hypoglycemia and hyperglycemia during the first days after transition to continuous subcutaneous insulin infusion (CSII) in patients with type 1 diabetes has not been systematically studied in children. The aim of this prospective study was to demonstrate that the protocol applied in our diabetes clinic is safe at CSII initiation in children.

METHODS

We assessed 22 pediatric patients with type 1 diabetes, using continuous glucose monitoring (CGM) before and after CSII initiation (±3 days).

RESULTS

After CSII initiation, there was no difference in the rates of hypoglycemic events expressed as relative rates (RRs) per person-reading (RR = 0.85, p = 0.52, 95% CI 0.52-1.39), as well as in the number of prolonged hypoglycemic events (>1 h) per day (RR = 1.12, p = 0.56, 95% CI 0.75-1.68). We observed only a trend toward prolonged episodes of hyperglycemia after pump initiation (RR = 1.52, p = 0.06, 95% CI 0.97-2.35).

CONCLUSION

Our study is the first to assess, through CGM and in a prospective way, the impact of a CSII initiation protocol on glycemic values. Our protocol provides a safe model to avoid hypoglycemia at CSII initiation in children.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier NCT01840358.

Continuous glucose monitoring and HbA1c in the evaluation of glucose metabolism in children at high risk for type 1 diabetes mellitus

AIMS

Continuous glucose monitoring (CGM) parameters, self-monitored blood glucose (SMBG), HbA1c and oral glucose tolerance test (OGTT) were studied during preclinical type 1 diabetes mellitus.

METHODS

Ten asymptomatic children with multiple (⩾2) islet autoantibodies (cases) and 10 age and sex-matched autoantibody-negative controls from the Type 1 Diabetes Prediction and Prevention (DIPP) Study were invited to 7-day CGM with Dexcom G4 Platinum Sensor. HbA1c and two daily SMBG values (morning and evening) were analyzed. Five-point OGTTs were performed and carbohydrate intake was assessed by food records. The matched pairs were compared with the paired sample t-test.

RESULTS

The cases showed higher mean values and higher variation in glucose levels during CGM compared to the controls. The time spent ⩾7.8mmol/l was 5.8% in the cases compared to 0.4% in the controls (p=0.040). Postprandial CGM values were similar except after the dinner (6.6mmol/l in cases vs. 6.1mmol/l in controls; p=0.023). When analyzing the SMBG values higher mean level, higher evening levels, as well as higher variation were observed in the cases when compared to the controls. HbA1c was significantly higher in the cases [5.7% (39mmol/mol) vs. 5.3% (34mmol/mol); p=0.045]. No differences were observed in glucose or C-peptide levels during OGTT. Daily carbohydrate intake was slightly higher in the cases (254.2g vs. 217.7g; p=0.034).

CONCLUSIONS

Glucose levels measured by CGM and SMBG are useful indicators of dysglycemia during preclinical type 1 diabetes mellitus. Increased evening glucose values seem to be common in children with preclinical type 1 diabetes mellitus.

Analysis of insulin pump settings in children and adolescents with type 1 diabetes mellitus

AIM

To characterize current insulin pump settings used in young patients with type 1 diabetes mellitus (T1DM) and to assess their relationship to glycemic control.

METHODS

This retrospective study included patients aged <18 yr old with T1DM >1 yr using a Medtronic pump device. Pump data including number of blood glucose (BG) tests per day, basal and bolus insulin parameters, carbohydrate ratio (CR), and insulin sensitivity factors (ISFs) were averaged over 14 d for statistical analyses. Anthropometric data and recent glycosylated hemoglobin A1c (HbA1c) were recorded.

RESULTS

A total of 292 patients (144 males and 148 females) were included in the study. Participants had a median age (interquartile range, IQR) of 12.9 yr (10.0-15.1 yr) and pump duration of 2.8 yr (1.5-4.2 yr). No significant differences in median HbA1c (IQR) were observed in preschool [n = 14; HbA1c 7.8% (7.3-8.3%)], prepubertal [n = 105; HbA1c 8.1% (7.7-8.9%)], and adolescent subjects [n = 173; HbA1c 8.4% (7.7-9.0%)]. Adolescents took significantly fewer boluses and BG tests per day compared with younger children (p < 0.05). Age-specific diurnal variation in basal insulin delivery was noted. Additionally, stronger carbohydrate cover and weaker corrections were used in real-life compared with theoretical 500 and 100 rules, respectively. Lower HbA1c was associated with higher number of daily boluses, greater number of BG tests per day, lower average CR/500 rule ratio, and higher average ISF/100 rule ratio adjusted for age (R(2) = 0.22; p < 0.01).

CONCLUSION

Insulin pump therapy requires continuous adjustments and glycemic targets are achieved by a minority. We believe this is the first study in pediatric cohort looking at association between CR and ISF with glycemic control.