Classification of distinct baseline insulin infusion patterns in children and adolescents with type 1 diabetes on continuous subcutaneous insulin infusion therapy

Expected Basal Insulin Requirement During Continuous Subcutaneous Insulin Infusion Therapy by Age Group, Sex, and Body Mass Index, Based on 25,718 Young People with Type 1 Diabetes in the DPV Registry

Background: Since the introduction of insulin pumps into the therapy of pediatric subjects, different approaches have been taken to find optimal basal rates. Previously, the DPV registry provided circadian basal rate patterns for different age groups. As the number of pump users has increased recently and short-acting insulin analogues are now predominant, we performed a new analysis with a larger data pool. Methods: We included all recent basal profiles from type 1 diabetes (T1D) patients between 1 and 25 years from the DPV 2021 data pool. We excluded night-time-only pump users, human regular insulin users, and daily basal rates <0.05 and >1.0 U/(kgBW·d). Results: In the analysis of profiles from 25,718 young persons with T1D, differences in the daily pattern of basal rates were found between age groups. In addition, we saw significant (P < 0.001) differences in total daily basal dose between genders in all age groups except adults. In addition, the shape of the expected basal-rate pattern differed by body mass index, HbA1c, and use of continuous glucose monitoring. Discussion: This analysis demonstrates multiple factors influencing basal patterns and insulin requirement, including age group, gender, overweight, HbA1c, bolus frequency, and sensor use. As circadian basal rates are still mandatory for initiating insulin pump therapy with or without automation, a multimodal approach is necessary to estimate optimal basal rates.

A simulator with realistic and challenging scenarios for virtual T1D patients undergoing CSII and MDI therapy

In silico simulations have become essential for the development of diabetes treatments. However, currently available simulators are not challenging enough and often suffer from limitations in insulin and meal absorption variability, which is unable to realistically reflect the dynamics of people with type 1 diabetes (T1D). Additionally, T1D simulators are mainly designed for the testing of continuous subcutaneous insulin infusion (CSII) therapies. In this work, a simulator is presented that includes a generated virtual patient (VP) cohort and both fast- and long-acting Glargine-100 U/ml (Gla-100), Glargine-300 U/ml (Gla-300), and Degludec-100 U/ml (Deg-100) insulin models. Therefore, in addition to CSII therapies, multiple daily injections (MDI) therapies can also be tested. The Hovorka model and its published parameter probability distributions were used to generate cohorts of VPs that represent a T1D population. Valid patients are filtered through restrictions that guarantee that they are physiologically acceptable. To obtain more realistic scenarios, basal insulin profile patterns from the literature have been used to identify variability in insulin sensitivity. A library of mixed meals identified from real data has also been included. This work presents and validates a methodology for the creation of realistic VP cohorts that include physiological variability and a simulator that includes challenging and realistic scenarios for in silico testing. A cohort of 47 VPs has been generated and in silico simulations of both CSII and MDI therapies were performed in open-loop. The simulation outcome metrics were contrasted with literature results.

Distinct Patterns of Daily Glucose Variability by Pubertal Status in Youth With Type 1 Diabetes

OBJECTIVE

To evaluate glycemia and metrics of glucose variability in youth with type 1 diabetes, and to assess patterns of 24-h glucose variability according to pubertal status.

RESEARCH DESIGN AND METHODS

Metrics of glycemia, glucose variability, and glucose patterns were assessed by using 4 weeks of continuous glucose monitoring (CGM) data from 107 youth aged 8-17 years with type 1 diabetes for ≥1 year. Glucose values per hour were expressed as percentages relative to the mean glucose over 24 h for a 4-week period. Glucose data were compared on the basis of pubertal status-prepubertal (Tanner stage [T] 1), pubertal (T2-4), and postpubertal (T5)-and A1C categories (<7.5% [<58 mmol/mol], ≥7.5% [≥58 mmol/mol]).

RESULTS

Youth (50% female, 95% white) had a mean ± SD age of 13.1 ± 2.6 years, diabetes duration of 6.3 ± 3.5 years, and A1C of 7.8 ± 0.8% (62 ± 9 mmol/mol); 88% were pump treated. Prepubertal youth had a higher mean glucose SD (86 ± 12 mg/dL [4.8 ± 0.7 mmol/L]; P = 0.01) and coefficient of variation (CV) (43 ± 5%; P = 0.06) than did pubertal (SD 79 ± 13 mg/dL [4.4 ± 0.7 mmol/L]; CV 41 ± 5%) and postpubertal (SD 77 ± 14 mg/dL [4.3 ± 0.8 mmol/L]; CV 40 ± 5%) youth. Over 24 h, prepubertal youth had the largest excursions from mean glucose and the highest CV across most hours compared with pubertal and postpubertal youth. Across all youth, CV was strongly correlated with the percentage of time with glucose <70 mg/dL (<3.9 mmol/L) (r = 0.79; P < 0.0001).

CONCLUSIONS

Prepubertal youth had greater glucose variability independent of A1C than did pubertal and postpubertal youth. A1C alone does not capture the full range of glycemic parameters, highlighting the added insight of CGM in managing youth with type 1 diabetes.

Determination of Pubertal Status in Youths With Type 1 Diabetes Using Height Velocity and Trajectories

CONTEXT

Assessment of pubertal change is important for the management of chronic pediatric diseases, such as type 1 diabetes. Physical and/or laboratory assessments of pubertal status are often unavailable, impractical, or costly.

OBJECTIVE

To develop and validate a practical and objective method to assess pubertal status using longitudinal linear growth in youths with type 1 diabetes.

DESIGN, PARTICIPANTS, AND OUTCOME MEASUREMENTS

Participants (n = 123) were part of a 2-year study assessing continuous glucose monitoring in youths with type 1 diabetes at a tertiary diabetes center. Pubertal status at visits was assigned by a tiered approach using clinical Tanner staging or indicators of pubertal maturation from the electronic medical record when available. For other visits, independent evaluations of height velocities and growth chart trajectories provided data for pubertal status assignments. Sensitivity analysis confirmed the validity of the pubertal status assignments.

RESULTS

The sample (50% female, 95% white) had a mean ± SD age of 12.7 ± 2.7 years, diabetes duration of 6.0 ± 3.6 years, and hemoglobin A1c of 7.9 ± 0.8%. Of 985 study visits, 50% received a pubertal status assignment based on clinical Tanner staging, 29% on additional medical record review, and 22% on an evaluation of height velocity and growth chart trajectory. For the sensitivity analysis, pubertal status assignments based on height velocity and growth chart trajectory matched clinical Tanner staging in 87% of visits.

CONCLUSIONS

Our practical and objective method to assess pubertal status based on height velocity and growth chart trajectory highlights growth as a reliable and objective bioassay for pubertal onset, status, and progression.

Basal rate tests (24-hour fasts) performed in type-1 diabetic subjects with either absolute fasting or snacks containing negligible carbohydrate amounts result in similar glucose profiles: A randomized controlled prospective trial

AIMS

Basal rate tests (24-hour fasting periods) may be necessary to optimize basal insulin replacement in type 1 diabetes. It was the aim of this study to prospectively compare the allowance of negligible carbohydrate snacks vs absolute fasting.

METHODS

A total of 20 patients with type 1 diabetes (age, 48 ± 15 years (9 women, 11 men); BMI, 28.5 ± 4.5 kg/m² ; HbA1c, 8.8% ± 2.0% (73.0 ± 21.9 mmol/mol); insulin dose, 0.69 ± 0.31 IU/kg body weight and per day) participated in 2 basal rate tests lasting 24 hours in random order with unchanged basal insulin replacement. On 1 occasion, negligible carbohydrate snacks (salads and vegetables, up to 5.1 g carbohydrate and 276.3 kJ per portion) were allowed; during the second test subjects were obliged to fast absolutely. Plasma glucose profiles were determined using an exact laboratory method. Hypoglycaemic episodes (plasma glucose < 70 mg/dL) were compared.

RESULTS

Plasma glucose concentrations during fasting periods, with and without negligible carbohydrate snacks, did not differ significantly ( P = .65) and differences were negligible (95% confidence intervals always included a difference of 0 mmol/L). Also, there was no difference in the number of hypoglycaemic plasma glucose values (P = .40) or in compensatory carbohydrate intake. Basal rate testing with negligible carbohydrate snacks was better tolerated (questionnaire, P = .046) and the desire to discontinue the fasting period was significantly reduced (P = .023).

CONCLUSIONS

Allowing negligible carbohydrate snacks results in unchanged plasma glucose profiles during basal rate testing and is better tolerated by patients with type 1 diabetes.

Lower dose basal insulin infusion has positive effect on glycaemic control for children with type I diabetes on continuous subcutaneous insulin infusion therapy

OBJECTIVE

The aim of our study was to explore a possible relationship between proportion of basal insulin dose (%BD/T) and glycaemic control in children with type I diabetes on continuous subcutaneous insulin infusion (CSII) therapy.

METHODS

All patients under the age of 18 with type I diabetes mellitus, treated in a general hospital in Utrecht, The Netherlands, who were on CSII therapy between 2000 and 2011 were selected for inclusion. All data as recorded during outpatient visits were retrospectively collected from patients' charts. Analyses were performed using R Statistical Software.

RESULTS

Data of 847 outpatient visits of 78 patients [31 males (39.7%) and 47 females (60.3%)] were analyzed. Mean age at diagnosis was 7.1 ± 3.7 yr, mean age at start of pump therapy 10.1 ± 3.8 yr. Mean HbA1c before pump start was 8.3 ± 1.0%, median BMI standard deviation score for age and gender was 0.64 (-1.89-3.79). Median follow-up time per patient was 29 months with an average of 10 visits (range: 3-25). Multivariate analysis revealed that a change of 10% in %BD/T resulted in a decrease or increase of HbA1c of 0.22% [95% confidence interval (CI): 0.15-0.29). No significant effect was observed from SDS BMI, sex, or duration of diabetes.

CONCLUSION

Low dose basal insulin infusion as a percentage of total insulin dose has a positive effect on metabolic outcome as expressed in HbA1c-levels. A change of 10% in %BD/T results in a decrease or increase of HbA1c of 0.22%. This supports the tendency to aim at the lowest basal insulin requirements in pump setting strategy.

Impact of ELKa, the Electronic Device for Prandial Insulin Dose Calculation, on Metabolic Control in Children and Adolescents with Type 1 Diabetes Mellitus: A Randomized Controlled Trial

Background. The ELKa system is composed of computer software, with a database of nutrients, and a dedicated USB kitchen scale. It was designed to automatize the everyday calculations of food exchanges and prandial insulin doses. Aim. To investigate the influence of the ELKa on metabolic control in children with type 1 diabetes mellitus (T1DM). Methods. A randomized, parallel, open-label clinical trial involved 106 patients aged <18 years with T1DM, HbA_1C ≤ 10%, undergoing intensive insulin therapy, allocated to the intervention group, who used the ELKa (n = 53), or the control group (n = 53), who used conventional calculation methods. Results. After the 26-week follow-up, the intention-to-treat analysis showed no differences to all endpoints. In per protocol analysis, 22/53 (41.5%) patients reporting ELKa usage for >50% of meals achieved lower HbA_1C levels (P = 0.002), lower basal insulin amounts (P = 0.049), and lower intrasubject standard deviation of blood glucose levels (P = 0.023) in comparison with the control. Moreover, in the intervention group, significant reduction of HbA_1C level, by 0.55% point (P = 0.002), was noted. No intergroup differences were found in the hypoglycemic episodes, BMI-SDS, bolus insulin dosage, and total daily insulin dosage. Conclusions. The ELKa system improves metabolic control in children with T1DM under regular usage. The trial is registered at ClinicalTrials.gov, number NCT02194517.

Polymorphic basal rates of continuous subcutaneous insulin infusion among Taiwanese children with type 1 diabetes

Introduction. The basal dose of insulin, proportion of total daily insulin, and circadian variation during continuous subcutaneous insulin infusion (CSII) therapy among children with type 1 diabetes mellitus (T1D) have not been fully elucidated. Materials and Methods. A total of 45 childhood patients with T1D receiving CSII therapy at Pediatrics Department of Chang Gung Memorial Hospital between 2004 and 2012 were analyzed. Patients were classified according to Tanner stage. Results. HbA1c was significantly reduced in all Tanner groups within three months of CSII therapy (from 67 mmol/mol (8.3%) to 54 mmol/mol (7.1%), P < 0.05). The actual basal proportion of total daily insulin use was 34–40%. The circadian distribution of basal insulin differed markedly between the five Tanner groups. Basal insulin requirement was highest between 3:00 and 7:00 h in Tanner stages 1-2. In stages 3-4, a lower nocturnal basal insulin that increased gradually until daytime was noted. Adolescents (stage 5) displayed a high insulin peak between 6:00 and 11:00 h, and a smaller peak between 19:00 and 23:00 h. Conclusions. A smaller proportion of basal insulin to total daily insulin use, as well as varied circadian patterns of insulin use, characterized these children with T1D.

Changes in Insulin Requirements From the Onset of Continuous Subcutaneous Insulin Infusion (CSII) Until Optimization of Glycemic Control

The aim was to evaluate changes in insulin requirements from onset of continuous subcutaneous insulin infusion (CSII) until glucose optimization in type 1 diabetes and to determine patient characteristics to be considered when CSII is implemented. We retrospectively analyzed 74 type 1 diabetic patients over a follow-up of 5 months after starting CSII. Patients without a decrease in HbA1c levels at the end of follow-up were excluded. We compared total daily doses (TDD), basal/bolus distribution, basal diurnal/nocturnal proportion, number of basal segments, and HbA1c levels in relation to sex, age, body mass index (BMI), diabetes duration, and indication for CSII. At follow-up, HbA1c decreased by 0.75%, TDD decreased by 18%, basal rate was 60% of TDD, and diurnal basal rate was 60% of total basal rate. Insulin requirements were higher in males and in obese patients. Female patients and patients with longer diabetes duration showed a higher percentage of basal insulin. The number of basal segments was 4.9 ± 2.9. Basal requirements were higher in the second half of the nocturnal period. The dawn phenomenon was more relevant in men. Improvements in glycemic control were more marked in younger patients, in patients with higher HbA1c, in patients using more basal segments, and in patients initiating CSII for glucose control before pregnancy. Sex, diabetes duration, and BMI should be considered when initiating CSII. Our findings may help clinicians in clinical decision making regarding CSII therapy.

Predicting the optimal basal insulin infusion pattern in children and adolescents on insulin pumps

OBJECTIVE

We aimed at developing and cross-validating a mathematical prediction model for an optimal basal insulin infusion pattern for children with type 1 diabetes on continuous subcutaneous insulin infusion therapy (CSII).

RESEARCH DESIGN AND METHODS

We used the German/Austrian DPV-Wiss database for quality control and scientific surveys in pediatric diabetology and retrieved all CSII patients <20 years of age (November 2009). A total of 1,248 individuals from our previous study were excluded (dataset 1), resulting in 6,063 CSII patients (dataset 2) (mean age 10.6 ± 4.3 years). Only the most recent basal insulin infusion rates (BRs) were considered. BR patterns were identified and corresponding patients sorted by unsupervised clustering. Logistic regression analysis was applied to calculate the probabilities for each BR pattern. Equations were based on both independent datasets separately, and probabilities for BR patterns were cross-validated using typical test patients.

RESULTS

Of the 6,063 children, 5,903 clustered in one of four major circadian BR patterns, confirming our previous study. The oldest age-group (mean age 12.8 years) was represented by 2,490 patients (42.18%) with a biphasic dawn-dusk pattern (BC). A broad single insulin maximum at 9-10 p.m. (F) was unveiled by 853 patients (14.45%) (mean age 6.3 years). Logistic regression analysis revealed that age, to a lesser extent duration of diabetes, and partly sex predicted BR patterns. Cross-validation revealed almost identical probabilities for BR patterns BC and F in the two datasets but some variation in the remaining two BR patterns.

CONCLUSIONS

Reconfirmation of four key BR patterns in two very large independent cohorts supports that these patterns are realistic approximations of the circadian distribution of insulin needs in children with type 1 diabetes. Prediction of an optimal pattern a priori can improve initiation and clinical follow-up of CSII in children and adolescents. In addition, these BR patterns represent valuable information for insulin-infusion algorithms in closed-loop CSII.

The interplay between retinoic acid receptor-related orphan receptors and human diseases

The retinoic acid receptor-related orphan receptors (RORs) are an important subfamily of transcriptional regulators of the nuclear receptors superfamily. Their discovery over a decade ago by gene cloning strategy have revealed three major isoforms of these orphan receptors in animals. Generation and analyses of isoform-specific ROR null mice have provided revealed-vital roles for the RORs in animals. The RORs undoubtedly participate in a host of biological functions such a metabolism, immunity, development and differentiation, angiogenesis, circadian clock, xenobiotic/drug metabolism and other tissue physiologies for optimal animal survival. Moreover, intense work in the last one decade also revealed a host of human diseases being modulated by the RORs. A number of diseases, such as cancer, autoimmune diseases, inflammation, osteoporosis, metabolic syndrome etc., strongly support the involvement of RORs in their onset and progression. By involving in such diseases, the RORs are indeed a critical factor for optimal cell function and are being intensely investigated as novel targets for drug interventions in the treatment of various diseases. This review focuses on the current knowledge and status about RORs in a number of human disease conditions.

Basal rates and circadian profiles in continuous subcutaneous insulin infusion (CSII) differ for preschool children, prepubertal children, adolescents and young adults

OBJECTIVE

Initiation of continuous subcutaneous insulin therapy (CSII) requires an appropriate basal rate profile. Different approaches exist; however, there is a lack of evidence-based recommendations, especially in young children.

STUDY DESIGN

In this large multicenter survey, 5941 CSII patients from the German/Austrian prospective documentation system (DPV) were analyzed. Patients were divided into four age groups: <6 yr (n = 837), 6 to <12 yr (n = 1739), 12 to <18 yr (n = 2985) and 18 to <25 yr (n = 380). Basal insulin requirement and diurnal distribution were evaluated based on the most recent documentation for each patient.

RESULTS

Basal insulin requirement differed significantly between the four age groups (<6: 0.25 ± 0.12; 6 to <12: 0.33 ± 0.12; 12 to <18: 0.43 ± 0.15; 18 to <25: 0.35 ± 0.13 U/kg; p < 0.001). Circadian insulin profiles were markedly different between the younger and older age groups. In addition to age, longer diabetes duration, female gender, higher HbA1c and lower body mass index standard deviation score (BMI-SDS) were related to higher basal insulin requirement per kilogram of body weight.

CONCLUSIONS

Age of the patient is the primary factor that influences both total daily requirement and circadian distribution of basal insulin in CSII. Experience from a large database may therefore facilitate the initiation of pump therapy in pediatric patients.

The REV-ERBs and RORs: molecular links between circadian rhythms and lipid homeostasis

Research efforts spanning the past two decades have established a clear link between nuclear receptor function, regulation of the circadian clock and lipid homeostasis. As such, this family of receptors represents an important area of research. Recent advances in the field have identified two nuclear receptor subfamilies, the REV-ERBs and the 'retinoic acid receptor-related orphan receptors' (RORs), as critical regulators of the circadian clock with significant roles in lipid homeostasis. In this review, the latest information garnered from cutting-edge research on these two nuclear receptor subfamilies will be discussed. Through direct targeting of the REV-ERBs and RORs with synthetic ligands, generation of novel tools aimed at characterizing their function in vivo have been developed, which may lead to novel therapeutics for the treatment of metabolic disorders.

Treatment of type 1 diabetes in children and adolescents using modern insulin pumps

In the last decades, we are experiencing an increasing use of insulin pumps for the treatment of type 1 diabetes in children and adolescents. The most frequent reasons for switching from insulin injection schemes to pump therapy are frequent and/or severe hypoglycaemia, dawn phenomenon, poor glycaemic control, wish for more flexibility in daily life, and needle phobia. In toddlers and preschoolers, pumps are frequently introduced from the onset of type 1 diabetes. Pumps offer the possibility of adjusting basal insulin rates individually on an age-depended manner as well as of optimizing meal-related insulin requirements according to the meal composition by using three different kinds of boluses. Structured and intensive education of patients and their families on basics and specific requirements of insulin pump therapy is essential in order to get them familiar with the devices and their features. There is increasing evidence both from multicentre cross-sectional studies as well as from meta-analyses of randomized clinical trials in paediatric populations showing that patients with pump therapy can achieve a more favourable metabolic control accompanied with less hypoglycaemic events than those with multiple daily injections.

Guidelines for optimal bolus calculator settings in adults

Bolus insulin calculators (BCs) became available in insulin pumps in 2002 and are being integrated into glucose meters and portable device applets for use with multiple daily injections. A retrospective analysis of continuous subcutaneous insulin infusion data from the Actual Pump Practices (APP) study is used in this article to generate formulas for more precise BC settings. A well-designed BC determines accurate bolus doses for carbohydrate intake and for correcting elevated glucose levels. It should also provide the logic necessary to track residual bolus insulin and reduce bolus recommendations to minimize insulin stacking. To provide appropriate bolus doses, a BC requires accurate settings for the carbohydrate factor or insulin:carbohydrate ratio, glucose correction factor, duration of insulin action, and correction target. We provide guidelines to select BC settings from the user's current total daily dose (TDD) of insulin and to determine more appropriate BC settings from an improved TDD based on the mean glucose level.

The use of insulin pumps in youth with type 1 diabetes

The use of insulin pump therapy (continuous subcutaneous insulin infusion) has increased dramatically in youth with type 1 diabetes (T1D) in the past decade. In this review we provide background and practical clinical advice on insulin basal rates and bolus doses and on the advantages of pump therapy with exercise. Acute complications of T1D (hypoglycemia and diabetic ketoacidosis) in the context of pump therapy are reviewed. The advantages of pump therapy in the school setting and in hospitalized patients are discussed. Finally, diabetes management in the 21st century, in which pump therapy is combined with continuous glucose monitoring, and its potential for a closed-loop pancreas are presented.

Circadian rhythms and metabolic syndrome: from experimental genetics to human disease

The incidence of the metabolic syndrome represents a spectrum of disorders that continue to increase across the industrialized world. Both genetic and environmental factors contribute to metabolic syndrome and recent evidence has emerged to suggest that alterations in circadian systems and sleep participate in the pathogenesis of the disease. In this review, we highlight studies at the intersection of clinical medicine and experimental genetics that pinpoint how perturbations of the internal clock system, and sleep, constitute risk factors for disorders including obesity, diabetes mellitus, cardiovascular disease, thrombosis and even inflammation. An exciting aspect of the field has been the integration of behavioral and physiological approaches, and the emerging insight into both neural and peripheral tissues in disease pathogenesis. Consideration of the cell and molecular links between disorders of circadian rhythms and sleep with metabolic syndrome has begun to open new opportunities for mechanism-based therapeutics.

Difference in insulin usage patterns with pubertal development in children with type 1 diabetes during transition from multiple daily injections to continuous subcutaneous insulin infusion (CSII) and through the CSII treatment

OBJECTIVE

This study analyzed the changes in insulin requirement in the transition from multiple daily injections (MDI) to continuous subcutaneous insulin infusion (CSII) and the differences through the CSII treatment in pediatric patients in different pubertal developmental stages.

METHODS

We analyzed, through a longitudinal retrospective study, the insulin usage patterns and glycemic control of 40 patients with type 1 diabetes on CSII treatment for 12 months. The patients were subdivided in three groups: group A, 13 prepubertal subjects (Tanner stage I); group B, 15 pubertal subjects (Tanner stage II-IV); and group C, 12 postpubertal subjects (Tanner stage V).

RESULTS

During the transition from MDI to CSII, the insulin requirements decreased significantly by 21 +/- 5% (0.89 +/- 0.26 U/kg/day vs. 0.70 +/- 0.11 U/kg/day). Through the CSII treatment the percentage of total daily insulin delivered as the basal rate in groups A, B, and C was 54-60%, 52-54%, and 52-54%, respectively. The number of basal rates per day was significantly higher in groups A and B. The overall profile of basal rate differed among the groups. During the night, prepubertal patients required more insulin from 12 p.m. to 2 a.m., whereas pubertal and postpubertal patients required more insulin between 2-3 a.m. to 7 a.m. Prepubertal patients had a maximum basal rate between 9 a.m. to 12 a.m. and 2 p.m. to 4 p.m., in contrast to pubertal and postpubertal patients between 2 p.m. to 3 p.m. and 5 p.m. to 6 p.m. The number of "extra" boluses per day was significantly higher in groups B and C compared to group A.

CONCLUSIONS

Age-related differences exist in insulin usage patterns of pediatric patients on pump treatment. A greater knowledge of these variations may help to obtain optimum conditions in the CSII treatment in pediatric patients.

Insulin sensitivity in prepubertal Caucasian normal weight children

BACKGROUND

Determining whether or not a child is insulin resistant is becoming a matter of fundamental interest even in childhood, as the incidence of metabolic complications of insulin resistance is rising. Thus reference values are needed.

AIM

To set percentiles for HOMA-IR and WBISI in Caucasian normal weight prepubertal children.

POPULATION

238 normal weight prepubertal Caucasian children (126 males/112 females).

METHODS

After physical examination including anthropometric measurements all children underwent an oral glucose tolerance test from which HOMA-IR and WBISI were calculated.

RESULTS

HOMA-IR values above the 95th percentile (2.03) and WBISI values below the 5th percentile (5.67) represent the cut-off values for the determination of insulin resistance.

CONCLUSION

These reference values are useful to easily detect insulin resistance within the prepubertal Caucasian population representing a helpful tool for clinicians to target such children in order to improve insulin sensitivity.

Age-dependent basal insulin patterns in children with type 1 diabetes treated with continuous subcutaneous insulin infusion

AIMS

Identifying age-dependent basal rates in type 1 diabetic children treated with continuous subcutaneous insulin infusion (CSII).

METHODS

CSII-treated children with type 1 diabetes exhibiting insulin requirement > 0.5 U/kg and glycated haemoglobin (HbA1c) < 8%. The study population was composed of 198 Caucasian children (111 girls) with mean age of 9.8 +/- 3.8 years, mean duration of diabetes of 4.3 +/- 3.1 years and mean HbA1c value of 6.7 +/- 0.7%. Data were evaluated for four age groups (0-6; 6-9; 9-12, 12-18 years). Basal rates records were downloaded from pump memory. HbA1c, weight, height were measured at scheduled visits.

RESULTS

Significant differences in the average hourly basal rate between groups were observed: I gr. 0.14 versus II gr. 0.24 versus III gr. 0.39 versus IV gr. 0.72 units/h; p < 0.0001. The average hourly basal rate correlated with age, body weight, BMI, diabetes duration and total insulin daily dose. Insulin peaks were observed for: I gr. - before midnight, II gr. - before midnight and in the early morning, gr. III and IV - in the early morning.

CONCLUSION

Basal insulin infusion rate profiles in well-controlled paediatric patients on CSII reflect the age-dependent amount of basal insulin (20-40%) and affect circadian distribution of insulin needs.

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.

The meter of metabolism

The circadian system orchestrates the temporal organization of many aspects of physiology, including metabolism, in synchrony with the 24 hr rotation of the Earth. Like the metabolic system, the circadian system is a complex feedback network that involves interactions between the central nervous system and peripheral tissues. Emerging evidence suggests that circadian regulation is intimately linked to metabolic homeostasis and that dysregulation of circadian rhythms can contribute to disease. Conversely, metabolic signals also feed back into the circadian system, modulating circadian gene expression and behavior. Here, we review the relationship between the circadian and metabolic systems and the implications for cardiovascular disease, obesity, and diabetes.

Basal insulin and total daily insulin dose in children with type 1 diabetes using insulin pumps

OBJECTIVE

To assess the contribution of basal insulin to the total daily dose (CBITDD) and to identify the determinant factors in children with type 1 diabetes mellitus.

STUDY DESIGN

Cross-sectional study in which the basal insulin requirement was established based on a memory read-out of insulin delivery from pumps. Factors such as glycated haemoglobin A1c (HbA1c), fasting C-peptide, standard deviation score of body mass index (sdsBMI) and demographic data were determined during routine hospital visits. Study group included a total of 90 well-controlled diabetic children with the mean HbA1c 6.6 +/- 0.7 (5.2-7.9), age 10.4 +/- 4.4 yr (1.1-17.9 yr), diabetes duration 3.0 +/- 2.6 yr (0.3-10.9 yr) and sdsBMI 0.08 (-2.27 to 1.79), excluding patients with ketoacidosis or infectious diseases.

RESULTS

Correlations between CBITDD and age (r = 0.39 and p < 0.005) and diabetes duration (r = 0.61 and p < 0.0001) and an inverse correlation with C-peptide (r = -0.41 and p = 0.0001) were found. C-peptide-positive patients had a significantly lower percentage of basal insulin compared with C-peptide-negative patients (20.6 +/- 11 vs. 31.6 +/- 11.0%, respectively; p = 0.0004); yet, no significant difference in total insulin daily dose (0.65 +/- 0.3 vs. 0.78 +/- 0.2 U/kg/d, respectively) was observed.

CONCLUSIONS

The percentage of basal insulin in diabetic children is below 50% and in well-controlled diabetic children is related to the fasting C-peptide level, age of patient and diabetes duration but not to HbA1c and sdsBMI.