[Will type I diabetes mellitus be treated with immunosuppressive drugs in the future?]

Even if the pathogenesis of type-I (insulin-dependent) diabetes mellitus is still not clarified in every detail, there is general agreement that this form of diabetes is induced by autoimmune mechanisms leading to beta-cell destruction. Therefore, it should theoretically be feasible to suppress the mechanism leading to type-I diabetes with appropriate and early immunotherapy. The current clinical data clearly document that the rate and duration of remissions in patients with newly diagnosed type-I diabetes can be increased significantly using appropriate immunosuppressive regimens. However, before these therapies can become standard therapy of type-I diabetes, the following important clinical requirements have to be fulfilled: the toxicity (especially to kidneys and beta-cells) has to be reduced, the patients should be diagnosed and treated in 'pre-diabetic' states, more selective immunosuppressive regimens have to be available in order to reduce the occurrence of treatment-associated lymphomas and neoplasias. Since accurate detection of 'pre-diabetic' patients is difficult and presents an immense logistic problem, it may take a long time before large-scale immunosuppressive therapies of type-I diabetes are feasible.

Angiotensin I-converting enzyme-gene-polymorphism: relationship to albumin excretion and blood pressure in pediatric patients with type-I-diabetes mellitus

The purpose of this study was the evaluation of a predictive genetic marker for nephropathy and hypertension in patients with type-I-diabetes mellitus (IDDM). The study was performed on 247 pediatric patients with IDDM. The mean age was 15.5 years (range 3.1-29.3), the mean duration of diabetes was 7.6 years (range 0.1-25.7). Age-related blood pressure and nocturnal albumin excretion rate were compared with the insertion/deletion-(I/D) polymorphism of the angiotensin-I converting enzyme gene. The genotype distribution did not differ significantly between IDDM patients (ID 48%, D 28%, I 24%) and the control group (ID 44%, D 37%, I 19%). Neither in the entire group, nor in patients with IDDM for more than 5 years, was a correlation found bet-ween allele distribution and albumin excretion rate. No correlation was found between genotype and blood pressure. When patients with a chronological age above 12 years were analysed separately, the genotype distribution between the groups with normal and elevated blood pressure showed no significant difference. The previously reported association of the I/D-polymorphism with nephropathy could not be confirmed in this study. The development of microalbuminuria, nephropathy and hypertension will be followed in our pediatric patients.

Insulin increases serum leptin concentrations in children and adolescents with newly diagnosed type I diabetes mellitus with and without ketoacidosis.

AIMS/HYPOTHESIS The aims of this study were to analyse the changes of serum leptin in newly diagnosed children and adolescents with Type I (insulin-dependent) diabetes mellitus after insulin treatment and to examine the possible impact of ketoacidosis on these changes. METHODS Baseline serum leptin concentrations were measured in 28 newly diagnosed Type I diabetic patients [age 8.75 +/- 4.05 years (means +/- SD); BMI 15.79 +/- 2.47 kg/m(2); HbA(1 c) 11.3 +/- 1.9 %] with (n = 18) and without (n = 10) ketoacidosis before commencement of insulin treatment, at the time of diagnosis. Thereafter, during a 4-day course of continuous intravenous insulin injection to gain and maintain euglycaemia, serum leptin concentrations were assessed. RESULTS Baseline serum leptin concentrations, adjusted to age, BMI, sex and pubertal stage, differed among these patients. There was, however, an increase of leptin in all subjects from 1.37 +/- 0.56 ng/ml (mean +/- SD) up to 2.97 +/- 1.52 ng/ml by 117 % (p < 0.0001) after insulin therapy. On average, peak serum leptin concentration was obtained after 42 h of insulin treatment. Further, there was no difference in the mean increase of serum leptin concentrations in the two groups, namely with and without ketoadicosis, of insulin-dependent diabetic children and adolescents. In addition, there was no correlation between serum leptin concentrations and correction of ketoacidosis during insulin treatment. CONCLUSIONS/INTERPRETATION Insulin increases serum leptin, within 1 day, in children and adolescents with newly diagnosed Type I diabetes. Ketoacidosis does not influence this interaction between insulin and leptin.

Metabolic control in children and adolescents with diabetes mellitus type I in Berne: a cross-sectional study.

AIMS/HYPOTHESIS In diabetes mellitus type I, good glycaemic control is crucial in preventing long-term diabetic complications. The aim of this study was to determine the current level of metabolic control in children and adolescents in our diabetes outpatient clinic at the University Children's Hospital, Berne. Furthermore, the impact of different factors such as age, pubertal stage, sex, duration of diabetes and insulin regimen on glycaemic control was studied. METHODS In a cross-sectional, prospective study 168 children and adolescents with type I diabetes mellitus (f:m = 87:81; prepubertal 48 [mean age 4.4 years, mean duration of diabetes 2.8 years]; pubertal 120 [mean age 9.4 years; mean duration of diabetes 5.2 years]) were studied for three months. Clinical data and HbA1c levels (latex immunoagglutination test) were recorded, statistically analysed and compared with the international literature. RESULTS In our type I diabetic children and adolescents the overall HbA1c was 8.07 +/- 1.15% (mean +/- SD; test-specific norm for healthy subjects: 4.1-6.1%). Glycaemic control was significantly worse in the pubertal group compared to the prepubertal (HbA1c 8.22 +/- 1.25% vs. 7.81 +/- 0.87%; p < 0.01). In addition, we found better metabolic control in patients with duration of diabetes below 2 years in children and adolescents (HbA1c prepubertal < 2 years: 7.45 +/- 0.67% vs. > 2 years: 8.05 +/- 0.93%, p < 0.05; pubertal < 2 years: 7.62 +/- 0.75% vs. > 2 years: 8.31 +/- 1.29%, p < 0.005). Importantly, sex and insulin regimen did not significantly influence glycaemic control. CONCLUSION/INTERPRETATION The current level of metabolic control in our children and adolescents with diabetes mellitus type I is comparable to the glycaemic control of the intensively treated adolescent group of the DCCT-study, in whom decreased risk of long-term diabetic complications was found. In contrast, our patients were intensively treated in terms of frequent contacts with the diabetes team, but were not necessarily on an intensified insulin regimen. The impact of biopsychosocial support from multidisciplinary diabetes team on good metabolic control in children and adolescents with type I diabetes mellitus and their families seems to be very important.

Persistent microalbuminuria in adolescents with type I (insulin-dependent) diabetes mellitus is associated to early rather than late puberty. Results of a prospective longitudinal study

Microalbuminuria is generally accepted to be highly predictive of overt diabetic nephropathy which is the leading cause of end-stage renal failure and, consequently, of death in patients with type 1 (insulin-dependent) diabetes mellitus (IDDM). Its early identification and therapy are exceedingly important. We studied prospectively the occurrence of microalbuminuria (MA) in relation to puberty and its pubertal stages in 164 children and adolescent patients (83 girls and 81 boys) with IDDM. Analysing 100 healthy subjects, normal values for albumin excretion (range: 0-10.1 micrograms/min/1.73 m2) according to sex and the different pubertal stages were defined. No significant difference between the groups were noted and, therefore, 20 micrograms/min per 1.73 m2 (3 SD above the mean) was generally defined as cutoff for MA. Of the patients with IDDM studied, 20% (20 females and 12 males) developed persistent MA (22.1-448.2 micrograms/min/1.73 m2) during the study period of 8 years. The first manifestation of persistent MA was in 69% (13 females and 9 males) during stages of early and midpuberty; and in 28% (6 females and 3 males) at a late pubertal stage or at the end of puberty. The only child who developed MA before the onset of puberty (range: 23.5-157.4 micrograms/min/1.73 m2) was found to have dystopic kidney. Therefore, all patients with IDDM should be screened for MA regardless of diabetes duration, sex and level of diabetes control beginning at the very first stage of puberty and neither earlier nor after puberty as suggested by the American Diabetes Association.

Effect of IGF-I therapy on VLDL apolipoprotein B100 metabolism in type 1 diabetes mellitus

Abnormal lipid metabolism may be related to the increased cardiovascular risk in type 1 diabetes. Secretion and clearance rates of very low density lipoprotein (VLDL) apolipoprotein B100 (apoB) determine plasma lipid concentrations. Type 1 diabetes is characterized by increased growth hormone (GH) secretion and decreased insulin-like growth factor (IGF) I concentrations. High-dose IGF-I therapy improves the lipid profile in type 1 diabetes. This study examined the effect of low-dose (40 microg.kg(-1).day(-1)) IGF-I therapy on VLDL apoB metabolism, VLDL composition, and the GH-IGF-I axis during euglycemia in type 1 diabetes. Using a stable isotope technique, VLDL apoB kinetics were estimated before and after 1 wk of IGF-I therapy in 12 patients with type 1 diabetes in a double-blind, placebo-controlled trial. Fasting plasma triglyceride (P < 0.03), VLDL-triglyceride concentrations (P < 0.05), and the VLDL-triglyceride-to-VLDL apoB ratio (P < 0.002) significantly decreased after IGF-I therapy, whereas VLDL apoB kinetics were not significantly affected by IGF-I therapy. IGF-I therapy resulted in a significant increase in IGF-I and a significant reduction in GH concentrations. The mean overnight insulin concentrations during euglycemia decreased by 25% after IGF-I therapy. These results indicate that low-dose IGF-I therapy restores the GH-IGF-I axis in type 1 diabetes. IGF-I therapy changes fasting triglyceride concentrations and VLDL composition probably because of an increase in insulin sensitivity.

IGF-I treatment in adults with type 1 diabetes: effects on glucose and protein metabolism in the fasting state and during a hyperinsulinemic-euglycemic amino acid clamp

Type 1 diabetes is associated with abnormalities of the growth hormone (GH)-IGF-I axis. Such abnormalities include decreased circulating levels of IGF-I. We studied the effects of IGF-I therapy (40 microg x kg(-1) x day(-1)) on protein and glucose metabolism in adults with type 1 diabetes in a randomized placebo-controlled trial. A total of 12 subjects participated, and each subject was studied at baseline and after 7 days of treatment, both in the fasting state and during a hyperinsulinemic-euglycemic amino acid clamp. Protein and glucose metabolism were assessed using infusions of [1-13C]leucine and [6-6-2H2]glucose. IGF-I administration resulted in a 51% rise in circulating IGF-I levels (P < 0.005) and a 56% decrease in the mean overnight GH concentration (P < 0.05). After IGF-I treatment, a decrease in the overnight insulin requirement (0.26+/-0.07 vs. 0.17+/-0.06 U/kg, P < 0.05) and an increase in the glucose infusion requirement were observed during the hyperinsulinemic clamp (approximately 67%, P < 0.05). Basal glucose kinetics were unchanged, but an increase in insulin-stimulated peripheral glucose disposal was observed after IGF-I therapy (37+/-6 vs. 52+/-10 micromol x kg(-1) x min(-1), P < 0.05). IGF-I administration increased the basal metabolic clearance rate for leucine (approximately 28%, P < 0.05) and resulted in a net increase in leucine balance, both in the basal state and during the hyperinsulinemic amino acid clamp (-0.17+/-0.03 vs. -0.10+/-0.02, P < 0.01, and 0.25+/-0.08 vs. 0.40+/-0.06, P < 0.05, respectively). No changes in these variables were recorded in the subjects after administration of placebo. These findings demonstrated that IGF-I replacement resulted in significant alterations in glucose and protein metabolism in the basal and insulin-stimulated states. These effects were associated with increased insulin sensitivity, and they underline the major role of IGF-I in protein and glucose metabolism in type 1 diabetes.

Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type?1 diabetes; a randomized controlled trial

To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes.

Influence of time point of calibration on accuracy of continuous glucose monitoring in individuals with type 1 diabetes

Abstract Background and Aims: Data on the influence of calibration on accuracy of continuous glucose monitoring (CGM) are scarce. The aim of the present study was to investigate whether the time point of calibration has an influence on sensor accuracy and whether this effect differs according to glycemic level. Subjects and Methods: Two CGM sensors were inserted simultaneously in the abdomen on either side of 20 individuals with type 1 diabetes. One sensor was calibrated predominantly using preprandial glucose (calibration(PRE)). The other sensor was calibrated predominantly using postprandial glucose (calibration(POST)). At minimum three additional glucose values per day were obtained for analysis of accuracy. Sensor readings were divided into four categories according to the glycemic range of the reference values (low, ≤4 mmol/L; euglycemic, 4.1-7 mmol/L; hyperglycemic I, 7.1-14 mmol/L; and hyperglycemic II, >14 mmol/L). Results: The overall mean±SEM absolute relative difference (MARD) between capillary reference values and sensor readings was 18.3±0.8% for calibration(PRE) and 21.9±1.2% for calibration(POST) (P<0.001). MARD according to glycemic range was 47.4±6.5% (low), 17.4±1.3% (euglycemic), 15.0±0.8% (hyperglycemic I), and 17.7±1.9% (hyperglycemic II) for calibration(PRE) and 67.5±9.5% (low), 24.2±1.8% (euglycemic), 15.5±0.9% (hyperglycemic I), and 15.3±1.9% (hyperglycemic II) for calibration(POST). In the low and euglycemic ranges MARD was significantly lower in calibration(PRE) compared with calibration(POST) (P=0.007 and P<0.001, respectively). Conclusions: Sensor calibration predominantly based on preprandial glucose resulted in a significantly higher overall sensor accuracy compared with a predominantly postprandial calibration. The difference was most pronounced in the hypo- and euglycemic reference range, whereas both calibration patterns were comparable in the hyperglycemic range.

An Actor-Critic based controller for glucose regulation in type 1 diabetes

A novel adaptive approach for glucose control in individuals with type 1 diabetes under sensor-augmented pump therapy is proposed. The controller, is based on Actor-Critic (AC) learning and is inspired by the principles of reinforcement learning and optimal control theory. The main characteristics of the proposed controller are (i) simultaneous adjustment of both the insulin basal rate and the bolus dose, (ii) initialization based on clinical procedures, and (iii) real-time personalization. The effectiveness of the proposed algorithm in terms of glycemic control has been investigated in silico in adults, adolescents and children under open-loop and closed-loop approaches, using announced meals with uncertainties in the order of ±25% in the estimation of carbohydrates. The results show that glucose regulation is efficient in all three groups of patients, even with uncertainties in the level of carbohydrates in the meal. The percentages in the A+B zones of the Control Variability Grid Analysis (CVGA) were 100% for adults, and 93% for both adolescents and children. The AC based controller seems to be a promising approach for the automatic adjustment of insulin infusion in order to improve glycemic control. After optimization of the algorithm, the controller will be tested in a clinical trial.

Systemic venous drainage of pancreas allografts as independent cause of hyperinsulinemia in type I diabetic recipients

To evaluate the metabolic consequences of pancreas transplantation with systemic venous drainage on beta-cell function, we examined insulin and C-peptide responses to glucose and arginine in type I (insulin-dependent) diabetic pancreas recipients (n = 30), nondiabetic kidney recipients (n = 8), and nondiabetic control subjects (n = 28). Basal insulin levels were 66 +/- 5 pM in control subjects, 204 +/- 18 pM in pancreas recipients (P less than 0.0001 vs. control), and 77 +/- 17 pM in kidney recipients. Acute insulin responses to glucose were 416 +/- 44 pM in control subjects, 763 +/- 91 pM in pancreas recipients (P less than 0.01 vs. control), and 589 +/- 113 pM in kidney recipients (NS vs. control). Basal and stimulated insulin levels in two pancreas recipients with portal venous drainage were normal. Integrated acute C-peptide responses were not statistically different (25.3 +/- 4.3 nM/min in pancreas recipients, 34.2 +/- 5.5 nM/min in kidney recipients, and 23.7 +/- 2.1 nM/min in control subjects). Similar insulin and C-peptide results were obtained with arginine stimulation, and both basal and glucose-stimulated insulin-C-peptide ratios in pancreas recipients were significantly greater than in control subjects. We conclude that recipients of pancreas allografts with systemic venous drainage have elevated basal and stimulated insulin levels and that these alterations are primarily due to alterations of first-pass hepatic insulin clearance, although insulin resistance secondary to immunosuppressive therapy (including prednisone) probably plays a contributing role. To avoid hyperinsulinemia and its possible long-term adverse consequences, transplantation of pancreas allografts into sites with portal rather than systemic venous drainage should be considered.

Establishing glycaemic control with continuous subcutaneous insulin infusion in children and adolescents with type 1 diabetes: experience of the PedPump Study in 17 countries

AIMS/HYPOTHESIS: To assess the use of paediatric continuous subcutaneous infusion (CSII) under real-life conditions by analysing data recorded for up to 90 days and relating them to outcome. METHODS: Pump programming data from patients aged 0-18 years treated with CSII in 30 centres from 16 European countries and Israel were recorded during routine clinical visits. HbA(1c) was measured centrally. RESULTS: A total of 1,041 patients (age: 11.8 +/- 4.2 years; diabetes duration: 6.0 +/- 3.6 years; average CSII duration: 2.0 +/- 1.3 years; HbA(1c): 8.0 +/- 1.3% [means +/- SD]) participated. Glycaemic control was better in preschool (n = 142; 7.5 +/- 0.9%) and pre-adolescent (6-11 years, n = 321; 7.7 +/- 1.0%) children than in adolescent patients (12-18 years, n = 578; 8.3 +/- 1.4%). There was a significant negative correlation between HbA(1c) and daily bolus number, but not between HbA(1c) and total daily insulin dose. The use of <6.7 daily boluses was a significant predictor of an HbA(1c) level >7.5%. The incidence of severe hypoglycaemia and ketoacidosis was 6.63 and 6.26 events per 100 patient-years, respectively. CONCLUSIONS/INTERPRETATION: This large paediatric survey of CSII shows that glycaemic targets can be frequently achieved, particularly in young children, and the incidence of acute complications is low. Adequate substitution of basal and prandial insulin is associated with a better HbA(1c).

A real time simulation model of glucose-insulin metabolism for type 1 diabetes patients

In this paper, a simulation model of glucose-insulin metabolism for Type 1 diabetes patients is presented. The proposed system is based on the combination of Compartmental Models (CMs) and artificial Neural Networks (NNs). This model aims at the development of an accurate system, in order to assist Type 1 diabetes patients to handle their blood glucose profile and recognize dangerous metabolic states. Data from a Type 1 diabetes patient, stored in a database, have been used as input to the hybrid system. The data contain information about measured blood glucose levels, insulin intake, and description of food intake, along with the corresponding time. The data are passed to three separate CMs, which produce estimations about (i) the effect of Short Acting (SA) insulin intake on blood insulin concentration, (ii) the effect of Intermediate Acting (IA) insulin intake on blood insulin concentration, and (iii) the effect of carbohydrate intake on blood glucose absorption from the gut. The outputs of the three CMs are passed to a Recurrent NN (RNN) in order to predict subsequent blood glucose levels. The RNN is trained with the Real Time Recurrent Learning (RTRL) algorithm. The resulted blood glucose predictions are promising for the use of the proposed model for blood glucose level estimation for Type 1 diabetes patients.

Long-term follow-up of patients with Bartter syndrome type I and II

BACKGROUND: Little information is available on a long-term follow-up in Bartter syndrome type I and II. METHODS: Clinical presentation, treatment and long-term follow-up (5.0-21, median 11 years) were evaluated in 15 Italian patients with homozygous (n = 7) or compound heterozygous (n = 8) mutations in the SLC12A1 (n = 10) or KCNJ1 (n = 5) genes. RESULTS: Thirteen new mutations were identified. The 15 children were born pre-term with a normal for gestational age body weight. Medical treatment at the last follow-up control included supplementation with potassium in 13, non-steroidal anti-inflammatory agents in 12 and gastroprotective drugs in five patients. At last follow-up, body weight and height were within normal ranges in the patients. Glomerular filtration rate was <90 mL/min/1.73 m(2) in four patients (one of them with a pathologically increased urinary protein excretion). In three patients, abdominal ultrasound detected gallstones. The group of patients with antenatal Bartter syndrome had a lower renin ratio (P < 0.05) and a higher standard deviation score (SDS) for height (P < 0.05) than a previously studied group of patients with classical Bartter syndrome. CONCLUSIONS: Patients with Bartter syndrome type I and II tend to present a satisfactory prognosis after a median follow-up of more than 10 years. Gallstones might represent a new complication of antenatal Bartter syndrome.