Lorenzo Lenzi

Opposite clinical phenotypes of glucokinase disease: Description of a novel activating mutation and contiguous inactivating mutations in human glucokinase (GCK) gene

Glucokinase is essential for glucose-stimulated insulin release from the pancreatic beta-cell, serving as glucose sensor in humans. Inactivating or activating mutations of glucokinase lead to different forms of glucokinase disease, i.e. GCK-monogenic diabetes of youth, permanent neonatal diabetes (inactivating mutations), and congenital hyperinsulinism, respectively. Here we present a novel glucokinase gene (GCK)-activating mutation (p.E442K) found in an infant with neonatal hypoglycemia (1.5 mmol/liter) and in two other family members suffering from recurrent hypoglycemic episodes in their childhood and adult life. In contrast to the severe clinical presentation in the index case, functional studies showed only a slight activation of the protein (relative activity index of 3.3). We also report on functional studies of two inactivating mutations of the GCK (p.E440G and p.S441W), contiguous to the activating one, that lead to monogenic diabetes of youth. Interestingly, adult family members carrying the GCK pE440G mutation show an unusually heterogeneous and progressive diabetic phenotype, a feature not typical of GCK-monogenic diabetes of youth. In summary, we identified a novel activating GCK mutation that although being associated with severe neonatal hypoglycemia is characterized by the mildest activation of the glucokinase enzyme of all previously reported.

Use of the predictive low glucose management (PLGM) algorithm in Italian adolescents with type 1 diabetes: CareLink™ data download in a real-world setting.

Actually, closed-loop systems have significantly enhanced, shifting from in-hospital to at-home studies [1], together with the use of integrated bi-hormonal artificial pancreas system [2]. However, Kovatchev et al. [3] summarize today’s artificial pancreas systems as a work in progress, as still there is much work to be done. Nonetheless, intermediate steps in introduction of automation of insulin delivery are already commercially available and in clinical use. As these early steps in automation need understanding and shift in mindset of both patients and care givers, a group of pediatrics endocrinologists formed a group (Sensor Experience Group) to study closely and intensively the onboarding of adolescent patients with type 1 diabetes on automated systems to gain first-hand experience and peer-to-peer insights in a unique free-living environment. The aim of our observational perspective anonymous data collection using CareLink was to evaluate safety and effectiveness of PLGM system under free-living conditions.

A Multicenter Retrospective Survey regarding Diabetic Ketoacidosis Management in Italian Children with Type 1 Diabetes

We conducted a retrospective survey in pediatric centers belonging to the Italian Society for Pediatric Diabetology and Endocrinology. The following data were collected for all new-onset diabetes patients aged 0–18 years: DKA (pH < 7.30), severe DKA (pH < 7.1), DKA in preschool children, DKA treatment according to ISPAD protocol, type of rehydrating solution used, bicarbonates use, and amount of insulin infused. Records (n = 2453) of children with newly diagnosed diabetes were collected from 68/77 centers (87%), 39 of which are tertiary referral centers, the majority of whom (n = 1536, 89.4%) were diagnosed in the tertiary referral centers. DKA was observed in 38.5% and severe DKA in 10.3%. Considering preschool children, DKA was observed in 72%, and severe DKA in 16.7%. Cerebral edema following DKA treatment was observed in 5 (0.5%). DKA treatment according to ISPAD guidelines was adopted in 68% of the centers. In the first 2 hours, rehydration was started with normal saline in all centers, but with different amount. Bicarbonate was quite never been used. Insulin was infused starting from third hour at the rate of 0.05–0.1 U/kg/h in 72% of centers. Despite prevention campaign, DKA is still observed in Italian children at onset, with significant variability in DKA treatment, underlying the need to share guidelines among centers.

Continuous subcutaneous infusion of protein C concentrate using an insulin pump in a newborn with congenital protein C deficiency.

We describe the case of a newborn presenting with multicystic encephalomalacy, hydrocephalus and bilateral hemovitreous. An underlying coagulation disorder was suspected and laboratory tests revealed severe protein C deficiency. At 25 days of life, after the appearance of purpura fulminans, replacement therapy with intravenous protein C concentrate (Ceprotin; Baxter, Vienna, Austria) was started.Due to difficulties in getting peripheral venous access and to repeated loss of the venous access, continuous subcutaneous infusion of protein C was started with an insulin pump (VEO 754; Medtronic, Minneapolis, Minnesota, USA), normally adopted in patients with type 1 diabetes mellitus. Protein C values increased into the normal range and the resolution of the purpuric skin lesion was achieved. Chronic prophylaxis with low-molecular-weight heparin failed and, due to cutaneous and cerebral recrudescence, replacement therapy with the pump was started again. The insulin pump allowed us to reduce the number of injections per day and to deal with the difficulties in getting peripheral venous access, permitting medical and paramedical staff an easier management of the therapy. The dosing schedule could be easily adapted with the insulin pump and the continuous subcutaneous administration of small amounts of protein C concentrate prevented fluctuation in trough levels of protein C. This is the first reported case of a novel, successful use of an insulin pump in an extremely rare disease, to administer a drug different from insulin, which needs to be further analyzed, underlining the importance of a multidisciplinary team approach in order to provide effective and efficient care in high-complexity diseases.

Type 1 diabetes onset and pandemic influenza A (H1N1).

Type 1 diabetes (T1D) is a heterogeneous disorder characterized by destruction of pancreatic beta cells, culminating in loss of insulin secretion. Data from large epidemiologic studies worldwide indicate that during the last decades the incidence of T1D has increased significantly, reaching percentages of 2–5% annually. This increase suggests that there is a significant environmental contribution impacting the development of the disease, since genetic factors alone can hardly explain the rapid increase. Studies regarding T1D epidemiology in diverse populations aim to identify the disease causal factors and new targets for intervention. Viruses are one of the environmental factors implicated in the development of T1D in susceptible individuals. Recent studies suggest an association of T1D with H1N1 influenza. We would like to comment on this association and report our experience. Prospective studies are necessary to assess whether H1N1 infection is involved in T1D pathogenesis and provide directions on how to deal with viral infections in diabetes-susceptible individuals.

Retrospective Evaluation of Metformin and/or Metformin Plus a New Polysaccharide Complex in Treating Severe Hyperinsulinism and Insulin Resistance in Obese Children and Adolescents with Metabolic Syndrome

Background: Pharmacological treatment of obesity and glucose-insulin metabolism disorders in children may be more difficult than in adults. Thus, we evaluate the effects of metformin in comparison with metformin plus a polysaccharide complex (Policaptil Gel Retard®, PGR) on body weight and metabolic parameters in obese children and adolescents with metabolic syndrome (MetS). Patients and methods: We retrospectively collected 129 children and adolescents (67 girls, 62 boys; median age 12.6 years) treated for a minimum of two years with metformin and low glycemic index (LGI) diet. Of these, 71 patients were treated with metformin plus PGR after at least 12 months of metformin alone. To minimize the confounding effect of the LGI on auxological and metabolic parameters, the patients were compared with age-, sex-, and BMI-matched control group with obesity and MetS (51 subjects; 24 males, 27 females) treated only with a LGI diet. Assessments included lipids, glucose and insulin (fasting and after oral glucose tolerance test) concentrations. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Matsuda, insulinogenic and disposition indices were calculated. Results: Metformin treatment led to a significant reduction in BMI SDS (p < 0.0001), with a significant difference in ΔBMI SDS between patients and controls (p < 0.0001). Moreover, metformin treated patients showed a reduction in HOMA-IR (p < 0.0001), HbA1c levels (p < 0.0001) and a significant increase in Matsuda index (p < 0.0001) in respect to the reduction discovered in controls (p < 0.05). Moreover, in contrast to the group treated with metformin alone and controls, patients treated with metformin plus PGR showed a further reduction in BMI SDS (p < 0.0001), HOMA-IR (p < 0.0001), HbA1c (p < 0.0001), total, HDL and LDL cholesterol (p < 0.0001), as well as an increase in Matsuda (p < 0.0001), disposition (p < 0.005) and insulinogenic (respectively, p < 0.05 and p < 0.0001) indices. Conclusions: Metformin appears to show short-term efficacy in reducing BMI, adiposity and glucose and insulin parameters in obese children and adolescents with MetS. However, PGR added to metformin may be useful to potentiate weight loss and to improve glucose-insulin metabolism and adiposity parameters in these patients.

Circulating Endothelial Progenitor Cells in Type 1 Diabetic Patients: Relation with Patients’ Age and Disease Duration

Objectives Circulating endothelial progenitor cells (cEPCs) have been reported to be dysfunctional in diabetes mellitus (DM) patients, accounting for the vascular damage and the ensuing high risk for cardiovascular disease (CVD) characteristic of this disease. The aim of the present study was to evaluate the number of circulating cEPCs in type 1 DM (T1DM) patients, without clinical vascular damage, of different ages and with different disease duration. Methods An observational, clinical-based prospective study was performed on T1DM patients enrolled in two clinical centers. cEPCs were determined by flow cytometry, determining the number of CD34/CD133/VEGFR2-positive cells within peripheral blood mononuclear cells (PBMCs). Results The number of cEPCs was lower in adult T1DM patients, whilst higher in childhood/young patients, compared to controls of the same age range. When patients were grouped into two age groups (≥ or <20 years) (and categorized on the basis of the duration of the disease), the number of cEPCs in young (<20 years) patients was higher compared with older subjects, regardless of disease duration. A subset of patients with very high cEPCs was identified in the <20 years group. Conclusion There is an association between the number of cEPCs and patients’ age: childhood/young T1DM patients have significantly higher levels of cEPCs, respect to adult T1DM patients. Such difference is maintained also when the disease lasts for more than 10 years. The very high levels of cEPCs, identified in a subset of childhood/young patients, might protect vessels against endothelial dysfunction and damage. Such protection would be less operative in older subjects, endowed with lower cEPC numbers, in which complications are known to develop more easily.

Recommendations for the use of sensor‐augmented pumps with predictive low‐glucose suspend features in children: The importance of education

Abstract: Sensor‐augmented pumps, which consist of a pump and a continuous glucose monitoring system, offer considerable therapeutic opportunities, despite requiring close attention in the early phase of their use. The aim of this paper is to provide recommendations on the use of a predictive low glucose management (PLGM) system (Minimed 640G™, Medtronic, Northridge, CA, USA) in adolescents with type 1 diabetes either at the start of therapy or during follow‐up. Sound clinical recommendations on PLGM are of increasing importance since several recent papers have reported significant clinical improvements in patients with PLGM, especially in adults. These recommendations are based on the experience of a group of pediatric endocrinologists who collaborated to closely and intensively study the on‐boarding of adolescent patients with type 1 diabetes on automated systems to gain first‐hand experience and peer‐to‐peer insights in a unique free‐living environment. The suggestions provided here are indicative, so can be adapted to the individual realities and experiences of different diabetes centers. However, we believe that close adherence to the proposed scheme is likely to increase the chances of improving the clinical and metabolic outcomes of patients treated with this therapy.

Combined therapy with insulin and growth hormone in 17 patients with type-1 diabetes and growth disorders.

Background/Aim: Combined growth hormone (GH) and insulin therapy is rarely prescribed by pediatric endocrinologists. We investigated the attitude of Italian physicians to prescribing that therapy in the case of short stature and type-1 diabetes (T1DM). Methods: A questionnaire was sent and if a patient was identified, data on growth and diabetes management were collected. Results: Data from 42 centers (84%) were obtained. Of these, 29 centers reported that the use of combined therapy was usually avoided. A total of 17 patients were treated in 13 centers (GH was started before T1DM onset in 9 patients and after the onset of T1DM in 8). Height SDS patterns during GH therapy in the 11 patients affected by GH deficiency ranged from -0.3 to +3.1 SDS. In the 8 diabetic patients in whom GH was added subsequently, mean insulin dose increased during the first 6 months of therapy from 0.7 ± 0.2 to 1.0 ± 0.2 U/kg (p = 0.004). HbA1c was unchanged during the first 6 months of combined therapy. Conclusions: Most Italian physicians do not consider prescribing the combined GH-insulin therapy in diabetic children with growth problems. However, the results of the 17 patients identified would confirm that the combined therapy was feasible and only caused mild insulin resistance. GH therapy was effective in promoting growth in most patients and did not affect diabetes metabolic control.