Outcomes of hybrid closed-loop insulin delivery activated 24/7 versus evening and night in free-living prepubertal children with type 1 diabetes: A multicentre, randomized clinical trial.

AIM: To assess the safety and efficacy of hybrid closed-loop (HCL) insulin delivery 24/7 versus only evening and night (E/N), and on extended 24/7 use, in free-living children with type 1 diabetes. MATERIALS AND METHODS: Prepubertal children (n = 122; 49 females/73 males; age, 8.6 ± 1.6 years; diabetes duration, 5.2 ± 2.3 years; insulin pump use, 4.6 ± 2.5 years; HbA1c 7.7% ± 0.7%/61 ± 5 mmol/mol) from four centres were randomized for 24/7 versus E/N activation of the Tandem Control-IQ system for 18 weeks. Afterwards, all children used the activated system 24/7 for 18 more weeks. The primary outcome was the percentage of time spent in the 70-180 mg/dL glucose range (TIR). RESULTS: HCL was active 94.1% and 51.1% of the time in the 24/7 and E/N modes, respectively. TIR from baseline increased more in the 24/7 versus the E/N mode (52.9% ± 9.5% to 67.3% ± 5.6% [+14.4%, 95% CI 12.4%-16.7%] vs. 55.1% ± 10.8% to 64.7% ± 7.0% [+9.6%, 95% CI 7.4%-11.6%]; P = .001). Mean percentage time below range was similarly reduced, from 4.2% and 4.6% to 2.7%, and the mean percentage time above range decreased more in the 24/7 mode (41.9% to 30.0% [-11.9%, 95% CI 9.7%-14.6%] vs. 39.8% to 32.6% [-7.2%, 95% CI 5.0%-9.9%]; P = .007). TIR increased through the whole range of baseline levels and always more with 24/7 use. The results were maintained during the extension phase in those initially on 24/7 use and improved in those with initial E/N use up to those with 24/7 use. Neither ketoacidosis nor severe hypoglycaemia occurred. CONCLUSIONS: The current study shows the safety and efficacy of the Tandem Control-IQ system in free-living children with type 1 diabetes for both E/N and 24/7 use; 24/7 use shows better outcomes, sustained for up to 36 weeks with no safety issues.

Validation of the "Good2Go": the first French-language transition readiness questionnaire.

The use of transition readiness questionnaires is strongly recommended in adolescents with chronic conditions. The aim of our study was to validate "Good2Go," the first French-language transition readiness questionnaire. We analyzed the data from 2 multicentric studies (Canada and France) involving adolescents with chronic conditions (type 1 diabetes, inflammatory bowel disease, cystic fibrosis, epilepsy, juvenile idiopathic arthritis). Content and construct validity were examined using factorial and Rasch analysis (structural validity), Spearman's correlation, and Mann-Whitney test (external validity). Cronbach's α and intra-class correlation coefficients explored reliability. Cognitive interviews assessed wording comprehension and item appropriateness. Good2Go was completed by 321 participants (boys = 51%; mean age = 16.4 years (standard deviation = 1.5; min = 14.0; max = 18.0); Canada = 51.1%). Factor analysis identified 3 domains: "health self-advocacy," "knowledge about chronic conditions," and "self-management skills." The 3-domain structure showed a satisfying Rasch fit, internal consistency, and test-retest reliability. Good2Go domain scores were significantly higher in participants over 17 years of age, indicating satisfactory external validity.Conclusion: Good2Go is a valid 20-item questionnaire to assess transition readiness in adolescents with chronic conditions and may be useful in routine care to propose individually tailored preparation for their transfer to adult healthcare. Further research is now needed to analyze correlation between domain scores and success of transition.What is Known:• In adolescents with chronic conditions, the use of transition readiness questionnaires is recommended to propose individually tailored preparation for their transfer to adult healthcare.• However, no French-language questionnaire has been so far validated.What is New:• Based on a complete validation methodology, this study highlights that the French-language 20-items Good2Go questionnaire has good psychometric properties.• It explores all transition key points though 3 scored domains: "health self-advocacy", "knowledge about chronic disease" and "self-management skills".

Closed-loop driven by control-to-range algorithm outperforms threshold-low-glucose-suspend insulin delivery on glucose control albeit not on nocturnal hypoglycaemia in prepubertal patients with type 1 diabetes in a supervised hotel setting.

This randomized control trial investigated glucose control with closed-loop (CL) versus threshold-low-glucose-suspend (TLGS) insulin pump delivery in pre-pubertal children with type 1 diabetes in supervised hotel conditions. The patients [n = 24, age range: 7-12, HbA1c: 7.5 ± 0.5% (58 ± 5 mmol/mol)] and their parents were admitted twice at a 3-week interval. CL control to range or TLGS set at 3.9 mmoL/L were assessed for 48 hour in randomized order. Admissions included three meals and one snack, and physical exercise. Meal boluses followed individual insulin/carb ratios. While overnight (22:00-08:00) per cent continuous glucose monitoring (CGM) time below 3.9 mmol/L (primary outcome) was similar, time in ranges 3.9 to 10.0 and 3.9 to 7.8 mmoL/L and mean CGM were all significantly improved with CL (P < 0.001). These results were confirmed over the whole 48 hour. Disconnections between devices and limited accuracy of glucose sensors in the hypoglycaemic range appeared as limiting factors for optimal control. CL mode was well accepted while fear of hypoglycaemia was unchanged. CL did not minimize nocturnal hypoglycaemia exposure but improved time in target range compared to TLGS. Although safe and well-accepted, CL systems would benefit from more integrated devices.

Is there an optimal strategy for real-time continuous glucose monitoring in pediatrics? A 12-month French multi-center, prospective, controlled randomized trial (Start-In!).

AIM: To compare the efficacy of three strategies for real-time continuous glucose monitoring (RT-CGM) over 12 months in children and adolescents with type 1 diabetes. METHODS: A French multicenter trial (NCT00949221) with a randomized, controlled, prospective, open, and parallel-group design was conducted. After 3 months of RT-CGM, patients were allocated to one of three groups: return to self-monitoring of blood glucose, continuous CGM (80% of the time), or discontinuous CGM (40% of the time). The primary outcome was hemoglobin A1c (HbA1c) levels from 3 to 12 months. The secondary outcomes were acute metabolic events, hypoglycemia, satisfaction with CGM and cost. RESULTS: We included 151 subjects, aged 2 to 17 years, with a mean HbA1c level of 8.5% (SD0.7; 69 mmol/mol). The longitudinal change in HbA1c levels was similar in all three groups, at 3, 6, 9 and 12 months. The medical secondary endpoints did not differ between groups. The rate of severe hypoglycemia was significantly lower than that for the pretreatment year for the entire study population. Subjects reported consistent use and good tolerance of the device, regardless of age or insulin treatment. The use of full-time RT-CGM for 3 months costs the national medical insurance system €2629 per patient. CONCLUSION: None of the three long-term RT-CGM strategies evaluated in pediatric type 1 diabetes was superior to the others in terms of HbA1c levels. CGM-use for 3 months decreased rates of severe hypoglycemia. Our results confirm the feasibility of long-term RT-CGM-use and the need to improve educational support for patients and caregivers.

[Technological innovations in the treatment of type 1 diabetes in pediatrics]. / Innovations technologiques dans le traitement du diabète de type 1 en pédiatrie.

Insulin pumps, continuous glucose monitoring sensors and algorithms for managing the doses of insulin necessary to control blood sugar levels within target values: more and more research is being carried out into "closed loop" systems. The artificial pancreas is today at the stage of clinical trials in adults and children.

Hybrid Closed Loop Overcomes the Impact of Missed or Suboptimal Meal Boluses on Glucose Control in Children with Type 1 Diabetes Compared to Sensor-Augmented Pump Therapy.

Background: It is unclear whether hybrid closed-loop (HCL) therapy attenuates the metabolic impact of missed or suboptimal meal insulin bolus compared with sensor-augmented pump (SAP) therapy in children with type 1 diabetes in free-living conditions. Methods: This is an ancillary study from a multicenter randomized controlled trial that compared 24/7 HCL with evening and night (E/N) HCL for 36 weeks in children between 6 and 12 years old. In the present study, the 60 children from the E/N arm underwent a SAP phase, an E/N HCL for 18 weeks, then a 24/7 phase for 18 weeks, extended for 36 more weeks. The last 28-30 days of each of the four phases were analyzed according to meal bolus management (cumulated 6817 days). The primary endpoint was the percentage of time that the sensor glucose was in the target range (TIR, 70-180 mg/dL) according to the number of missed boluses per day. Findings: TIR was 54% ± 10% with SAP, 63% ± 7% with E/N HCL, and steadily 67% ± 7% with 24/7 HCL. From the SAP phase to 72 weeks of HCL, the percentage of days with at least one missed meal bolus increased from 12% to 22%. Estimated marginal (EM) mean TIR when no bolus was missed was 54% (95% confidence intervals [CI] 53-56) in SAP and it was 13% higher (95% CI 11-15) in the 24/7 HCL phase. EM mean TIR with 1 and ≥2 missed boluses/day was 49.5% (95% CI 46-52) and 45% (95% CI 39-51) in SAP, and it was 15% (95% CI 14-16) and 17% higher (95% CI 6-28), respectively, in the 24/7 HCL phase (P < 0.05 for all comparisons vs. SAP). Interpretation: HCL persistently improves glycemic control compared with SAP, even in case of meal bolus omission. ClinicalTrials.gov (NCT03739099).

Childhood onset diabetes posttransplant in a girl with TCF2 mutation.

Heterozygous mutations of TCF2 (transcription factor 2) have been associated with maturity onset diabetes of the young, renal malformations, hyperuricemia, and occasionally internal genital malformations in female. We report a female patient with bilateral renal hypodysplasia and de novo heterozygous TCF2 gene mutation. At the age of 9 yr, she developed transient ketoacidosis immediately posttransplant, temporarily requiring insulin. During glucocorticoid tapering, impaired glucose tolerance persisted and overt insulin-dependent diabetes mellitus developed 1 yr later. Pathogenic factors which might have played a role in the acceleration of diabetes were (i) switch from cyclosporine to tacrolimus, (ii) weight excess, and (iii) cytomegalovirus infection. TCF2 analysis might, therefore, be of interest in patients with congenital abnormalities of the kidney and the urinary tract in order to improve posttransplant management in terms of steroid and tacrolimus exposure.

[The Ceduc, a multi-pathology therapeutic education centre]. / Le Ceduc, un centre d'éducation thérapeutique multipathologies.

The Ceduc, a multi-pathology therapeutic education centre. Patient therapeutic education has undergone rapid development in France. In 2005, at the Robert-Debré hospital in Paris, the professionals involved in education activities grouped together to create a multipathology centre, the Ceduc. This centre benefits from experiences and resources of the various actors who take care of sick children and their families.

How to collect non-medical data in a pediatric trial: diaries or interviews.

BACKGROUND: Non-medical data, such as the amount of time that patients and caregivers spend managing their condition, may be relevant when assessing therapeutic strategies. For chronic pediatric conditions, the time that patients and caregivers spend in seeking and providing care (which are the indirect costs in an economic evaluation) can be significantly different depending on the treatment arm. To explore methods for collecting information on the care burden for caregivers and patients, we investigated whether a patient diary provided additional information compared to retrospective investigator-led interviews and whether a diary that was completed intermittently produced more or less information than a diary completed continually. The main objective of this study was to identify which type of data collection was most effective for measuring the time spent by caregivers and for estimating indirect treatment costs over 9 months. METHODS: Start-In! is a randomized controlled trial comparing the efficacy of three strategies of real-time continuous glucose monitoring for 12 months in children and adolescents with type 1 diabetes. We designed an ancillary study to assess methods of collecting information on the time spent by patients and caregivers in managing their condition (indirect costs). Data were entered retrospectively in case report forms (CRFs) by investigators during quarterly follow-up visits, which were supplemented with diaries completed prospectively by children or caregivers either continuously or intermittently. Data about absences from school and work as well as the time that caregivers spent on diabetes care were collected and the three collection methods were compared. RESULTS: At the end of the 9-month study, 42% of the study participants failed to return their diary. For the diaries that were received, less than 10% of expected data were collected versus 82% during investigators'interviews. Based on all the information collected, we calculated that over 9 months, caregivers lost on average 3.9 days of working time (€786) and 4 days of personal time, i.e. the equivalent of €526, and spent around 15 min of time on care per day, i.e. the equivalent of €1700. CONCLUSIONS: The CRFs completed by investigators during quarterly visits cannot be replaced by a diary. Completing the diaries appeared to represent an important additional burden to children and their caregivers, and the diaries provided little additional information compared to investigators' entries in the CRF. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00949221. Registered on 30 July 2009. Registry name: Study of Insulin Therapy Augmented by Real Time Sensor in Type 1 Children and Adolescents (START-IN!).

How Should We Assess Glycemic Variability in Type 1 Diabetes? Contribution of Principal Component Analysis for Interstitial Glucose Indices in 142 Children.

BACKGROUND: Glycemic variability (GV) can be used to assess glycemic control in diabetes, but there is no clear consensus concerning the methods to use for its assessment. Methodological differences have resulted in differences in the outcome of GV metrics used in research studies, controversies over clinical impact, and an absence of integration into routine care. AIM: To identify the indicators of GV most meaningful for clinicians, patients, and clinical researchers. MATERIALS AND METHODS: Continuous glucose monitoring data were collected during the first 3 months of a pediatric diabetes clinical trial (Start-In!; n = 142). We used principal component analysis (PCA) to analyze weekly averages for 22 parameters relating to GV. RESULTS: PCA identified five groups of parameters and three components explaining 85.7% of the variance. These components represented the amplitude, direction (hypoglycemia vs. hyperglycemia), and timing (within-day vs. between-days) of glucose excursions. CONCLUSIONS: This study provides elements that could make GV parameters more useful in clinical practice and research. No single parameter was sufficient to represent the complexity of GV, but it was possible to restrict the number of indicators required. The five groups of parameters identified by PCA could facilitate the choice of the most relevant outcomes for GV analysis in pediatric diabetes according to the purpose of the analysis (e.g., exploration of GV associated with hypo- or hyperglycemia, with short- or long-term periodicity, or GV in its entirety).

Insulin pump therapy in neonatal diabetes.

Neonatal diabetes mellitus is rare. Typically, infants are of low birth weight and develop hyperglycemia requiring exogenous insulin within the first 6 weeks. Although pediatricians face numerous difficulties in managing insulin therapy at this age, very few data are available on possible methods of insulin delivery in neonatal diabetes. We report our experience over 18 years of continuous subcutaneous insulin infusion (CSII) in cases of neonatal diabetes requiring insulin therapy for more than 15 days (n=17; 8 permanent). CSII therapy in neonatal diabetes allows easy adaptation of insulin delivery, closely following the current feeding regimen (a basal infusion only being needed when using continuous enteral or parenteral feeding; preprandial boluses being started with intermittent bottle feeding). Management of the very small insulin doses (for example: bolus=0.20 U and basal rate=0.02 U/h) required is possible after insulin dilution (5-10 U/ml) and is more accurate with CSII than with syringes. Controlling blood glucose with few hypoglycemic events, which are particularly frequent and dangerous at this age, is more efficient with CSII than with injections. Infants tolerate the subcutaneous infusion lines well and we did not observe any side effects. For all children, CSII was utilized throughout the whole period of insulin therapy. In conclusion, during the neonatal period, and under the supervision of an experienced team, CSII is safe, more physiological and accurate and easier to manage than injections allowing easier matching of the insulin requirements of a newborn.

High Prevalence of Polycystic Ovary Syndrome in Type 1 Diabetes Mellitus Adolescents: Is There a Difference Depending on the NIH and Rotterdam Criteria?

BACKGROUND: Polycystic ovary syndrome (PCOS) is more frequently observed in type 1 diabetes mellitus (T1DM) adult women than in nondiabetic women. No such prevalence has yet been studied in adolescent girls with T1DM. AIM: The aim of this study was to evaluate the prevalence of PCOS in adolescent girls with T1DM and to determine the clinical and hormonal features associated with the disorder. METHODS: A cross-sectional study of 53 adolescent girls (gynecological age >2 years) referred for routine evaluation for T1DM was conducted. We diagnosed PCOS using the National Institutes of Health (NIH) and Rotterdam criteria. RESULTS: 26.4 and 47.9% of adolescents had PCOS according to NIH (NIH-PCOS) and Rotterdam (Rotterdam-PCOS) criteria. 66.7% of NIH-PCOS adolescents had a complete phenotype associated with hyperandrogenism, oligomenorrhea, and polycystic ovarian morphology, unlike only 33.3% of the Rotterdam-PCOS adolescents. A family history of type 2 diabetes mellitus (T2DM) was more frequent in PCOS than in non-PCOS girls, whichever criteria were used. Late pubertal development and a T1DM diagnosis close to puberty were factors associated with NIH-PCOS. CONCLUSION: Adolescents with T1DM had a high prevalence of PCOS. More differences between PCOS and non-PCOS patients were found using the NIH criteria, suggesting that clinical characteristics might be more accurate for diagnosing PCOS in girls with T1DM. A family history of T2DM is associated with a high risk of PCOS.

Characterization of insulin secretion and resistance in type 2 diabetes of adolescents.

CONTEXT: Type 2 diabetes (T2D) in obese children is an emerging problem, including in Europe. Its presentation at diagnosis very often differs from that in adults. OBJECTIVE: The objective of this study was to investigate the relative contributions of the two components of T2D, insulin resistance and insulin secretion, early in the history of the disease in adolescents. PATIENTS AND METHODS: Six obese adolescents with T2D were included 2 months to 4.3 yr after diagnosis (five girls and one boy; median age, 15.4 yr; median body mass index, 4.4 sd). Peripheral and hepatic insulin sensitivity was evaluated with euglycemic hyperinsulinemic (40 mU/m(2).min) clamp. First-phase insulin release was evaluated after iv glucose stimulation. A graded iv glucose infusion and an arginine test were performed to measure insulin secretion. RESULTS: All patients showed decreased peripheral glucose uptake to the same extent. Five patients showed hepatic insulin resistance. First-phase insulin release was very low in two patients. Three patients showed an exaggerated insulin response under graded glucose infusion and preserved secretion under arginine stimulation. Three other patients, with elevated fasting plasma glucose levels, demonstrated a very low insulin response under glucose stimulation and a low insulin response under arginine stimulation. CONCLUSIONS: These data emphasize that together with marked insulin resistance, the failure of beta-cell function is a major component in the course of T2D in childhood.

Lower bone mineral content in children with type 1 diabetes mellitus is linked to female sex, low insulin-like growth factor type I levels, and high insulin requirement.

CONTEXT: Studies on bone mineral characteristics in children with type 1 diabetes mellitus (T1DM) have generated conflicting results. OBJECTIVE: Our objective was to investigate bone mineral characteristics in children with T1DM and to analyze their associations with bone metabolism and the IGF-I system. DESIGN: We recruited a cohort of Caucasian patients with T1DM for at least 3 yr and healthy children between January 2003 and June 2004. SETTING: This was a university hospital-based study. PARTICIPANTS: A total of 127 patients and 319 controls aged 6 to 20 yr participated. METHODS: Dual-energy x-ray absorptiometry was performed in patients and controls. Serum bone alkaline phosphatase, CrossLaps, IGF-I, and IGF-binding protein 3 levels were determined in patients with values analyzed using our normative data from 1150 healthy children. RESULTS: After adjustment for age, sex, pubertal stage, and body mass index sd score, total body bone mineral content (BMC)/lean body mass was significantly lower in patients than in controls (P < 0.04). This difference was a result of the differences between the girls of the two groups. Girls with T1DM had significantly lower lumbar spine and total body BMC than control girls (P = 0.002), whereas no such difference was observed in boys. Serum bone alkaline phosphatase level was significantly lower in girls than in boys (P = 0.04). Low serum IGF-I levels and the administration of large amounts of insulin were found to have independent deleterious effects on BMC for children of all ages and both sexes, whereas disease duration and glycosylated hemoglobin levels did not. CONCLUSIONS: A sex-related difference in the impairment of bone mineral characteristics was identified in children with T1DM. Longitudinal studies are required to investigate whether boys may gain slightly less bone mass during skeletal growth.

Prevalence of mutations in AGPAT2 among human lipodystrophies.

Berardinelli-Seip congenital lipodystrophy (BSCL) is a heterogeneous genetic disease characterized by near absence of adipose tissue and severe insulin resistance. We have previously identified mutations in the seipin gene in a subset of our patients' cohort. Recently, disease-causing mutations in AGPAT2 have been reported in BSCL patients. In this study, we have performed mutation screening in AGPAT2 and the related AGPAT1 in patients with BSCL or other forms of lipodystrophy who have no detectable mutation in the seipin gene. We found 38 BSCL patients from 30 families with mutations in AGPAT2. Three of the known mutations were frequently found in our families. Of the eight new alterations, six are null mutations and two are missense mutations (Glu172Lys and Ala238Gly). All the patients harboring AGPAT2 mutations presented with typical features of BSCL. We did not find mutations in patients with other forms of lipodystrophies, including the syndromes of Lawrence, Dunnigan, and Barraquer-Simons, or with type A insulin resistance. In conclusion, mutations in the seipin gene and AGPAT2 are confined to the BSCL phenotype. Because we found mutations in 92 of the 94 BSCL patients studied, the seipin gene and AGPAT2 are the two major genes involved in the etiology of BSCL.

[Emergence of type 2 diabetes in French children]. / Emergence du diabète de type II chez l'enfant, en France.

Increasing awareness of the heterogeneity of diabetes mellitus (DM) at presentation is changing our approach to this disease. We used the American Diabetes Association (ADA) criteria to determine the distribution of DM patterns in a large pediatric cohort, with the aim of documenting the emergence of type 2 diabetes mellitus. Charts of diabetic children aged 1 to 16 years and admitted to our center between 1993 and 1998 were reviewed for data needed to classify the type of diabetes mellitus. They were compared with the charts of diabetic children admitted to our center in 2001. During the first period, 370 children were admitted for diabetes, and type 2 diabetes was diagnosed in 8 cases. In 2001, 90 children were admitted for diabetes, of whom 5 were diagnosed with type 2 diabetes. The incidence of type 2 diabetes in France remains relatively low. Even though our data seem to indicate a slight increase, they are far below the figures reported by American pediatricians. However, cases in France are marked by major obesity. With the increase in childhood obesity in France, the incidence of type 2 diabetes may eventually rise to North American levels.

A simple and fast non-radioactive bridging immunoassay for insulin autoantibodies.

Type 1 diabetes (T1D) is an autoimmune disease which results from the destruction of pancreatic beta cells. Autoantibodies directed against islet antigens are valuable diagnostic tools. Insulin autoantibodies (IAAs) are usually the first to appear and also the most difficult to detect amongst the four major islet autoantibodies. A non-radioactive IAA bridging ELISA was developed to this end. In this assay, one site of the IAAs from serum samples is bound to a hapten-labeled insulin (GC300-insulin), which is subsequently captured on anti-GC300 antibody-coated 96-well plates. The other site of the IAAs is bound to biotinylated insulin, allowing the complex to be detected by an enzyme-streptavidin conjugate. In the present study, 50 serum samples from patients with newly diagnosed T1D and 100 control sera from non-diabetic individuals were analyzed with our new assay and the results were correlated with an IAA radioimmunoassay (RIA). Using IAA bridging ELISA, IAAs were detected in 32 out of 50 T1D children, whereas with IAA RIA, 41 out of 50 children with newly diagnosed T1D were scored as positive. In conclusion, the IAA bridging ELISA could serve as an attractive approach for rapid and automated detection of IAAs in T1D patients for diagnostic purposes.

Neuropsychological dysfunction and developmental defects associated with genetic changes in infants with neonatal diabetes mellitus: a prospective cohort study [corrected].

BACKGROUND: Neonatal diabetes mellitus is a rare genetic form of pancreatic ß-cell dysfunction. We compared phenotypic features and clinical outcomes according to genetic subtypes in a cohort of patients diagnosed with neonatal diabetes mellitus before age 1 year, without ß-cell autoimmunity and with normal pancreas morphology. METHODS: We prospectively investigated patients from 20 countries referred to the French Neonatal Diabetes Mellitus Study Group from 1995 to 2010. Patients with hyperglycaemia requiring treatment with insulin before age 1 year were eligible, provided that they had normal pancreatic morphology as assessed by ultrasonography and negative tests for ß-cell autoimmunity. We assessed changes in the 6q24 locus, KATP-channel subunit genes (ABCC8 and KCNJ11), and preproinsulin gene (INS) and investigated associations between genotype and phenotype, with special attention to extra-pancreatic abnormalities. FINDINGS: We tested 174 index patients, of whom 47 (27%) had no detectable genetic defect. Of the remaining 127 index patients, 40 (31%) had 6q24 abnormalities, 43 (34%) had mutations in KCNJ11, 31 (24%) had mutations in ABCC8, and 13 (10%) had mutations in INS. We reported developmental delay with or without epilepsy in 13 index patients (18% of participants with mutations in genes encoding KATP channel subunits). In-depth neuropsychomotor investigations were done at median age 7 years (IQR 1-15) in 27 index patients with mutations in KATP channel subunit genes who did not have developmental delay or epilepsy. Developmental coordination disorder (particularly visual-spatial dyspraxia) or attention deficits were recorded in all index patients who had this testing. Compared with index patients who had mutations in KATP channel subunit genes, those with 6q24 abnormalities had specific features: developmental defects involving the heart, kidneys, or urinary tract (8/36 [22%] vs 2/71 [3%]; p=0·002), intrauterine growth restriction (34/37 [92%] vs 34/70 [48%]; p<0·0001), and early diagnosis (median age 5·0 days, IQR 1·0-14·5 vs 45·5 days, IQR 27·2-95·0; p<0·0001). Remission of neonatal diabetes mellitus occurred in 89 (51%) index patients at a median age of 17 weeks (IQR 9·5-39·0; median follow-up 4·7 years, IQR 1·5-12·8). Recurrence was common, with no difference between the groups who had 6q24 abnormalities versus mutations in KATP channel subunit genes (82% vs 86%; p=0·36). INTERPRETATION: Neonatal diabetes mellitus is often associated with neuropsychological dysfunction and developmental defects that are specific to the underlying genetic abnormality. A multidisciplinary assessment is therefore essential when patients are diagnosed. Features of neuropsychological dysfunction and developmental defects should be tested for in adults with a history of neonatal diabetes mellitus. FUNDING: Agence Nationale de la Recherche-Maladies Rares Research Program Grant, the Transnational European Research Grant on Rare Diseases, the Société Francophone du Diabète-Association Française du Diabète, the Association Française du Diabète, Aide aux Jeunes Diabétiques, a CIFRE grant from the French Government, HRA-Pharma, the French Ministry of Education and Research, and the Société Française de Pédiatrie.