Randomized Trial of Closed-Loop Control in Very Young Children with Type 1 Diabetes.

BACKGROUND: The possible advantage of hybrid closed-loop therapy (i.e., artificial pancreas) over sensor-augmented pump therapy in very young children with type 1 diabetes is unclear. METHODS: In this multicenter, randomized, crossover trial, we recruited children 1 to 7 years of age with type 1 diabetes who were receiving insulin-pump therapy at seven centers across Austria, Germany, Luxembourg, and the United Kingdom. Participants received treatment in two 16-week periods, in random order, in which the closed-loop system was compared with sensor-augmented pump therapy (control). The primary end point was the between-treatment difference in the percentage of time that the sensor glucose measurement was in the target range (70 to 180 mg per deciliter) during each 16-week period. The analysis was conducted according to the intention-to-treat principle. Key secondary end points included the percentage of time spent in a hyperglycemic state (glucose level, >180 mg per deciliter), the glycated hemoglobin level, the mean sensor glucose level, and the percentage of time spent in a hypoglycemic state (glucose level, <70 mg per deciliter). Safety was assessed. RESULTS: A total of 74 participants underwent randomization. The mean (±SD) age of the participants was 5.6±1.6 years, and the baseline glycated hemoglobin level was 7.3±0.7%. The percentage of time with the glucose level in the target range was 8.7 percentage points (95% confidence interval [CI], 7.4 to 9.9) higher during the closed-loop period than during the control period (P<0.001). The mean adjusted difference (closed-loop minus control) in the percentage of time spent in a hyperglycemic state was -8.5 percentage points (95% CI, -9.9 to -7.1), the difference in the glycated hemoglobin level was -0.4 percentage points (95% CI, -0.5 to -0.3), and the difference in the mean sensor glucose level was -12.3 mg per deciliter (95% CI, -14.8 to -9.8) (P<0.001 for all comparisons). The time spent in a hypoglycemic state was similar with the two treatments (P = 0.74). The median time spent in the closed-loop mode was 95% (interquartile range, 92 to 97) over the 16-week closed-loop period. One serious adverse event of severe hypoglycemia occurred during the closed-loop period. One serious adverse event that was deemed to be unrelated to treatment occurred. CONCLUSIONS: A hybrid closed-loop system significantly improved glycemic control in very young children with type 1 diabetes, without increasing the time spent in hypoglycemia. (Funded by the European Commission and others; ClinicalTrials.gov number, NCT03784027.).

AiDAPT: automated insulin delivery amongst pregnant women with type 1 diabetes: a multicentre randomized controlled trial - study protocol.

BACKGROUND: Pregnant women with type 1 diabetes strive for tight glucose targets (3.5-7.8 mmol/L) to minimise the risks of obstetric and neonatal complications. Despite using diabetes technologies including continuous glucose monitoring (CGM), insulin pumps and contemporary insulin analogues, most women struggle to achieve and maintain the recommended pregnancy glucose targets. This study aims to evaluate whether the use of automated closed-loop insulin delivery improves antenatal glucose levels in pregnant women with type 1 diabetes. METHODS/DESIGN: A multicentre, open label, randomized, controlled trial of pregnant women with type 1 diabetes and a HbA1c of ≥48 mmol/mol (6.5%) at pregnancy confirmation and ≤ 86 mmol/mol (10%) at randomization. Participants who provide written informed consent before 13 weeks 6 days gestation will be entered into a run-in phase to collect 96 h (24 h overnight) of CGM glucose values. Eligible participants will be randomized on a 1:1 basis to CGM (Dexcom G6) with usual insulin delivery (control) or closed-loop (intervention). The closed-loop system includes a model predictive control algorithm (CamAPS FX application), hosted on an android smartphone that communicates wirelessly with the insulin pump (Dana Diabecare RS) and CGM transmitter. Research visits and device training will be provided virtually or face-to-face in conjunction with 4-weekly antenatal clinic visits where possible. Randomization will stratify for clinic site. One hundred twenty-four participants will be recruited. This takes into account 10% attrition and 10% who experience miscarriage or pregnancy loss. Analyses will be performed according to intention to treat. The primary analysis will evaluate the change in the time spent in the target glucose range (3.5-7.8 mmol/l) between the intervention and control group from 16 weeks gestation until delivery. Secondary outcomes include overnight time in target, time above target (> 7.8 mmol/l), standard CGM metrics, HbA1c and psychosocial functioning and health economic measures. Safety outcomes include the number and severity of ketoacidosis, severe hypoglycaemia and adverse device events. DISCUSSION: This will be the largest randomized controlled trial to evaluate the impact of closed-loop insulin delivery during type 1 diabetes pregnancy. TRIAL REGISTRATION: ISRCTN 56898625 Registration Date: 10 April, 2018.

Index60 as an additional diagnostic criterion for type 1 diabetes.

AIMS/HYPOTHESIS: We aimed to compare characteristics of individuals identified in the peri-diagnostic range by Index60 (composite glucose and C-peptide measure) ≥2.00, 2 h OGTT glucose ≥11.1 mmol/l, or both. METHODS: We studied autoantibody-positive participants in the Type 1 Diabetes TrialNet Pathway to Prevention study who, at their baseline OGTT, had 2 h blood glucose ≥11.1 mmol/l and/or Index60 ≥2.00 (n = 354, median age = 11.2 years, age range = 1.7-46.6; 49% male, 83% non-Hispanic White). Type 1 diabetes-relevant characteristics (e.g., age, C-peptide, autoantibodies, BMI) were compared among three mutually exclusive groups: 2 h glucose ≥11.1 mmol/l and Index60 <2.00 [Glu(+), n = 76], 2 h glucose <11.1 mmol/l and Index60 ≥2.00 [Ind(+), n = 113], or both 2 h glucose ≥11.1 mmol/l and Index60 ≥2.00 [Glu(+)/Ind(+), n = 165]. RESULTS: Participants in Glu(+), vs those in Ind(+) or Glu(+)/Ind(+), were older (mean ages = 22.9, 11.8 and 14.7 years, respectively), had higher early (30-0 min) C-peptide response (1.0, 0.50 and 0.43 nmol/l), higher AUC C-peptide (2.33, 1.13 and 1.10 nmol/l), higher percentage of overweight/obesity (58%, 16% and 30%) (all comparisons, p < 0.0001), and a lower percentage of multiple autoantibody positivity (72%, 92% and 93%) (p < 0.001). OGTT-stimulated C-peptide and glucose patterns of Glu(+) differed appreciably from Ind(+) and Glu(+)/Ind(+). Progression to diabetes occurred in 61% (46/76) of Glu(+) and 63% (71/113) of Ind(+). Even though Index60 ≥2.00 was not a Pathway to Prevention diagnostic criterion, Ind(+) had a 4 year cumulative diabetes incidence of 95% (95% CI 86%, 98%). CONCLUSIONS/INTERPRETATION: Participants in the Ind(+) group had more typical characteristics of type 1 diabetes than participants in the Glu(+) did and were as likely to be diagnosed. However, unlike Glu(+) participants, Ind(+) participants were not identified at the baseline OGTT.

Functional Vision in Patients With Biallelic USH2A Variants.

PURPOSE: To describe functional vision (FV) and investigate the relationship between FV, visual acuity (VA), and hill of vision (VTOT) at baseline in patients with biallelic USH2A variants. DESIGN: Multicenter, international, cross-sectional study. METHODS: In individuals with biallelic disease-causing variants in USH2A, clinical diagnosis of Usher syndrome type 2 (USH2) or autosomal recessive nonsyndromic retinitis pigmentosa (ARRP) was based on history of hearing loss and audiology examinations. The VALVVFQ-48 was administered verbally to participants ≥18 years old. VA was measured in both eyes; VTOT was determined from static perimetry in the study eye (better VA). FV scores were calculated using Rasch analysis. RESULTS: Median age of 121 participants (76 with USH2, 45 with ARRP) was 41 years (range: 19-80); 54% were female. FV scores varied from -2.0 to 7.6 logits (median [interquartile range (IQR)]: 2.8 [1.5-3.8]). ARRP and USH2 participants had similar FV scores, both before [mean (95% CI): 2.8 (2.3-3.4) and 2.7 (2.3-3.2), respectively], and after [mean (95% CI): 2.5 (2.1-3.0) and 2.9 (2.6-3.3), respectively; P = .24] adjusting for age, VA, disease duration, and VTOT. VA and VTOT accounted for 29% and 26% of the variance in FV scores, respectively (P < .001 for each). Together, they accounted for 36% of variance observed. CONCLUSIONS: Biallelic USH2A variants were associated with a large range of FV, yet similar in ARRP and USH2, despite hearing loss in USH2. The modified VALVVFQ-48 we evaluated is not ideal for detecting the impact of USH2A-associated retinal degenerations on activities of daily living.

Accuracy of Three Commercial Home-Use Hemoglobin A1c Tests.

Background: The COVID-19 pandemic and the rapid expansion of telemedicine have increased the need for accurate and reliable capillary hemoglobin A1c (HbA1c) testing. Nevertheless, validation studies of commercially available products suitable for home use have been in short supply. Methods: Three commercial home-use capillary blood sample HbA1c tests (Home Access, CoreMedica, and A1cNow+) were evaluated in 219 participants with type 1 or type 2 diabetes (4-80 years years of age, HbA1c 5.1%-13.4% [32-123 mmol/mol]) at four clinical sites. Comparisons were made between HbA1c measurements from the commercial tests and paired venous samples for which HbA1c was measured at two central reference laboratories. The primary outcome was percentage of commercial HbA1c values within 5% of the corresponding reference values. Results: HbA1c values were within 5% (relative difference) of paired reference values for 82% of Home Access samples, 29% of CoreMedica samples, and 46% of A1cNow+ samples. Absolute differences were within 0.3% of the reference value for 75% of Home Access samples, 28% of CoreMedica samples, and 44% of A1cNow+ samples and exceeded 0.5% for 8%, 55%, and 37%, respectively. Conclusions: None of the commercial home-use HbA1c tests produced the National Glycohemoglobin Standardization Program goal of ≥90% measurements within 5% of a DCCT venous reference. However, the Home Access product performed substantially better than the CoreMedica or A1cNow+ products. Telemedicine is likely to persist as a mainstay of diabetes care well after the COVID-19 era. As such, accurate home-based HbA1c assessment represents an urgent need for the diabetes community.

Cambridge Hybrid Closed-Loop System in Very Young Children With Type 1 Diabetes Reduces Caregivers' Fear of Hypoglycemia and Improves Their Well-Being.

OBJECTIVE: To evaluate the impact of CamAPS FX hybrid closed-loop (HCL) automated insulin delivery in very young children with type 1 diabetes (T1D) on caregivers' well-being, fear of hypoglycemia, and sleepiness. RESEARCH DESIGN AND METHODS: We conducted a multinational, open-label, randomized crossover study. Children (age 1-7 years) with T1D received treatment for two 4-month periods in random order, comparing HCL with sensor augmented pump (control). At baseline and after each treatment period, caregivers were invited to complete World Health Organization-Five Well-Being Index, Hypoglycemia Fear Survey, and Epworth Sleepiness Scale questionnaires. RESULTS: Caregivers of 74 children (mean ± SD age 5 ± 2 years and baseline HbA1c 7.3 ± 0.7%; 42% female) participated. Results revealed significantly lower scores for hypoglycemia fear (P < 0.001) and higher scores for well-being (P < 0.001) after HCL treatment. A trend toward a reduction in sleepiness score was observed (P = 0.09). CONCLUSIONS: Our results suggest better well-being and less hypoglycemia fear in caregivers of very young children with T1D on CamAPS FX HCL.

Impact of bariatric surgery and weight loss medications in adults with type 1 diabetes in the T1D Exchange Clinic Registry.

AIM: To investigate the impact of bariatric surgery and weight loss medications in adults with type 1 diabetes. MATERIALS AND METHODS: Subjects enrolled in the T1D Exchange (T1DX) Clinic Registry age ≥ 18 years with a diabetes duration of ≥1 year were included in the analysis (n = 13,501). Data for participants (n = 37) with bariatric surgery after diabetes onset were assessed before and after surgery and also compared to a matched control group. Data for participants who reported the use of FDA-approved weight loss medications (n = 483) were assessed before starting, during use, and after stopping the medications and also compared to a matched control group. Variables of interest included BMI, HbA1c, blood pressure, lipid profile, rates of acute complications. Data were analyzed using linear mixed models. RESULTS: Bariatric surgery resulted in BMI reduction from 38.8 ±â€¯9.1 kg/m2 to 33.3 ±â€¯6.7 kg/m2 (P = 0.006) and HbA1c reduction from 8.8 ±â€¯1.3% (73 ±â€¯14.2 mmol/mol) to 8.1 ±â€¯1.1% (65 ±â€¯12.0 mmol/mol) (P = 0.05). Weight loss medications were not associated with weight loss or better glycemic control although stopping liraglutide favored weight gain. Both interventions were not associated with a significant change in blood pressure or lipid profile. There were no adverse events associated with the use of weight loss medications. CONCLUSIONS: Bariatric surgery is effective for weight loss and may improve glycemic control in selected patients. Weight loss medications are not associated with diabetes improvement. A trial with liraglutide may be attempted for weight control, but weight loss medications in general do not show a significant effect.

TCF7L2 Genetic Variants Do Not Influence Insulin Sensitivity or Secretion Indices in Autoantibody-Positive Individuals at Risk for Type 1 Diabetes.

OBJECTIVE: We aimed to test whether type 2 diabetes (T2D)-associated TCF7L2 genetic variants affect insulin sensitivity or secretion in autoantibody-positive relatives at risk for type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: We studied autoantibody-positive TrialNet Pathway to Prevention study participants (N = 1,061) (mean age 16.3 years) with TCF7L2 single nucleotide polymorphism (SNP) information and baseline oral glucose tolerance test (OGTT) to calculate indices of insulin sensitivity and secretion. With Bonferroni correction for multiple comparisons, P values < 0.0086 were considered statistically significant. RESULTS: None, one, and two T2D-linked TCF7L2 alleles were present in 48.1%, 43.9%, and 8.0% of the participants, respectively. Insulin sensitivity (as reflected by 1/fasting insulin [1/IF]) decreased with increasing BMI z score and was lower in Hispanics. Insulin secretion (as measured by 30-min C-peptide index) positively correlated with age and BMI z score. Oral disposition index was negatively correlated with age, BMI z score, and Hispanic ethnicity. None of the indices were associated with TCF7L2 SNPs. In multivariable analysis models with age, BMI z score, ethnicity, sex, and TCF7L2 alleles as independent variables, C-peptide index increased with age, while BMI z score was associated with higher insulin secretion (C-peptide index), lower insulin sensitivity (1/IF), and lower disposition index; there was no significant effect of TCF7L2 SNPs on any of these indices. When restricting the analyses to participants with a normal OGTT (n = 743; 70%), the results were similar. CONCLUSIONS: In nondiabetic autoantibody-positive individuals, TCF7L2 SNPs were not related to insulin sensitivity or secretion indices after accounting for BMI z score, age, sex, and ethnicity.

An Evaluation of Two Capillary Sample Collection Kits for Laboratory Measurement of HbA1c.

Background: The COVID-19 pandemic has impacted the conduct of clinic visits. We conducted a study to evaluate two academic laboratories' fingerstick capillary blood collection kits suitable for home use for laboratory measurement of HbA1c. Methods: Four clinical sites recruited 240 participants (aged 4-80 years, HbA1c 5.1%-13.5%). Capillary blood samples were obtained by the participant or parent using collection kits from two laboratories (University of Minnesota Advanced Research and Diagnostic Laboratory (ARDL) and Children's Mercy Hospital Laboratory (CMH)) and mailed under varying shipping conditions by United States Postal Service to the laboratories. Comparisons were made between HbA1c measurements from capillary samples and contemporaneously obtained venous samples. The primary outcome was percentage of capillary HbA1c values within 5% of the corresponding venous values. Results: HbA1c values were within 5% of venous values for 96% of ARDL kit specimens shipped with a cold pack and 98% without a cold pack and 99% and 99%, respectively, for the CMH kits. R2 values were 0.98, 0.99, 0.99, and 0.99, respectively. Results appeared similar across HbA1c levels and for pediatric and adult participants. Usability survey scores were high. Conclusions: Capillary blood collection kits, suitable for home use, from two academic laboratories, were demonstrated to be easy to use and provided results that are comparable with those obtained from venous specimens. Based on these results, there is strong evidence that HbA1c measurements from capillary specimens obtained with these specific kits can be used interchangeably with HbA1c measurements from venous specimens for clinical research and clinical care.