Medtronic MiniMed Research Articles

215-OR: Safety and Performance of the Omnipod Hybrid Closed-Loop System in Young Children Aged 2-6 Years with Type 1 Diabetes

T1D therapies must be proven safe for young children, who face unique diabetes management challenges. The safety and performance of the Omnipod® hybrid closed-loop (HCL) personalized model predictive control algorithm were assessed in those with T1D aged 2-5.9 y with A1C <10% using an investigational device in a supervised hotel setting. A 7-day at-home standard therapy (ST) phase with CGM use preceded the 48-72 h HCL phase. Meals during HCL were unrestricted, with boluses administered per usual routine. Exercise was performed for ≥30 min/d. The 14 participants were age 4.2 ± 0.9 y, T1D duration 2.4 ± 1.0 y, A1C 7.4 ± 1.0%, and TDD 0.77 ± 0.13 U/kg (mean ± SD). Mean glucose was lower during HCL vs. ST, 148 ± 16 mg/dL vs. 172 ± 27 mg/dL overall and 135 ± 17 mg/dL vs. 167 ± 28 mg/dL overnight. The percent time 70-180 mg/dL was 32% higher during HCL vs. ST overall, 72.6 ± 8.4% vs. 55.2 ± 13.1%, respectively, and 47% higher overnight, 85.3 ± 9.4% vs. 58.2 ± 16.4%. Percent time <70 mg/dL was reduced nearly 2-fold overall and overnight. Glycemic outcomes are reported in the Table. There was 1 severe hypoglycemic event after exercise which was treated with oral carbohydrates. The Omnipod HCL system was safe and performed well in these very young children in a supervised setting, similar to the performance previously observed in older pediatric, adolescent and adult participants. Disclosure B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. G.P. Forlenza: Advisory Panel; Self; Dexcom, Inc. Consultant; Self; Medtronic MiniMed, Inc., Tandem Diabetes Care. Research Support; Self; Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. J. Sherr: Advisory Panel; Self; Bigfoot Biomedical, Eli Lilly and Company, Insulet Corporation. Consultant; Self; Lexicon Pharmaceuticals, Inc., Medtronic, Sanofi. Research Support; Self; Dexcom, Inc., Insulet Corporation. A. Galderisi: None. L. Ekhlaspour: None. J. Lee: Employee; Self; Insulet Corporation. J.B. OConnor: Employee; Self; Insulet Corporation. B. Dumais: None. L.M. Huyett: Employee; Self; Insulet Corporation. Stock/Shareholder; Self; Insulet Corporation. J.E. Layne: Employee; Self; Insulet Corporation. T.T. Ly: Employee; Self; Insulet Corporation. Funding Insulet Corporation

939-P: Real-World Performance of the Guardian Connect System with Sugar.IQ

Background: The Guardian Connect continuous glucose monitoring (CGM) system displays current and trending sensor glucose (SG) via smartphone; records insulin, carbohydrate and exercise; and sends predictive high and low SG alerts up to one hour in advance. When used with the Sugar.IQ diabetes assistant application, personalized insights based on behavior patterns (e.g., food log or insulin dose entry) and glycemic outcomes can be tracked with the Glycemic Assist feature. Methods: System data uploaded between June-November of 2018, by 1765 individuals with diabetes were analyzed. Time in target glucose range (TIR, 70-180 mg/dL) and the Glucose Management Indicator (GMI) were compared between those who used (N=530) or did not use Sugar.IQ. Both groups had ≥5 days of SG data and similar demographic and initial glucose profiles. Results: System users had a mean GMI of 7.1%, mean±SD SG of 157.0±49.1mg/dL (8.7±2.7mmol/L), and a mean TIR of 64.5%, over the data upload period. When predictive alerts were enabled, excursions were avoided after 31% of high SG alerts and 62% of low SG alerts. Those who accessed Sugar.IQ experienced a TIR increase of 2.7% (p=0.006) and a mean SG decrease of -3.0% (p<0.001), with reductions in SD of SG (47.9mg/dL to 41.5mg/dL, p<0.001) and coefficient of variation of SG (0.32 to 0.29, p<0.001), versus those who did not. Their GMI was also 6.8% versus 6.9% (p=0.007). Those who tracked food at least once/day increased TIR by 5% (p<0.001). Users considered 88% of insights helpful. Discussion: The Guardian Connect CGM system with Sugar.IQ may advance patient understanding of glucose trends, aid in behavioral change that improves therapy adherence, and lead to better glycemic outcomes. Disclosure S. Arunachalam: Employee; Self; Medtronic. Y. Zhong: None. S. Abraham: Employee; Self; Medtronic MiniMed, Inc. P. Agrawal: Employee; Self; Medtronic MiniMed, Inc. Stock/Shareholder; Self; Medtronic. R. Vigersky: Employee; Self; Medtronic MiniMed, Inc. T.L. Cordero: Employee; Self; Medtronic. F.R. Kaufman: Employee; Self; Medtronic.

1041-P: Feasibility Study of a Hybrid Closed-Loop System with Automated Correction Boluses

Background: Automated insulin delivery, or closed-loop (CL), systems are emerging as a management tool for individuals with T1D. The MiniMed™ 670G system is a single hormone hybrid closed-loop (HCL) system that adjusts basal insulin delivery based on sensor glucose (SG)levels and is already used in clinical practice. An enhanced HCL system (e-HCL) prototype with an automated correction bolus feature was developed and evaluated in a small feasibility study. Methods: Subjects (n=12) aged a mean±SD of 17.6±2.9 years with T1D and an A1C of 7.3±0.7% (56.5±7.7 mmol/mol) completed a 6-day run-in period with the e-HCL system in open-loop (OL) (i.e., Auto Mode OFF and Suspend before low ON). Thereafter, a supervised hotel period (6 days/5 nights) with CL challenges (missed meal bolus, late meal bolus, and physical activity) was completed, and followed by a 3-week at-home period with Auto Mode and automated correction boluses ON, without restrictions. Glycemic control was compared between the OL run-in period and CL period. Results: During the at-home period, subjects spent 93±4% of the time in Auto Mode. Time within target glucose range of 70-180 mg/dL (3.9-10.0 mmol/L) increased from 68.8±10.5% to 74±6.1%, time >180 mg/dL reduced from 27.1±11.9% to 23.7±8.8%, and time <70mg/dL dropped from 4.1±3.7% to 3±2.8%. Total daily insulin dose was 56.3±10.9 units and 53.4±12.5 units during the OL run-in and CL periods, respectively. A greater percentage of insulin was delivered as bolus than as basal, during the CL period (54.3±8.9% versus 41.7±4.36%). No serious adverse events occurred. Conclusions: Incorporating automated correction boluses to an HCL system was safe and effective in controlling day and night glucose levels, during a 3-week at-home period. Disclosure R. Nimri: Employee; Self; DreaMed Diabetes. Research Support; Self; Dexcom, Inc., Glooko, Inc., Insulet Corporation, JDRF, Medtronic, National Institutes of Health. Speaker's Bureau; Self; Lilly Diabetes. Stock/Shareholder; Self; DreaMed Diabetes. B. Grosman: Employee; Self; Medtronic. N. Kurtz: Employee; Self; Medtronic MiniMed, Inc. A. Roy: Employee; Self; Medtronic MiniMed, Inc. J. Nir: None. N. Loewenthal: None. F.R. Kaufman: Employee; Self; Medtronic. M. Phillip: Consultant; Self; Qulab Medical, RSP Systems A/S. Research Support; Self; Bristol-Myers Squibb Company, Dexcom, Inc., JDRF, Lexicon Pharmaceuticals, Inc., Merck & Co., Inc., OPKO. Stock/Shareholder; Self; DreaMed Diabetes, Ltd., NG Solutions Ltd., Nutriteen Professional Ltd. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Insulet Corporation, Medtronic MiniMed, Inc., Novo Nordisk A/S, Pfizer Inc., Sanofi-Aventis.

1040-P: Evaluation of a Medtronic Enhanced Hybrid Closed-Loop (e-HCL) System during Unannounced Meals of Medium Size

Background: Forgetting a premeal bolus can lead to hyperglycemia in patients with type 1 diabetes (T1D). A prototype e-HCL system was designed to automatically deliver basal insulin and correction boluses based on sensor glucose (SG) values. The effect of the system on hyperglycemia due to unannounced medium-sized meals was assessed. Methods: Twelve subjects with T1D aged 15-25 years (median 17 years) underwent a 1-week hotel phase of e-HCL Auto Mode use, followed by a 3-week unsupervised at-home phase of use. On the third day of the hotel phase, a ∼40gm-carbohydrate (carb) dinner was consumed without a premeal bolus. Five hours of postprandial data were analyzed and compared to data captured after 40gm-carb meals eaten during the at-home phase, but accompanied by a premeal bolus. Results: Meals without a premeal bolus resulted in postprandial SG levels statistically similar to those observed for meals accompanied by a premeal bolus (Table). Conclusion: These data suggest that e-HCL can handle unannounced medium-sized meals to a similar extent as meals of equal size accompanied by premeal boluses. This may improve overall glycemic control of patients who underestimate or frequently forget to administer premeal boluses. Disclosure A. Roy: Employee; Self; Medtronic MiniMed, Inc. B. Grosman: Employee; Self; Medtronic. N. Parikh: None. D. Wu: None. L.J. Lintereur: Employee; Self; Medtronic MiniMed, Inc. N. Kurtz: Employee; Self; Medtronic MiniMed, Inc. F.R. Kaufman: Employee; Self; Medtronic.

1369-P: Continuous Glucose Monitoring Interventions in Toddlers with Type 1 Diabetes (T1D)

Introduction: Achieving optimal glycemic control is difficult in children with T1D even with insulin pumps and continuous glucose monitoring (CGM). Additional support focused on improving technology use may improve diabetes management. Methods: Children aged 2-6 years were enrolled in a 6-month adaptive study design (SMART) utilizing Dexcom G5 CGM. Monthly data were collected to assess time in range (70-180mg/dL) and adherence. If time in range was <60% or adherence was <6 of 7 days worn, participants’ families randomized to one of four interventions focusing on diabetes distress, developmental demands, fear of hypoglycemia, or remote monitoring. Parents completed surveys on diabetes distress, glucose monitoring satisfaction, hypoglycemia fear and confidence at enrollment and study end. HbA1c was collected at study initiation and study end. Results: Of 77 participants, 52.6% were male, mean age 4.94 ± 1.42y (2.03-7.00), diabetes duration 2.12 ± 1.13y (0.58-4.26). Each participant received an average of 3 intervention sessions. HbA1c decreased and psychological outcomes improved at statistically and clinically significant levels (Table). Conclusion: Providing interventions that address common diabetes management problem areas may help parents of young children with T1D improve glucose control and quality of life. More work is needed to identify which interventions were associated with the greatest benefit. Disclosure M.S. Lanning: None. L. DiMeglio: Research Support; Self; Amgen Inc., Caladrius Biosciences, Inc., Janssen Research & Development, Medtronic, Sanofi. Other Relationship; Self; Dexcom, Inc. S. Lange: Other Relationship; Self; Medtronic MiniMed, Inc. K.A. Driscoll: None. T.S. Hannon: Advisory Panel; Self; Eli Lilly and Company. A.M. Lagges: None. S. Woerner: None. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. K.K. Hood: Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc. Speaker's Bureau; Self; Johnson & Johnson Diabetes Institute. Funding National Institutes of Health

93-LB: Defining High Glycemic Variability in Type 1 Diabetes: Comparison of Multiple Indexes to Identify Patients at Risk of Hypoglycemia

Background: International consensus on the use of continuous glucose monitoring (CGM) recommends coefficient of variation (CV) as the metric of choice to express glycemic variability (GV) with a cutoff of 36% to define unstable diabetes. Even though, CV is associated with hypoglycemia in T2DM patients, the evidence on the use of one particular measure of GV in T1DM patients as a predictor of hypoglycemia is limited. Methods: A cohort of T1DM ambulatory patients was evaluated using CGM. Number and incidence rate of events < 54 and < 70 mg/dL were calculated. Bivariate and multivariate analysis of different glycemic indexes and clinical variables were performed to identify those associated with hypoglycemia. ROC curve analysis for each of the glycemic indexes were performed to define the best indexes and optimal cutoff thresholds to discriminate patients at risk of hypoglycemia. Results: Seventy-three patients were included. A total of 128 events of hypoglycemia < 54 mg/dL were recorded in 34 patients and 350 events < 70 mg/dL were registered in 51 patients. CV was the only variable significantly associated with hypoglycemia <54 mg/dL in the multivariate analysis (aRR: 1.44, 95% CI: 1.10-1.88; p=0.008). %CV, HbA1c and mean glucose were associated with events <70 mg/dL. Analysis of ROC curves showed that, among GV metrics, CV had the best performance to discriminate patients with events < 54 mg/dL (AUC: 0.87, 95% CI: 0.79-0.95) and events <70 mg/dL (AUC: 0.79, 95% CI: 0.68-0.90) with optimal cutoff thresholds values of 34% and 31% respectively. Among glycemic risk indexes, LBGI showed the best performance. Conclusions: This analysis shows that CV is the the best GV index, and LBGI the best glycemic risk index, to identify patients at risk of clinically significant hypoglycemia and hypoglycemia alert events in T1DM patients. Disclosure A. Gomez: Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Novo Nordisk Inc. Speaker’s Bureau; Self; Abbott, AstraZeneca, Medtronic MiniMed, Inc., Merck Sharp & Dohme Corp. D. Henao: Research Support; Self; Novo Nordisk Inc. Speaker’s Bureau; Self; Abbott, Medtronic MiniMed, Inc., Novo Nordisk Inc. A.M. Imitola: None. L.B. Taboada: Other Relationship; Self; Medtronic MiniMed, Inc. M. Robledo: None. K.V. Cruz: None. M. Rondón: None. O.M. Munoz: None. M. Garcia Jaramillo: None. F. León-Vargas: None.

77-OR: First Human Study Testing the iLet, a Purpose-Built Bionic Pancreas Platform

The Gen3 iLet (iLet) is a purpose-built, fully integrated, bionic pancreas (BP) platform that can operate in a bihormonal, insulin-only, or glucagon-only mode and can receive data from the Dexcom G5 or the Senseonics Eversense implanted CGM. We performed a random-order, cross-over, outpatient study comparing the insulin-only mode of the iLet to usual care (UC) for 7 days each as a bridge from past studies using the BP algorithm on an iPhone connected wirelessly to an insulin pump. The study enrolled adults with T1D who used either MDI (n=12) or CSII (n=22) for their UC. Participants enrolled at Massachusetts General Hospital (n=17) used the Eversense while those at Stanford (n=17) used the G5 as the input CGM signal for the iLet. There was no statistically significant difference between the iLet and UC in % time <54 mg/dl (0.6 [0.2,1.1] vs. 0.6 [0.1,1.2], p=0.87) or mean CGM glucose (155±12 vs. 162±26 mg/dl, p=0.097). The iLet significantly increased % time within 70-180 mg/dl vs. UC (70.1% vs. 61.5%, p=0.006). The mean insulin TDD was not significantly different between iLet and UC (44±20 vs. 42±20 u/day). No serious adverse events occurred during either arm. Several device issues occurred that led to changes in the Gen4 iLet under development to improve safety and usability in pivotal trials. These results suggest that the iLet, using either the Eversense or G5 CGMs, may provide safe and effective glucose control to users with MDI or CSII as their UC. Disclosure R.Z. Jafri: None. C.A. Balliro: None. J. Sherwood: None. M. Hillard: None. L. Ekhlaspour: None. L. Hsu: None. R. Selagamsetty: Employee; Self; Beta Bionics. Other Relationship; Self; Boston University. J.R. Costik: Board Member; Self; Nightscout Foundation. Employee; Self; Beta Bionics. Employee; Spouse/Partner; Ortho Clinical Diagnostics. J. Sloane: None. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. F. El-Khatib: Employee; Self; Beta Bionics. Stock/Shareholder; Self; Beta Bionics. E. Damiano: Advisory Panel; Self; Novo Nordisk A/S. Board Member; Self; Beta Bionics. Employee; Self; Beta Bionics. Stock/Shareholder; Self; Beta Bionics. Stock/Shareholder; Spouse/Partner; Beta Bionics. Other Relationship; Self; Ascensia Diabetes Care, Senseonics. S.J. Russell: Advisory Panel; Self; Companion Medical, Unomedical a/s. Consultant; Self; Flexion Therapeutics. Research Support; Self; Beta Bionics, MITRE Corporation, Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Self; ADOCIA, Ascensia Diabetes Care, Ascensia Diabetes Care, Lilly Diabetes, Roche Diabetes Care, Senseonics. Funding National Institute of Diabetes and Digestive and Kidney Diseases (UC4DK108612)

1053-P: Automated Adaptation of the Bionic Pancreas while Transitioning from Multiple Daily Injection Insulin Regimens

In a random-order, outpatient crossover trial we compared automated glycemic control with the insulin-only bionic pancreas (BP) to usual care in subjects with T1D. Subjects transitioned directly to the BP from CSII or MDI (insulins glargine n=6, detemir n=1, or degludec n=5). The BP continuously adapts to individual insulin needs and was initialized based on body mass only, without information about the baseline insulin regimen. The first 24 hours of BP control was compared to days 3-7 (the 5-day period considered for the primary outcome) to examine the effect of having received long-acting insulin the day prior to initiation of the BP. As shown in the Table, the mean CGM glucose and time-in-range did not differ between the first 24 hours and days 3-7 after starting the BP in subjects on MDI at baseline, while there was a reduction in mean and an increase in time-in-range among those on CSII at baseline. Subjects on MDI at baseline did not experience more hypoglycemia in the first 24 hours despite having long-acting insulin on board. Both subjects on MDI and CSII at baseline achieved good glucose control on the BP (see Table). Surprisingly, there was no difference in the insulin total daily dose (TDD) between the first 24 hours and days 3-7 in the MDI users despite an average TDD of basal insulin at baseline of 15 u/day. These results suggest that BP therapy can be safely initiated directly from MDI regimens. Disclosure J. Sherwood: None. C.A. Balliro: None. F. El-Khatib: Employee; Self; Beta Bionics. Stock/Shareholder; Self; Beta Bionics. L. Ekhlaspour: None. L. Hsu: None. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. E. Damiano: Advisory Panel; Self; Novo Nordisk A/S. Board Member; Self; Beta Bionics. Employee; Self; Beta Bionics. Stock/Shareholder; Self; Beta Bionics. Stock/Shareholder; Spouse/Partner; Beta Bionics. Other Relationship; Self; Ascensia Diabetes Care, Senseonics. S.J. Russell: Advisory Panel; Self; Companion Medical, Unomedical a/s. Consultant; Self; Flexion Therapeutics. Research Support; Self; Beta Bionics, MITRE Corporation, Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Self; ADOCIA, Ascensia Diabetes Care, Ascensia Diabetes Care, Lilly Diabetes, Roche Diabetes Care, Senseonics. Funding National Institutes of Health (NIDDKUC4DK108612)

85-OR: Modifiers of C-Peptide Change during the Progression to Type 1 Diabetes (T1D) in the TrialNet Pathway to Prevention Study

It is not known to what extent characteristics of individuals modify C-peptide changes prior to T1D diagnosis. Thus, we assessed whether 4 characteristics [age, BMIZ, autoantibodies (abs), and HLA genotype] modified changes in 2-hr OGTT indices [AUC C-peptide and 30-0 minutes (early) C-peptide in ng/ml] during the progression to T1D. We studied 519 progressors to T1D (mean±SD age at first OGTT: 14.2±11.0 yo; BMIZ: 0.8±1.2; 50.0% male). Slopes were derived for changes in C-peptide indices from 36 to 6 months before diagnosis using mixed effects regression models. Slopes differed significantly by DR3/DR4 both (more inverse) vs. not both (30-0 minutes: p=0.005; AUC: p=0.034) and by ≥12.0 (more inverse) vs. <12.0 yo (30-0 minutes: p=0.002; AUC: p=0.001) with narrowed differences in C-peptide at 6 months. In contrast, the slopes were similar in 1 vs. ≥2 abs and BMIZ ≤1.0 vs. >1.0 comparisons. The Figures show curves for the changes in the C-peptide indices according to age and BMIZ categories from 36 to 6 months (* indicates significant differences at the 36 and 6 months time points). These novel findings indicate that slopes of C-peptide change vary according to DR3/DR4 and age during the progression to T1D, resulting in smaller differences at 6 months. BMIZ and ab slopes have little variation. Attributes of individuals should be considered when studying β-cell function decline during the progression to T1D. Disclosure H.M. Ismail: None. M.A. Cleves: None. S.E. Gitelman: Advisory Panel; Self; Avortes, Intermountain Therapeutics, Lilly Diabetes, Tolerion, Inc. Research Support; Self; Caladrius Biosciences, Inc., Janssen Research & Development. Other Relationship; Self; Novo Nordisk Inc. J.S. Skyler: Advisory Panel; Self; ADOCIA, Applied Therapeutics, Dance Biopharm Holdings Inc., Orgenesis Ltd., Tolerion, Inc., Viacyte, Inc. Board Member; Self; Dexcom, Inc., Intarcia Therapeutics, Inc., Moerae Matrix, Inc. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Dalcor, Dialogics, Elcelyx Therapeutics, Inc., Esperion, GeNeuro Innovation, Ideal Life, Immunomolecular Therapeutics, Intrexon, Kamada, Nestlé, Sanofi, Valeritas, Inc., Zafgen, Inc. Stock/Shareholder; Self; Dexcom, Inc., Ideal Life, Intarcia Therapeutics, Inc., Intrexon, Moerae Matrix, Inc. A. Steck: None. H. Rodriguez: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Daiichi Pharm Corp, MannKind Corporation, Medtronic MiniMed, Inc. Research Support; Spouse/Partner; Medtronic MiniMed, Inc. Research Support; Self; Takeda Pharmaceutical Company Limited. Other Relationship; Self; Merck & Co., Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc. M.A. Atkinson: None. B.M. Nathan: None. M.J. Redondo: None. K.C. Herold: Consultant; Self; Provention Bio, Roche Pharma. J.P. Palmer: None. C. Evans-Molina: None. L. DiMeglio: Research Support; Self; Amgen Inc., Caladrius Biosciences, Inc., Janssen Research & Development, Medtronic, Sanofi. Other Relationship; Self; Dexcom, Inc. J.M. Sosenko: None. Funding National Institutes of Health

926-P: Frequency of Hypoglycemia by Gender in Healthy Individuals without Diabetes—Not So Different After All

It is a common belief that females experience more hypoglycemia than males. We aimed to assess whether this was true in a cohort of healthy individuals without diabetes. In this multicenter study, healthy, nondiabetic children and adults (age 7 to 80 years, normal BMI, HbA1c <5.7%, and no positive islet antibodies) were included. Each participant wore a blinded Dexcom G6 for ∼10 days. Overall, 153 participants were analyzed, 66% female, 84% non-Hispanic white, with a mean HbA1c of 5.1±0.3%. Race/ethnicity, BMI, and HbA1c were similar between females (n=101) and males (n=52) but females were older (mean age 34±21 years vs. 25±20 years). Mean average glucose, time in range (TIR) 70-140 mg/dL and coefficient of variation (CV) were similar between females and males (100 vs. 99 mg/dL; 95% TIR and 17% CV for both). There were no statistically significant differences in the percentage of participants with at least one hypoglycemic event (15 consecutive minutes <54 mg/dL), the number of events, or the duration of events between females and males. Additionally, the percentages of time spent below various cutoffs of hypoglycemia were similar between females and males (Table). At least when it comes to frequency, severity and duration of hypoglycemia, these data support the contention that men and women are not so different after all. Disclosure S. DuBose: None. Z. Li: None. V.N. Shah: Advisory Panel; Self; Sanofi US. Consultant; Self; Dexcom, Inc. J. Sherr: Advisory Panel; Self; Bigfoot Biomedical, Eli Lilly and Company, Insulet Corporation. Consultant; Self; Lexicon Pharmaceuticals, Inc., Medtronic, Sanofi. Research Support; Self; Dexcom, Inc., Insulet Corporation. W.V. Tamborlane: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medtronic MiniMed, Inc., Novo Nordisk Inc., Sanofi, Takeda Pharmaceutical Company Limited. R.M. Bergenstal: Research Support; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Dexcom, Inc., Glooko, Inc., Hygieia, JDRF, Johnson & Johnson Medical Devices Companies, Lilly Diabetes, Medtronic MiniMed, Inc., Merck & Co., Inc., National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk Inc., Roche Diabetes Care, Sanofi. Other Relationship; Self; Abbott, Helmsley Charitable Trust, Hygieia, Lilly Diabetes, Novo Nordisk Inc., Onduo LLC, Sanofi, UnitedHealth Group Inc. R. Beck: Other Relationship; Self; Abbott Laboratories, Ascensia Diabetes Care, Bigfoot Biomedical, Dexcom, Inc., Insulet Corporation, Lilly Diabetes, Roche Diabetes Care, Tandem Diabetes Care. Funding The Leona M. and Harry B. Helmsley Charitable Trust

127-LB: Longevity of the Coated ConvaTec Infusion Set with Lantern Technology

Objective: Current insulin infusion sets are approved for 2-3 days of wear; however, glucose sensors are approved for 7-14 days of wear. A commonly reported reason for discontinuing use of CGM within 1 year is not wanting to wear devices on two sites of the body. Any attempt to create a combined glucose sensor and infusion set for closed-loop control requires a set with greater longevity. The coated ConvaTec Infusion Set with Lantern Technology is a new infusion set with multiple slits and coating intended to reduce foreign body response and occlusion from bending or kinking. Methods: A pilot safety and extended wear tolerability study is being performed at Stanford University. To date, 15 adult subjects on tethered insulin pump therapy using insulin aspart or lispro have completed the study. Each participant places the set and wears it for 10 days or until set failure to establish a maximum length of infusion set wear when 80% of sets are still functional (excluding accidental “pull-outs”). Infusion set failures are based on: (1) Presence of serum ketones with hyperglycemia; (2) Unexplained hyperglycemia, unresolved with correction dose; (3) Signs of infection at the infusion site; (4) Pump occlusion alarm; and (5) Adhesive failure. Results: Two subjects did not meet failure criteria and were excluded. Of the remaining, 6 (46%) wore the novel infusion set the full 10 days and all sets lasted 7 days or more (mean 8.8 days). 3 premature set failures were associated with persistent hyperglycemia unresponsive to correction boluses on days 7-8, 3 with adhesive failure on days 7-9, and 1 with infection on day 9. Conclusions: In our previous studies assessing 353 infusion set insertions for 7 days, average length of wear was 5.1 ± 1.7 days. Thus far, the novel set has demonstrated increased longevity. The duration of wear established in this pilot study will be used to perform a masked, randomized controlled crossover study comparing the coated ConvaTec Infusion Set with Lantern Technology against standard infusion sets. Disclosure R. Lal: Consultant; Self; Abbott. P.K. Schøndorff: Employee; Self; ConvaTec Inc. L. Hsu: None. M. Heschel: Employee; Self; Unomedical a/s. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care.

116-LB: New Insulin-to-Carb Ratio Formulas for Hybrid Closed-Loop Pump Use

Objective: Formulas to determine Insulin-Carbohydrate Ratio (ICR) use total daily dose (TDD) such as the 450 Rule (450/TDD=ICR) or body weight (BW) (2.8*weight in pounds/TDD). These do not account for age differences or adjust for HCL therapy. Methods: We analyzed data from Medtronic 670G users meeting the following criteria: Time in Range (TIR, 70-180mg/dl) >65%, Time <70mg/dl <5%, A1c <8%, HCL for >3 months. Subjects were grouped by age: pre-pubertal, pubertal, and adult (18+). Subjects’ current ICR was multiplied by TDD at each meal to determine a formula starting point. Results: 50 subjects were included (age 6-62, mean A1c 7.2%, TDD 0.8 u/kg/day, TIR 75%, 2.5% <70mg/dl). Compared to baseline, ICRs in HCL were made 10-26% more aggressive. ICRs calculated from the 450 rule were 15-41% less aggressive compared to the ratios used by HCL subjects. BW formula ICRs were too aggressive for pre-pubertal, closely matched the pubertal subjects, and underestimated meal bolus needs in adults on HCL. Conclusions: Our data offers new initial ICR formulas for HCL users instead of the 450/TDD rule, i.e., a 300/TDD for adults and a 350/TDD for pubertal and prepubertal children at lunch/dinner, and a breakfast 300/TDD rule. Fine-tuning is necessary for each patient, but this offers a better tuned starting point for subjects starting HCL, helping minimize HCL exits due to post-prandial hyperglycemia. Disclosure I. Tabatabai: None. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care.

60-LB: Evaluating the Efficacy of a Novel Insulin Dosing Regimen to Prevent Lows at High-Intensity Diabetes Sports Camp

Objectives: To determine the efficacy of reductions in long acting and basal insulin to prevent lows in T1D sports campers. The Sam Fuld’s T1D Sports Camp is a camp for children with T1D taking place each February. It involves high-intensity exercise for up to six hours in a day. We began adjusting our insulin dosing recommendation in 2017 to prevent incidence of hypoglycemia and ensure more campers are able to fully participate. Methods: We compared incidence of hypo and hyperglycemic events at camp from 2016-2019. Using bg data recorded for all T1D campers. Starting in 2017, we recommended MDI campers decrease long acting insulin by 30% the night before camp and pump users decrease basal rates by 30% beginning at breakfast prior to camp. In 2019, meal boluses for lunch were also cut by 50%. Results: From 2016 to 2018 there was a 40% decrease in campers with low bgs, and an expected increase in hyperglycemic values. In 2019, we saw an increase in lows compared with 2018 with lower overall prevalence than seen in prior years and fewer hyperglycemic events than in 2018. Of those campers who followed the recommendations, in 2017, no incidents of hypo or hypoglycemia occurred, in 2018 there were just three incidents of hyperglycemia and in 2019, one bg value < 50 mg/dL and 8 bg values > 250 mg/dL (mostly in the morning). Conclusion: More research is needed to determine the best dosing guidelines for intense exercise in children with T1D. Disclosure A.M. Terry: None. S. Bollepalli: None. L. Smith: None. H. Rodriguez: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Daiichi Pharm Corp, MannKind Corporation, Medtronic MiniMed, Inc. Research Support; Spouse/Partner; Medtronic MiniMed, Inc. Research Support; Self; Takeda Pharmaceutical Company Limited. Other Relationship; Self; Merck & Co., Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc.

1277-P: Diabetes Management Supplies in Youth with Type 1 Diabetes: Don’t Leave Home Without Them!

Youth with type 1 diabetes (T1D) require 24/7 access to T1D management supplies. This study aims to characterize access to T1D supplies when youth are away from home. We emailed a comprehensive survey to 4756 parents of T1D Exchange participants <18 years old; 752 respondents completed the survey (83% completed by parents). Results were age-stratified: <6 (N=21), 6-12 (N=271) and 13-18 (N=459). The majority of youth carry rapid-acting insulin most of the time or always, yet the proportion decreases as age increases (Table 1). ≥80% of injection users carry an extra pen or syringe, while >55% of pump users carry an extra infusion set. Among CGM users, 100% of ≤6 years old vs. 67% of adolescents carry a receiver or phone; 33% of 13-18 years old never carry an extra sensor. 38% of youth ≤6 years old vs. 27% of teens carry blood or urine ketone testing supplies. In total, 64% reported carrying glucose tablets or gel; 87% carry another rapid acting carbohydrate. 64% of respondents carry glucagon, again decreasing across adolescence. Over 2/3 carry at least one form of T1D identification. Technology to optimize glycemic control and detect/prevent acute complications of T1D have improved. Yet, adolescents are less likely than younger T1D-affected youth, to carry supplies to detect, prevent and/or treat acute events. These findings call for novel and ongoing T1D emergency preparedness training to strike a balance between supervision and autonomy of adolescents. Disclosure M. Quinn: None. R. Bailey: None. N.C. Foster: None. J. Simmons: None. E. Eyth: None. H. Rodriguez: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Daiichi Pharm Corp, MannKind Corporation, Medtronic MiniMed, Inc. Research Support; Spouse/Partner; Medtronic MiniMed, Inc. Research Support; Self; Takeda Pharmaceutical Company Limited. Other Relationship; Self; Merck & Co., Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc. S. Corathers: None. C.J. Levy: Advisory Panel; Self; Novo Nordisk A/S, Sanofi. Employee; Spouse/Partner; Allergan. N.M. Sheanon: None. R.M. Wasserman: None. D. Sparling: None. D. Adkins: None. A. Albanese-O'Neill: None. D.J. DeSalvo: Consultant; Self; Dexcom, Inc., Insulet Corporation. Funding The Leona M. and Harry B. Helmsley Charitable Trust

931-P: Hyperglycemia following Early vs. Late Meal Boluses

Background: Late-meal blousing increases the risk of hyperglycemia following a meal using meter blood glucose data. We used data from the Donors to the Tidepool Big Data Donation project to evaluate real-life bolusing and glycemic excursions using continuous glucose monitoring (CGM). Methods: We analyzed 214,087 meal boluses from 120 subjects, mean age 22 years (range 3-66), average CGM glucose 155mg/dL (range 103-239 mg/dL). We screened for meals meeting the following criteria: carbs of ≥20g, premeal glucose between 70 and 200mg/dL, no glucose <70mg/dL in the hour prior to bolus, no other insulin bolus 2 hours prior and 4 hours post bolus, 95% of CGM readings available 30 min before and 4 hour after the meal bolus. A pre-meal bolus was defined by the glucose rising <0.4mg/dL/min and a late meal boluses by a glucose rise of ≥1mg/dL/min in the 20 minutes prior to the bolus. Results: The post meal bolus had significantly higher CGM glucose levels at the time of bolus (p<0.001), and a significantly higher post prandial peak glucose (p<0.001). There was no statistical difference in the average amount of meal carbs for the two groups. Conclusions: Using integrated pump and CGM data from a large data base, late meal bolusing occurred with 12% of selected meal boluses and was associated with higher CGM values at the time of bolus, and higher peak post prandial CGM values. Disclosure L.M. Norlander: None. E.T. Nykaza: None. B. Arbiter: Employee; Self; Tidepool Project. Stock/Shareholder; Self; Abbott Laboratories, Dexcom, Inc. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. R. Lal: Consultant; Self; Abbott.

67-LB: Time Spent in Glycaemic Ranges and Carbohydrate Intake during Cycling in Professional Cyclists with Type 1 Diabetes

Aim: This observational study examined in-ride interstitial glucose data and nutritional intake in a UCI-accredited professional cycling team with type 1 diabetes (T1D) over a nine-day training camp. Methods: Sixteen male professional road cyclists with T1D (age 27±4 years, T1D duration 11±5 years, BMI 21.6±1.5 kg·min-2, HbA1c 6.8±0.6 %, O2max 71.3±3.9 ml·kg·min-1) on multiple daily injections performed eight rides over nine days lasting between 2 and 6 h, traversing 56 to 182 km/day. Cycle glycemic information (G6, Dexcom) was collected, stratified into glycemic time in ranges; hypoglycemia (Level 1: 54-70, Level 2: <54 mg/dL), euglycemia (71-180 mg/dL) and hyperglycemia (Level 1: 181-299, Level 2: >299 mg/dL) and analyzed for time spent (%) within each range. Nutritional intake during each ride was determined and reported as median (range). Results: Average percentage time spent in euglycemia during cycling was 78±6% (daily range 70-86%). Hypoglycemia during cycling was 3±4% (range 0-11%, Level 1), and 1±2% (range 0-2%, Level 2). No hypoglycemic event required assistance. Percentage time spent in hyperglycemia during cycling was 17±7% (range 8-27%, Level 1), and 1±2 % (range 0-5%, Level 2). The contribution of carbohydrates, fat and protein to total in-ride energy intake was 83.8±15.4, 12.6±8.1 and 1.2±0.6 %, respectively. Macronutrient intake was dependent on cycle duration with greater carbohydrate intake rate on longer rides (2-hour cycle: 20 (4-82) g/h vs. 6-hour cycle: 51 (17-86) g/h). Conclusions: Professional cyclists with T1D maintained a large proportion of time in a euglycemic range during intense cycling sessions over a nine-day training period. The low occurrence of in-ride hypoglycemia, mostly at Level 1, suggests a protective role for consumption of carbohydrate-rich foods to maintain glycaemia, especially during longer rides. However, time spent in Level 1 hyperglycemia during cycling was notable and should be monitored. Disclosure O. McCarthy: None. O. Moser: Research Support; Self; Abbott, Dexcom, Inc., Novo Nordisk A/S. M.L. Eckstein: Research Support; Self; Novo Nordisk A/S. S.N. Scott: None. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation, Novo Nordisk Inc., Sanofi. Speaker’s Bureau; Self; Medtronic MiniMed, Inc., OmniPod. Stock/Shareholder; Self; Zucara Therapeutics Inc. M. Fisher: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Mylan, NAPP Pharmaceuticals Limited, Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company, Sanofi. F.Y. Fontana: None. K. Skroce: None. L. Festa: None. P.H. Lagrou: None. P. Southerland: Other Relationship; Self; Novo Nordisk Inc. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. M.P. Christiansen: Research Support; Self; Abbott, Biolinq, Dexcom, Inc., Eli Lilly and Company, Janssen Pharmaceuticals, Inc., Medtronic MiniMed, Inc., Novo Nordisk A/S, Sanofi-Aventis, Xeris Pharmaceuticals, Inc. B.W. Bode: Consultant; Self; ADOCIA, Lexicon Pharmaceuticals, Inc., Novo Nordisk Inc. Research Support; Self; Becton, Dickinson and Company, Dexcom, Inc., Diasome Pharmaceuticals, Inc., Eli Lilly and Company, Eyenuk Inc., Insulet Corporation, National Institutes of Health, Novo Nordisk Inc., Sanofi Research & Development, Senseonics, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Novo Nordisk Inc., Sanofi US, Senseonics. Stock/Shareholder; Self; AgaMatrix, Glytec, LLC. C. Stettler: None. R.M. Bracken: None.

65-LB: Sweet Performance: Associations of Maximum Physiological Performance and Diabetes in a Group of World Class Road Cyclists with Type 1 Diabetes

Aim: This study investigated whether markers related to type 1 diabetes (T1D) influence cardiopulmonary exercise (CPX) test performance in a group of world class road cyclists with T1D. Methods: Fifteen elite male road cyclists with T1D (age 27±4 years, T1D duration 11±5 years, BMI 21.6±1.5 kg·min-2, HbA1c 6.8±0.6%) performed a ramped (10 W per min) CPX test to exhaustion. Adjusted stepwise linear regression analysis was performed to investigate relationships between markers of T1D control and absolute maximum markers of performance, maximum oxygen consumption (V O2max), maximum power output (Pmax) and maximum heart rate (HRmax). Associations between submaximal CPX parameters and V O2max, Pmax and HRmax were also investigated. Results: Starting-CPX blood glucose (BG), post-CPX BG, ΔBG, T1D duration, HbA1c and BMI were not associated with V O2max (r2=0.51, P=0.32) and Pmax (r2=0.48, P=0.37) during CPX testing. However, HRmax was associated with T1D duration (r2=0.31, P=0.03). CO2 expiration at the lactate turn point 2 (V CO2LTP2) and power at the heart rate turn point (PHRTP) were associated with V O2max (r2=0.87, P<0.0001). These results were also associated when adjusted for T1D parameters (r2=0.95, p=0.002). Pmax was solely associated with V O2HRTP (r2=0.71, P<0.0001). Also, this association remained significant when adjusted for T1D parameters (r2=0.86, P=0.03). HRmax was associated with ventilation at the LTP2 (VELTP2), LactateLTP1, VCO2LTP2 and PLTP2 (r2=0.91, P=0.002). When this result was adjusted for T1D parameters the association was significant (r2=0.93, P=0.05). Conclusion: This is the first dataset presenting CPX data from a world class cycle team with T1D. The study shows that not all markers of maximum physiological performance are influenced by T1D, solely HRmax by T1D duration. Yet, maximum performance is dependent on several submaximal cardiopulmonary markers of performance. Disclosure M.L. Eckstein: Research Support; Self; Novo Nordisk A/S. O. Moser: Research Support; Self; Abbott, Dexcom, Inc., Novo Nordisk A/S. O. McCarthy: None. S.N. Scott: None. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation, Novo Nordisk Inc., Sanofi. Speaker’s Bureau; Self; Medtronic MiniMed, Inc., OmniPod. Stock/Shareholder; Self; Zucara Therapeutics Inc. F.Y. Fontana: None. K. Skroce: None. M.P. Christiansen: Research Support; Self; Abbott, Biolinq, Dexcom, Inc., Eli Lilly and Company, Janssen Pharmaceuticals, Inc., Medtronic MiniMed, Inc., Novo Nordisk A/S, Sanofi-Aventis, Xeris Pharmaceuticals, Inc. L. Festa: None. M. Fisher: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Mylan, NAPP Pharmaceuticals Limited, Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company, Sanofi. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. P. Southerland: Other Relationship; Self; Novo Nordisk Inc. C. Stettler: None. P.H. Lagrou: None. B.W. Bode: Consultant; Self; ADOCIA, Lexicon Pharmaceuticals, Inc., Novo Nordisk Inc. Research Support; Self; Becton, Dickinson and Company, Dexcom, Inc., Diasome Pharmaceuticals, Inc., Eli Lilly and Company, Eyenuk Inc., Insulet Corporation, National Institutes of Health, Novo Nordisk Inc., Sanofi Research & Development, Senseonics, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Novo Nordisk Inc., Sanofi US, Senseonics. Stock/Shareholder; Self; AgaMatrix, Glytec, LLC. R.M. Bracken: None. Funding Novo Nordisk A/S

1358-P: Early CGM Initiation in New-Onset Type 1 Diabetes Patients

A minority of children and adolescents with T1D meet HbA1c targets as recommended in the ADA guidelines. We have previously shown that in our clinic there is a sharp inflection point in HbA1c trajectory starting between 5 and 6 months of diagnosis with a rise in HbA1c from 7.0 ± 1.5% at 5 months post-diagnosis to 8.0 ± 1.7% at 12 months post-diagnosis. Given the benefits of CGM and improved CGM technology, we started a clinical program to initiate CGM therapy within the first month of diabetes diagnosis aimed at decreasing the rise in HbA1c that occurs over the first year of diagnosis. Since initiating this program in August 2018, 20 youth with T1D were started on the Dexcom G6 CGM system within the first month of diagnosis (average time to start is 8.5 ± 1.3 days post-diagnosis, 3 declined CGM initiation). The average age at T1D onset was 10.1 ± 0.8 years and 50% presented in DKA. Mean HbA1c at diagnosis was 12.0 ± 4.0%. In this cohort, 45% were male, 50% non-Hispanic white, 85% had private insurance, and 85% spoke English as the primary language. A majority of clinic patients used the mobile phone as their CGM receiver (73%) and all of these individuals used the Share feature. A majority of clinic patients (75%) have had at least 2 follow-up visits. By the second follow-up visit (46.1 ± 3.9 days since CGM start), patients were wearing the CGM on average of 94.5 ± 5.9% of the days over the last 2 weeks. Of the 20 individuals initially started on CGM, 3 were no longer using it at the time of their most recent visit. Two of the individuals had issues with insurance coverage and the third had issues with the transmitter. The incidence of hypoglycemia was low (2.2 ± 0.7%) and the patients had a time in range (TIR, glucose 70 - 180 mg/dL) of 71.1 ± 4.6%. In our cohort, patients continued to use CGM with a high percent of wear time. Although we do not have a control or comparison group, our population had a low incidence of hypoglycemia and high percentage of TIR. These data suggest that CGM can be successfully started within 2 weeks of T1D diagnosis with potential benefits on glucose control. Disclosure P. Prahalad: None. D. Scheinker: Advisory Panel; Self; Carta Healthcare. K.K. Hood: Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc. Speaker's Bureau; Self; Johnson & Johnson Diabetes Institute. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. D.M. Wilson: Advisory Panel; Self; Tolerion, Inc. Research Support; Self; Beta Bionics, Dexcom, Inc., Medtronic. A. Chmielewski: None. B.P. Conrad: None. E. Geels: None. J. Leverenz: None. K. Peterson: None. D.M. Maahs: Advisory Panel; Self; Novo Nordisk Inc. Consultant; Self; Abbott, Sanofi. Research Support; Self; Dexcom, Inc., Tandem Diabetes Care.

66-LB: Greater Time Spent in Hypoglycemia during Night Compared with Day during Intensified Training in Professional Cyclists with Type 1 Diabetes—A Prospective Observational Study

Aim: To compare time spent in pre-specified glycemic ranges in day and night-time during intensive training in professional cyclists with type 1 diabetes (T1D). Methods: Fifteen male professional cyclists with T1D on multiple daily injections (age 27±4 years, duration T1D 11±5 years, BMI 21.6±1.5 kg·min-2, HbA1c 7.2±0.7%, O2max 73±4 ml·kg·min-1) performed road cycle sessions (50-90% of the anaerobic threshold, duration 1-6 hours) over 9 consecutive days. Time spent in pre-specified glycemic ranges was compared between day and night time using paired t-test and Wilcoxon matched-pairs signed rank test, P≤0.05. Results: Overall glycemia is shown in Figure 1. More time was spent in level 1 (54-70 mg·dl-1) (6±5% vs. 4±3%, P=0.05) and level 2 hypoglycemia (<54 mg·dL-1) (3±5% vs. 1±4%, P=0.002) during night vs. day periods. During daytime, more time was spent in level 2 hyperglycemia (>299 mg dL-1) (night 0.2±0.4% vs. day 1.4±2.3%, P=0.02). Conclusion: Professional cyclists with T1D spent more time in hypoglycemia during the night compared to day-time during intensified training. Long-lasting insulin-sensitizing effects of endurance exercise may suggest a greater need for additional pre-bed carbohydrates and/or insulin dose reductions. Disclosure O. Moser: Research Support; Self; Abbott, Dexcom, Inc., Novo Nordisk A/S. M.L. Eckstein: Research Support; Self; Novo Nordisk A/S. O. McCarthy: None. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation, Novo Nordisk Inc., Sanofi. Speaker’s Bureau; Self; Medtronic MiniMed, Inc., OmniPod. Stock/Shareholder; Self; Zucara Therapeutics Inc. F.Y. Fontana: None. K. Skroce: None. L. Festa: None. P.H. Lagrou: None. P. Southerland: Other Relationship; Self; Novo Nordisk Inc. M.P. Christiansen: Research Support; Self; Abbott, Biolinq, Dexcom, Inc., Eli Lilly and Company, Janssen Pharmaceuticals, Inc., Medtronic MiniMed, Inc., Novo Nordisk A/S, Sanofi-Aventis, Xeris Pharmaceuticals, Inc. B.W. Bode: Consultant; Self; ADOCIA, Lexicon Pharmaceuticals, Inc., Novo Nordisk Inc. Research Support; Self; Becton, Dickinson and Company, Dexcom, Inc., Diasome Pharmaceuticals, Inc., Eli Lilly and Company, Eyenuk Inc., Insulet Corporation, National Institutes of Health, Novo Nordisk Inc., Sanofi Research & Development, Senseonics, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Novo Nordisk Inc., Sanofi US, Senseonics. Stock/Shareholder; Self; AgaMatrix, Glytec, LLC. C. Stettler: None. S.N. Scott: None. M. Fisher: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Mylan, NAPP Pharmaceuticals Limited, Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company, Sanofi. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. R.M. Bracken: None. Funding Novo Nordisk A/S

80-OR: 670G Clinical Experience

Objective: In September 2016, the FDA approved the Medtronic 670G “hybrid” closed-loop system. In “Auto Mode,” this system automatically controls basal insulin delivery based on CGM data, but requires users to enter carbohydrate intake and blood sugar for boluses. Studies show improved time in range associated with the use of Auto Mode. In an effort to track our real-world experience with this first commercial closed-loop device, we followed pediatric and adult patients placed on the 670G. Methods: This was a 1-year prospective observational study, recruiting 5/2017-9/2018, of patients with type 1 diabetes, ≥7 years, starting the 670G system. Results: 84 patients started on the 670G (range 9-61 years), 26 (31%) were <18 years. Figure 1 shows a violin plot of percentage time in Auto Mode at each visit. Upon starting Auto Mode, 96% of participants continued for the first week. For those with available data by 3 months 22% stopped using Auto Mode, at 6 months 30%, at 9 months 43% and by 12 months 50% (70% <18, 40% ≥18). Reasons for discontinuation included CGM issues, too many alarms and lack of control. At 6 months there was a significant correlation between improved A1c and time in Auto Mode (r = 0.4, p = 0.01). Conclusions: While use of closed-loop technology correlates with improved glycemic control, a focus on usability and human factors is necessary to ensure patients stay on treatment. Alarms and sensor calibration are a major patient concern, which next generation technology should alleviate. Disclosure R. Lal: Consultant; Self; Abbott. M. Basina: None. D.M. Maahs: Advisory Panel; Self; Novo Nordisk Inc. Consultant; Self; Abbott, Sanofi. Research Support; Self; Dexcom, Inc., Tandem Diabetes Care. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. K.K. Hood: Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc. Speaker's Bureau; Self; Johnson & Johnson Diabetes Institute. B.P. Conrad: None. J. Leverenz: None. A. Chmielewski: None. K. Peterson: None. D. Wilson: Advisory Panel; Self; Tolerion, Inc. Research Support; Self; Beta Bionics, Dexcom, Inc., Medtronic. Funding National Institute of Diabetes and Digestive and Kidney Diseases (T32DK007217); Seiler Fund