Concordance of Blood Glucose and CGM During a Pilot Trial of Automated Insulin Delivery in Type 1 Diabetes Pregnancies.

Background: Customized and standard automated insulin delivery (AID) systems for use in pregnancies of women with preexisting type 1 diabetes (T1D) are being developed and tested to achieve pregnancy appropriate continuous glucose monitoring (CGM) targets. Guidance on the use of CGM for treatment decisions during pregnancy in the United States is limited. Methods: Ten pregnant women with preexisting T1D participated in a trial evaluating at-home use of a pregnancy-specific AID system. Seven-point self-monitoring of blood glucose (SMBG) was compared to the closest sensor glucose (Dexcom G6 CGM) value biweekly to assess safety and reliability based on the 20%/20 mg/dL criteria. Results: All participants completed the study with 7 participants satisfying the safety and reliability criteria with a mean absolute relative difference of 10.3%. Three participants did not fulfill the criteria, mainly because the frequency of SMBG did not meet the requirements. Conclusion: Dexcom G6 CGM is safe and accurate in the real-world setting for use in pregnant women with preexisting T1D with reduced SMBG testing as part of a pregnancy-specific AID system.

Continuous Glucose Monitoring Metrics for Pregnancies Complicated by Diabetes: Critical Appraisal of Current Evidence.

Ascertaining the utility of continuous glucose monitoring (CGM) in pregnancy complicated by diabetes is a rapidly evolving area, as the prevalence of type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes mellitus (GDM) escalates. The seminal randomized controlled trial (RCT) evaluating CGM use added to standard care in pregnancy in T1D demonstrated significant improvements in maternal glycemia and neonatal health outcomes. Current clinical guidance recommends targets for percentage time in range (TIR), time above range (TAR), and time below range (TBR) during pregnancy complicated by T1D that are widely used in clinical practice. However, the superiority of CGM over blood glucose monitoring (BGM) is still questioned in both T2D and GDM, and whether glucose targets should be different than in T1D is unknown. Questions requiring additional research include which CGM metrics are superior in predicting clinical outcomes, how should pregnancy-specific CGM targets be defined, whether CGM targets should differ according to gestational age, and if CGM metrics during pregnancy should be similar across all types of diabetes. Limiting the potential for CGM to improve pregnancy outcomes may be our inability to maintain TIR > 70% throughout gestation, a goal achieved in the minority of patients studied. Adverse pregnancy outcomes remain high in women with T1D and T2D in pregnancy despite CGM technology, and this review explores the potential reasons and questions yet to be investigated.

Performance of the Dexcom G7 Continuous Glucose Monitoring System in Pregnant Women with Diabetes.

Background: We evaluated accuracy and safety of a seventh-generation real-time continuous glucose monitoring (CGM) system during pregnancy. Materials and Methods: Evaluable data for accuracy analysis were obtained from 96 G7 sensors (Dexcom, Inc.) worn by 96 of 105 enrolled pregnant women with type 1 (n = 59), type 2 (n = 21), or gestational diabetes (n = 25). CGM values were compared with arterialized venous glucose values from the YSI comparator instrument during 6-h clinic sessions at different time points throughout the sensors' 10-day wear period. The primary endpoint was the proportion of CGM values in the 70-180 mg/dL range within 15% of comparator glucose values. Secondary endpoints included the proportion of CGM values within 20% or 20 mg/dL of comparator values ≥ or <100 mg/dL, respectively (the %20/20 agreement rate). Results: Of the 1739 pairs with CGM in the 70-180 mg/dL range, 83.2% were within 15% of comparator values. The lower bound of the 95% confidence interval was 79.8%. Of the 2102 pairs with CGM values in the 40-400 mg/dL range, the %20/20 agreement rate was 92.5%. Of the 1659 pairs with comparator values in the 63-140 mg/dL range, the %20/20 agreement rate was 92.3%. The %20/20 agreement rates on days 1, 4 and 7, and 10 were 78.6%, 96.3%, and 97.3%, respectively. Consensus error grid analysis showed 99.8% of pairs in the clinically acceptable A and B zones. There were no serious adverse events. The sensors' 10-day survival rate was 90.3%. Conclusion: The G7 system is accurate and safe during pregnancies complicated by diabetes and does not require confirmatory fingerstick testing. Clinical Trial Registration: clinicaltrials.gov NCT04905628.

Beneficial Effects of Control-IQ Automated Insulin Delivery in Basal-Bolus and Basal-Only Insulin Users With Type 2 Diabetes.

The t:slim X2 insulin pump with Control-IQ technology (Control-IQ) advanced hybrid closed-loop automated insulin delivery system was evaluated in this prospective single-arm trial. Thirty adults with type 2 diabetes using the Control-IQ system showed substantial glycemic improvement with no increase in hypoglycemia. Mean time in range (70-180 mg/dL) improved 15%, representing an increase of 3.6 hours/day, and mean glucose decreased by 22 mg/dL.

A Novel Algorithm for the Management of Inpatient COVID-19 Glucocorticoid-Induced Hyperglycemia.

Hyperglycemia in hospitalized patients with coronavirus disease 2019 (COVID-19) is linked to increased morbidity and mortality. This article reports on a novel insulin titration protocol for the management of glucocorticoid-induced hyperglycemia in hospitalized patients with COVID-19. Sixty-five patients with COVID-19 and glucocorticoid-induced hyperglycemia admitted after the protocol implementation were matched 1:1 to patients admitted before the treatment protocol rollout for analysis. In a large, diverse health system, the protocol achieved reductions in hypoglycemic events without increasing hyperglycemia or insulin use.

At-Home Use of a Pregnancy-Specific Zone-MPC Closed-Loop System for Pregnancies Complicated by Type 1 Diabetes: A Single-Arm, Observational Multicenter Study.

OBJECTIVE: There are no commercially available hybrid closed-loop insulin delivery systems customized to achieve pregnancy-specific glucose targets in the U.S. This study aimed to evaluate the feasibility and performance of at-home use of a zone model predictive controller-based closed-loop insulin delivery system customized for pregnancies complicated by type 1 diabetes (CLC-P). RESEARCH DESIGN AND METHODS: Pregnant women with type 1 diabetes using insulin pumps were enrolled in the second or early third trimester. After study sensor wear collecting run-in data on personal pump therapy and 2 days of supervised training, participants used CLC-P targeting 80-110 mg/dL during the day and 80-100 mg/dL overnight running on an unlocked smartphone at home. Meals and activities were unrestricted throughout the trial. The primary outcome was the continuous glucose monitoring percentage of time in the target range 63-140 mg/dL versus run-in. RESULTS: Ten participants (HbA1c 5.8 ± 0.6%) used the system from mean gestational age of 23.7 ± 3.5 weeks. Mean percentage time in range increased 14.1 percentage points, equivalent to 3.4 h per day, compared with run-in (run-in 64.5 ± 16.3% versus CLC-P 78.6 ± 9.2%; P = 0.002). During CLC-P use, there was significant decrease in both time over 140 mg/dL (P = 0.033) and the hypoglycemic ranges of less than 63 mg/dL and 54 mg/dL (P = 0.037 for both). Nine participants exceeded consensus goals of above 70% time in range during CLC-P use. CONCLUSIONS: The results show that the extended use of CLC-P at home until delivery is feasible. Larger, randomized studies are needed to further evaluate system efficacy and pregnancy outcomes.

Automated Insulin Delivery Systems as a Treatment for Type 2 Diabetes Mellitus: A Review.

OBJECTIVE: Approximately 6.3% of the worldwide population has type 2 diabetes mellitus (T2DM), and the number of people requiring insulin is increasing. Automated insulin delivery (AID) systems integrate continuous subcutaneous insulin infusion and continuous glucose monitoring with a predictive control algorithm to provide more physiologic glycemic control. Personalized glycemic targets are recommended in T2DM owing to the heterogeneity of the disease. Based on the success of hybrid closed-loop systems in improving glycemic control and safety in type 1 diabetes mellitus, there has been further interest in the use of these systems in people with T2DM. METHODS: We performed a review of AID systems with a focus on the T2DM population. RESULTS: In 5 randomized controlled trials, AID systems improve time in range and reduce glycemic variability, without increasing insulin requirements or the risk of hypoglycemia. CONCLUSION: AID systems in T2DM are safe and effective in hospitalized and closely monitored settings. Home studies of longer duration are required to assess for long-term benefit and identify target populations of benefit.

Outcomes in Pump- and CGM-Baseline Use Subgroups in the International Diabetes Closed-Loop Trial.

BACKGROUND: We investigated the potential benefits of automated insulin delivery (AID) among individuals with type 1 diabetes (T1D) in sub-populations of baseline device use determined by continuous glucose monitor (CGM) use status and insulin delivery via multiple daily injections (MDI) or insulin pump. MATERIALS AND METHODS: In a six-month randomized, multicenter trial, 168 individuals were assigned to closed-loop control (CLC, Control-IQ, Tandem Diabetes Care), or sensor-augmented pump (SAP) therapy. The trial included a two- to eight-week run-in phase to train participants on study devices. The participants were stratified into four subgroups: insulin pump and CGM (pump+CGM), pump-only, MDI and CGM (MDI+CGM), and MDI users without CGM (MDI-only) users. We compared glycemic outcomes among four subgroups. RESULTS: At baseline, 61% were pump+CGM users, 18% pump-only users, 10% MDI+CGM users, and 11% MDI-only users. Mean time in range 70-180 mg/dL (TIR) improved from baseline in the four subgroups using CLC: pump+CGM, 62% to 73%; pump-only, 61% to 70%; MDI+CGM, 54% to 68%; and MDI-only, 61% to 69%. The reduction in time below 70 mg/dL from baseline was comparable among the four subgroups. No interaction effect was detected with baseline device use for TIR (P = .67) or time below (P = .77). On the System Usability Questionnaire, scores were high at 26 weeks for all subgroups: pump+CGM: 87.2 ± 12.1, pump-only: 89.4 ± 8.2, MDI+CGM 87.2 ± 9.3, MDI: 78.1 ± 15. CONCLUSIONS: There was a consistent benefit in patients with T1D when using CLC, regardless of baseline insulin delivery modality or CGM use. These data suggest that this CLC system can be considered across a wide range of patients.

Hypoglycemia in Prospective Multicenter Study of Pregnancies with Pre-Existing Type 1 Diabetes on Sensor-Augmented Pump Therapy: The LOIS-P Study.

Background: Pregnancies in type 1 diabetes are high risk, and data in the United States are limited regarding continuous glucose monitoring (CGM)-based hypoglycemia throughout pregnancy while on sensor-augmented insulin pump therapy. Materials and Methods: Pregnant women with type 1 diabetes in the LOIS-P Study (Longitudinal Observation of Insulin use and glucose Sensor metrics in Pregnant women with type 1 diabetes using continuous glucose monitors and insulin pumps) were enrolled before 17 weeks gestation at three U.S. centers and we used their personal insulin pump and a study Dexcom G6 CGM. We analyzed data of 25 pregnant women for CGM hypoglycemia based on international consensus guidelines for percentage time <63 and 54 mg/dL, hypoglycemic events and prolonged hypoglycemia events for 24-h, daytime, and overnight periods, and severe hypoglycemia (SH) episodes. Results: For a 24-h period, biweekly median percentage of time <63 mg/dL ranged from 0.8% at biweek 4-5 to 3.7% at biweek 14-15 with high variability throughout pregnancy. Median percentage of time <63 and 54 mg/dL was higher overnight than daytime (P < 0.01). Hypoglycemic events occurred throughout the pregnancy, ranged 1-4 events per 2 weeks, significantly decreased after the 20th week, and occurred predominantly during daytime (P < 0.01). For overnight period, hypoglycemia and events were more concentrated from 12 to 3 am. Seven prolonged hypoglycemia events without any associated SH occurred in four participants (16%), primarily overnight. Three participants experienced a single episode of SH. Conclusions: Our results suggest a higher overall risk of hypoglycemia throughout pregnancy during the overnight period with continued daytime risk of hypoglycemic events in pregnancies complicated by type 1 diabetes.

Benefit of Continuous Glucose Monitoring in Reducing Hypoglycemia Is Sustained Through 12 Months of Use Among Older Adults with Type 1 Diabetes.

Objective: To evaluate glycemic outcomes in the Wireless Innovation for Seniors with Diabetes Mellitus (WISDM) randomized clinical trial (RCT) participants during an observational extension phase. Research Design and Methods: WISDM RCT was a 26-week RCT comparing continuous glucose monitoring (CGM) with blood glucose monitoring (BGM) in 203 adults aged ≥60 years with type 1 diabetes. Of the 198 participants who completed the RCT, 100 (98%) CGM group participants continued CGM (CGM-CGM cohort) and 94 (98%) BGM group participants initiated CGM (BGM-CGM cohort) for an additional 26 weeks. Results: CGM was used a median of >90% of the time at 52 weeks in both cohorts. In the CGM-CGM cohort, median time <70 mg/dL decreased from 5.0% at baseline to 2.6% at 26 weeks and remained stable with a median of 2.8% at 52 weeks (P < 0.001 baseline to 52 weeks). Participants spent more time in range 70-180 mg/dL (TIR) (mean 56% vs. 64%; P < 0.001) and had lower hemoglobin A1c (HbA1c) (mean 7.6% [59 mmol/mol] vs. 7.4% [57 mmol/mol]; P = 0.01) from baseline to 52 weeks. In BGM-CGM, from 26 to 52 weeks median time <70 mg/dL decreased from 3.9% to 1.9% (P < 0.001), TIR increased from 56% to 60% (P = 0.006) and HbA1c decreased from 7.5% (58 mmol/mol) to 7.3% (57 mmol/mol) (P = 0.025). In BGM-CGM, a severe hypoglycemic event was reported for nine participants while using BGM during the RCT and for two participants during the extension phase with CGM (P = 0.02). Conclusions: CGM use reduced hypoglycemia without increasing hyperglycemia in older adults with type 1 diabetes. These data provide further evidence for fully integrating CGM into clinical practice. Clinicaltrials.gov (NCT03240432).

Feasibility of Closed-Loop Insulin Delivery with a Pregnancy-Specific Zone Model Predictive Control Algorithm.

Objective: Evaluating the feasibility of closed-loop insulin delivery with a zone model predictive control (zone-MPC) algorithm designed for pregnancy complicated by type 1 diabetes (T1D). Research Design and Methods: Pregnant women with T1D from 14 to 32 weeks gestation already using continuous glucose monitor (CGM) augmented pump therapy were enrolled in a 2-day multicenter supervised outpatient study evaluating pregnancy-specific zone-MPC based closed-loop control (CLC) with the interoperable artificial pancreas system (iAPS) running on an unlocked smartphone. Meals and activities were unrestricted. The primary outcome was the CGM percentage of time between 63 and 140 mg/dL compared with participants' 1-week run-in period. Early (2-h) postprandial glucose control was also evaluated. Results: Eleven participants completed the study (age: 30.6 ± 4.1 years; gestational age: 20.7 ± 3.5 weeks; weight: 76.5 ± 15.3 kg; hemoglobin A1c: 5.6% ± 0.5% at enrollment). No serious adverse events occurred. Compared with the 1-week run-in, there was an increased percentage of time in 63-140 mg/dL during supervised CLC (CLC: 81.5%, run-in: 64%, P = 0.007) with less time >140 mg/dL (CLC: 16.5%, run-in: 30.8%, P = 0.029) and time <63 mg/dL (CLC: 2.0%, run-in:5.2%, P = 0.039). There was also less time <54 mg/dL (CLC: 0.7%, run-in:1.6%, P = 0.030) and >180 mg/dL (CLC: 4.9%, run-in: 13.1%, P = 0.032). Overnight glucose control was comparable, except for less time >250 mg/dL (CLC: 0%, run-in:3.9%, P = 0.030) and lower glucose standard deviation (CLC: 23.8 mg/dL, run-in:42.8 mg/dL, P = 0.007) during CLC. Conclusion: In this pilot study, use of the pregnancy-specific zone-MPC was feasible in pregnant women with T1D. Although the duration of our study was short and the number of participants was small, our findings add to the limited data available on the use of CLC systems during pregnancy (NCT04492566).

Insulin Delivery and Glucose Variability Throughout the Menstrual Cycle on Closed Loop Control for Women with Type 1 Diabetes.

Objective: To analyze insulin delivery and glycemic metrics throughout the menstrual cycle for women with type 1 diabetes using closed loop control (CLC) insulin delivery. Methods: Menstruating women using a CLC system in a clinical trial were invited to record their menstrual cycles through a cycle-tracking application. Sixteen participants provided data for this secondary analysis over three or more complete cycles. Insulin delivery and continuous glucose monitoring (CGM) data were analyzed in relation to reported cycle phases. Results: Insulin delivery and CGM metrics remained consistent during cycle phases. Intraparticipant variability of CGM metrics and weight-based insulin delivery did not change through cycle phases. Conclusions: For this sample of menstruating women with type 1 diabetes using a CLC system, insulin delivery and glycemic metrics remained stable throughout menstrual cycle phases. Additional studies in this population are needed, particularly among women who report variable glycemic control during their cycles. Trial Registration: NCT03591354.

Impact of a Novel Diabetes Support System on a Cohort of Individuals With Type 1 Diabetes Treated With Multiple Daily Injections: A Multicenter Randomized Study.

OBJECTIVE: Achieving optimal glycemic control for many individuals with type 1 diabetes (T1D) remains challenging, even with the advent of newer management tools, including continuous glucose monitoring (CGM). Modern management of T1D generates a wealth of data; however, use of these data to optimize glycemic control remains limited. We evaluated the impact of a CGM-based decision support system (DSS) in patients with T1D using multiple daily injections (MDI). RESEARCH DESIGN AND METHODS: The studied DSS included real-time dosing advice and retrospective therapy optimization. Adults and adolescents (age >15 years) with T1D using MDI were enrolled at three sites in a 14-week randomized controlled trial of MDI + CGM + DSS versus MDI + CGM. All participants (N = 80) used degludec basal insulin and Dexcom G5 CGM. CGM-based and patient-reported outcomes were analyzed. Within the DSS group, ad hoc analysis further contrasted active versus nonactive DSS users. RESULTS: No significant differences were detected between experimental and control groups (e.g., time in range [TIR] +3.3% with CGM vs. +4.4% with DSS). Participants in both groups reported lower HbA1c (-0.3%; P = 0.001) with respect to baseline. While TIR may have improved in both groups, it was statistically significant only for DSS; the same was apparent for time spent <60 mg/dL. Active versus nonactive DSS users showed lower risk of and exposure to hypoglycemia with system use. CONCLUSIONS: Our DSS seems to be a feasible option for individuals using MDI, although the glycemic benefits associated with use need to be further investigated. System design, therapy requirements, and target population should be further refined prior to use in clinical care.

Baseline Quality Improvement Capacity of 33 Endocrinology Centers Participating in the T1D Exchange Quality Improvement Collaborative.

This article describes the evolution of the Type 1 Diabetes Exchange Quality Improvement Collaborative (T1DX-QI) and provides insight into the development and growth of a successful type 1 diabetes quality improvement (QI) program. Since its inception 8 years ago, the collaborative has expanded to include centers across the United States with varying levels of QI experience, while simultaneously achieving many tangible improvements in type 1 diabetes care. These successes underscore the importance of learning health systems, data-sharing, benchmarking, and peer collaboration as drivers for continuous QI. Future efforts will include recruiting additional small- to medium-sized centers focused on adult care and underserved communities to further the goal of improving care and outcomes for all people living with type 1 diabetes.

Assessing Glycemic Control Using CGM for Women with Diabetes in Pregnancy.

PURPOSE OF REVIEW: Diabetes during pregnancy increases the risk of maternal and fetal complications. This article reviews the types of CGM currently available, the glucose metrics which correlate with pregnancy outcomes, endocrine organization recommendations, clinical considerations for CGM implementation, and anticipated directions for future research. RECENT FINDINGS: CGM use during pregnancy is increasing, and recommendations for use have been incorporated into many organizations' consensus guidelines. Increased time spent within a target range of 63-140 mg/dL and lower mean glucose are associated with lower risk of neonatal complications including large for gestational age infants. Use of CGM during pregnancy can detect postprandial and nocturnal hyperglycemia missed by self-monitoring of blood glucose (SMBG) which can be used for prognosis and to guide pharmacologic interventions. The use of continuous glucose monitoring (CGM) during pregnancies complicated by type 1, type 2, and gestational diabetes has been shown to improve outcomes.

Longitudinal Observation of Insulin Use and Glucose Sensor Metrics in Pregnant Women with Type 1 Diabetes Using Continuous Glucose Monitors and Insulin Pumps: The LOIS-P Study.

Background: Suboptimal glycemic control is associated with maternal and neonatal morbidity and mortality in pregnancy complicated by type 1 diabetes (T1D). Prospective analysis of continuous glucose monitoring (CGM) metrics, insulin pump settings, and insulin delivery can better characterize the changes in glycemic levels and insulin use throughout pregnancy with T1D. Materials and Methods: Prescribed parameters, insulin delivery, carbohydrate intake, and CGM data for 25 pregnant women with T1D from three U.S. sites were collected. Participants enrolled before 17 weeks gestation and used personal insulin pumps and study CGM. Mean daily total, basal, and bolus insulin doses (units/kg), CGM time in range (TIR: 63-140 mg/dL), and pump-entered carbohydrates were analyzed for every 2-week gestational interval. Linear mixed-effects regression models were used to evaluate changes across gestational ages compared to 12-14 weeks. Results: Basal insulin was higher during weeks 6-12 and 24-40. Daily bolus and total insulin were higher during weeks 20-40. Pump parameters were adjusted to intensify insulin therapy from 22 weeks onward. Average TIR across pregnancy was 59% ± 14%. Between 18 and 30 weeks, TIR was significantly lower, and time above range was significantly higher compared to the reference biweek. Time below target was lower between 22 and 34 weeks. Seven participants achieved >70% recommended TIR for pregnancy. Participants with maternal complications or infant neonatal intensive care unit admissions had lower TIR. Conclusion: While insulin dosing changed significantly with advancing gestation, most participants did not achieve >70% TIR. Customized anticipatory pump setting adjustments and automated systems aimed toward the designated TIR are needed to improve outcomes for this population. NCT03761615.

First Outpatient Evaluation of a Tubeless Automated Insulin Delivery System with Customizable Glucose Targets in Children and Adults with Type 1 Diabetes.

Background: The objective of this study was to assess the safety and effectiveness of the first commercial configuration of a tubeless automated insulin delivery system, Omnipod® 5, in children (6-13.9 years) and adults (14-70 years) with type 1 diabetes (T1D) in an outpatient setting. Materials and Methods: This was a single-arm, multicenter, prospective clinical study. Data were collected over a 14-day standard therapy (ST) phase followed by a 14-day hybrid closed-loop (HCL) phase, where participants (n = 36) spent 72 h at each of three prespecified glucose targets (130, 140, and 150 mg/dL, 9 days total) then 5 days with free choice of glucose targets (110-150 mg/dL) using the Omnipod 5. Remote safety monitoring alerts were enabled during the HCL phase. Primary endpoints were difference in time in range (TIR) (70-180 mg/dL) between ST and HCL phases and proportion of participants reporting serious device-related adverse events. Results: Mean TIR was significantly higher among children in the free-choice period overall (64.9% ± 12.2%, P < 0.01) and when using a 110 mg/dL target (71.2% ± 10.2%, P < 0.01), a 130 mg/dL target (61.5% ± 7.7%, P < 0.01), and a 140 mg/dL target (64.8% ± 11.6%, P < 0.01), and among adults using a 130 mg/dL target (75.1% ± 11.6%, P < 0.05), compared to the ST phase (children: 51.0% ± 13.3% and adults: 65.6% ± 15.7%). There were no serious device-related adverse events reported during the HCL phase, nor were there episodes of severe hypoglycemia or diabetic ketoacidosis. Conclusion: The Omnipod 5 System was safe and effective when used at glucose targets from 110 to 150 mg/dL for 14 days at home in children and adults with T1D.

COVID-19 Hospitalization in Adults with Type 1 Diabetes: Results from the T1D Exchange Multicenter Surveillance Study.

CONTEXT: Diabetes mellitus is associated with increased COVID-19 morbidity and mortality, but there are few data focusing on outcomes in people with type 1 diabetes. OBJECTIVE: The objective of this study was to analyze characteristics of adults with type 1 diabetes for associations with COVID-19 hospitalization. DESIGN: An observational multisite cross-sectional study was performed. Diabetes care providers answered a 33-item questionnaire regarding demographics, symptoms, and diabetes- and COVID-19-related care and outcomes. Descriptive statistics were used to describe the study population, and multivariate logistic regression models were used to analyze the relationship between glycated hemoglobin (HbA1c), age, and comorbidities and hospitalization. SETTING: Cases were submitted from 52 US sites between March and August 2020. PATIENTS OR OTHER PARTICIPANTS: Adults over the age of 19 with type 1 diabetes and confirmed COVID-19 infection were included. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Hospitalization for COVID-19 infection. RESULTS: A total of 113 cases were analyzed. Fifty-eight patients were hospitalized, and 5 patients died. Patients who were hospitalized were more likely to be older, to identify as non-Hispanic Black, to use public insurance, or to have hypertension, and less likely to use continuous glucose monitoring or insulin pumps. Median HbA1c was 8.6% (70 mmol/mol) and was positively associated with hospitalization (odds ratio 1.42, 95% confidence interval 1.18-1.76), which persisted after adjustment for age, sex, race, and obesity. CONCLUSIONS: Baseline glycemic control and access to care are important modifiable risk factors which need to be addressed to optimize care of people with type 1 diabetes during the worldwide COVID-19 pandemic.