Kristin Castorino

Background: This study evaluates the performance of a 15-day factory-calibrated continuous glucose monitoring sensor used in FreeStyle Libre 2 Plus (Libre 2 Plus) and FreeStyle Libre 3 Plus (Libre 3 Plus) Systems, featuring an improved sensor design to reduce vitamin C interference. Methods: Participants aged 2 years and above were enrolled for this study at seven sites in the United States. Depending on their age and bodyweight, participants attended up to three in-clinic sessions where venous blood was obtained for comparator measurement. For 2- to 5-year-olds, only capillary comparator data were collected. Participants aged 11 years and older underwent supervised glycemic manipulation to achieve glucose levels across the sensor’s measurement range. Performance measures included the proportion of continuous glucose monitoring (CGM) values within ±20%/±20 mg/dL of comparator glucose values and mean absolute relative difference (MARD) between CGM and comparator values. Results: Of the total 332 participants enrolled in the study, 149 adults and 124 pediatric participants (ages 6-17 years) had paired data for analysis against YSI comparator. Percentages within ±20 mg/dL/20% were 94.2% and 94.0%, and MARDs were 8.2% and 8.1% for the adults and pediatric participants, respectively. For 12 pediatric participants of 2 to 5 years, the percentage within ±20 mg/dL/20% was 86.6%, with an MARD of 11.2% against self-monitoring of blood glucose (SMBG) comparator. The sensor performed well in the hypoglycemic range, with 97.1% and 98.0% of results within ±15 mg/dL of the YSI comparator for the adult and pediatric participants, respectively. Conclusions: The Libre 2 Plus and Libre 3 Plus Systems provide accurate glucose results across the dynamic range during the 15-day sensor wear period.

OBJECTIVE: To evaluate a regimen of inhaled Technosphere insulin (TI) plus insulin degludec in adults with type 1 diabetes, who prestudy were predominately using either an automated insulin delivery (AID) system or multiple daily insulin injections (MDI) with continuous glucose monitoring. RESEARCH DESIGN AND METHODS: At 19 sites, adults with type 1 diabetes were randomly assigned to TI plus insulin degludec (N = 62) or usual care (UC) with continuation of prestudy insulin delivery method (N = 61) for 17 weeks. RESULTS: Prestudy, AID was used by 48% and MDI by 45%. Mean ± SD HbA1c was 7.57% ± 0.97% at baseline and 7.62% ± 1.06% at 17 weeks in the TI group and 7.59% ± 0.80% and 7.54% ± 0.77%, respectively, in the UC group (adjusted difference 0.11%, 95% CI −0.10 to 0.33, P value for noninferiority = 0.01). HbA1c improved from baseline to 17 weeks by >0.5% (5.5 mmol/mol) in 12 (21%) in the TI group and in 3 (5%) in the UC group and worsened by >0.5% (5.5 mmol/mol) in 15 (26%) in the TI group and in 2 (3%) in the UC group. The most common TI side effect was a brief cough; eight participants discontinued TI due to side effects. CONCLUSIONS: In adults with type 1 diabetes, HbA1c after 17 weeks with a regimen of TI and degludec was noninferior to UC, which consisted predominately of either AID or MDI. TI should be considered an option for people with type 1 diabetes, particularly those who are motivated to further reduce postprandial hyperglycemia.

OBJECTIVE: To examine the efficacy and safety of the tubeless Omnipod 5 automated insulin delivery (AID) system compared with pump therapy with a continuous glucose monitor (CGM) in adults with type 1 diabetes with suboptimal glycemic outcomes. RESEARCH DESIGN AND METHODS: In this 13-week multicenter, parallel-group, randomized controlled trial performed in the U.S. and France, adults aged 18–70 years with type 1 diabetes and HbA1c 7–11% (53–97 mmol/mol) were randomly assigned (2:1) to intervention (tubeless AID) or control (pump therapy with CGM) following a 2-week standard therapy period. The primary outcome was a treatment group comparison of time in range (TIR) (70–180 mg/dL) during the trial period. RESULTS: A total of 194 participants were randomized, with 132 assigned to the intervention and 62 to the control. TIR during the trial was 4.2h/day higher in the intervention compared with the control group (mean difference 17.5% [95% CI 14.0%, 21.1%]; P < 0.0001). The intervention group had a greater reduction in HbA1c from baseline compared with the control group (mean ± SD −1.24 ± 0.75% [−13.6 ± 8.2 mmol/mol] vs. −0.68 ± 0.93% [−7.4 ± 10.2 mmol/mol], respectively; P < 0.0001), accompanied by a significantly lower time 180 mg/dL (37.6 ± 11.4% vs. 54.5 ± 15.4%; P < 0.0001). All primary and secondary outcomes were met. No instances of diabetes-related ketoacidosis or severe hypoglycemia occurred in the intervention group. CONCLUSIONS: Use of the tubeless AID system led to improved glycemic outcomes compared with pump therapy with CGM among adults with type 1 diabetes, underscoring the clinical benefit of AID and bolstering recommendations to establish AID systems as preferred therapy for this population.

OBJECTIVE: To compare postprandial glucose excursions following a bolus with inhaled technosphere insulin (TI) or subcutaneous rapid-acting analog (RAA) insulin. RESEARCH DESIGN AND METHODS: A meal challenge was completed by 122 adults with type 1 diabetes who were using multiple daily injections (MDI), a nonautomated pump, or automated insulin delivery (AID) and who were randomized to bolus with their usual RAA insulin (n = 61) or TI (n = 61). RESULTS: The primary outcome, the treatment group difference in area under the curve for glucose >180 mg/dL over 2 h, was less with TI versus RAA (adjusted difference −12 mg/dL, 95% CI −22 to −2, P = 0.02). With TI, the glucose excursion was smaller (P = 0.01), peak glucose lower (P = 0.01), and time to peak glucose shorter (P = 0.006). Blood glucose <70 mg/dL occurred in one participant in each group. CONCLUSIONS: Postmeal glucose excursion was smaller with TI than with RAA insulin in a cohort that included both AID and MDI users.

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

Introduction Insulin is the first-line pharmacologic therapy for women with diabetes in pregnancy. However, conducting well-designed randomized clinical trials (RCTs) and achieving recommended glycemic targets remains a challenge for this unique population. This systematic literature review (SLR) aimed to understand the evidence for insulin use in pregnancy and the outcome metrics most often used to characterize its effect on glycemic, maternal and fetal outcomes in gestational diabetes mellitus (GDM) and in pregnant women with diabetes. Methods An SLR was conducted using electronic databases in Medline, EMBASE via Ovid platform, evidence-based medicine reviews (2010–2020) and conference proceedings (2018–2019). Studies were included if they assessed the effect of insulin treatment on glycemic, maternal or fetal outcomes in women with diabetes in pregnancy. Studies on any type of diabetes other than gestational or pre-existing diabetes as well as non-human studies were excluded. Results In women diagnosed with GDM or pre-existing diabetes, most studies compared treatment of insulin with metformin (n = 35) followed by diet along with lifestyle intervention (n = 24) and glibenclamide (n = 12). Most studies reporting on glycemic outcomes compared insulin with metformin (n = 22) and glibenclamide (n = 4). Fasting blood glucose was the most reported clinical outcome of interest. Among the studies reporting maternal outcomes, method of delivery and delivery complications were most commonly reported. Large for gestational age, stillbirth and perinatal mortality were the most common fetal outcomes reported. Conclusion This SLR included a total of 108 clinical trials and observational studies with diverse populations and treatment arms. Outcomes varied across the studies, and a lack of consistent outcome measures to manage diabetes in pregnant women was observed. This elucidates a need for global consensus on study design and standardized clinical, maternal and fetal outcomes metrics.

Ketone bodies are an energy substrate produced by the liver and used during states of low carbohydrate availability, such as fasting or prolonged exercise. High ketone concentrations can be present with insulin insufficiency and are a key finding in diabetic ketoacidosis (DKA). During states of insulin deficiency, lipolysis increases and a flood of circulating free fatty acids is converted in the liver into ketone bodies—mainly beta-hydroxybutyrate and acetoacetate. During DKA, beta-hydroxybutyrate is the predominant ketone in blood. As DKA resolves, beta-hydroxybutyrate is oxidized to acetoacetate, which is the predominant ketone in the urine. Because of this lag, a urine ketone test might be increasing even as DKA is resolving. Point-of-care tests are available for self-testing of blood ketones and urine ketones through measurement of beta-hydroxybutyrate and acetoacetate and are cleared by the US Food and Drug Administration (FDA). Acetone forms through spontaneous decarboxylation of acetoacetate and can be measured in exhaled breath, but currently no device is FDA-cleared for this purpose. Recently, technology has been announced for measuring beta-hydroxybutyrate in interstitial fluid. Measurement of ketones can be helpful to assess compliance with low carbohydrate diets; assessment of acidosis associated with alcohol use, in conjunction with SGLT2 inhibitors and immune checkpoint inhibitor therapy, both of which can increase the risk of DKA; and to identify DKA due to insulin deficiency. This article reviews the challenges and shortcomings of ketone testing in diabetes treatment and summarizes emerging trends in the measurement of ketones in the blood, urine, breath, and interstitial fluid.

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

OBJECTIVE For people with type 1 diabetes, there are limited evidence-based resources to support self-management when traveling across multiple time zones. Here, we compared glycemic control on insulin degludec versus glargine U100 as the basal insulin for adults using multiple daily injections (MDI) while traveling across multiple time zones. RESEARCH DESIGN AND METHODS This randomized crossover pilot study compared insulin degludec versus glargine U100 for adults with type 1 diabetes using MDI insulin during long-haul travel to and from Hawaii to New York. Insulin degludec was administered daily at the same time regardless of time zone, and glargine was administered per travel algorithm. Primary end point was the percentage of time in range (TIR) between 70 and 140 mg/dL during the initial 24 h after each direction of travel. Secondary end points included standard continuous glucose monitoring metrics, jet lag, fatigue, and sleep. RESULTS The study enrolled 25 participants (56% women, mean ± SD age of 35 ± 14.5 years, HbA_1c of 7.4 ± 1.2% [57 ± 13.1 mmol/mol], and diabetes duration of 20.6 ± 15 years). There was no significant difference in glycemic outcomes between the two arms of the study, including TIR, hypoglycemia, or hyperglycemia. Neither group achieved >70% TIR 70–180 mg/dL during travel. Jet lag was greater on glargine U100 in eastward travel but not westward. Fatigue was greater after westward travel on glargine. Sleep was not significantly different between basal insulins. CONCLUSION In adults with type 1 diabetes using MDI of insulin and traveling across multiple time zones, glycemic outcomes were similar comparing insulin degludec and glargine U100.

This article is the work product of the Continuous Ketone Monitoring Consensus Panel, which was organized by Diabetes Technology Society and met virtually on April 20, 2021. The panel consisted of 20 US-based experts in the use of diabetes technology, representing adult endocrinology, pediatric endocrinology, advanced practice nursing, diabetes care and education, clinical chemistry, and bioengineering. The panelists were from universities, hospitals, freestanding research institutes, government, and private practice. Panelists reviewed the medical literature pertaining to ten topics: (1) physiology of ketone production, (2) measurement of ketones, (3) performance of the first continuous ketone monitor (CKM) reported to be used in human trials, (4) demographics and epidemiology of diabetic ketoacidosis (DKA), (5) atypical hyperketonemia, (6) prevention of DKA, (7) non-DKA states of fasting ketonemia and ketonuria, (8) potential integration of CKMs with pumps and automated insulin delivery systems to prevent DKA, (9) clinical trials of CKMs, and (10) the future of CKMs. The panelists summarized the medical literature for each of the ten topics in this report. They also developed 30 conclusions (amounting to three conclusions for each topic) about CKMs and voted unanimously to adopt the 30 conclusions. This report is intended to support the development of safe and effective continuous ketone monitoring and to apply this technology in ways that will benefit people with diabetes.