Sensor-Augmented Insulin Pump with Predictive Low-Glucose Suspend (PLGS): Determining Optimal Settings of Pump and Sensor in a Multicenter Cohort of Patients with Type 1 Diabetes

INTRODUCTION

The use of predictive low-glucose suspend (PLGS) sensor-augmented pumps has been shown to lead to a significant reduction in hypoglycemic episodes in patients with type 1 diabetes (T1D), but their effects on hyperglycemia exposure are heterogeneous. The aim of this study was to determine the settings of the Medtronic 640G system to obtain the optimal balance between occurrence of both hypoglycemia and hyperglycemia.

METHODS

The hypo- and hyperglycemia area under the curve (AUC), as well as system settings [hypoglycemic threshold, mean insulin total daily dose (TDD), mean basal insulin percentage, and mean daily duration of PLGS] were collected between 2 and 12 times during 1 year in patients from four university hospital centers. Univariate/multivariate analyses and receiver operating characteristics (ROC) curves were performed to determine factors associated with hyper- and hypoglycemia AUC.

RESULTS

A total of 864 observations were analyzed from 110 patients with T1D. Two preselected settings predictive of low hyperglycemia AUC were a basal insulin percentage < 52.0% [sensitivity (Se) = 0.66 and specificity (Sp) = 0.53] and a PLGS duration > 157.5 min/day (Se = 0.47 and Sp = 0.73). The preselected setting predictive of a low hypoglycemia AUC was a PLGS duration ≤ 174.4 min (Se = 0.83 and Sp = 0.51). Between-visit variation of PLGS and TDD was positively correlated (r = 0.61; p < 0.0001).

CONCLUSION

The most important Medtronic 640G setting was the mean daily PLGS duration, where a value between 157.5 and 174.4 min/day was associated with the best reduction in both hypo- and hyperglycemia AUC. In this study, we showed that PLGS duration could be indirectly modified through total daily insulin dose adaptation.

TRIAL REGISTRATION

This study is registered in clinicaltrials.gov (NCT03047486).

Predictive Low-Glucose Suspend Necessitates Less Carbohydrate Supplementation to Rescue Hypoglycemia: Need to Revisit Current Hypoglycemia Treatment Guidelines

Current guidelines recommend 15-20 g of carbohydrate (CHO) for treatment of mild to moderate hypoglycemia. However, these guidelines do not account for reduced insulin during suspensions with predictive low-glucose suspend (PLGS). We assessed insulin suspensions, hypoglycemic events, and CHO treatment during a 20-h inpatient evaluation of an investigational system with a PLGS feature, including an overnight basal up-titration period to activate the PLGS. Among 10 adults with type 1 diabetes, there were 59 suspensions; 7 suspensions were associated with rescue CHO and 5 with hypoglycemia. Rescue treatment consisted of median 9 g CHO (range: 5-16 g), with no events requiring repeat CHO. No rescue CHO were given during or after insulin suspension for the overnight basal up-titration. To minimize rebound hyperglycemia and needless calorie intake from hypoglycemia overtreatment, updated guidance for PLGS systems should reflect possible need to reduce CHO amounts for hypoglycemia rescue associated with an insulin suspension. The clinical trial was registered with ClinicalTrials.gov (NCT03890003).

Safety and Feasibility of the PEPPER Adaptive Bolus Advisor and Safety System: A Randomized Control Study

Background: The Patient Empowerment through Predictive Personalized Decision Support (PEPPER) system provides personalized bolus advice for people with type 1 diabetes. The system incorporates an adaptive insulin recommender system (based on case-based reasoning, an artificial intelligence methodology), coupled with a safety system, which includes predictive glucose alerts and alarms, predictive low-glucose suspend, personalized carbohydrate recommendations, and dynamic bolus insulin constraint. We evaluated the safety and efficacy of the PEPPER system compared to a standard bolus calculator. Methods: This was an open-labeled multicenter randomized controlled crossover study. Following 4-week run-in, participants were randomized to PEPPER/Control or Control/PEPPER in a 1:1 ratio for 12 weeks. Participants then crossed over after a washout period. The primary end-point was percentage time in range (TIR, 3.9-10.0 mmol/L [70-180 mg/dL]). Secondary outcomes included glycemic variability, quality of life, and outcomes on the safety system and insulin recommender. Results: Fifty-four participants on multiple daily injections (MDI) or insulin pump completed the run-in period, making up the intention-to-treat analysis. Median (interquartile range) age was 41.5 (32.3-49.8) years, diabetes duration 21.0 (11.5-26.0) years, and HbA1c 61.0 (58.0-66.1) mmol/mol. No significant difference was observed for percentage TIR between the PEPPER and Control groups (62.5 [52.1-67.8] % vs. 58.4 [49.6-64.3] %, respectively, P = 0.27). For quality of life, participants reported higher perceived hypoglycemia with the PEPPER system despite no objective difference in time spent in hypoglycemia. Conclusions: The PEPPER system was safe, but did not change glycemic outcomes, compared to control. There is wide scope for integrating PEPPER into routine diabetes management for pump and MDI users. Further studies are required to confirm overall effectiveness. Clinical trial registration: ClinicalTrials.gov NCT03849755.

Impact of Sensor-Augmented Pump Therapy with Predictive Low-Glucose Suspend Function on Glycemic Control and Patient Satisfaction in Adults and Children with Type 1 Diabetes

AIMS

The aim was to evaluate the effectiveness of sensor-augmented pump therapy with predictive low-glucose suspend function (SAP-PLGS) in real-world use in children and adults with type 1 diabetes (T1D).

METHODS

Patients with T1D treated with the MiniMed 640G^® pump with PLGS function at three referral hospitals were retrospectively evaluated. Hb_A1c at baseline and at 6, 12, 18, and 24 months was analyzed. Two weeks of data from pumps, sensors, and/or glucose meters were downloaded. Patients completed satisfaction questionnaires at the last follow-up visit.

RESULTS

A total of 162 patients were included. Mean age was 32 ± 17 years, 28% were (n = 46) children, and 29% (n = 47) were with a history of severe hypoglycemia. Median follow-up was 12 months (6-18). Hb_A1c was reduced from 55 ± 9 to 54 ± 8 mmol/mol (7.2% ± 0.8% to 7.1% ± 0.7%) at 12 months (P < 0.03, n = 100). In patients with suboptimal control, there was a reduction in Hb_A1c from 66% ± 7% to 61 ± 10 mmol/mol (8.2% ± 0.6% to 7.7% ± 0.9%) at the end of follow-up (n = 26, P < 0.01). Three percent (n = 5) of the patients experienced severe hypoglycemia during follow-up. A reduction in the percentage of self-monitoring of blood glucose values <70 mg/dL was achieved (10% ± 7% to 6% ± 5%, P = 0.001, n = 144). Time in range 70-180 mg/dL was 67% ± 13% at the end of follow-up and predictors of a higher time in range were identified. The use of sensors was high (86%) and 73% of the patients showed high satisfaction. In patients using sensors at baseline (n = 54), the time spent at <54 and <70 mg/dL was reduced.

CONCLUSION

SAP-PLGS reduces hypoglycemia frequency while maintaining glycemic control in adults and children under real-life conditions.

Efficacy and safety of sensor-augmented pump therapy (SAPT) with predictive low-glucose management in patients diagnosed with type 1 diabetes mellitus previously treated with SAPT and low glucose suspend

BACKGROUND

Sensor-augmented insulin pump therapy (SAPT) with low-glucose suspend (LGS) is an effective and safe alternative for treating patients with type 1 diabetes mellitus (T1DM). New predictive low-glucose management (PLGM) systems decrease the severity and duration of hypoglycemic events. However, evidence of benefits in patients previously treated with SAPT-LGS is limited.

METHODS

A prospective before-after study was conducted in patients with T1DM treated with SAPT-LGS, who were switched to the Minimed^® 640G system with SmartGuard^® to assess the impact on A1c levels, severe hypoglycemia (SH), hypoglycemia unawareness (HU), and area under the curve (AUC) <70mg/dL after three months of follow-up.

RESULTS

Fifty-five patients with T1DM with a mean age of 37.9 (IQR 6, 79) years and a mean baseline A1c level of 7.52±1.11% were enrolled. After three months under PLGM, A1c levels significantly decreased to 7.18±0.91% (p=0.004). SH rate decreased from 2.47 (CI 0.44, 4.90) to 0.87 (CI 0.22, 1.52) events/patient-year (Incidence rate ratio 0.353, 95% CI 0.178, 0.637), AUC <70mg/dL decreased from 0.59±0.76 to 0.35±0.65mg/dL x minute (p=0.030). HU determined by Clarke questionnaire resolved in 23 out of 30 patients (p=0.002).

CONCLUSIONS

This study suggests that SAPT with PLGM decreases the frequency of SH, HU, exposure to glucose levels below 70mg/dL, and A1c levels. Based on these results, this therapy should be considered in T1DM patients previously treated with SAPT-LGS with persistent SH and HU. Further clinical trials comparing the efficacy and safety of these features are required.