Alarms Based on Real-Time Sensor Glucose Values Alert Patients to Hypo- and Hyperglycemia: The Guardian Continuous Monitoring System

Abstract

The purposes of this study were to demonstrate the accuracy and effectiveness of the Guardian Continuous Monitoring System (Medtronic MiniMed, Northridge, California) and to demonstrate that the application of real-time alarms to continuous monitoring alerts users to hypo and hyperglycemia and reduces excursions in people with diabetes. A total of 71 subjects with type 1 diabetes, mean hemoglobin A1c of 7.6 +/- 1.1%, age 44.0 +/- 11.4 years, and duration of diabetes 23.6 +/- 10.6 years were enrolled in this two-period, randomized, multicenter study. Subjects were randomized into either an Alert group or a Control group. The accuracy of the Guardian was evaluated by treating the study data as a single-sample correlational design. Effectiveness of the Guardian alerts was evaluated by comparing the Alert group with the Control group. The mean (median) absolute relative error between home blood glucose meter readings and sensor values was 21.3% (17.3%), and the Guardian, on average, read 12.8 mg/dL below the concurrent home blood glucose meter readings. The hypoglycemia alert was able to distinguished glucose values < or =70 mg/dL with 67% sensitivity, 90% specificity, and 47% false alerts. The hyperglycemia alert showed a similar ability to detect sensor values > or =250 mg/dL with 63% sensitivity, 97% specificity, and 19% false alerts. The Alert group demonstrated a median decrease in the duration of hypoglycemic excursions (-27.8 min) that was significantly greater than the median decrease in the duration of hypoglycemic excursions in the Control group (-4.5 min) (P = 0.03). A marginally significant increase in the frequency of hyperglycemic excursions (P = 0.07) between Period 1 and Period 2 was accompanied by a decrease of 9.6 min in the duration of hyperglycemic excursions in the Alert group. Glucose measurements differ between blood samples taken from the finger and interstitial fluid, especially when levels are changing rapidly; however, these results demonstrate that the Guardian is reasonably accurate while performing continuous glucose monitoring. The subjects' responses to hypoglycemia alerts resulted in a significant reduction in the duration of hypoglycemic excursions; however, overtreating hypoglycemia may have resulted in a marginally significant increase in the frequency of hyperglycemic excursions.

Continuous Glucose Monitoring System in children with type 1 diabetes mellitus: a systematic review and meta-analysis

“…Table 1 summarises characteristics of the included trials. Five RCTs involving 131 participants met our predefined inclusion criteria [15][16][17][18][19]; the remaining 20 studies were excluded [7,[11][12][13][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Table 2 summarises the characteristics of excluded trials, including reasons for exclusion.…”

“…One trial [17] showed an Bode et al [20] Non-randomised, uncontrolled trial Bode et al [7] RCT performed in adults. Guardian Continuous Monitoring System used Boland et al [21] Non-randomised, uncontrolled trial Burdick et al [22] Non-randomised, uncontrolled trial.…”

“…There are several devices for CGM [5][6][7][8][9][10]. Generally, two types of CGM are distinguished.…”

Tight glycemic control in critical care – The leading role of insulin sensitivity and patient variability: A review and model-based analysis

“…Thus, while better measurements are always beneficial, measurement error itself does not appear to have a greater impact than the TGC protocol design or its ability to manage inter-and intra-patient variability. [142][143][144][145]). For TGC in the ICU this area was also reviewed in [66].…”

A Novel Adaptive-Weighted-Average Framework for Blood Glucose Prediction

“…These CGMS devices incorporate real-time alarms when the measurement exceeds the safe range threshold. 1,2 Using general guidelines that patients follow in their daily life, some diabetes management systems have been proposed to further assist patients in self-managing their disease, such as CareLink personal software (Medtronic, Northridge, CA), which is a secure, Web-based therapy management software that allows patients to easily store their information and allows a healthcare professional access to it. 3 One of the most essential components of a diabetes management system is the BG prediction scheme.…”