This is a Collaborative Learning Community (CLC) assignment.
As a group, identify a research or evidence-based article published within the last 5 years that focuses comprehensively on a specific intervention or new treatment tool for the management of diabetes in adults or children. The article must be relevant to nursing practice.
Create a 10-15 slide PowerPoint presentation on the study’s findings and how they can be used by nurses as an intervention. Include speaker notes for each slide and additional slides for the title page and references.
Include the following:
- Describe the intervention or treatment tool and the specific patient population used in the study.
- Summarize the main idea of the research findings for a specific patient population. The research presented must include clinical findings that are current, thorough, and relevant to diabetes and nursing practice.
- Provide a descriptive and reflective discussion of how the new tool or intervention can be integrated into nursing practice. Provide evidence to support your discussion.
- Explain why psychological, cultural, and spiritual aspects are important to consider for a patient who has been diagnosed with diabetes. Describe how support can be offered in these respective areas as part of a plan of care for the patient. Provide examples.
You are required to cite to a minimum of two sources to complete this assignment. Sources must be published within the last 5 years and appropriate for the assignment criteria and relevant to nursing practice.
While APA style is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.
This assignment uses a rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.
You are required to submit this assignment to LopesWrite. Refer to the
LopesWrite Technical Support articles
for assistance.
ORIGINAL ARTICLE
The Hybrid Closed-Loop System:
Evolution and Practical Applications
Kathryn W. Weaver, MD, and Irl B. Hirsch, MD
Abstract
Achievement of well-controlled blood glucose is essential for preventing complications in patients with type 1
diabetes. Since the inception of continuous subcutaneous insulin infusion, the aim has been to develop an
artificial pancreas, with the ability to use an automated algorithm to deliver one or more hormones in response
to blood glucose with the intent to keep blood sugar as close to a prespecified target as possible. Development
and rapid improvement of continuous glucose sensor technology has recently allowed swift progress toward a
fully closed-loop insulin delivery system. In 2017, Medtronic began marketing the 670G insulin pump with
Guardian 3 sensor. When in auto mode, this is a hybrid closed-loop insulin delivery system that automatically
adjusts basal insulin delivery every 5 min based on sensor glucose to maintain blood glucose levels as close to a
specific target as possible. Patients receive prandial insulin by entering carbohydrate amount into the bolus
calculator. Early studies show improvement in HbA1c in both adults and adolescents with this technology.
Initial safety trials showed no occurrence of diabetic ketoacidosis or hypoglycemia. The utility of this device is
limited by blood glucose targets of 120 and 150 mg/dL that are unacceptably high for some patients. Not-
withstanding recent advances, we are far from a system that is able to replicate islet function in the form of a
fully automated, multihormonal blood glucose control device.
Keywords: Type 1 diabetes, Hybrid closed-loop, Artificial pancreas, Continuous subcutaneous insulin infusion,
670G.
Introduction
People with type 1 diabetes mellitus face a perpetualuphill battle in achieving optimal glycemic control. The
fine line between preventing hypoglycemia and avoiding
complications from hyperglycemia is challenging to navigate.
Our objective is to describe the history of continuous sub-
cutaneous insulin infusion (CSII) and continuous glucose
monitor (CGM) and how these components allowed the de-
velopment of the first commercially available ‘‘artificial pan-
creas’’ (AP), although many would prefer the nomenclature of
‘‘closed-loop insulin delivery.’’ We then go on to describe
practicalities of the initial hybrid closed-loop (HCL) insulin
delivery system released by Medtronic.
Since the first use of CSII in the late 1970s, real-time
CGM in the early 2000s, and the eventual sensor-augmented
pump and ‘‘low-glucose suspend’’ after that, the obvious
next step was further integration between the two for a
closed-loop system, which ideally would require minimal
interaction from the patient. The accuracy of the sensors has
only recently become adequate to safely move this tech-
nology forward.
Devices designed to mimic pancreatic endocrine function
have been under development since the 1970s. Initial sys-
tems
1,2
were plagued by mixed results and overly complex
devices requiring intravenous insulin infusions. Tamborlane
et al.
3
further refined the use of CSII by providing flexibility in
the dosing of bolus insulin (independent of basal infusion rate).
In 1983, MiniMed commercialized the first insulin pump, the
502. Soon after development of CSII, the vision has been for
development of the ‘‘artificial pancreas.’’
4
The development of CGM was the next major step in cre-
ating the AP. In 1999, the FDA approved the first physician-
use CGM system. CGM technology progressed rapidly, with
five devices on the market internationally by 2005.
5
In 2006, the Juvenile Diabetes Research Foundation
( JDRF) launched the AP Project and has been funding de-
velopment in this area since that time. Also in 2006, Med-
tronic (purchased MiniMed in 2001) introduced the 530G
with integrated insulin pump and CGM. This is the system on
Department of Medicine, Division of Metabolism, Endocrinology, and Nutrition, University of Washington School of Medicine, Seattle,
Washington.
DIABETES TECHNOLOGY & THERAPEUTICS
Volume 20, Supplement 2, 2018
ª Mary Ann Liebert, Inc.
DOI: 10.1089/dia.2018.0091
S2-16
which the AP system has been built. In 2013, the threshold
suspend feature was approved by the FDA as part of the
MiniMed 530G and Enlite sensor combination. This com-
bined insulin pump-CGM was the first in the United States to
allow the blood glucose readings on the sensor to control the
function of the insulin infusion in the form of the low-glucose
suspend feature. This CGM-CSII combination was promoted
as a ‘‘first-generation artificial pancreas device.’’
6
Before the recent pivotal trial
7
evaluating safety of the
Medtronic HCL system, several groups have demonstrated
feasibility, safety, and effectiveness of closed-loop technol-
ogy. In 2008, Weinzimer et al.
8
showed for the first time that
HCL insulin delivery could improve glucose control at night.
This group used a device that was the precursor to the
Medtronic 670G. Time in range (TIR, 70–180 mg/dL) im-
proved significantly from 58% to 85% (P < 0.002) in the
open-loop versus closed-loop groups. In 2010, Kovatchev
et al.
9
published results of a multicenter, international study
of open- versus closed-loop insulin delivery with the use of
OmniPod Insulin Management System (Insulet Corp.) and
FreeStyle Navigator CGM (Abbott Diabetes Care). TIR im-
proved (64% vs. 78%, P = 0.029) and hypoglycemia de-
creased (23 vs. 5, P = 0.01) with closed-loop insulin delivery.
In 2013, Phillip et al.
10
showed that use of an AP system
reduced hypoglycemia in pediatric patients. In 2014, Ko-
vatchev et al. published results
11
of hypoglycemia risk in
open-loop versus closed-loop insulin delivery and demon-
strated significantly less hypoglycemia in adult patients using
the closed-loop system. In 2014, Russell et al. released data
12
evaluating the safety and effectiveness of a bihormonal AP
and showed improved mean glucose with less hypoglycemia
in adults and adolescents. In 2015, Thabit et al.
13
did a pro-
longed (12-week) study of a closed-loop system in adults and
children, compared with sensor-augmented pump, and
showed improved glucose control, decreased hypoglycemia,
and a decreased HbA1c in the adults.
As more groups have demonstrated safety and improved
glycemic control with closed-loop systems, device develop-
ment has been rapid, with several companies designing
promising new technologies and/or infusion algorithms. No-
tably, Buckingham et al. recently published data
14
on the safety
and feasibility of an HCL system with OmniPod, DexCom G4
CGM, and a model predictive control (MPC) algorithm. The
tslim insulin pump (Tandem Diabetes Care, Inc.) was previ-
ously shown to improve TIR with the Diabetes Assistant USS
algorithm and DexCom CGM by Ly et al.
15
Currently, Tandem
and Type Zero are collaborating on a trial (Clinicaltrials.gov:
NCT03368937) using the tslim pump, DexCom CGM, and the
Control-IQ algorithm. Bigfoot Biomedical has completed re-
cruitment for a study (Clinicaltrials.gov: NCT02849288)
evaluating the performance and safety of a closed-loop system.
Finally, Beta Bionics has demonstrated safety and effective-
ness of the ‘‘iLet’’ bionic pancreas in several recent trials.
12,16
A study is ongoing to evaluate two different types of stable
glucagon in the bihormonal ‘‘iLet’’ bionic pancreas (Clin-
icaltrials.gov: NCT02971228).
Regarding the current commercially available HCL by
Medtronic, Bergenstal et al.
7
released a Research Letter
summarizing results of the pivotal trial, in October 2016,
evaluating safety of the HCL insulin delivery system. One
hundred twenty-four patients were studied on the HCL sys-
tem for 3 months after a 2-week run-in period. There was no
control group, and thus, no claims regarding effectiveness
can be made. There were few serious or device-related ad-
verse events. Garg et al.
17
expanded on these data for adults.
Sensor glucose average between the run-in period (146.1 mg/dL)
and the study period (148.3 mg/dL) was borderline significant
(P = 0.04203). Hypoglycemia was reduced below 50 mg/dL
(<0.001) and below 70 mg/dL (P < 0.001). Other notable
findings for adults in this trial were an increase in weight
(79.9 kg vs. 81.3 kg, P < 0.001), an increase in total daily
insulin (44.9 U vs. 47.9 U, P < 0.001), and a decrease in the
within-day coefficient of variation of glucose (33.1% vs.
30.3%, P < 0.001). Although HbA1c decreased, this trial
was not designed to evaluate effectiveness because of lack
of a control arm. Based on the established safety data, the
FDA approved the Medtronic 670G automated insulin de-
livery system in the United States. In 2017, Medtronic began
to market this system.
It is widely agreed that success of a closed-loop system is
based equally on the quality and efficacy of the infusion al-
gorithm and accuracy of the sensor. CGM quality, as mea-
sured with mean absolute relative difference ( MARD), has
evolved since initial release of glucose sensors. The MARD
is the difference between laboratory (or occasionally finger-
stick) glucose and sensor glucose. The lower the MARD, the
more accurate the sensor. Medtronic has released several
sensors over the years: the Guardian Real-Time, the Sof-
Sensor, the Enlite Sensor, and the Guardian 3 sensor (known
as the Enlite 3 in Europe and Asia), which is currently part of
the 670G HCL system.
MARD data reported are highly variable and differ where
the study is conducted, especially when comparing the clin-
ical research unit versus ambulatory setting.
18
The reported
values also may be influenced by the reporter and funder of
the study. For example, Calhoun et al. reported the MARDs
for the Medtronic Sof-Sensor and the Enlite to be 16% and
18%, respectively.
19
However, in 2012, a group from Med-
tronic wrote a letter to the editor that reported the MARD for
the Sof-Sensor was 9.9%.
20
Similarly, a Medtronic-funded
study published in 2014 reported the MARD for the Enlite
sensor to be 13.6%.
21
This is the figure that is quoted in the
patient and provider information for the Enlite sensor. In
2017, another group reported the MARD for Enlite sensor to
be 19%.
22
The new Guardian 3 sensor, which is used in the
new HCL insulin delivery system, is less well studied. In
2017, Christiansen
23
evaluated the accuracy and performance
of the Guardian 3 CGM and reported an MARD of 10.3%
when calibrating every 12 h and 9.6% when calibrating 3 to 4
times per day. The MARD reported in promotional materials
by Medtronic is 9.64% for the new Guardian 3 sensor.
670G Pump Basics
The function of the ‘‘artificial pancreas’’ in its current state
is threefold: CGM monitoring, insulin delivery, and hormone
delivery control. The final component, considered the brain
of the system, is evolving. As described above, its first form
came as the threshold suspend feature. The 670G provides
more sophisticated automation. When in ‘‘auto mode,’’ the
Medtronic 670G automatically adjusts basal insulin delivery
every 5 min based on sensor glucose to maintain blood glu-
cose levels at a specific target. In addition, the suspend before
low function stops insulin delivery before hypoglycemia is
A CRITICAL APPRAISAL OF HYBRID CLOSED-LOOP INSULIN DELIVERY S2-17
predicted to occur, and restarts insulin once blood glucose
levels normalize.
The 670G insulin pump functions in two different modes:
auto mode and manual mode. Manual mode is similar to
previous CSII with linked CGM, with the added feature of
stopping insulin before hypoglycemia occurs. Basal rates are
adjusted in manual mode just as they are in other insulin
pumps: with a provider-set basal rate during a specific time
block. Both modes require manual bolus administration by
entering carbohydrate information into the insulin pump,
from which the bolus calculator determines a recommended
bolus.
The insulin pump becomes quite different when in ‘‘auto
mode.’’ While in this mode, the technology uses proportional
integral derivative (PID) algorithms that respond to measured
glucose levels.
24
With this algorithm, small adjustments are
made in the basal insulin rate. The PID algorithm is just one
of several control algorithms that have been used in auto-
mated insulin delivery. Other algorithms that have previously
been used are MPC, described by Hovorka et al. in 2004,
25
and MD-Logic.
26
The basal insulin can be thought of more as
microboluses infused every 5 min. It is possible, and typical,
for auto mode users to exit to manual mode. Automatic push
to manual mode occurs for a variety of reasons, such as
persistent hyperglycemia, sensor problems, and user prob-
lems (e.g., failure to calibrate).
Because of automatic adjustment of the basal insulin de-
livery based on sensor glucose, there are fewer modifiable
parameters when in auto mode. The only settings that can be
changed are active insulin time (AIT), insulin to carbohydrate
ratio (ICR), and basal target glucose. There are two pre-
specified, nonmodifiable blood glucose targets for basal in-
sulin: 120 and 150 mg/dL. Typically, patients are advised to
use the 120 mg/dL target. During periods of exercise, it is
recommended to use the 150 mg/dL target. Mealtime insulin
is given as calculated by the bolus calculator after the user
enters the amount of carbohydrates to be consumed. It is not
possible to give a manual bolus without entering carbohy-
drates consumed while in auto mode. For hyperglycemia, the
insulin pump will suggest a correction based on a blood
glucose target of 150 mg/dL with an insulin sensitivity factor
that is calculated by the algorithm every 24 h. Although the
AIT can be changed while in auto mode, the modification
does not feedback to the algorithm. In other words, a change
in AIT from 3 to 4 h will not lead to less insulin delivered
while in auto mode. The AIT remains necessary in manual
mode, where it does impact the amount of insulin given
through the bolus calculator.
Protocol for patient initiation onto HCL varies among
clinics. At our academic center, we have found it most ef-
fective to standardize the process. Appropriate training, even
for experienced CSII users, can be time-intensive, which is
why we now accept assistance from the Medtronic trainers.
Our preference was to do the training independently, but the
intensity of the training for our large number of patients
makes this impossible. All patients who receive the 670G
insulin pump are transitioned from the previous pump to the
670G (in manual mode) with settings from the previous
pump. The new insulin pump needs a minimum of 48 h of data
to function in auto mode. Ideal amount of time is unknown,
but we have found 48 h to be inadequate. In our practice, we
target 1 week in manual mode before entering auto mode.
Before entering auto mode, it is required that patients upload
their data to the CareLink
�
personal account and allow either
our certified diabetes educator or Medtronic representative to
review the data. In our clinic, patients who are ready to enter
into auto mode are those who are blousing through the bolus
calculator, calibrating the sensor 2.5 times per day, and
measuring fingerstick glucose levels four times per day.
Once readiness has been demonstrated, the patients par-
ticipate in a short tutorial about auto mode. Before entering
auto mode, adjustments are made to the insulin pump set-
tings. Typically, basal insulin is decreased by about 10% (for
when patients enter manual mode), ICR is strengthened (by
about 10%), and the AIT is set between 3.5 to 4.0 h.
Anecdotally, most patients require significantly less basal
insulin in auto mode than they receive while in manual mode.
There may be many reasons for this observation, but we find
most patients when doing well only require about 40% of
their insulin as basal insulin, not the typical 50% historically
recommended. The higher carbohydrate ratios indicate that
many patients in manual mode (or even on multiple injec-
tions) receive too much basal insulin, which helps to mitigate
the postprandial spikes. Patients in auto mode, now on a more
appropriate basal dose, need to appreciate they may spike
higher without the excess basal insulin, and thus waiting a
longer time between the bolus and eating can be useful.
Along with the new pump, algorithm, sensor, and trans-
mitter, the CareLink reports that give details about pump and
sensor data have changed. CareLink is a cloud-based pro-
gram that was created by Medtronic, is available to both
patients and providers, and gathers information from the
Medtronic insulin pumps and CGMs. Reports can be gener-
ated for and by patients and providers. The CareLink reports
on the new platform have changed significantly compared
with previous versions.
Before discussing the new CareLink reports from the HCL,
it is prudent to describe the features from older reports that
included the following sections: Adherence, Sensor and Meter
Overview, Logbook, Device Settings Snapshot, and Daily
Detail (Fig. 1). The Daily Detail section shows blood glucose
average, carbohydrates consumed, and daily insulin. The for-
mat in which these data are provided allows the provider to
view the patient’s response to insulin delivery for a meal and/or
a correction. Access to these data allows the provider to assess
the appropriateness of settings for bolus and correction.
The sections on the updated CareLink reports are as fol-
lows: Meal Bolus Wizard (Fig. 1), Assessment and Progress
(Fig. 2), Weekly Review, Logbook, and Device Settings.
The Meal Bolus Wizard portion provides information on
meal boluses timed by the meal. Similar to the Daily Details
described above, details are provided on average carbohy-
drates consumed and average bolus amount. The Meal Bolus
Wizard data are unfortunately aggregated, meaning individ-
ual boluses are not reported, which is a departure from earlier
versions of the reports. The removal of this valuable tool has
thwarted the provider’s ability to evaluate in an effective
manner blood glucose response to boluses in manual mode.
The Assessment and Progress page is arguably the most
useful. It provides a high-level view of blood glucose control
with the aggregate sensor data. It contains an ambulatory
glucose profile (AGP), similar to those provided by DexCom
and FreeStyle Libre (Abbott Diabetes Care) CGMs. Com-
pared with older CareLink report versions that provided a
S2-18 WEAVER AND HIRSCH
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S2-19
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S2-20
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24-h overlay of CGM data, the updated reports present sensor
data as a percentile comparison with three curves: average
glucose, 25% to 75% percentile blood glucose, and 0% to
90% blood glucose. TIR is included, showing a snapshot of
blood glucose control and frequency of hypoglycemia. Also
included in this section is the statistics (Fig. 3), which pro-
vides the time the patient was in auto mode, the sensor wear,
sensor glucose, total daily insulin, bolus insulin amount, and
carbohydrates entered. One-month data are collected and
compared in 2-week blocks.
The Adherence section from older CareLink reports is
eliminated in the new reports. When in auto mode, the details
are admittedly obsolete. However, for patients who use the
pump primarily in manual mode, the Adherence portion could
be useful. The Adherence section provides data on bolus
events, specifically about the number of manual boluses,
bolus calculator events, and overrides (when patient gives
more or less insulin than recommended by bolus calculator).
The use of the downloaded data in care of patients with
diabetes mellitus using insulin is essential. It becomes even
more important when these people are using CSII and CGM.
However, the use of downloaded data is not done uniformly in
clinics. Extracting data from the devices (meters, pumps, and
sensors) can be costly and time-intensive. As multiple dif-
ferent pump and sensor platforms are developed, the ability to
quickly download and interpret data will become more dif-
ficult. Innovation is ongoing in this area, with private groups
working to develop platforms that standardize the data.
It is possible, and expected, for patients to upload data to
CareLink. By uploading data to the cloud, information can be
shared with device representatives, providers, and nurses
outside of the visit. It is unreasonable to assume, however,
that patients will reliably upload data to the cloud on a regular
basis,
27
still leaving the burden of data gathering on the cli-
nician and the team during the office visit.
The Reality Check
Despite the advances in technology, the current artificial
insulin delivery system requires significant patient and pro-
vider involvement in addition to high-resource utilization on
initialization. The novelty of this system demands ongoing
involvement from device representatives to help users and
providers learn the new system. We have undoubtedly in-
creased utilization of the Medtronic representatives in our
practice. With this increased demand on the manufacturer for
patient care and education, our concern is that total costs
increase.
In addition to use of company representatives, hospital and
clinic diabetes educators and nurses are spending more time
interfacing with patients and product agents. Data must be
downloaded to provide optimal patient care, an additional
point of staff involvement and resource utilization. Non-
reimbursed time from our nonphysicians before the 670G was
*$100,000 per year in our clinic.28 The physician involve-
ment of learning the technology, interpreting the download,
and troubleshooting questions is impactful and of question-
able sustainability in our productivity-centered system.
However, as our experience has increased, the learning
curve has flattened, and patients and providers are more
comfortable with this new technology. We are seeing that a
subset of patients demands less from the healthcare system. It
FIG. 3. Statistics portion, found in the Assessment and Progress section of updated CareLink reports, provides information
about time in auto mode, sensor wear, average glucose, insulin use, and carbohydrates consumed. ‘‘A’’ and ‘‘B’’ represent 2-week
blocks within the last month with ‘‘A’’ being the most recent 2 weeks.
A CRITICAL APPRAISAL OF HYBRID CLOSED-LOOP INSULIN DELIVERY S2-21
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is our hope that this trend continues, especially as the de-
velopment of a fully closed-loop system progresses.
The HCL insulin pump will of course not work on all types
of patients. The preset blood glucose target of 120 mg/dL is
simply too high for many patients who prefer (and can achieve)
much tighter control. In addition, pregnant women (or women
planning pregnancy) cannot be in auto-mode, as the factory-set
blood sugar target is too high to achieve necessary goals for
pregnancy. Another obvious limitation in the usefulness of auto
mode are those patients on high-dose steroids, especially dur-
ing tapers, as insulin resistance changes daily and it is unclear if
the algorithm would be able to adapt. Patients who are very ill
and/or have dynamic health challenges (cancer, infection, etc.)
should wait until these health problems are stable before
starting a new diabetes technology. Finally, people whose di-
abetes is not well controlled have major depression or other
psychiatric disease, are not adherent, or who have trouble
coming to clinic visits should not be started on the HCL system
due to the initial high involvement for the patient.
The number of fingersticks required per day for calibration
is four. As other continuous glucose sensors completely move
away from requirement or capacity for calibration, the need
to check blood sugar four times per day is burdensome for
many. Many patients in our practice have become frustrated
with the increased workload with the Medtronic 670G insulin
pump, as the perception of and goal for HCL insulin delivery
are to decrease patient responsibility.
Despite the terminology of ‘‘auto mode’’ and the non-
modifiable blood glucose targets of 120 and 150 mg/dL,
people have found ways to consistently decrease blood
glucose levels below the target. This is achieved by the ad-
ministration of ‘‘phantom carbohydrates,’’ where the users in-
form the insulin pump that they are going to eat carbohydrates,
when they are not going to eat anything. We have affectionately
termed this ‘‘fake carbs’’ in our practice. Phantom carbo-
hydrates can lead to hypoglycemia. It is in the patients using
this strategy who are those with hypoglycemia on the HCL
system. Behaviors such as this are potentially dangerous and
highlight that this HCL system is not for all patients, es-
pecially those who find the blood sugar target of 120 mg/dL
too high.
Conclusion
The development of the ‘‘artificial pancreas’’ is underway.
Despite recent advances, we are far from a system that is able
to replicate islet function in the form of a fully automated,
multihormonal blood glucose control device. The current
HCL system by Medtronic relies on a PID algorithm to make
constant small adjustments in basal insulin delivery to target
a blood glucose of 120 mg/dL. Patients must continue to use
the bolus calculator by entering a carbohydrate amount to
deliver bolus insulin.
Limitations of this device include the limited number of
blood glucose targets: 120 and 150 mg/dL, making it an un-
acceptable device for many patients. Specifically, the use of
150 mg/dL as a target blood glucose during exercise is too
low based on our early experience. We typically advise our
patients to enter manual mode 2 to 3 h before exercise or
consume small carbohydrate meals regularly during exercise
to avoid hypoglycemia. The modified reports from the HCL
system now use the TIR and AGP as primary data points to
assess blood glucose control. The modified CareLink reports
have eliminated some very useful data. Finally, patients need
to be willing to measure blood glucose more frequently than
previously when using CGM, often four times per day.
Currently, much of our practice refinement is through trial
and error. It will take long-term observations and clinical
trials to determine how robust this technology is.
The increase in TIR and decreased amount of hypoglyce-
mia, especially in the fasting state, observed in patients in our
practice have been notable and important improvements
while using this new system. Data from the initial safety trial
7
showed no development of severe hypoglycemia or diabetic
ketoacidosis. HbA1c was also shown to decrease in this trial,
although this was limited by lack of a control group. Anec-
dotally, we have found this device most helpful in patients
who struggle to keep their HbA1c below 8%. Further studies
are underway (Clinicaltrials.gov: NCT03017482) to evaluate
this technology on a larger scale.
The first HCL is an important advance in our ability to
control blood glucose in type 1 diabetes. Like past develop-
ments, this likely will be seen as an incremental improvement
from our previous diabetes treatments, but more importantly
it is a bridge to a truly automated closed loop. Both clinicians
and users need to understand how this technology may ulti-
mately impact patient quality of life.
Author Disclosure Statement
K.W.W.: No competing financial interests exist; I.B.H.:
Research funding from Medtronic Diabetes; Consulting:
Abbott Diabetes Care, Adocia, Bigfoot, and Roche.
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Address correspondence to:
Irl B. Hirsch, MD
Department of Medicine
Division of Metabolism, Endocrinology, and Nutrition
University of Washington School of Medicine
4245 Roosevelt Way, NE, 3rd Floor
Seattle, WA 98195
E-mail: ihirsch@uw.edu
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