1
|
Teigen IA, Riaz M, Åm MK, Christiansen SC, Carlsen SM. Vasodilatory effects of glucagon: A possible new approach to enhanced subcutaneous insulin absorption in artificial pancreas devices. Front Bioeng Biotechnol 2022; 10:986858. [PMID: 36213069 PMCID: PMC9532737 DOI: 10.3389/fbioe.2022.986858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/25/2022] [Indexed: 11/18/2022] Open
Abstract
Patients with diabetes mellitus type 1 depend on exogenous insulin to keep their blood glucose concentrations within the desired range. Subcutaneous bihormonal artificial pancreas devices that can measure glucose concentrations continuously and autonomously calculate and deliver insulin and glucagon infusions is a promising new treatment option for these patients. The slow absorption rate of insulin from subcutaneous tissue is perhaps the most important factor preventing the development of a fully automated artificial pancreas using subcutaneous insulin delivery. Subcutaneous insulin absorption is influenced by several factors, among which local subcutaneous blood flow is one of the most prominent. We have discovered that micro-doses of glucagon may cause a substantial increase in local subcutaneous blood flow. This paper discusses how the local vasodilative effects of micro-doses of glucagon might be utilised to improve the performance of subcutaneous bihormonal artificial pancreas devices. We map out the early stages of our hypothesis as a disruptive novel approach, where we propose to use glucagon as a vasodilator to accelerate the absorption of meal boluses of insulin, besides using it conventionally to treat hypoglycaemia.
Collapse
Affiliation(s)
- Ingrid Anna Teigen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
- *Correspondence: Ingrid Anna Teigen,
| | - Misbah Riaz
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Endocrinology, St. Olav’s Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Marte Kierulf Åm
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sverre Christian Christiansen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Endocrinology, St. Olav’s Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Sven Magnus Carlsen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Endocrinology, St. Olav’s Hospital, Trondheim University Hospital, Trondheim, Norway
| |
Collapse
|
2
|
The effect of glucagon on local subcutaneous blood flow in non-diabetic volunteers; a proof-of-concept study. Eur J Pharmacol 2022; 926:175045. [DOI: 10.1016/j.ejphar.2022.175045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/04/2022] [Accepted: 05/18/2022] [Indexed: 01/26/2023]
|
3
|
Hettiarachchi C, Daskalaki E, Desborough J, Nolan CJ, O'Neal D, Suominen H. Integrating Multiple Inputs Into an Artificial Pancreas System: Narrative Literature Review. JMIR Diabetes 2022; 7:e28861. [PMID: 35200143 PMCID: PMC8914747 DOI: 10.2196/28861] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/07/2021] [Accepted: 01/01/2022] [Indexed: 12/02/2022] Open
Abstract
Background Type 1 diabetes (T1D) is a chronic autoimmune disease in which a deficiency in insulin production impairs the glucose homeostasis of the body. Continuous subcutaneous infusion of insulin is a commonly used treatment method. Artificial pancreas systems (APS) use continuous glucose level monitoring and continuous subcutaneous infusion of insulin in a closed-loop mode incorporating a controller (or control algorithm). However, the operation of APS is challenging because of complexities arising during meals, exercise, stress, sleep, illnesses, glucose sensing and insulin action delays, and the cognitive burden. To overcome these challenges, options to augment APS through integration of additional inputs, creating multi-input APS (MAPS), are being investigated. Objective The aim of this survey is to identify and analyze input data, control architectures, and validation methods of MAPS to better understand the complexities and current state of such systems. This is expected to be valuable in developing improved systems to enhance the quality of life of people with T1D. Methods A literature survey was conducted using the Scopus, PubMed, and IEEE Xplore databases for the period January 1, 2005, to February 10, 2020. On the basis of the search criteria, 1092 articles were initially shortlisted, of which 11 (1.01%) were selected for an in-depth narrative analysis. In addition, 6 clinical studies associated with the selected studies were also analyzed. Results Signals such as heart rate, accelerometer readings, energy expenditure, and galvanic skin response captured by wearable devices were the most frequently used additional inputs. The use of invasive (blood or other body fluid analytes) inputs such as lactate and adrenaline were also simulated. These inputs were incorporated to switch the mode of the controller through activity detection, directly incorporated for decision-making and for the development of intermediate modules for the controller. The validation of the MAPS was carried out through the use of simulators based on different physiological models and clinical trials. Conclusions The integration of additional physiological signals with continuous glucose level monitoring has the potential to optimize glucose control in people with T1D through addressing the identified limitations of APS. Most of the identified additional inputs are related to wearable devices. The rapid growth in wearable technologies can be seen as a key motivator regarding MAPS. However, it is important to further evaluate the practical complexities and psychosocial aspects associated with such systems in real life.
Collapse
Affiliation(s)
- Chirath Hettiarachchi
- School of Computing, College of Engineering and Computer Science, The Australian National University, Canberra, Australia
| | - Elena Daskalaki
- School of Computing, College of Engineering and Computer Science, The Australian National University, Canberra, Australia
| | - Jane Desborough
- Department of Health Services Research and Policy, Research School of Population Health, College of Health and Medicine, The Australian National University, Canberra, Australia
| | - Christopher J Nolan
- Australian National University Medical School, College of Health and Medicine, The Australian National University, Canberra, Australia.,John Curtin School of Medical Research, College of Health and Medicine, The Australian National University, Canberra, Australia
| | - David O'Neal
- Department of Medicine, University of Melbourne, Melbourne, Australia.,Department of Endocrinology and Diabetes, St Vincent's Hospital Melbourne, Melbourne, Australia
| | - Hanna Suominen
- School of Computing, College of Engineering and Computer Science, The Australian National University, Canberra, Australia.,Data61, Commonwealth Industrial and Scientific Research Organisation, Canberra, Australia.,Department of Computing, University of Turku, Turku, Finland
| |
Collapse
|
4
|
Åm MK, Dirnena-Fusini I, Fougner AL, Carlsen SM, Christiansen SC. Intraperitoneal and subcutaneous glucagon delivery in anaesthetized pigs: effects on circulating glucagon and glucose levels. Sci Rep 2020; 10:13735. [PMID: 32792580 PMCID: PMC7426268 DOI: 10.1038/s41598-020-70813-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 07/07/2020] [Indexed: 12/18/2022] Open
Abstract
Glucagon is a pancreatic hormone and increases the blood glucose levels. It may be incorporated in a dual hormone artificial pancreas, a device to automatically and continuously control blood glucose levels of individuals with diabetes. Artificial pancreas systems have been developed for use in the subcutaneous tissue; however, the systems are not fully automated due to slow dynamics. The intraperitoneal space is therefore investigated as an alternative location for an artificial pancreas. Glucose dynamics after subcutaneous and intraperitoneal glucagon delivery in ten anaesthetized pigs were investigated. The pigs received intraperitoneal boluses of 0.3 µg/kg and 0.6 µg/kg and a subcutaneous bolus of 0.6 µg/kg in randomized order. They also received an intraperitoneal bolus of 1 mg given at the end of the experiments to test the remaining capacity of rapid glucose release. Six pigs were included in the statistical analysis. The intraperitoneal glucagon bolus of 0.6 µg/kg gave a significantly higher glucose response from 14 to 30 min compared with the subcutaneous bolus. The results indicate that glucagon induces a larger glucose response after intraperitoneal delivery compared with subcutaneous delivery and is encouraging for the incorporation of glucagon in an intraperitoneal artificial pancreas.
Collapse
Affiliation(s)
- Marte Kierulf Åm
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Postboks 8905, 7491, Trondheim, Norway. .,Department of Endocrinology, St Olav's Hospital, Trondheim, Norway.
| | - Ilze Dirnena-Fusini
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Postboks 8905, 7491, Trondheim, Norway.,Department of Endocrinology, St Olav's Hospital, Trondheim, Norway
| | - Anders Lyngvi Fougner
- Department of Engineering Cybernetics, Faculty of Information Technology and Electrical Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Sven Magnus Carlsen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Postboks 8905, 7491, Trondheim, Norway.,Department of Endocrinology, St Olav's Hospital, Trondheim, Norway
| | - Sverre Christian Christiansen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Postboks 8905, 7491, Trondheim, Norway.,Department of Endocrinology, St Olav's Hospital, Trondheim, Norway
| |
Collapse
|
5
|
|
6
|
Tetzschner R, Ranjan AG, Schmidt S, Nørgaard K. Preference for Subcutaneously Administered Low-Dose Glucagon Versus Orally Administered Glucose for Treatment of Mild Hypoglycemia: A Prospective Survey Study. Diabetes Ther 2019; 10:2107-2113. [PMID: 31552599 PMCID: PMC6848710 DOI: 10.1007/s13300-019-00696-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Intensive insulin treatment for type 1 diabetes is associated with high risk of mild hypoglycemia. Mild hypoglycemia is usually treated orally with glucose, which may contribute to weight gain. Subcutaneous injection of low-dose glucagon may be a new treatment option for some occasions of mild hypoglycemia in individuals aiming for optimal glycemic control without gaining weight. We investigated under which occasions patients were interested to use low-dose glucagon. METHODS In a prospective 2-week event-driven survey, participants registered every event of mild hypoglycemia (sensor or blood glucose ≤ 3.9 mmol/l and/or hypoglycemia symptoms). For each hypoglycemia event, participants registered whether they would have preferred to use low-dose glucagon if the treatment had been available. RESULTS A total of 51 participants (13 men, mean ± SD age 43.6 ± 12.5 years, HbA1c 7.3 ± 0.7% (57 ± 8 mmol/mol), BMI 24.9 ± 3 kg/m2) were included. Each participant had on average 10 (range 3-23) mild hypoglycemia events during the 2-week survey period. Glucagon was preferred in 58% of the 514 mild hypoglycemia events (p > 0.05). Twelve percent of the participants had no desire to use glucagon for any hypoglycemia event. The preference pattern did not differ between sex, patient treatment modalities, and possible causes for hypoglycemia (all p > 0.05). CONCLUSION This study showed that a majority of our participants with type 1 diabetes were interested in using low-dose glucagon for the treatment of mild hypoglycemia. FUNDING This work was funded by a research grant from the Copenhagen University Hospital Hvidovre and by the Danish Diabetes Academy supported by the Novo Nordisk Foundation.
Collapse
Affiliation(s)
- Rikke Tetzschner
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Ajenthen G Ranjan
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
- Steno Diabetes Center Copenhagen, Gentofte, Denmark.
- Danish Diabetes Academy, Odense, Denmark.
| | - Signe Schmidt
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Danish Diabetes Academy, Odense, Denmark
| | - Kirsten Nørgaard
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
| |
Collapse
|
7
|
Blauw H, Keith-Hynes P, Koops R, DeVries JH. A Review of Safety and Design Requirements of the Artificial Pancreas. Ann Biomed Eng 2016; 44:3158-3172. [PMID: 27352278 PMCID: PMC5093196 DOI: 10.1007/s10439-016-1679-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 06/13/2016] [Indexed: 01/03/2023]
Abstract
As clinical studies with artificial pancreas systems for automated blood glucose control in patients with type 1 diabetes move to unsupervised real-life settings, product development will be a focus of companies over the coming years. Directions or requirements regarding safety in the design of an artificial pancreas are, however, lacking. This review aims to provide an overview and discussion of safety and design requirements of the artificial pancreas. We performed a structured literature search based on three search components—type 1 diabetes, artificial pancreas, and safety or design—and extended the discussion with our own experiences in developing artificial pancreas systems. The main hazards of the artificial pancreas are over- and under-dosing of insulin and, in case of a bi-hormonal system, of glucagon or other hormones. For each component of an artificial pancreas and for the complete system we identified safety issues related to these hazards and proposed control measures. Prerequisites that enable the control algorithms to provide safe closed-loop control are accurate and reliable input of glucose values, assured hormone delivery and an efficient user interface. In addition, the system configuration has important implications for safety, as close cooperation and data exchange between the different components is essential.
Collapse
Affiliation(s)
- Helga Blauw
- Department of Endocrinology, Academic Medical Center, University of Amsterdam, P.O Box 22660, 1100 DD, Amsterdam, The Netherlands. .,Inreda Diabetic BV, Goor, The Netherlands.
| | - Patrick Keith-Hynes
- TypeZero Technologies, LLC, Charlottesville, VA, USA.,Center for Diabetes Technology, University of Virginia, Charlottesville, VA, USA
| | | | - J Hans DeVries
- Department of Endocrinology, Academic Medical Center, University of Amsterdam, P.O Box 22660, 1100 DD, Amsterdam, The Netherlands
| |
Collapse
|
8
|
Colmegna PH, Sánchez-Peña RS, Gondhalekar R, Dassau E, Doyle FJ. Reducing Glucose Variability Due to Meals and Postprandial Exercise in T1DM Using Switched LPV Control: In Silico Studies. J Diabetes Sci Technol 2016; 10:744-53. [PMID: 27022097 PMCID: PMC5038547 DOI: 10.1177/1932296816638857] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Time-varying dynamics is one of the main issues for achieving safe blood glucose control in type 1 diabetes mellitus (T1DM) patients. In addition, the typical disturbances considered for controller design are meals, which increase the glucose level, and physical activity (PA), which increases the subject's sensitivity to insulin. In previous works the authors have applied a linear parameter-varying (LPV) control technique to manage unannounced meals. METHODS A switched LPV controller that switches between 3 LPV controllers, each with a different level of aggressiveness, is designed to further cope with both unannounced meals and postprandial PA. Thus, the proposed control strategy has a "standard" mode, an "aggressive" mode, and a "conservative" mode. The "standard" mode is designed to be applied most of the time, while the "aggressive" mode is designed to deal only with hyperglycemia situations. On the other hand, the "conservative" mode is focused on postprandial PA control. RESULTS An ad hoc simulator has been developed to test the proposed controller. This simulator is based on the distribution version of the UVA/Padova model and includes the effect of PA based on Schiavon.(1) The test results obtained when using this simulator indicate that the proposed control law substantially reduces the risk of hypoglycemia with the conservative strategy, while the risk of hyperglycemia is scarcely affected. CONCLUSIONS It is demonstrated that the announcement, or anticipation, of exercise is indispensable for letting a mono-hormonal artificial pancreas deal with the consequences of postprandial PA. In view of this the proposed controller allows switching into a conservative mode when notified of PA by the user.
Collapse
Affiliation(s)
- Patricio H Colmegna
- National Scientific and Technical Research Council, Buenos Aires, Argentina Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Ricardo S Sánchez-Peña
- National Scientific and Technical Research Council, Buenos Aires, Argentina Centro de Sistemas y Control, Instituto Tecnológico de Buenos Aires, Buenos Aires, Argentina
| | - Ravi Gondhalekar
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Eyal Dassau
- John A. Paulson School of Engineering & Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Francis J Doyle
- John A. Paulson School of Engineering & Applied Sciences, Harvard University, Cambridge, MA, USA
| |
Collapse
|
9
|
Trevitt S, Simpson S, Wood A. Artificial Pancreas Device Systems for the Closed-Loop Control of Type 1 Diabetes: What Systems Are in Development? J Diabetes Sci Technol 2016; 10:714-23. [PMID: 26589628 PMCID: PMC5038530 DOI: 10.1177/1932296815617968] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Closed-loop artificial pancreas device (APD) systems are externally worn medical devices that are being developed to enable people with type 1 diabetes to regulate their blood glucose levels in a more automated way. The innovative concept of this emerging technology is that hands-free, continuous, glycemic control can be achieved by using digital communication technology and advanced computer algorithms. METHODS A horizon scanning review of this field was conducted using online sources of intelligence to identify systems in development. The systems were classified into subtypes according to their level of automation, the hormonal and glycemic control approaches used, and their research setting. RESULTS Eighteen closed-loop APD systems were identified. All were being tested in clinical trials prior to potential commercialization. Six were being studied in the home setting, 5 in outpatient settings, and 7 in inpatient settings. It is estimated that 2 systems may become commercially available in the EU by the end of 2016, 1 during 2017, and 2 more in 2018. CONCLUSIONS There are around 18 closed-loop APD systems progressing through early stages of clinical development. Only a few of these are currently in phase 3 trials and in settings that replicate real life.
Collapse
Affiliation(s)
- Sara Trevitt
- NIHR Horizon Scanning Research & Intelligence Centre, University of Birmingham, Birmingham, UK
| | - Sue Simpson
- NIHR Horizon Scanning Research & Intelligence Centre, University of Birmingham, Birmingham, UK
| | - Annette Wood
- NIHR Horizon Scanning Research & Intelligence Centre, University of Birmingham, Birmingham, UK
| |
Collapse
|
10
|
Castle JR, El Youssef J, Bakhtiani PA, Cai Y, Stobbe JM, Branigan D, Ramsey K, Jacobs P, Reddy R, Woods M, Ward WK. Effect of Repeated Glucagon Doses on Hepatic Glycogen in Type 1 Diabetes: Implications for a Bihormonal Closed-Loop System. Diabetes Care 2015; 38:2115-9. [PMID: 26341131 PMCID: PMC4613914 DOI: 10.2337/dc15-0754] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/10/2015] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate subjects with type 1 diabetes for hepatic glycogen depletion after repeated doses of glucagon, simulating delivery in a bihormonal closed-loop system. RESEARCH DESIGN AND METHODS Eleven adult subjects with type 1 diabetes participated. Subjects underwent estimation of hepatic glycogen using (13)C MRS. MRS was performed at the following four time points: fasting and after a meal at baseline, and fasting and after a meal after eight doses of subcutaneously administered glucagon at a dose of 2 µg/kg, for a total mean dose of 1,126 µg over 16 h. The primary and secondary end points were, respectively, estimated hepatic glycogen by MRS and incremental area under the glucose curve for a 90-min interval after glucagon administration. RESULTS In the eight subjects with complete data sets, estimated glycogen stores were similar at baseline and after repeated glucagon doses. In the fasting state, glycogen averaged 21 ± 3 g/L before glucagon administration and 25 ± 4 g/L after glucagon administration (mean ± SEM) (P = NS). In the fed state, glycogen averaged 40 ± 2 g/L before glucagon administration and 34 ± 4 g/L after glucagon administration (P = NS). With the use of an insulin action model, the rise in glucose after the last dose of glucagon was comparable to the rise after the first dose, as measured by the 90-min incremental area under the glucose curve. CONCLUSIONS In adult subjects with well-controlled type 1 diabetes (mean A1C 7.2%), glycogen stores and the hyperglycemic response to glucagon administration are maintained even after receiving multiple doses of glucagon. This finding supports the safety of repeated glucagon delivery in the setting of a bihormonal closed-loop system.
Collapse
Affiliation(s)
- Jessica R Castle
- Department of Medicine, Division of Endocrinology, Harold Schnitzer Diabetes Health Center Oregon Health & Science University, Portland, OR
| | - Joseph El Youssef
- Department of Medicine, Division of Endocrinology, Harold Schnitzer Diabetes Health Center Oregon Health & Science University, Portland, OR
| | - Parkash A Bakhtiani
- Department of Medicine, Division of Endocrinology, Harold Schnitzer Diabetes Health Center Oregon Health & Science University, Portland, OR
| | - Yu Cai
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR
| | - Jade M Stobbe
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR
| | - Deborah Branigan
- Department of Medicine, Division of Endocrinology, Harold Schnitzer Diabetes Health Center Oregon Health & Science University, Portland, OR
| | - Katrina Ramsey
- Oregon Clinical and Translational Research Institute Biostatistics & Design Program, Oregon Health & Science University, Portland, OR
| | - Peter Jacobs
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
| | - Ravi Reddy
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
| | - Mark Woods
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR Portland State University, Portland, OR
| | - W Kenneth Ward
- Department of Medicine, Division of Endocrinology, Harold Schnitzer Diabetes Health Center Oregon Health & Science University, Portland, OR
| |
Collapse
|
11
|
Jacobs PG, Resalat N, El Youssef J, Reddy R, Branigan D, Preiser N, Condon J, Castle J. Incorporating an Exercise Detection, Grading, and Hormone Dosing Algorithm Into the Artificial Pancreas Using Accelerometry and Heart Rate. J Diabetes Sci Technol 2015; 9:1175-84. [PMID: 26438720 PMCID: PMC4667295 DOI: 10.1177/1932296815609371] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this article, we present several important contributions necessary for enabling an artificial endocrine pancreas (AP) system to better respond to exercise events. First, we show how exercise can be automatically detected using body-worn accelerometer and heart rate sensors. During a 22 hour overnight inpatient study, 13 subjects with type 1 diabetes wearing a Zephyr accelerometer and heart rate monitor underwent 45 minutes of mild aerobic treadmill exercise while controlling their glucose levels using sensor-augmented pump therapy. We used the accelerometer and heart rate as inputs into a validated regression model. Using this model, we were able to detect the exercise event with a sensitivity of 97.2% and a specificity of 99.5%. Second, from this same study, we show how patients' glucose declined during the exercise event and we present results from in silico modeling that demonstrate how including an exercise model in the glucoregulatory model improves the estimation of the drop in glucose during exercise. Last, we present an exercise dosing adjustment algorithm and describe parameter tuning and performance using an in silico glucoregulatory model during an exercise event.
Collapse
Affiliation(s)
- Peter G Jacobs
- Department of Biomedical Engineering, Oregon Health and Science University, Portland OR, USA
| | - Navid Resalat
- Department of Biomedical Engineering, Oregon Health and Science University, Portland OR, USA
| | - Joseph El Youssef
- Harold Schnitzer Diabetes Health Center, Oregon Health and Science University, Portland OR, USA
| | - Ravi Reddy
- Department of Biomedical Engineering, Oregon Health and Science University, Portland OR, USA
| | - Deborah Branigan
- Harold Schnitzer Diabetes Health Center, Oregon Health and Science University, Portland OR, USA
| | - Nicholas Preiser
- Department of Biomedical Engineering, Oregon Health and Science University, Portland OR, USA
| | - John Condon
- Department of Biomedical Engineering, Oregon Health and Science University, Portland OR, USA
| | - Jessica Castle
- Harold Schnitzer Diabetes Health Center, Oregon Health and Science University, Portland OR, USA
| |
Collapse
|
12
|
Abstract
PURPOSE OF REVIEW Autoimmune destruction of the β cells is considered the key abnormality in type 1 diabetes mellitus and insulin replacement the primary therapeutic strategy. However, a lack of insulin is accompanied by disturbances in glucagon release, which is excessive postprandially, but insufficient during hypoglycaemia. In addition, replacing insulin alone appears insufficient for adequate glucose control. This review focuses on the growing body of evidence that glucagon abnormalities contribute significantly to the pathophysiology of diabetes and on recent efforts to target the glucagon axis as adjunctive therapy to insulin replacement. RECENT FINDINGS This review discusses recent (since 2013) advances in abnormalities of glucagon regulation and their link to the pathophysiology of diabetes; new mechanisms of glucagon action and regulation; manipulation of glucagon in diabetes treatment; and analytical and systems biology tools to study glucagon regulation. SUMMARY Recent efforts 'resurrected' glucagon as a key hormone in the pathophysiology of diabetes. New studies target its abnormal regulation and action that is key for improving diabetes treatment. The progress is promising, but major questions remain, including unravelling the mechanism of loss of glucagon counterregulation in type 1 diabetes mellitus and how best to manipulate glucagon to achieve more efficient and safer glycaemic control.
Collapse
Affiliation(s)
- Leon S Farhy
- Division of Endocrinology and Metabolism, Department of Medicine and Center for Diabetes Technology, University of Virginia, Charlottesville, Virginia, USA
| | | |
Collapse
|
13
|
Abstract
Artificial pancreas (AP) systems, a long-sought quest to replicate mechanically islet physiology that is lost in diabetes, are reaching the clinic, and the potential of automating insulin delivery is about to be realized. Significant progress has been made, and the safety and feasibility of AP systems have been demonstrated in the clinical research center and more recently in outpatient "real-world" environments. An iterative road map to AP system development has guided AP research since 2009, but progress in the field indicates that it needs updating. While it is now clear that AP systems are technically feasible, it remains much less certain that they will be widely adopted by clinicians and patients. Ultimately, the true success of AP systems will be defined by successful integration into the diabetes health care system and by the ultimate metric: improved diabetes outcomes.
Collapse
|
14
|
Abstract
The primary goal of type 1 diabetes treatment is attaining near-normal glucose values. This currently remains out of reach for most people with type 1 diabetes despite intensified insulin treatment in the form of insulin analogues, educational interventions, continuous glucose monitoring, and sensor augmented insulin pump. The main remaining problem is risk of hypoglycaemia, which cannot be sufficiently reduced in all patient groups. Additionally, patients' burn-out often develops with years of tedious day-to-day diabetes management, rendering available diabetes-related technology less efficient. Over the past 40 years, several attempts have been made towards computer-programmed insulin delivery in the form of closed loop, with faster developments especially in the past decade. Automated insulin delivery has reduced human error in glycaemic control and considerably lessened the burden of routine self-management. In this chapter, data from randomized controlled trials with closed-loop insulin delivery that included type 1 diabetes population are summarized, and an evidence-based vision for possible routine utilization of closed loop is provided.
Collapse
Affiliation(s)
- Tadej Battelino
- Department of Endocrinology, Diabetes and Metabolism, UMC - University Children's Hospital, Ljubljana, Slovenia; Faculty of Medicine, University of Ljubljana, Slovenia.
| | - Jasna Šuput Omladič
- Department of Endocrinology, Diabetes and Metabolism, UMC - University Children's Hospital, Ljubljana, Slovenia
| | - Moshe Phillip
- Jesse Z. and Sara Lea Shafer Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, Petah Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|