Heterogeneity of glycaemic phenotypes in type 1 diabetes.

AIMS/HYPOTHESIS: Our study aims to uncover glycaemic phenotype heterogeneity in type 1 diabetes. METHODS: In the Study of the French-speaking Society of Type 1 Diabetes (SFDT1), we characterised glycaemic heterogeneity thanks to a set of complementary metrics: HbA1c, time in range (TIR), time below range (TBR), CV, Gold score and glycaemia risk index (GRI). Applying the Discriminative Dimensionality Reduction with Trees (DDRTree) algorithm, we created a phenotypic tree, i.e. a 2D visual mapping. We also carried out a clustering analysis for comparison. RESULTS: We included 618 participants with type 1 diabetes (52.9% men, mean age 40.6 years [SD 14.1]). Our phenotypic tree identified seven glycaemic phenotypes. The 2D phenotypic tree comprised a main branch in the proximal region and glycaemic phenotypes in the distal areas. Dimension 1, the horizontal dimension, was positively associated with GRI (coefficient [95% CI]) (0.54 [0.52, 0.57]), HbA1c (0.39 [0.35, 0.42]), CV (0.24 [0.19, 0.28]) and TBR (0.11 [0.06, 0.15]), and negatively with TIR (-0.52 [-0.54, -0.49]). The vertical dimension was positively associated with TBR (0.41 [0.38, 0.44]), CV (0.40 [0.37, 0.43]), TIR (0.16 [0.12, 0.20]), Gold score (0.10 [0.06, 0.15]) and GRI (0.06 [0.02, 0.11]), and negatively with HbA1c (-0.21 [-0.25, -0.17]). Notably, socioeconomic factors, cardiovascular risk indicators, retinopathy and treatment strategy were significant determinants of glycaemic phenotype diversity. The phenotypic tree enabled more granularity than traditional clustering in revealing clinically relevant subgroups of people with type 1 diabetes. CONCLUSIONS/INTERPRETATION: Our study advances the current understanding of the complex glycaemic profile in people with type 1 diabetes and suggests that strategies based on isolated glycaemic metrics might not capture the complexity of the glycaemic phenotypes in real life. Relying on these phenotypes could improve patient stratification in type 1 diabetes care and personalise disease management.

[Translated article] Medical Devices in Patients With Diabetes and Contact Dermatitis.

The development and commercialization of glucose sensors and insulin pumps has revolutionized the management of diabetes. These devices have been linked to multiple cases of contact dermatitis in recent years, however, giving rise to a growing interest in identifying the sensitizing allergens. Isobornyl acrylate was clearly identified as one of the main allergens responsible for contact dermatitis among users of the FreeStyle glucose sensor and was subsequently removed from the product ingredients. Remarkably, however, it is still used in most other sensors on the market. The common adhesive ingredients colophony and abietic acid derivatives have also been shown to be sensitizing agents. New components under study, such as dipropylene glycol diacrylate, N,N-dimethylacrylamide, and triethylene glycol methacrylate have recently been identified as allergens, though they are not commercially available for clinical testing. The benefits offered by glucose sensors and insulin pumps may be offset by sensitization to product ingredients, in some cases forcing discontinuation and diminishing quality of life. Dermatologists should play a role in this clinical and research scenario, offering case-by-case guidance to endocrinologists on skin care and possible alternatives for patients with glucose sensors and insulin pumps who develop contact dermatitis. They should also collaborate with the manufacturers developing these devices.

UK's Association of British Clinical Diabetologist's Diabetes Technology Network (ABCD-DTN): Best practice guide for hybrid closed-loop therapy.

This best practice guide is written with the aim of providing an overview of current hybrid closed-loop (HCL) systems in use within the United Kingdom's (UK) National Health Service (NHS) and to provide education and advice for their management on both an individual and clinical service level. The environment of diabetes technology, and particularly HCL systems, is rapidly evolving. The past decade has seen unprecedented advances in the development of HCL systems. These systems improve glycaemic outcomes and reduce the burden of treatment for people with type 1 diabetes (pwT1D). It is anticipated that access to these systems will increase in England as a result of updates in National Institute of Health and Care Excellence (NICE) guidance providing broader support for the use of real-time continuous glucose monitoring (CGM) for pwT1D. NICE is currently undertaking multiple-technology appraisal into HCL systems. Based on experience from centres involved in supporting advanced technologies as well as from the recent NHS England HCL pilot, this guide is intended to provide healthcare professionals with UK expert consensus on the best practice for initiation, optimisation and ongoing management of HCL therapy.

Innovations in Diabetes Device Training: A Scoping Review.

OBJECTIVE: The coronavirus disease 2019 pandemic highlighted a pre-existing need for alternatives to traditional in-person diabetes device trainings. Barriers to care, which include the heavy burden of training, pose a threat to optimal adoption and utilization of these devices. We searched the literature for alternative methods of training, evaluated user satisfaction, and compared short-term clinical outcomes with guideline-based glucometric targets and historical training results. METHODS: A scoping review of Embase articles from 2019 to 2021 was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines using key words relevant to diabetes technologies. Original full-text articles investigating training of new users on devices were included. Titles and abstracts were screened for eligibility by 2 independent reviewers, and results were summarized. RESULTS: Of 25 articles retrieved from the database, 11 met the criteria. Alternative training strategies included video conferencing, phone calls, mobile applications, and hybrids with traditional trainings. Overall, there was a high degree of user satisfaction with virtual visits, with a preference for hybrid approaches (6 articles). Although glucometrics varied between articles, short-term glucometrics were satisfactory overall (8 articles), including improved glycated hemoglobin measurements and time in range. Two articles compared time in range over various time points after traditional and remote training. One found equivalency, and the other identified a 5% improvement with remote training. CONCLUSION: Alternative training approaches are a viable option to reduce the barriers to care and to alleviate training burden. Intentional implementation of alternatives should be considered a solution to address current barriers.

Use of Telemedicine in Adults with Type 1 Diabetes: Do Age and Use of Diabetes-Related Technology Matter?

Objective: Older adults are generally less proficient in technology use compared with younger adults. Data on telemedicine use during the COVID-19 pandemic in older persons with type 1 diabetes (T1D) and the association of telemedicine with the use of diabetes-related technology are limited. We evaluated care delivery to older adults compared with younger adults with T1D in a prepandemic and pandemic period. Methods: Data from electronic health records were evaluated for visit types (in-person, phone, and video) from two sequential 12-month intervals: prepandemic (April 2019-March 2020) and pandemic (April 2020-March 2021). Results: Data from 2,832 unique adults with T1D were evaluated in two age cohorts: younger (40-64 years) and older (≥65 years). Half of each group used continuous glucose monitoring (CGM), whereas 54% of the younger and 37% of the older cohort used pump therapy (p < 0.001). During the pandemic compared with the prepandemic period, visit frequency increased in both the younger (0.65 vs. 0.76 visits/patient/quarter; p < 0.01) and older (0.72 vs. 0.80 visits/patient/quarter; p < 0.01) cohorts. During the pandemic, older adults used more phone visits compared with younger adults (48% vs. 32%; p = 0.001). Patients using either pump therapy or CGM were more likely to use video visits compared with phone visits in both younger (41% vs. 24%; p < 0.001) and older cohorts (53% vs. 42%; p < 0.001). Conclusions: Adults using diabetes-related technologies, independent of age, accessed more video visits than those not using devices. Telemedicine visits appeared to maintain continuity of care for younger and older adults with T1D, supporting the future of a hybrid-care model.

Contact Dermatitis to Diabetes Medical Devices.

Skin adverse reactions to diabetes medical devices have been reported frequently over recent years. Adhesives attaching glucose sensors and continuous insulin infusion sets to the skin are proven to cause both allergic contact dermatitis and irritant contact dermatitis in patients with diabetes mellitus. Several allergens contained in adhesives and/or parts of medical devices are documented to cause allergic contact dermatitis, with acrylate chemicals being the most common culprit-especially isobornyl acrylate (IBOA), but also 2,2'-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate or cyanoacrylates. Epoxy resin, colophonium and nickel were also identified as causative allergens. However, repetitive occlusion, maceration of the skin and resulting disruption of the skin barrier seem to have an impact on the development of skin lesions as well. The purpose of this study is to highlight the burden of contact dermatitis triggered by diabetes medical devices and to show possible mechanisms responsible for the development of contact dermatitis in a group of diabetic patients.

Barriers and Facilitators to Diabetes Device Adoption for People with Type 1 Diabetes.

PURPOSE OF REVIEW: Diabetes technology (insulin pumps, continuous glucose monitoring, automated insulin delivery systems) has advanced significantly and provides benefits to the user. This article reviews the current barriers to diabetes device adoption and sustained use, and outlines the known and potential facilitators for increasing and sustaining device adoption. RECENT FINDINGS: Barriers to diabetes device adoption continue to exist at the system-, provider-, and individual-level. Known facilitators to promote sustained adoption include consistent insurance coverage, support for providers and clinics, structured education and support for technology users, and device user access to support as needed (e.g., through online resources). Systemic barriers to diabetes device adoption persist while growing evidence demonstrates the increasing benefits of newest devices and systems. There are ongoing efforts to develop evidence-based structured education programs to support device adoption and sustained use.

Personalized insulin dose manipulation attack and its detection using interval-based temporal patterns and machine learning algorithms.

Many patients with diabetes are currently being treated with insulin pumps and other diabetes devices which improve their quality of life and enable effective treatment of diabetes. These devices are connected wirelessly and thus, are vulnerable to cyber-attacks which have already been proven feasible. In this paper, we focus on two types of cyber-attacks on insulin pump systems: an overdose of insulin, which can cause hypoglycemia, and an underdose of insulin, which can cause hyperglycemia. Both of these attacks can result in a variety of complications and endanger a patient's life. Specifically, we propose a sophisticated and personalized insulin dose manipulation attack; this attack is based on a novel method of predicting the blood glucose (BG) level in response to insulin dose administration. To protect patients from the proposed sophisticated and malicious insulin dose manipulation attacks, we also present an automated machine learning based system for attack detection; the detection system is based on an advanced temporal pattern mining process, which is performed on the logs of real insulin pumps and continuous glucose monitors (CGMs). Our multivariate time-series data (MTSD) collection consists of 225,780 clinical logs, collected from real insulin pumps and CGMs of 47 patients with type I diabetes (13 adults and 34 children) from two different clinics at Soroka University Medical Center in Beer-Sheva, Israel over a four-year period. We enriched our data collection with additional relevant medical information related to the subjects. In the extensive experiments performed, we evaluated the proposed attack and detection system and examined whether: (1) it is possible to accurately predict BG levels in order to create malicious data that simulate a manipulation attack and the patient's body in response to it; (2) it is possible to automatically detect such attacks based on advanced machine learning (ML) methods that leverage temporal patterns; (3) the detection capabilities of the proposed detection system differ for insulin overdose and underdose attacks; and (4) the granularity of the learning model (general / adult vs. pediatric clinic / individual patient) affects the detection capabilities. Our results show that (a) it is possible to predict, with nearly 90% accuracy, BG levels using our proposed methods, and by doing so, enable malicious data creation for our detection system evaluation; (b) it is possible to accurately detect insulin manipulation attacks using temporal patterns mining using several ML methods, including Logistic Regression, Random Forest, TPF class model, TPF top k, and ANN algorithms; (c) it is easier to detect an overdose attack than an underdose attack in more than 25%, in terms of AUC scores; and (d) the adult vs. pediatric model outperformed models of other granularities in the detection of overdose attacks, while the general model outperformed the other models in the case of detecting underdose attacks; for both attacks, attack detection among children was found to be more challenging than among adults. In addition to its use in the evaluation of our detection system, the proposed BG prediction method has great importance in the medical domain where it can contribute to improved care of patients with diabetes.

A Pharmacist-Driven Glycemic Control Protocol to Reduce the Rate of Severe Hypoglycemia in High-Risk Patients.

Purpose: Hospital pharmacists contribute to patient safety and quality initiatives by overseeing the prescribing of antidiabetic medications. A pharmacist-driven glycemic control protocol was developed to reduce the rate of severe hypoglycemia events (SHE) in high-risk hospitalized patients. Methods: We retrospectively analyzed the rates of SHE (defined as blood glucose ≤40 mg/dL), before and after instituting a pharmacist-driven glycemic control protocol over a 4-year period. A hospital glucose management team that included a lead Certified Diabetes Educator Pharmacist (CDEP), 5 pharmacists trained in diabetes, a lead hospitalist, critical care and hospital providers established a process to first identify patients at risk for severe hypoglycemia and then implement our protocol. Criteria from the American Diabetes Association and the American Association of Clinical Endocrinologists was utilized to identify and treat patients at risk for SHE. We analyzed and compared the rate of SHE and physician acceptance rates before and after protocol initiation. Results: From January 2015 to March 2019, 18 297 patients met criteria for this study; 139 patients experienced a SHE and approximately 80% were considered high risk diabetes patients. Physician acceptance rates for the new protocol ranged from 77% to 81% from the year of initiation (2016) through 2018. The absolute risk reduction of SHE was 9 events per 1000 hospitalized diabetic patients and the relative risk reduction was 74% SHE from the start to the end of the protocol implementation. Linear regression analysis demonstrated that SHE decreased by 1.5 events per 1000 hospitalized diabetic patients (95% confidence interval, -1.54 to -1.48, P < .001) during the 2 years following the introduction of the protocol. This represents a 15% relative reduction of SHE per year. Conclusion: The pharmacist-driven glycemic control protocol was well accepted by our hospitalists and led to a significant reduction in SHE in high-risk diabetes patient groups at our hospital. It was cost effective and strengthened our physician-pharmacist relationship while improving diabetes care.

Education programmes for persons with type 1 diabetes using an insulin pump: A systematic review.

Education is essential in insulin pump therapy, but literature in the field is limited. We systematically reviewed insulin pump education programmes and their effects in two situations as follows: (1) basic education at the start of insulin pump therapy, providing the study design enabled us to separate the effects of insulin pump therapy itself from the effects of education and (2) re-education of experienced pump users. Population: individuals ≥16 years with type 1 diabetes using insulin pumps with or without continuous glucose monitoring. Systematic searches were run in MEDLINE, Embase, CINAHL and ERIC. Original studies reporting an effect of insulin pump education programmes were included if published in English between January 1999 and May 2019. Of 988 potentially relevant studies, 48 were assessed in full text. Nine studies fulfilled the inclusion criteria, including one randomised controlled trial. Educational approaches and settings were sparsely described in all studies, and the content was usually reported as teaching points. Two studies considered basic education, reporting evaluations of knowledge and application skills, and programme satisfaction. The remaining seven studies referred to re-education. Two studies measured severe hypoglycaemic events before and after a re-education intervention, both reporting a significant event reduction. HbA1c decreased significantly in three of four studies. Two studies reported increased knowledge and improved application skills. In conclusion, this review indicates benefits from basic education and from re-education. The strength of the conclusions is limited by the low number of studies and study designs. High-quality studies are needed comparing different approaches for insulin pump education.

American Association of Clinical Endocrinology Clinical Practice Guideline: The Use of Advanced Technology in the Management of Persons With Diabetes Mellitus.

OBJECTIVE: To provide evidence-based recommendations regarding the use of advanced technology in the management of persons with diabetes mellitus to clinicians, diabetes-care teams, health care professionals, and other stakeholders. METHODS: The American Association of Clinical Endocrinology (AACE) conducted literature searches for relevant articles published from 2012 to 2021. A task force of medical experts developed evidence-based guideline recommendations based on a review of clinical evidence, expertise, and informal consensus, according to established AACE protocol for guideline development. MAIN OUTCOME MEASURES: Primary outcomes of interest included hemoglobin A1C, rates and severity of hypoglycemia, time in range, time above range, and time below range. RESULTS: This guideline includes 37 evidence-based clinical practice recommendations for advanced diabetes technology and contains 357 citations that inform the evidence base. RECOMMENDATIONS: Evidence-based recommendations were developed regarding the efficacy and safety of devices for the management of persons with diabetes mellitus, metrics used to aide with the assessment of advanced diabetes technology, and standards for the implementation of this technology. CONCLUSIONS: Advanced diabetes technology can assist persons with diabetes to safely and effectively achieve glycemic targets, improve quality of life, add greater convenience, potentially reduce burden of care, and offer a personalized approach to self-management. Furthermore, diabetes technology can improve the efficiency and effectiveness of clinical decision-making. Successful integration of these technologies into care requires knowledge about the functionality of devices in this rapidly changing field. This information will allow health care professionals to provide necessary education and training to persons accessing these treatments and have the required expertise to interpret data and make appropriate treatment adjustments.

Contact dermatitis caused by glucose sensors, insulin pumps, and tapes: Results from a 5-year period.

BACKGROUND: The number of patients with contact dermatitis from glucose sensors and insulin infusion sets is increasing. Patch testing is challenging because of a lack of information concerning the constituent materials of medical devices. OBJECTIVES: To report on products and causes of allergic reactions to glucose sensors or insulin infusion sets over a 5-year period and suggest a short screening series. METHODS: Analysis of patch test data from consecutive patients suspected of allergic contact dermatitis (ACD) to glucose sensors and/or insulin infusion sets from 2015-2019. RESULTS: Patient numbers increased from 4 to 15 per year; 30/38 (78.9%) were children. In 29 (76.3%), a diagnosis of allergic/probable ACD was established, mostly due to the tapes of the device or allergens in these tapes (n = 23) followed by allergens in the device housing (n = 10). Isobornyl acrylate, abitol, and colophonium were the most common allergens. Information from manufacturers was often difficult to obtain and, if accessible, inadequate. For this reason, the diagnosis was delayed for more than 1.5 years in 12 (31%) patients. CONCLUSIONS: The increasing number of patients, mostly children, with ACD from devices used in treatment of type 1 diabetes demonstrates the importance of this problem. Allergies can easily be overlooked, due to the lack of mandatory labeling of the constituent materials of the devices.

How does a predictive low glucose suspend (PLGS) system tackle pediatric lifespan challenges in diabetes treatment? Real world data analysis.

OBJECTIVES: The aim of the study was to assess the benefits of a predictive low glucose suspend (PLGS) system in real-life in children and adolescents with type 1 diabetes of different age and age-related clinical challenges. METHODS: Real life retrospective and descriptive analysis included 44 children (26 girls) with type 1 diabetes who were introduced to PLGS system. We divided them in three age groups: I (3-6 years old, n = 12), II (7-10 y/o, n = 16), III (11-19 y/o, n = 16). All children and their caregivers received unified training in self-management during PLGS therapy. Patients' data included: age, HbA1C levels, sex. While from the CGM metric, we obtained: time of sensor use (SENSuse), time in range (TiR): in, below and over target range and average blood glycemia (AVG), insulin suspension time (INSsusp). RESULTS: SENSuse was 93% in total, with 92%, 94%, and 87% in age groups I, II, III, respectively. In total the reduction of mean HbA1C from 7.61% to 6.88% (P < .05), while for the I, II, and III it was 7.46% to 6.72%, 6.91% to 6.41%, and 8.46 to 7.44%, respectively (P < .05). Although we observed a significant reduction of HbA1C, the time below target range was minimal. Specific findings included: group I-longest INSsusp (17%), group II-lowest glycemic variability (CV) (36%), and group III-highest AVG (169 mg/dL). There was a reverse correlation between suspend before low and age (-0.32, P < .05). In group I CV reduced TiR in target range (TiRin) (-0.82, P < .05), in group II use of complex boluses increased TiRin (0.52, P < .05). In group III higher CV increased HbA1C (0.64, P < .05) while reducing TiRin (-0.72, P < .05). CONCLUSIONS: PLGS is a suitable and safe therapeutic option for children with diabetes of all age and it is effective in addressing age-specific challenges. PLGS improves glycemic control in children of all age, positively affecting its different parameters.

Insulin Pump Use in Children with Type 1 Diabetes: Over a Decade of Disparities.

PURPOSE: Racial disparities have been shown in outcomes and treatment of children with type 1 diabetes (T1D). The purpose of this study was to examine temporal trends in insulin pump use among non-Hispanic white (NHW), non-Hispanic black (NHB) and Hispanic children attending a large urban diabetes center. . This study was a retrospective chart review of insulin pump usage by race (NHW/ NHB) in 2005, and race/ethnicity (NHW/NHB/Hispanic) in 2011-2019. Demographic data (age, sex, diabetes duration, SES) and most recent hemoglobin A1c were also abstracted in 2011-2019. RESULTS: In 2005, NHW children were twice as likely to use an insulin pump as NHB children. From 2011 to 2019, the odds ratio increased to 2.5 for NHW compared to NHB children. The odds of Hispanic children using insulin pumps were also higher than NHB. Insurance status (government versus private), a surrogate for SES, had very little influence on these trends, with NHW children consistently more likely than NHB children to be treated with insulin pumps in 2011, 2013, 2017, 2019 (p < 0.001). CONCLUSIONS: We have demonstrated that racial disparities in insulin pump use have persisted over the past 15 years, and are not determined by SES. This inequity in diabetes treatment may be playing a role in the poorer glycemic control and higher rates of diabetes complications in NHB children. PRACTICE IMPLICATIONS: Healthcare providers should be cognizant of racial and ethnic disparities in the treatment of children with T1D. Standardized treatment protocols may reduce unconscious bias in prescribing.

[What is the current state of the artificial pancreas in diabetes care?] / Wo steht das künstliche Pankreas in der Diabetestherapie?

The artificial pancreas (also referred to as closed-loop system) brings us one step closer to the decade-long dream of automated insulin delivery. The closed-loop system directs subcutaneous insulin delivery corresponding to the glucose concentration using a control algorithm. Evidence shows that closed-loop systems substantially improve glucose control and quality of life; however, fully automated closed-loop systems have not yet been accomplished. Active input from patients is required for mealtime insulin dosing and corrections. This article provides an overview on the current state of development of the artificial pancreas in the treatment of diabetes.

Hypoglycaemia in type 1 diabetes: technological treatments, their limitations and the place of psychology.

Advances in technology allowing improved insulin delivery and glucose monitoring can significantly reduce the burden of hypoglycaemia when used appropriately. However, limitations of the current technology, and the skills, commitment and motivation required to use them, mean that it does not work for all people. Education and informed professional support are key to success. In the context of problematic hypoglycaemia, data suggest that newer technology has lower efficacy and uptake in those with most need. Identifying the causes of hypoglycaemia and understanding some of the underlying behavioural drivers may prove useful and psycho-educational strategies may be effective in selected individuals. Ultimately, as in many spheres of medicine, successful management of problematic hypoglycaemia depends upon matching the right treatment to the right individual.

Biopsychosocial Factors Associated With Satisfaction and Sustained Use of Artificial Pancreas Technology and Its Components: a Call to the Technology Field.

PURPOSE OF REVIEW: Summarize biopsychosocial factors associated with using continuous glucose monitors (CGMs), insulin pumps, and artificial pancreas (AP) systems and provide a "call to the field" about their importance to technology uptake and maintained use. RECENT FINDINGS: Insulin pumps and CGMs are becoming standard of care for individuals with type 1 diabetes (T1D). AP systems combining a CGM, insulin pump, and automated dosing algorithm are available for commercial use. Despite improved glycemic control with AP system use, numerous barriers exist which may limit their benefit. Studies on components of AP systems (pumps, CGMs) are limited and demonstrate mixed results of their impact on fear of hypoglycemia, adherence, quality of life, depression and anxiety, and diabetes distress. Studies examining biopsychological factors associated specifically with sustained use of AP systems are also sparse. Biological, psychological and social impacts of AP systems have been understudied and the information they provide has not been capitalized upon.

The process of incorporating insulin pumps into the everyday lives of people with Type 1 diabetes: A critical interpretive synthesis.

BACKGROUND: Insulin pump therapy (IPT) is a technological advancement that has been developed to help people manage Type 1 diabetes (T1D). However, ways of managing diabetes requiring the implementation of health technologies bring new complexities and a need to understand the factors which enable people with T1D to incorporate a novel device. This new comprehension could provide an exemplar for people with long-term conditions to incorporate new technologies more generally. OBJECTIVE: To determine what influences the incorporation, adaptation and use of IPT into the everyday lives of people living with diabetes. DESIGN: Critical interpretive synthesis (CIS) using systematic searches undertaken in 7 electronic databases of literature, published 2008 onwards. RESULTS: A total of 4998 titles were identified, 274 abstracts reviewed, 39 full articles retrieved and 22 papers selected for analysis. Three themes emerged which were of relevance to the introduction and use of IPT; Tensions between expectations and experiences in adoption and early adaptation; Negotiation of responsibility and accessing support; Reflexivity, active experimentation and feedback. CONCLUSIONS: This CIS builds on earlier reviews on lived experiences of IPT. Novel insights are offered through examination of the experiences of pump users from children through to adults, their families and health-care professionals. Expectations of what the device can do to improve self-management impacts on the early stages of adoption as the reality of the technology requires substantial thought and action. Areas for intervention to improve IPT incorporation include establishing who is responsible for management tasks of the device and enabling navigation to further means of support and resources.

Modeling the acute effects of exercise on insulin kinetics in type 1 diabetes.

Our objective is to develop a physiology-based model of insulin kinetics to understand how exercise alters insulin concentrations in those with type 1 diabetes (T1D). We reveal the relationship between the insulin absorption rate ([Formula: see text]) from subcutaneous tissue, the insulin delivery rate ([Formula: see text]) to skeletal muscle, and two physiological parameters that characterize the tissue: the perfusion rate (Q) and the capillary permeability surface area (PS), both of which increase during exercise because of capillary recruitment. We compare model predictions to experimental observations from two pump-wearing T1D cohorts [resting subjects ([Formula: see text]) and exercising subjects ([Formula: see text])] who were each given a mixed-meal tolerance test and a bolus of insulin. Using independently measured values of Q and PS from literature, the model predicts that during exercise insulin concentration increases by 30% in plasma and by 60% in skeletal muscle. Predictions reasonably agree with experimental observations from the two cohorts, without the need for parameter estimation by curve fitting. The insulin kinetics model suggests that the increase in surface area associated with exercise-induced capillary recruitment significantly increases [Formula: see text] and [Formula: see text], which explains why insulin concentrations in plasma and skeletal muscle increase during exercise, ultimately enhancing insulin-dependent glucose uptake. Preventing hypoglycemia is of paramount importance in determining the proper insulin dose during exercise. The presented model provides mechanistic insight into how exercise affects insulin kinetics, which could be useful in guiding the design of decision support systems and artificial pancreas control algorithms.