bluuebunny/crossref_metadata_2025 huggingface dataset:
Near Infrared Wound Monitor Helps Clinical Assessment of Diabetic Foot Ulcers
Authors: Neidrauer Michael , Zubkov Leonid , Weingarten Michael S. , Pourrezaei Kambiz , Papazoglou Elisabeth S.
Published: January 2014

Background:

The efficacy of using diffuse near infrared spectroscopy (NIRS) in predicting wound healing in diabetic foot ulcers was demonstrated by conducting a pilot human study.

Method:

Sixteen chronic diabetic wounds were followed and assessed for subsurface oxyhemoglobin concentration using the NIRS device. Weekly measurements were conducted until there was wound closure, limb amputation, or 20 completed visits without healing. Wound size and degree of wound contraction were measured by image analysis of digital photographs, and results were compared to NIRS results.

Results:

In the 16 patients followed, seven wounds healed, six limbs were amputated, and three wounds remained opened after 20 visits. Initial values of subsurface hemoglobin concentration, in all wounds, were higher than in nonwound control sites. Healed wounds exhibited a consistent reduction of hemoglobin concentration several weeks prior to closure, and the absolute hemoglobin concentration approached the value at the control site. In wounds that did not heal or ended in amputations, the hemoglobin concentration remained elevated throughout the study. A negative slope for the rate of change of hemoglobin concentration was indicative of healing across all wounds.

Conclusions:

Evaluation of diabetic foot ulcers using NIRS may provide an effective and more complete measurement of wound healing compared to current clinical approaches.
Novel Use of Insulin in Continuous-Instillation Negative Pressure Wound Therapy as “Wound Chemotherapy”
Authors: Scimeca Christy L. , Bharara Manish , Fisher Timothy K. , Kimbriel Heather , Mills Joseph L. , Armstrong David G.
Published: January 2014

Negative pressure wound therapy (NPWT) is frequently employed in the treatment of complex wounds. A variety of wound chemotherapeutic agents such as insulin, which acts as a growth factor, may prove helpful in treatment as well. We present a case report in which insulin was used as a chemotherapeutic agent in continuous-instillation NPWT. To our knowledge, this is the first report in the literature describing this method of delivery.
Continuing Medical Education Methodology: Current Trends and Applications in Wound Care
Authors: Sherman Alan
Published: January 2014

The field of professional medical continuing education is changing rapidly. The traditional format for continuing education for health care professionals has long been classroom learning. This form of learning has been found to be relatively ineffective in changing learners' practice patterns. The reasons most often cited are that there is little interaction and that the learning does not occur when the learner is ready to learn. Interaction greatly enhances retention and the tendency for the learner to later apply the learning in actual clinical encounters. There are a growing number of online continuing medical education (CME) Web sites that combine on-demand didactic presentations with the ability to discuss the content with peers. The easy access and interaction potential of this new CME media promises to improve the effectiveness of future CME.
Making a Case: Nanofabrication Techniques in Encapsulated Cell Therapy for People with Diabetes
Authors: Gimi Barjor
Published: January 2014

A nanoporous immunoisolative case/capsule that encases/encapsulates insulin-secreting cells vastly expands the source of therapeutic cells available for grafting in people with diabetes, including cells from animal sources, stem cells, and genetically engineered cells. These encapsulated cellular grafts potentially provide an endogenous, renewable, and long-term source of insulin without the need for pharmacological immunosuppression.

Micro- and nanofabrication techniques used principally in the semiconductor industry can play a positive role in encapsulated cell therapy. Many of these techniques do not have direct applicability in cell encapsulation, but can be leveraged to develop processes suitable for this application. This commentary highlights the salient features of an effective cell encapsulation system, enumerates limitations of existing encapsulation schemes, and touches upon progress in key areas of encapsulation technology; one example of how micro- and nanofabrication technology may be used to develop a more effective platform for cell encapsulation is presented. This commentary urges further exploration and expansion of techniques used traditionally in electronics and optics for cell-based therapy in people with diabetes.
Guidelines for Insulin Dosing in Continuous Subcutaneous Insulin Infusion Using New Formulas from a Retrospective Study of Individuals with Optimal Glucose Levels
Authors: Walsh John , Roberts Ruth , Bailey Timothy
Published: January 2014

Background:

Successful insulin pump therapy depends on correct insulin doses based on an optimal total daily dose (TDD) and optimal pump settings for basal infusion, carbohydrate factor (CarbF), and glucose correction factor (CorrF) based on the TDD. There are limited data in the literature to guide providers and patients regarding methods to optimize these critical parameters for glucose control.

Methods:

Anonymous data downloads from 1020 insulin pumps used throughout the United States and overseen by a variety of clinicians were analyzed retrospectively to find insulin doses that provided the best glucose control. A subset of 396 pumps was chosen for glucose data reliability, with over 85% of their glucose data directly entered from a meter. This subset was divided into tertiles based on glucose levels, and the low glucose tertile was analyzed to derive formulas for optimal insulin pump settings.

Results:

An inconsistent clustering of pump settings was found for the CarbF and the CorrF. This was less pronounced when CarbFs and CorrFs were determined from the actual bolus doses delivered once adjustments were made to the initial dose calculations by users and, to a larger extent, internally by the bolus calculator itself. Common beliefs that hyperglycemia is related to less carb counting, fewer carb boluses, or delivery of less insulin per day were not substantiated in this data. New or verified insulin dosing formulas presented include basal U/day = TDD x 0.48; CarbF = [2.6 x Wt(lb)]/TDD; and CorrF = 1960/TDD.

Conclusions:

Insulin pump users cannot reap full benefit from their pump bolus calculator if the settings on which bolus doses are based are less than optimal. Our data show that CarbFs and CorrFs tend to be unevenly distributed, suggesting that these factors are not selected in a systematic manner through use of formulas. Poor glucose outcomes among insulin pump users appear to be related to pump setting errors and being relatively underinsulinized, even though those in poor control use more total insulin per day. We have developed a model with the hypothesis that improved glucose outcomes will result from the use of formulas to derive appropriate pump settings. Prospective validation of these concepts is needed.
Accuracy and Reliability of the Nova StatStrip® Glucose Meter for Real-Time Blood Glucose Determinations during Glucose Clamp Studies
Authors: Rabiee Atoosa , Magruder J. Trent , Grant Crystal , Salas-Carrillo Rocio , Gillette Audrey , DuBois Jeffrey , Shannon Richard P. , Andersen Dana K. , Elahi Dariush
Published: January 2014

Aims/Hypothesis:

The Andres clamp technique, which requires accurate and timely determination of glucose, utilizes the Beckman or Yellow Springs Instruments (YSI) glucose analyzers. Both instruments require maintenance, a dedicated operator, preparation of a plasma sample, and a duplicate measurement that takes ≥2 minutes. The Nova StatStrip glucose meter was evaluated for accuracy, reliability, and near-real-time availability of glucose.

Methods:

Blood samples from 24 patients who underwent 6-hour clamp studies and 12 patients who had a standardized meal tolerance test (SMT) were measured. Specimens were analyzed simultaneously and immediately upon collection by Beckman, YSI, and Nova.

Results:

Of 1004 data pairs for the Nova device versus Beckman, the Nova data points ranged from 32 to 444, while Beckman ranged from 42 to 412. The coefficient for the slope of Beckman versus Nova was 1.009 ( r = 0.978). Using error grid analysis, the number and percentage of values for Nova were 976 (97.2%) in the A zone and 28 (2.8%) in the B zone. Of 399 data pairs for the Nova device versus YSI, the Nova data points ranged from 46 to 255, whereas YSI ranged from 47 to 231. The coefficient for the slope of YSI versus Nova was 1.023 ( r = 0.989). All Nova readings fell in the A zone. Time required for final reading, in duplicate, was 15 seconds for Nova and 120–180 seconds for Beckman and YSI.

Conclusions:

The simplicity of Nova and its reliability, accuracy, and speed make it an acceptable replacement device for Beckman and YSI in the conduct of clamps, especially when perturbations require rapid glucose determination.
Analysis: Including Visually Impaired Participants in Validation Design Studies of Diabetes Technology
Authors: Uslan Mark , Blubaugh Morgan
Published: January 2014

In an article in this issue of Journal of Diabetes Science and Technology, Sherwyn Schwartz, M.D., presents a study to validate the design of the ClikSTAR® insulin pen from sanofi-aventis and demonstrates that the device can be used correctly by participants with diabetes. Concern with this article lies with the selection of participants, which was meant to reflect the intended audience for the insulin pen device but does not address the inclusion of visually impaired individuals, who comprise over 20% of the adult diabetes population. Visually impaired individuals need to be included as part of the intended audience for insulin administration technology, and manufacturers of these devices need to design their products for safe use by all people, including those who are visually impaired. The study demonstrated successful use of the ClikSTAR insulin pen in a population that did not include subjects with severe visual impairment. We believe that future validation studies for insulin administration technology should also include samples of visually impaired users and that visually impaired patients will embrace the use of insulin pens designed with their needs in mind.
Efficacy Determinants of Subcutaneous Microdose Glucagon during Closed-Loop Control
Authors: Russell Steven J. , El-Khatib Firas H. , Nathan David M. , Damiano Edward R.
Published: January 2014

Background:

During a previous clinical trial of a closed-loop blood glucose (BG) control system that administered insulin and microdose glucagon subcutaneously, glucagon was not uniformly effective in preventing hypoglycemia (BG <70 mg/dl). After a global adjustment of control algorithm parameters used to model insulin absorption and clearance to more closely match insulin pharmacokinetic (PK) parameters observed in the study cohort, administration of glucagon by the control system was more effective in preventing hypoglycemia. We evaluated the role of plasma insulin and plasma glucagon levels in determining whether glucagon was effective in preventing hypoglycemia.

Methods:

We identified and analyzed 36 episodes during which glucagon was given and categorized them as either successful or unsuccessful in preventing hypoglycemia.

Results:

In 20 of the 36 episodes, glucagon administration prevented hypoglycemia. In the remaining 16, BG fell below 70 mg/dl (12 of the 16 occurred during experiments performed before PK parameters were adjusted). The (dimensionless) levels of plasma insulin (normalized relative to each subject's baseline insulin level) were significantly higher during episodes ending in hypoglycemia (5.2 versus 3.7 times the baseline insulin level, p = .01). The relative error in the control algorithm's online estimate of the instantaneous plasma insulin level was also higher during episodes ending in hypoglycemia (50 versus 30%, p = .003), as were the peak plasma glucagon levels (183 versus 116 pg/ml, p = .007, normal range 50–150 pg/ml) and mean plasma glucagon levels (142 versus 75 pg/ml, p = .02). Relative to mean plasma insulin levels, mean plasma glucagon levels tended to be 59% higher during episodes ending in hypoglycemia, although this result was not found to be statistically significant (p = .14). The rate of BG descent was also significantly greater during episodes ending in hypoglycemia (1.5 versus 1.0 mg/dl/min, p = .02).

Conclusions:

Microdose glucagon administration was relatively ineffective in preventing hypoglycemia when plasma insulin levels exceeded the controller's online estimate by >60%. After the algorithm PK parameters were globally adjusted, insulin dosing was more conservative and microdose glucagon administration was very effective in reducing hypoglycemia while maintaining normal plasma glucagon levels. Improvements in the accuracy of the controller's online estimate of plasma insulin levels could be achieved if ultrarapid-acting insulin formulations could be developed with faster absorption and less intra- and intersubject variability than the current insulin analogs available today.
Optimization of the Native Glucagon Sequence for Medicinal Purposes
Authors: Chabenne Joseph R. , DiMarchi Maria A. , Gelfanov Vasily M. , DiMarchi Richard D.
Published: January 2014

Background:

Glucagon is a life-saving medication used in the treatment of hypoglycemia. It possesses poor solubility in aqueous buffers at or near physiological pH values. At low and high pH, at which the peptide can be formulated to concentrations of a milligram or more per milliliter, the chemical integrity of the hormone is limited, as evidenced by the formation of multiple degradation-related peptides. Consequently, the commercial preparation is provided as a lyophilized solid with an acidic diluent and directions for rendering it soluble at the time of use. Any unused material is recommended for disposal immediately after initial use.

Methods:

A set of glucagon analogs was prepared by solid-phase peptide synthesis to explore the identification of a glucagon analog with enhanced solubility and chemical stability at physiological pH. The physical properties of the peptide analogs were studied by solubility determination, high-performance chromatography, and mass spectral analysis. The biochemical properties were determined in engineered human embryonic kidney cell line 293 (HEK293) cells that overexpressed either the human glucagon or glucagon-like peptide-1 (GLP-1) receptors linked to a luciferase reporter gene.

Results:

We observed the previously characterized formation of glucagon degradation products upon incubation of the peptide in dilute acid for extended periods or elevated temperature. Lowering the isoelectric point of the hormone through the substitution of asparagine-28 with aspartic acid significantly increased the solubility at physiological pH. Similarly, the C-terminal extension (Cex) of the hormone with an exendin-based, 10-residue, C-terminal sequence yielded a peptide of dramatically enhanced solubility. These two glucagon analogs, D28 and Cex, maintained high potency and selectivity for the glucagon receptor relative to GLP-1 receptor.

Conclusions:

Glucagon presents unique structural challenges to the identification of an analog of high biological activity and selectivity that also possesses sufficient aqueous solubility and stability such that it might be developed as a ready-to-use medicine. The glucagon analogs D28 and Cex demonstrated all of the chemical, physical, and biochemical properties supportive of further study as potential clinical candidates for treatment of hypoglycemia.
The Minimum Frequency of Glucose Measurements from Which Glycemic Variation Can Be Consistently Assessed
Authors: Baghurst Peter A. , Rodbard David , Cameron Fergus J.
Published: January 2014

Aims:

While there has been much debate about the clinical importance of glycemic variation (GV), little attention has been directed to the properties of data sets from which it is measured. The purpose of this study is to assess the minimum frequency of glucose measurements from which GV can be consistently and meaningfully measured.

Methods:

Forty-eight 72 h continuous glucose monitoring traces from children with type 1 diabetes were assessed. Measures of GV included standard deviation (SD), mean amplitude of glycemic excursion (MAGE), and continuous overlapping net glycemic action (CONGA1–4). Measures of GV calculated using 5 min sampling were designated as the 100% or “best estimate” value. Calculations were then repeated for each patient using glucose values spaced at increasing intervals. For each of the specified sampling frequencies, the ratio (%) of the between-subject SD based on the reduced subset of data to the estimate of the SD based on the full 5 min sampling data set was calculated.

Results:

As the interval between observations increased, so did the variability of the estimators of GV. Standard deviation exhibited the least systematic change at all measurement intervals, and MAGE exhibited the greatest systematic change.

Conclusions:

In patients with type 1 diabetes, GV as measured by SD or CONGA4, becomes unreliable if observations are more than 2–4 h apart, and estimates of MAGE become unreliable if glucose measurements are more than 1 h apart. MAGE is more unstable and prone to random measurement error than either SD or CONGA. The frequency of glycemic measurements is thus pivotal when selecting a parameter for measurement of GV.
Correlation between Plantar Foot Temperature and Diabetic Neuropathy: A Case Study by Using an Infrared Thermal Imaging Technique
Authors: Bagavathiappan Subramnaiam , Philip John , Jayakumar Tammana , Raj Baldev , Rao Pallela Narayana Someshwar , Varalakshmi Muthukrishnan , Mohan Viswanathan
Published: January 2014

Background:

Diabetic neuropathy consists of multiple clinical manifestations of which loss of sensation is most prominent. High temperatures under the foot coupled with reduced or complete loss of sensation can predispose the patient to foot ulceration. The aim of this study was to look at the correlation between plantar foot temperature and diabetic neuropathy using a noninvasive infrared thermal imaging technique.

Methods:

Infrared thermal imaging, a remote and noncontact experimental tool, was used to study the plantar foot temperatures of 112 subjects with type 2 diabetes selected from a tertiary diabetes centre in South India.

Results:

Patients with diabetic neuropathy (defined as vibration perception threshold (VPT) values on biothesiometry greater than 20 V) had a higher foot temperature (32–35 °C) compared to patients without neuropathy (27–30 °C). Diabetic subjects with neuropathy also had higher mean foot temperature (MFT) ( p = .001) compared to non-neuropathic subjects. MFT also showed a positive correlation with right great toe ( r = 0.301, p = .001) and left great toe VPT values ( r = 0.292, p = .002). However, there was no correlation between glycated hemoglobin and MFT.

Conclusion:

Infrared thermal imaging may be used as an additional tool for evaluation of high risk diabetic feet.
Combining Basal-Bolus Insulin Infusion for Tight Postprandial Glucose Control: An in Silico Evaluation in Adults, Children, and Adolescents
Authors: Revert Ana , Rossetti Paolo , Calm Remei , Vehí Josep , Bondia Jorge
Published: January 2014

Background:

Achieving good postprandial glycemic control, without triggering hypoglycemia events, is a challenge of treatment strategies for type 1 diabetes subjects. Continuous subcutaneous insulin infusion, the gold standard of therapy, is based on heuristic adjustments of both basal and prandial insulin. Some tools, such as bolus calculators, are available to aid patients in selecting a meal-related insulin dose. However, they are still based on empiric parameters such as the insulin-to-carbohydrate ratio and on the physicians' and patients' ability to fit bolus mode to meal composition.

Method:

In this article, a nonheuristic method for assessment of prandial insulin administration is presented and evaluated. An algorithm based on set inversion via interval analysis is used to coordinate basal and bolus insulin infusions to deal with postprandial glucose excursions. The evaluation is carried out through an in silico study using the 30 virtual patients available in the educational version of the Food and Drug Administration-accepted University of Virginia simulator. Results obtained using the standard bolus strategy and different coordinated basal-bolus solutions provided by the algorithm are compared.

Results:

Coordinated basal-bolus solutions improve postprandial glucose performance in most cases, mainly in terms of reducing hypoglycemia risk, but also increasing the percentage of time in normoglycemia. Moreover, glycemic variability is reduced considerably by using these innovative solutions.

Conclusions:

The algorithm presented here is a robust nonheuristic alternative to deal with postprandial glycemic control. It is shown as a powerful tool that could be integrated in future smart insulin pumps.
Dose Accuracy and Injection Force of Disposable Pens Delivering Pramlintide for the Treatment of Diabetes
Authors: Merritt Douglas , Schreiner Barb , Harris Scott , DeYoung Mary Beth , Strobel Susan , Lauinger Joseph
Published: January 2014

Background:

The pen injection format, typically used for insulin administration, has been adapted for the injectable, noninsulin diabetes therapy pramlintide. Administered before major meals, pramlintide therapy requires two to four injections/day in addition to the patients' usual insulin injections. The dose accuracy and injection force was determined for the 60 and 120 μg pramlintide pens.

Methods:

Dose accuracy testing was conducted at two sites on multiple 60 μg (15, 30, and 60 μg doses) and 120 μg pens (60 and 120 μg doses) at prespecified temperatures (5–40 °C) and humidities (0–75%) using 29 G half-inch needles. All pens were stabilized under testing conditions for 4 h prior to testing. One site used a compression load cell (Zwick device) to test pens; one site performed tests manually. Injection-force testing was conducted at one site on multiple 60 and 120 μg pens at multiple temperatures (18–28 °C) and humidities (25–75%) using 29 and 31 G half-inch needles and an injection speed of 150 m/min. Injection-force testing was performed using a Zwick device.

Results:

Dose accuracy for all pens tested, regardless of location, reproducibly met/exceeded acceptance criteria. Mean percentage of dose accuracy was 96.04 to 102.45% [standard deviations (SDs) 0.3 to 1.4 μg] for the 60 μg pen and 98.16 to 101.83% (SDs 0.4 to 2.5 μg) for the 120 μg pen. The average injection force across both pens did not exceed 7 N regardless of needle size.

Conclusions:

High dose accuracy and low injection force were observed for the 60 and 120 μg pens under a variety of conditions.
Helping High-Risk Youth Move through High-Risk Periods: Personally Controlled Health Records for Improving Social and Health Care Transitions
Authors: Weitzman Elissa R. , Kaci Liljana , Quinn Maryanne , Mandl Kenneth D.
Published: January 2014

Background:

New patient-centered information technologies are needed to address risks associated with health care transitions for adolescents and young adults with diabetes, including systems that support individual and structural impediments to self- and clinical-care.

Methods:

We describe the personally controlled health record (PCHR) system platform and its key structural capabilities and assess its alignment with tenets of the chronic care model (CCM) and the social-behavioral and health care ecologies within which adolescents and young adults with diabetes mature.

Results:

Confgured as Web-based platforms, PCHRs can support a new class of patient-facing applications that serve as monitoring and support systems for adolescents navigating complex social, developmental, and health care transitions. The approach can enable supportive interventions tailored to individual patient needs to boost adherence, self-management, and monitoring.

Conclusions:

The PCHR platform is a paradigm shift for the organization of health information systems and is consistent with the CCM and conceptualizations of patient- and family-centered care for diabetes. Advancing the approach augers well for improvement around health care transitions for youth and also requires that we address (i) structural barriers impacting diabetes care for maturing youth; (ii) challenges around health and technology literacy; (iii) privacy and confidentiality issues, including sharing of health information within family and institutional systems; and (iv) needs for evaluation around uptake, impacts, and outcomes.
Smart Telemedicine Support for Continuous Glucose Monitoring: The Embryo of a Future Global Agent for Diabetes Care
Authors: Rigla Mercedes
Published: January 2014

Although current systems for continuous glucose monitoring (CGM) are the result of progressive technological improvement, and although a beneficial effect on glucose control has been demonstrated, few patients are using them. Something similar has happened to telemedicine (TM); in spite of the long-term experience, which began in the early 1980s, no TM system has been widely adopted, and presential visits are still almost the only way diabetologists and patients communicate. The hypothesis developed in this article is that neither CGM nor TM will ever be routinely implemented separately, and their consideration as essential elements for standard diabetes care will one day come from their integration as parts of a telemedical monitoring platform. This platform, which should include artificial intelligence for giving decision support to patients and physicians, will represent the core of a more complex global agent for diabetes care, which will provide control algorithms and risk analysis among other essential functions.
The Design and Development of Fluorescent Nano-Optodes for in Vivo Glucose Monitoring
Authors: Balaconis Mary K. , Billingsley Kelvin , Dubach J. Matthew , Cash Kevin J. , Clark Heather A.
Published: January 2014

Background:

The advent of fluorescent nanosensors has enabled intracellular monitoring of several physiological analytes, which was previously not possible with molecular dyes or other invasive techniques. We have extended the capability of these sensors to include the detection of small molecules with the development of glucose-sensitive nano-optodes. Herein, we discuss the design and development of glucose-sensitive nano-optodes, which have been proven functional both in vitro and in vivo.

Methods:

Throughout the design process, each of the sensor formulations was evaluated based on their response to changes in glucose levels. The percent change in signal, sensor reversibility, and the overall fluorescence intensity were the specific parameters used to assess each formulation.

Results:

A hydrophobic boronic acid was selected that yielded a fully reversible fluorescence response to glucose in accordance with the sensor mechanism. The change in fluorescence signal in response to glucose was approximately 11%. The use of different additives or chromophores did not improve the response; however, modifications to the plasticized polymeric membrane extended sensor lifetime.

Conclusions:

Sensors were developed that yielded a dynamic response to glucose and through further modification of the components, sensor lifetime was improved. By following specific design criteria for the macrosensors, the sensors were miniaturized into nano-optodes that track changes in glucose levels in vivo.
Use of a Continuous Glucose Sensor in an Extracorporeal Life Support Circuit
Authors: Steil Garry M. , Alexander Jamin , Papas Alexandra , Langer Monica , Modi Biren P. , Piper Hannah , Jaksic Tom , Gottlieb Rebecca , Agus Michael S. D.
Published: January 2014

Background:

Standard care for infants on extracorporeal life support (ECLS) relies on intermittent measurement of blood glucose (BG); however, this can lead to significant changes in BG that go unrecognized for several hours. The present study was designed to assess performance and clinical applicability of a subcutaneous glucose sensor technology modified for use as a blood-contacting sensor within the ECLS circuit.

Methods:

Twelve children, aged 3 years or less, requiring ECLS support were studied. Three continuous glucose sensors (Medtronic MiniMed) were inserted into hubs placed in line with the ECLS circuit. Blood glucose was assessed with a laboratory analyzer ( BGLAB; Bayer Rapidlab 860) approximately every 5 h (mean 4.9 ± 3.3 h) with more frequent samples obtained with a bedside monitor (HemoCue) as needed. Sensor current ( ISIG) was transmitted to a laptop computer and retrospectively calibrated using BGLAB. Sensor performance was assessed by mean absolute relative difference (MARD), linear regression slope and intercept, and correlation, all with BGLAB as reference.

Results:

The BGLAB averaged 107.6 ± 36.4 mg/dl (mean ± standard deviation) ranging from 58 to 366 mg/dl. The MARD was 11.4%, with linear regression slope (0.86 ± 0.030) and intercept (9.0 ± 3.2 mg/dl) different from 1 and 0, respectively ( p < .05), and correlation ( r2 = 0.76; p < .001). The system was not associated with any adverse events, and placement and removal into the hubs was easily accomplished. Instances in which more frequent BG values were obtained using a bedside HemoCue ( BGHEMO) monitor showed the sensor to respond rapidly to changes.

Conclusions:

We conclude that continuous sensors can be adapted for use in an ECLS circuit with accuracy similar to or better than that achieved with the subcutaneous site. Continuous glucose monitoring in this population can rapidly detect changes in BG that would not otherwise be observed. Further studies will be needed to assess the benefit of continuous glucose monitoring in this population.
Explorative Study of Pharmacokinetics and Pharmacodynamics after Change in Basal Insulin Infusion Rate
Authors: Ihlo Charlotte A. , Lauritzen Torsten , Sturis Jeppe , Skyggebjerg Ole , Christiansen Jens S. , Laursen Torben
Published: January 2014

Background:

The use of insulin pumps is rapidly increasing and new, technologically more advanced pumps are continuously being developed. It is of interest to assess the clinical relevance of the many technical features of these pumps, e.g., the effect on pharmacokinetics and pharmacodynamics with change in infusion rate.

Method:

The aim of this study was to explore the sequence of pharmacokinetic and pharmacodynamic changes after dose doubling of the basal insulin infusion rate with subcutaneous bolus insulin injections once an hour, continuous subcutaneous insulin infusion, and continuous intravenous insulin infusion. Ten type 1 diabetes mellitus patients were included. The insulin doses were calculated based on the habitual insulin doses. The study was designed as an open-labeled, single-center, randomized, crossover exploratory trial.

Results:

Dose doubling of the basal insulin infusion rate with the three different administration protocols did not result in any clinically relevant differences in the time courses of the pharmacokinetic and pharmacodynamic parameters. With all three administration protocols, we observed a time interval of more than 6 hours before a new steady state of insulin was achieved.

Conclusions:

Our results indicate that frequent changes in basal subcutaneous insulin infusion rates are not of significant clinical relevance on a 24-hour basis. Regarding technological features of subcutaneous insulin pumps, no discernable advantages of increasing pump stroke frequency were found. This indicates that pump stroke frequency sophistication might not be of clinical relevance in pumps used for basal subcutaneous insulin infusion.
Do Different Body Colors and Labels of Insulin Pens Enhance a Patient's Ability to Correctly Identify Pens for Injecting Long-Acting versus Short-Acting Insulins?
Authors: Lefkowitz Mark
Published: January 2014

Background:

The objective of this study was to characterize how successfully patients with diabetes are able to distinguish between pens of the same pen type containing long- and short-acting insulins.

Methods:

Structured one-on-one interviews were conducted with 400 patients with diabetes in the United States, using either a differentiated ( n = 100) or undifferentiated ( n = 100) SoloSTAR® (insulin glargine vs insulin glulisine) or ( n = 200) FlexPen® (insulin detemir vs insulin aspart). A pair of each pen type was presented simultaneously, and participants were asked to identify the pen that they would use to (1) inject at lunch, (2) inject once daily, and (3) inject at breakfast and how they differentiated between pens. The short-acting insulin pen was then presented, and the interviewer asked whether this was the correct pen to administer insulin once or thrice daily.

Results:

More patients successfully identified the correct SoloSTAR pen across the tests vs FlexPen, and the error rate (incorrect selection/inability to select) was Significantly lower, respectively [2.7% ( n = 8) vs 16.3% ( n = 98)]. The most common reason cited for correct responses among all patients was color (of the label/pen, according to pen type).

Conclusions:

This study suggests that the full pen body color used on SoloSTAR pens enhances the patient's ability to differentiate between the pens for long- and short-acting insulin and is a notable improvement compared with the standard approach of differing label color.
Pilot Study of Aurora, a Social, Mobile-Phone-Based Emotion Sharing and Recording System
Authors: Gay Geri , Pollak J. P. , Adams Phil , Leonard John P.
Published: January 2014

Background:

Emotion is a ubiquitous aspect of humanity that governs behavior in a number of ways and is linked inextricably with health. Pausing to evaluate one's emotional state in the face of decisions and reflecting on past patterns of emotion have been shown to improve behaviors. Further, social expression of emotion has been shown to directly improve health outcomes. While the virtual reality research community does not ignore emotion on the whole, there does exist a need to explore what roles emotional awareness and emotion sharing can play in this domain.

Methods:

A mobile-phone-based social emotion recording and sharing system, Aurora, was developed to provide individuals with a means to pause and evaluate their emotional state, reflect on past emotions, share emotions with others, and participate in socially supportive activities with peers. A study was conducted with 65 subjects to evaluate Aurora as a tool to encourage emotional reflection and awareness as well as social sharing of emotion.

Results:

Users of Aurora reported an increased comfort in socially expressing emotion and were encouraged to share emotions, even with strangers. Subjects also reported liking reflecting on their emotional state and found it valuable. Subjects' behavior also suggested that the system encouraged individuals to reach out to one another in acts of social support.

Conclusions:

The Aurora system offers a tool for encouraging emotional awareness, emotion sharing, and socially supportive behavior. Such a tool could be impactful in numerous health settings where emotion is considered to be an important indicator of or influence on outcome, such as for weight loss, alcohol cessation, or cancer sufferers.
The Potential of Virtual Reality Technologies to Improve Adherence to Weight Loss Behaviors
Authors: Coons Michael J. , Roehrig Megan , Spring Bonnie
Published: January 2014

A significant proportion of the global population is obese, foreshadowing an epidemic of chronic disease. Self-monitoring (of diet, exercise, and body weight), decreasing energy intake, and increasing energy expenditure are robust predictors of successful weight loss. However, few individuals consistently practice these behaviors, making long-term weight loss and maintenance unlikely. Technologies afford unique opportunities to overcome barriers and increase the reach of traditional obesity interventions. In this article, we introduce ENGAGED, a technology-enhanced modification of the Diabetes Prevention Program designed to improve adherence to weight loss behaviors. Using a treatment implementation framework, we suggest how virtual reality technologies might further improve the delivery, receipt, and enactment of ENGAGED to maximize patient impact.
Assessment of Blood Glucose Control in the Pediatric Intensive Care Unit: Extension of the Glycemic Penalty Index toward Children and Infants
Authors: Van Herpe Tom , Gielen Marijke , Vanhonsebrouck Koen , Wouters Pieter J. , Van den Berghe Greet , De Moor Bart , Mesotten Dieter
Published: January 2014

Background:

The glycemic penalty index (GPI) is a measure to assess blood glucose (BG) control in critically ill adult patients but needs to be adapted for children and infants.

Method:

The squared differences between a clinical expertise penalty function and the corresponding polynomial function are minimized for optimization purposes. The average of all penalties (individually assigned to all BG readings) represents the patient-specific GPI.

Results:

Penalization in the hypoglycemic range is more severe than in the hyperglycemic range as the developing brains of infants and children may be more vulnerable to hypoglycemia. Similarly, hypoglycemia is also more heavily penalized in infants than in children.

Conclusions:

Extending the adult GPI toward the age-specific GPI is an important methodological step. Long-term clinical studies are needed to determine the clinically acceptable GPI cut-off level.
A Closed-Loop Artificial Pancreas Based on Risk Management
Authors: Cameron Fraser , Bequette B. Wayne , Wilson Darrell M. , Buckingham Bruce A. , Lee Hyunjin , Niemeyer Günter
Published: January 2014

Background:

Control algorithms that regulate blood glucose (BG) levels in individuals with type 1 diabetes mellitus face several fundamental challenges. Two of these are the asymmetric risk of clinical complications associated with low and high glucose levels and the irreversibility of insulin action when using only insulin. Both of these nonlinearities force a controller to be more conservative when uncertainties are high. We developed a novel extended model predictive controller (EMPC) that explicitly addresses these two challenges.

Method:

Our extensions to model predictive control (MPC) operate in three ways. First, they explicitly minimize the combined risk of hypoglycemia and hyperglycemia. Second, they integrate the effect of prediction uncertainties into the risk. Third, they understand that future control actions will vary if measurements fall above or below predictions. Using the University of Virginia/Padova Simulator, we compared our novel controller (EMPC) against optimized versions of a proportional-integral-derivative (PID) controller, a traditional MPC, and a basal/bolus (BB) controller, as well as against published results of an independent MPC (IMPC). The BB controller was optimized retrospectively to serve as a bound on the possible performance.

Results:

We tuned each controller, where possible, to minimize a published blood glucose risk index (BGRI). The simulated controllers (PID/MPC/EMPC/BB) provided BGRI values of 2.99/3.05/2.51/1.27 as compared to the published IMPC BGRI value of 4.10. These correspond to 73/79/84/92% of BG values lying in the euglycemic range (70–180 mg/dl), respectively, with mean BG levels of 151/156/147/140 mg/dl.

Conclusion:

The EMPC strategy extends MPC to explicitly address the issues of asymmetric glycemic risk and irreversible insulin action using estimated prediction uncertainties and an explicit risk function. This controller reduces the avoidable BGRI by 56% ( p < .05) relative to a published MPC algorithm studied on a similar population.
Noninvasive Polarimetric-Based Glucose Monitoring: An in Vivo Study
Authors: Purvinis Georgeanne , Cameron Brent D. , Altrogge Douglas M.
Published: January 2014

Background:

Since 1990, there has been significant research devoted toward development of a noninvasive physiological glucose sensor. In this article, we report on the use of optical polarimetry for the noninvasive measurement of physiological glucose concentration in the anterior chamber of the eye of New Zealand white (NZW) rabbits.

Method:

Measurements were acquired using a custom-designed laser-based optical polarimetry system in a total of seven NZW rabbits anesthetized using an isoflurane-only anesthesia protocol. Aqueous humor-based polarimetric measurements were obtained by coupling light through the anterior chamber of the eye. Blood glucose levels were first stabilized and then altered with intravenous dextrose and insulin administration and measured every 3–5 min with a standard glucometer and intermittently with a YSI 2300 glucose analyzer. Acquired polarimetric glucose signals are calibrated to measured blood glucose concentration.

Results:

Based on a total of 41 data points, Clarke error grid analysis indicated 93% in zone A, 7% in zone B, and 0% in zones C and D, with reference concentrations between 93 and 521 mg/dl. Errors in prediction are shown to be related to gross movement of the rabbit during the procedures, incurring time-varying corneal birefringence effects that directly affect the measured polarimetric signal. These effects can be compensated for with appropriate design modifications.

Conclusions:

An optical polarimetry technique was used for in vivo physiological glucose monitoring. The technique demonstrated provides a basis for the development of a noninvasive polarimetric glucose monitor for home, personal, or hospital use.
Effects of a Structured Self-Monitoring of Blood Glucose Method on Patient Self-Management Behavior and Metabolic Outcomes in Type 2 Diabetes Mellitus
Authors: Khamseh Mohammad E. , Ansari Majid , Malek Mojtaba , Shafiee Gita , Baradaran Hamid
Published: January 2014

Background:

The purpose of this study was to evaluate the effect of structured self-monitoring of blood glucose (SMBG) on patient self-management behavior and metabolic outcomes in patients with type 2 diabetes mellitus (T2DM).

Methods:

From January to June 2009, 30 patients with basic diabetes education were followed for a period of 90 days. To provide assessment of glycemic control and frequency of dysglycemia, patients, underwent 3 consecutive days of seven-point SMBG during each month for 3 consecutive months, using the ACCU-CHEK 360° View tool. Glucose profiles of the first and third month were used for comparison.

Results:

Hemoglobin A1c (HbA1c) improved significantly during the 90-day period in all patients [confidence interval (CI) 95%, 0.32–1.64%, p < .05] and those with poor metabolic control (group B; CI 95%, 0.86–2.64%, p < .05). Mean blood glucose (MBG) values decreased significantly in group B (CI 95%, 0.56–24.78 mg/dl, p < .05) and all cases (CI 95%, 1.61–19.73 mg/dl, p < .05). Meanwhile, there was an average decrease of 15.7 mg/dl in fasting blood sugar (FBS) levels in the whole subjects. Mean postprandial blood glucose levels (MPP) decreased by 19.3 and 11.3 mg/dl in group B and in all cases, respectively. However, there were no significant changes in HbA1c, MBG, FBS, and MPP in people with good metabolic control.

Conclusion:

A structured SMBG program improves HbA1c, FBS, MPP, and MBG in people with poorly controlled diabetes. This improvement shows the importance of patient self-management behavior on metabolic outcomes in T2DM.
Self-Monitoring Technologies for Type 2 Diabetes and the Prevention of Cardiovascular Complications: Perspectives from End Users
Authors: Chudyk Anna , Shapiro Sheree , Russell-Minda Elizabeth , Petrella Robert
Published: January 2014

Background:

The objective of this study was to explore facilitators and barriers to the adoption of self-monitoring devices in individuals with type 2 diabetes mellitus (T2DM).

Methods:

Individuals with T2DM who were currently using one or more devices to monitor their disease participated in focus groups. Transcripts of focus group meetings were coded into themes by two reviewers using NVivo qualitative software.

Results:

Twenty-eight adults with T2DM reported using a blood glucose meter, and almost half reported monitoring their blood pressure. Few individuals consistently monitored other aspects of their cardiovascular health. Four major themes impacting device use/disuse were identified: Knowledge gaps, relationships with health care providers, environment, and personal experience. Knowledge barriers included lack of information regarding diabetes and the associated risk of complications. Perceptions of inconvenience, pain, and financial restrictions were important factors influencing the adoption, use, and abandonment of self-monitoring devices. Community-run programs, as well as dieticians and pharmacists, were identified as important resources for accessing information related to T2DM.

Conclusions:

We identified the need for development of accessible and relevant education material; improved communication of disease-specific information between patients and providers, as well as providers and community resources; and strategies to improve the convenience and cost of monitoring devices.
Prevalence and Clinical Profile of Metabolic Obesity and Phenotypic Obesity in Asian Indians
Authors: Geetha Loganathan , Deepa Mohan , Anjana Ranjit Mohan , Mohan Viswanathan
Published: January 2014

Background:

We estimated the prevalence of metabolically obese nonobese (MONO), metabolically obese obese (MOO), and metabolically healthy obese (MHO) individuals and correlated this with the prevalence of coronary artery disease (CAD) compared to metabolically healthy nonobese (MHNO) in urban South Indians.

Method:

Study subjects ( n = 2350) were recruited from the Chennai Urban Rural Epidemiology Study. Generalized obesity was defined as a body mass index (BMI) ≥25 kg/m2, based on the World Health Organization Asia Pacific guidelines. Metabolic syndrome (MS) was diagnosed based on the South Asian Modified-National Cholesterol Education Programme criteria. Coronary artery disease was defined by known myocardial infarction or Q waves on resting electrocardiogram.

Results:

Metabolically obese nonobese was defined as nonobese subjects (BMI < 25 kg/m2) with MS, MOO as obesity (BMI = 25 kg/m2) with MS, MHO as obese subjects (BMI = 25 kg/m2) with no MS, and MHNO as no obesity or MS. Metabolically obese nonobese was identified in 355 (15.1%), MOO in 348 (14.8%), MHO in 312 (13.3%), and MHNO in 1335 (56.8%) subjects. The prevalence of CAD among the MONO, MOO, MHO, and MHNO was 5.5%, 4.2%, 1.4%, and 2.6%. However, when age standardization was done, there was no statistically significant increase in the risk of CAD among MONO [odds ratio (OR) = 1.300, 95% confidence interval (CI) 0.706–2.394, p = .339], MOO (OR = 1.651, 95% CI 0.852–3.199, p = .137), and MHO (OR = 0.524, 95% CI 0.250–2.130, p = .564) groups compared to MHNO, perhaps due to small numbers.

Conclusion:

Metabolic obesity may have different clinical implications than phenotypic obesity.