David Klonoff - Academia.edu (original) (raw)

Papers by David Klonoff

Research paper thumbnail of Innovations in technology for the treatment of diabetes: clinical development of the artificial pancreas (an autonomous system)

Journal of diabetes science and technology

The Food and Drug Administration in collaboration with the National Institutes of Health presente... more The Food and Drug Administration in collaboration with the National Institutes of Health presented a public workshop to facilitate medical device innovation in the development of the artificial pancreas (or autonomous system) for the treatment of diabetes mellitus on November 10, 2010 in Gaithersburg, Maryland. The purpose of the workshop was to discuss four aspects of artificial pancreas research and development, including: (1) the current state of device systems for autonomous systems for the treatment of diabetes mellitus; (2) challenges in developing this expert device system using existing technology; (3) clinical expectations for these systems; and (4) development plans for the transition of this device system toward an outpatient setting. The patients discussed how clinical science, system components, and regulatory policies will all need to harmonize in order to achieve the goal of seeing an AP product brought forward to the marketplace for patients to use.

Research paper thumbnail of Evaluation of the JuniorSTAR® Half-unit Insulin Pen in Young People with Type 1 Diabetes – User Perspectives

European Endocrinology, 2010

Research paper thumbnail of ASPIRE In-Home: Rationale, Design, and Methods of a Study to Evaluate the Safety and Efficacy of Automatic Insulin Suspension for Nocturnal Hypoglycemia

Journal of diabetes science and technology

Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm®... more Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm® Veo™ system may mitigate nocturnal hypoglycemia by automatically suspending insulin when a prespecified sensor glucose threshold is reached. ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) In-Home (NCT01497938) was a multicenter, randomized, parallel, adaptive study of subjects with type 1 diabetes. The control arm used sensor-augmented pump therapy. The treatment arm used sensor-augmented pump therapy with threshold suspend, which automatically suspends the insulin pump in response to a sensor glucose value at or below a prespecified threshold. To be randomized, subjects had to have demonstrated ≥2 episodes of nocturnal hypoglycemia, defined as >20 consecutive minutes of sensor glucose values ≤65 mg/dl starting between 10:00 PM and 8:00 AM in the 2-week run-in phase. The 3-month study phase evaluated safety by comparing changes in glycated hemoglobin (A1C) values and eva...

Research paper thumbnail of The ASPIRE study: design and methods of an in-clinic crossover trial on the efficacy of automatic insulin pump suspension in exercise-induced hypoglycemia

Journal of diabetes science and technology

The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin deli... more The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin delivery when a prespecified glucose threshold setting is reached by the associated continuous glucose monitoring (CGM) sensor. The ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) study is a multicenter, in-clinic, randomized, crossover study to examine the efficacy of LGS in exercise-induced hypoglycemia. Insulin-pump users underwent two separate exercise sessions, one with the LGS feature set to suspend insulin (LGS-on) when the CGM-detected glucose concentration was ≤ 70 mg/dl and one with the LGS feature off. Exercise sessions were conducted after an overnight fast and with initial plasma glucose level as measured by the YSI 2300 STAT Plus glucose analyzer (YSI) of 100-140 mg/dl. Subjects exercised until their YSI value fell to ≤ 85 mg/dl; subsequent YSI values <70 mg/dl were recorded for up to 4 h to measure the duration and nadir of hypoglycemia. The protocol required th...

Research paper thumbnail of Reduction in duration of hypoglycemia by automatic suspension of insulin delivery: the in-clinic ASPIRE study

Diabetes Technology &amp Therapeutics

The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects w... more The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects with type 1 diabetes was evaluated. In this randomized crossover study, subjects used a sensor-augmented insulin pump system with a low glucose suspend (LGS) feature that automatically stops insulin delivery for 2 h following a sensor glucose (SG) value ≤70 mg/dL. Subjects fasted overnight and exercised until their plasma glucose (measured with the YSI 2300 STAT Plus™ glucose and lactate analyzer [YSI Life Sciences, Yellow Springs, OH]) value reached ≤85 mg/dL on different occasions separated by washout periods lasting 3-10 days. Exercise sessions were done with the LGS feature turned on (LGS-On) or with continued insulin delivery regardless of SG value (LGS-Off). The order of LGS-On and LGS-Off sessions was randomly assigned. YSI glucose data were used to compare the duration and severity of hypoglycemia from successful LGS-On and LGS-Off sessions and to estimate the risk of rebound hype...

Research paper thumbnail of Predictors of Hypoglycemia in the ASPIRE In-Home Study and Effects of Automatic Suspension of Insulin Delivery

Journal of diabetes science and technology, Jan 18, 2015

Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy int... more Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy intensification. We investigated known and potential risk factors for hypoglycemia in subjects with type 1 diabetes. In the ASPIRE In-Home study (NCT01497938), a randomized trial of the threshold suspend (TS) feature of sensor-augmented insulin pump (SAP) therapy, subjects' propensity to nocturnal hypoglycemia (NH) was established in a 2-week run-in phase and assessed in a 3-month study phase via continuous glucose monitoring. Categorical variables were tested for association with NH rates in both phases. Elevated rates of NH were significantly associated with baseline A1C ≤7%, with bolus insulin deliveries unassisted by the bolus estimation calculator, and with assignment to the control group during the study phase. Routine use of the TS feature and the bolus estimation calculator are strategies that may reduce the risk of NH.

Research paper thumbnail of Technical aspects of the Parkes error grid

Journal of diabetes science and technology, 2013

The Parkes error grid, which was developed in 1994, presented performance zones for blood glucose... more The Parkes error grid, which was developed in 1994, presented performance zones for blood glucose (BG) monitors with borders that were not mathematically specified at the time the grid was published. In this article, we (1) review the history of the Parkes error grid, (2) present the never-before-published exact coordinates and specifications of the grid so that others may produce an exact replica of the original grid, and (3) discuss our suggestions how this metric should be applied. The new ISO15197:2013 guideline for system accuracy assessment of BG meters for patient self-measurement incorporates use of this metric for defining acceptable accuracy of BG monitors. It is expected that, for regulatory purposes, this document will stipulate that the error grid version for type 1 diabetes should be applied with the caveat that only the A zone represents acceptable accuracy. It remains to be seen by how much the new error grid, which is currently being developed by the Food and Drug A...

Research paper thumbnail of Freedom of speech and science: can companies force us to withdraw data they don't like?

Journal of diabetes science and technology, 2013

Research paper thumbnail of A Clinical Trial of the Accuracy and Treatment Experience of the Dexcom G4 Sensor (Dexcom G4 System) and Enlite Sensor (Guardian REAL-Time System) Tested Simultaneously in Ambulatory Patients with Type 1 Diabetes

Diabetes Technology & Therapeutics, 2014

Continuous glucose monitoring (CGM) is a tool widely used in the treatment of patients with type ... more Continuous glucose monitoring (CGM) is a tool widely used in the treatment of patients with type 1 diabetes. The purpose of the current study was to evaluate whether accuracy and patient treatment satisfaction differ between the Enlite™ (Medtronic MiniMed, Inc., Northridge, CA) and Dexcom(®) (San Diego, CA) G4 PLATINUM CGM sensors. Thirty-eight ambulatory patients with type 1 diabetes used the Dexcom G4 and Enlite sensors simultaneously for a minimum of 4 and maximum of 6 days. Patients measured capillary glucose levels with a HemoCue(®) (Ängelholm, Sweden) system six to 10 times a day. In addition, two inpatient studies were performed between Days 1-3 and 4-6. The mean absolute relative difference (MARD) in blood glucose for the Dexcom G4 was significantly lower (13.9%) than for the Enlite sensor (17.8%) (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The corresponding MARDs for Days 1-3 were 15.0% versus 19.4% (P=0.0027) and 13.6% versus 15.9% (P=0.026) for Days 4-6. For glucose levels in the hypoglycemic range (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.0 mmol/L), the MARD for the Dexcom G4 was 20.0% compared with 34.7% for the Enlite (P=0.0041). On a visual analog scale (VAS) (0-100), patients rated the Dexcom G4 more favorably than the Enlite in 12 out of the 13 user experience questions. For example, more patients rated their experience with the Dexcom G4 as positive (VAS, 79.7 vs. 46.6; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001) and preferred to use it in their daily lives (VAS, 79.1 vs. 42.1; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The Dexcom G4 sensor was associated with greater overall accuracy than the Enlite sensor during initial (Days 1-3) and later (Days 4-6) use and for glucose levels in the hypoglycemic range. Patients reported a significantly more positive experience using the Dexcom G4 than the Enlite.

Research paper thumbnail of A Review of the Security of Insulin Pump Infusion Systems

Insulin therapy has enabled diabetic patients to maintain blood glucose control to lead healthier... more Insulin therapy has enabled diabetic patients to maintain blood glucose control to lead healthier lives. Today, rather than manually injecting insulin using syringes, a patient can use a device, such as an insulin pump, to programmatically deliver insulin. This allows for more granular insulin delivery while attaining blood glucose control. The insulin pump system features have increasingly benefited patients, but

Research paper thumbnail of Clinical Evaluation of a Rapid A1C Test (A1cNow) for Home Use

Point of Care: The Journal of Near-Patient Testing & Technology, 2006

Abstract Introduction: A1C can be measured by portable point-of-care methods that might offer adv... more Abstract Introduction: A1C can be measured by portable point-of-care methods that might offer advantages compared with conventional sampling of venous blood for eventual laboratory testing. Methods: In a 2-part study, we compared the performance and ease of ...

Research paper thumbnail of Technologies for metabolic monitoring (TMM): A new research initiative

ING PROGRAM (TMM) is a joint initiative of the US Army Medical Research and Materiel Command (MRM... more ING PROGRAM (TMM) is a joint initiative of the US Army Medical Research and Materiel Command (MRMC), the Juvenile Diabetes Research Foundation (JDRF), NASA, and NIH (NIDDK). It was initiated by and is directly sponsored by Congress and has been chiefly ...

Research paper thumbnail of Insulin Pump System Security

Physicians are using medical devices to treat an array of sicknesses including Parkinson s, Alzhe... more Physicians are using medical devices to treat an array of sicknesses including Parkinson s, Alzheimer s, pain, gastroparesis, diabetes, and heart disease. Among other features, many of these devices now include the ability to wirelessly interface with a patient or other devices. With these new abilities, security and reliability can be compromised. To avoid future security and reliability problems, new

Research paper thumbnail of Hyperprolactinemia in a Patient with a Pituitary and an Ovarian Dermoid Tumor: Case Report

Neurosurgery, 1990

A patient with galactorrhea, amenorrhea, and hyperprolactinemia caused by a dermoid tumor of the ... more A patient with galactorrhea, amenorrhea, and hyperprolactinemia caused by a dermoid tumor of the pituitary gland is presented. The patient had a prior history of an ovarian dermoid tumor. The pathology of dermoid tumors is discussed along with the management of pituitary tumor-associated hyperprolactinemia. This is the first reported case of an intracranial and an ovarian dermoid tumor occurring in the same patient.

Research paper thumbnail of A Review of the Security of Insulin Pump Infusion Systems

Journal of Diabetes Science and Technology, 2011

Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead heal... more Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead healthier lives. Today, rather than injecting insulin manually using syringes, a patient can use a device such as an insulin pump to deliver insulin programmatically. This allows for more granular insulin delivery while attaining blood glucose control. Insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result, security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this article, we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components, which include the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues.

Research paper thumbnail of Consensus Report: The Current Role of Self-Monitoring of Blood Glucose in Non-Insulin-Treated Type 2 Diabetes

Journal of Diabetes Science and Technology, 2011

Research paper thumbnail of Consensus Report of the Coalition for Clinical Research--Self-Monitoring of Blood Glucose

Journal of Diabetes Science and Technology, 2008

Research paper thumbnail of Continuous Glucose Monitoring: An Endocrine Society Clinical Practice Guideline

The Journal of Clinical Endocrinology & Metabolism, 2011

The aim was to formulate practice guidelines for determining settings where patients are most lik... more The aim was to formulate practice guidelines for determining settings where patients are most likely to benefit from the use of continuous glucose monitoring (CGM).

Research paper thumbnail of Pathways to Quality Inpatient Management of Hyperglycemia and Diabetes: A Call to Action

Diabetes Care, 2013

Currently patients with diabetes comprise up to 25-30% of the census of adult wards and critical ... more Currently patients with diabetes comprise up to 25-30% of the census of adult wards and critical care units in our hospitals. Although evidence suggests that avoidance of hyperglycemia (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;180 mg/dL) and hypoglycemia (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;70 mg/dL) is beneficial for positive outcomes in the hospitalized patient, much of this evidence remains controversial and at times somewhat contradictory. We have recently formed a consortium for Planning Research in Inpatient Diabetes (PRIDE) with the goal of promoting clinical research in the area of management of hyperglycemia and diabetes in the hospital. In this article, we outline eight aspects of inpatient glucose management in which randomized clinical trials are needed. We refer to four as system-based issues and four as patient-based issues. We urge further progress in the science of inpatient diabetes management. We hope this call to action is supported by the American Diabetes Association, The Endocrine Society, the American Association of Clinical Endocrinologists, the American Heart Association, the European Association for the Study of Diabetes, the International Diabetes Federation, and the Society of Hospital Medicine. Appropriate federal research funding in this area will help ensure high-quality investigations, the results of which will advance the field. Future clinical trials will allow practitioners to develop optimal approaches for the management of hyperglycemia in the hospitalized patient and lessen the economic and human burden of poor glycemic control and its associated complications and comorbidities in the inpatient setting.

Research paper thumbnail of Efficacy and Safety of Technosphere Inhaled Insulin Compared With Technosphere Powder Placebo in Insulin-Naive Type 2 Diabetes Suboptimally Controlled With Oral Agents

Diabetes Care, 2008

OBJECTIVE -This double-blind, placebo-controlled, randomized, multicenter, parallelgroup study co... more OBJECTIVE -This double-blind, placebo-controlled, randomized, multicenter, parallelgroup study compared the efficacy, safety, and tolerability of Technosphere insulin with Technosphere powder as placebo in insulin-naive type 2 diabetic patients whose diabetes was suboptimally controlled with oral antidiabetic agents.

Research paper thumbnail of Innovations in technology for the treatment of diabetes: clinical development of the artificial pancreas (an autonomous system)

Journal of diabetes science and technology

The Food and Drug Administration in collaboration with the National Institutes of Health presente... more The Food and Drug Administration in collaboration with the National Institutes of Health presented a public workshop to facilitate medical device innovation in the development of the artificial pancreas (or autonomous system) for the treatment of diabetes mellitus on November 10, 2010 in Gaithersburg, Maryland. The purpose of the workshop was to discuss four aspects of artificial pancreas research and development, including: (1) the current state of device systems for autonomous systems for the treatment of diabetes mellitus; (2) challenges in developing this expert device system using existing technology; (3) clinical expectations for these systems; and (4) development plans for the transition of this device system toward an outpatient setting. The patients discussed how clinical science, system components, and regulatory policies will all need to harmonize in order to achieve the goal of seeing an AP product brought forward to the marketplace for patients to use.

Research paper thumbnail of Evaluation of the JuniorSTAR® Half-unit Insulin Pen in Young People with Type 1 Diabetes – User Perspectives

European Endocrinology, 2010

Research paper thumbnail of ASPIRE In-Home: Rationale, Design, and Methods of a Study to Evaluate the Safety and Efficacy of Automatic Insulin Suspension for Nocturnal Hypoglycemia

Journal of diabetes science and technology

Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm®... more Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm® Veo™ system may mitigate nocturnal hypoglycemia by automatically suspending insulin when a prespecified sensor glucose threshold is reached. ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) In-Home (NCT01497938) was a multicenter, randomized, parallel, adaptive study of subjects with type 1 diabetes. The control arm used sensor-augmented pump therapy. The treatment arm used sensor-augmented pump therapy with threshold suspend, which automatically suspends the insulin pump in response to a sensor glucose value at or below a prespecified threshold. To be randomized, subjects had to have demonstrated ≥2 episodes of nocturnal hypoglycemia, defined as >20 consecutive minutes of sensor glucose values ≤65 mg/dl starting between 10:00 PM and 8:00 AM in the 2-week run-in phase. The 3-month study phase evaluated safety by comparing changes in glycated hemoglobin (A1C) values and eva...

Research paper thumbnail of The ASPIRE study: design and methods of an in-clinic crossover trial on the efficacy of automatic insulin pump suspension in exercise-induced hypoglycemia

Journal of diabetes science and technology

The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin deli... more The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin delivery when a prespecified glucose threshold setting is reached by the associated continuous glucose monitoring (CGM) sensor. The ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) study is a multicenter, in-clinic, randomized, crossover study to examine the efficacy of LGS in exercise-induced hypoglycemia. Insulin-pump users underwent two separate exercise sessions, one with the LGS feature set to suspend insulin (LGS-on) when the CGM-detected glucose concentration was ≤ 70 mg/dl and one with the LGS feature off. Exercise sessions were conducted after an overnight fast and with initial plasma glucose level as measured by the YSI 2300 STAT Plus glucose analyzer (YSI) of 100-140 mg/dl. Subjects exercised until their YSI value fell to ≤ 85 mg/dl; subsequent YSI values <70 mg/dl were recorded for up to 4 h to measure the duration and nadir of hypoglycemia. The protocol required th...

Research paper thumbnail of Reduction in duration of hypoglycemia by automatic suspension of insulin delivery: the in-clinic ASPIRE study

Diabetes Technology &amp Therapeutics

The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects w... more The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects with type 1 diabetes was evaluated. In this randomized crossover study, subjects used a sensor-augmented insulin pump system with a low glucose suspend (LGS) feature that automatically stops insulin delivery for 2 h following a sensor glucose (SG) value ≤70 mg/dL. Subjects fasted overnight and exercised until their plasma glucose (measured with the YSI 2300 STAT Plus™ glucose and lactate analyzer [YSI Life Sciences, Yellow Springs, OH]) value reached ≤85 mg/dL on different occasions separated by washout periods lasting 3-10 days. Exercise sessions were done with the LGS feature turned on (LGS-On) or with continued insulin delivery regardless of SG value (LGS-Off). The order of LGS-On and LGS-Off sessions was randomly assigned. YSI glucose data were used to compare the duration and severity of hypoglycemia from successful LGS-On and LGS-Off sessions and to estimate the risk of rebound hype...

Research paper thumbnail of Predictors of Hypoglycemia in the ASPIRE In-Home Study and Effects of Automatic Suspension of Insulin Delivery

Journal of diabetes science and technology, Jan 18, 2015

Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy int... more Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy intensification. We investigated known and potential risk factors for hypoglycemia in subjects with type 1 diabetes. In the ASPIRE In-Home study (NCT01497938), a randomized trial of the threshold suspend (TS) feature of sensor-augmented insulin pump (SAP) therapy, subjects' propensity to nocturnal hypoglycemia (NH) was established in a 2-week run-in phase and assessed in a 3-month study phase via continuous glucose monitoring. Categorical variables were tested for association with NH rates in both phases. Elevated rates of NH were significantly associated with baseline A1C ≤7%, with bolus insulin deliveries unassisted by the bolus estimation calculator, and with assignment to the control group during the study phase. Routine use of the TS feature and the bolus estimation calculator are strategies that may reduce the risk of NH.

Research paper thumbnail of Technical aspects of the Parkes error grid

Journal of diabetes science and technology, 2013

The Parkes error grid, which was developed in 1994, presented performance zones for blood glucose... more The Parkes error grid, which was developed in 1994, presented performance zones for blood glucose (BG) monitors with borders that were not mathematically specified at the time the grid was published. In this article, we (1) review the history of the Parkes error grid, (2) present the never-before-published exact coordinates and specifications of the grid so that others may produce an exact replica of the original grid, and (3) discuss our suggestions how this metric should be applied. The new ISO15197:2013 guideline for system accuracy assessment of BG meters for patient self-measurement incorporates use of this metric for defining acceptable accuracy of BG monitors. It is expected that, for regulatory purposes, this document will stipulate that the error grid version for type 1 diabetes should be applied with the caveat that only the A zone represents acceptable accuracy. It remains to be seen by how much the new error grid, which is currently being developed by the Food and Drug A...

Research paper thumbnail of Freedom of speech and science: can companies force us to withdraw data they don't like?

Journal of diabetes science and technology, 2013

Research paper thumbnail of A Clinical Trial of the Accuracy and Treatment Experience of the Dexcom G4 Sensor (Dexcom G4 System) and Enlite Sensor (Guardian REAL-Time System) Tested Simultaneously in Ambulatory Patients with Type 1 Diabetes

Diabetes Technology & Therapeutics, 2014

Continuous glucose monitoring (CGM) is a tool widely used in the treatment of patients with type ... more Continuous glucose monitoring (CGM) is a tool widely used in the treatment of patients with type 1 diabetes. The purpose of the current study was to evaluate whether accuracy and patient treatment satisfaction differ between the Enlite™ (Medtronic MiniMed, Inc., Northridge, CA) and Dexcom(®) (San Diego, CA) G4 PLATINUM CGM sensors. Thirty-eight ambulatory patients with type 1 diabetes used the Dexcom G4 and Enlite sensors simultaneously for a minimum of 4 and maximum of 6 days. Patients measured capillary glucose levels with a HemoCue(®) (Ängelholm, Sweden) system six to 10 times a day. In addition, two inpatient studies were performed between Days 1-3 and 4-6. The mean absolute relative difference (MARD) in blood glucose for the Dexcom G4 was significantly lower (13.9%) than for the Enlite sensor (17.8%) (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The corresponding MARDs for Days 1-3 were 15.0% versus 19.4% (P=0.0027) and 13.6% versus 15.9% (P=0.026) for Days 4-6. For glucose levels in the hypoglycemic range (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.0 mmol/L), the MARD for the Dexcom G4 was 20.0% compared with 34.7% for the Enlite (P=0.0041). On a visual analog scale (VAS) (0-100), patients rated the Dexcom G4 more favorably than the Enlite in 12 out of the 13 user experience questions. For example, more patients rated their experience with the Dexcom G4 as positive (VAS, 79.7 vs. 46.6; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001) and preferred to use it in their daily lives (VAS, 79.1 vs. 42.1; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The Dexcom G4 sensor was associated with greater overall accuracy than the Enlite sensor during initial (Days 1-3) and later (Days 4-6) use and for glucose levels in the hypoglycemic range. Patients reported a significantly more positive experience using the Dexcom G4 than the Enlite.

Research paper thumbnail of A Review of the Security of Insulin Pump Infusion Systems

Insulin therapy has enabled diabetic patients to maintain blood glucose control to lead healthier... more Insulin therapy has enabled diabetic patients to maintain blood glucose control to lead healthier lives. Today, rather than manually injecting insulin using syringes, a patient can use a device, such as an insulin pump, to programmatically deliver insulin. This allows for more granular insulin delivery while attaining blood glucose control. The insulin pump system features have increasingly benefited patients, but

Research paper thumbnail of Clinical Evaluation of a Rapid A1C Test (A1cNow) for Home Use

Point of Care: The Journal of Near-Patient Testing & Technology, 2006

Abstract Introduction: A1C can be measured by portable point-of-care methods that might offer adv... more Abstract Introduction: A1C can be measured by portable point-of-care methods that might offer advantages compared with conventional sampling of venous blood for eventual laboratory testing. Methods: In a 2-part study, we compared the performance and ease of ...

Research paper thumbnail of Technologies for metabolic monitoring (TMM): A new research initiative

ING PROGRAM (TMM) is a joint initiative of the US Army Medical Research and Materiel Command (MRM... more ING PROGRAM (TMM) is a joint initiative of the US Army Medical Research and Materiel Command (MRMC), the Juvenile Diabetes Research Foundation (JDRF), NASA, and NIH (NIDDK). It was initiated by and is directly sponsored by Congress and has been chiefly ...

Research paper thumbnail of Insulin Pump System Security

Physicians are using medical devices to treat an array of sicknesses including Parkinson s, Alzhe... more Physicians are using medical devices to treat an array of sicknesses including Parkinson s, Alzheimer s, pain, gastroparesis, diabetes, and heart disease. Among other features, many of these devices now include the ability to wirelessly interface with a patient or other devices. With these new abilities, security and reliability can be compromised. To avoid future security and reliability problems, new

Research paper thumbnail of Hyperprolactinemia in a Patient with a Pituitary and an Ovarian Dermoid Tumor: Case Report

Neurosurgery, 1990

A patient with galactorrhea, amenorrhea, and hyperprolactinemia caused by a dermoid tumor of the ... more A patient with galactorrhea, amenorrhea, and hyperprolactinemia caused by a dermoid tumor of the pituitary gland is presented. The patient had a prior history of an ovarian dermoid tumor. The pathology of dermoid tumors is discussed along with the management of pituitary tumor-associated hyperprolactinemia. This is the first reported case of an intracranial and an ovarian dermoid tumor occurring in the same patient.

Research paper thumbnail of A Review of the Security of Insulin Pump Infusion Systems

Journal of Diabetes Science and Technology, 2011

Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead heal... more Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead healthier lives. Today, rather than injecting insulin manually using syringes, a patient can use a device such as an insulin pump to deliver insulin programmatically. This allows for more granular insulin delivery while attaining blood glucose control. Insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result, security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this article, we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components, which include the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues.

Research paper thumbnail of Consensus Report: The Current Role of Self-Monitoring of Blood Glucose in Non-Insulin-Treated Type 2 Diabetes

Journal of Diabetes Science and Technology, 2011

Research paper thumbnail of Consensus Report of the Coalition for Clinical Research--Self-Monitoring of Blood Glucose

Journal of Diabetes Science and Technology, 2008

Research paper thumbnail of Continuous Glucose Monitoring: An Endocrine Society Clinical Practice Guideline

The Journal of Clinical Endocrinology & Metabolism, 2011

The aim was to formulate practice guidelines for determining settings where patients are most lik... more The aim was to formulate practice guidelines for determining settings where patients are most likely to benefit from the use of continuous glucose monitoring (CGM).

Research paper thumbnail of Pathways to Quality Inpatient Management of Hyperglycemia and Diabetes: A Call to Action

Diabetes Care, 2013

Currently patients with diabetes comprise up to 25-30% of the census of adult wards and critical ... more Currently patients with diabetes comprise up to 25-30% of the census of adult wards and critical care units in our hospitals. Although evidence suggests that avoidance of hyperglycemia (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;180 mg/dL) and hypoglycemia (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;70 mg/dL) is beneficial for positive outcomes in the hospitalized patient, much of this evidence remains controversial and at times somewhat contradictory. We have recently formed a consortium for Planning Research in Inpatient Diabetes (PRIDE) with the goal of promoting clinical research in the area of management of hyperglycemia and diabetes in the hospital. In this article, we outline eight aspects of inpatient glucose management in which randomized clinical trials are needed. We refer to four as system-based issues and four as patient-based issues. We urge further progress in the science of inpatient diabetes management. We hope this call to action is supported by the American Diabetes Association, The Endocrine Society, the American Association of Clinical Endocrinologists, the American Heart Association, the European Association for the Study of Diabetes, the International Diabetes Federation, and the Society of Hospital Medicine. Appropriate federal research funding in this area will help ensure high-quality investigations, the results of which will advance the field. Future clinical trials will allow practitioners to develop optimal approaches for the management of hyperglycemia in the hospitalized patient and lessen the economic and human burden of poor glycemic control and its associated complications and comorbidities in the inpatient setting.

Research paper thumbnail of Efficacy and Safety of Technosphere Inhaled Insulin Compared With Technosphere Powder Placebo in Insulin-Naive Type 2 Diabetes Suboptimally Controlled With Oral Agents

Diabetes Care, 2008

OBJECTIVE -This double-blind, placebo-controlled, randomized, multicenter, parallelgroup study co... more OBJECTIVE -This double-blind, placebo-controlled, randomized, multicenter, parallelgroup study compared the efficacy, safety, and tolerability of Technosphere insulin with Technosphere powder as placebo in insulin-naive type 2 diabetic patients whose diabetes was suboptimally controlled with oral antidiabetic agents.