Showing papers on "Glucose Measurement published in 2014"

Design, development, and evaluation of a novel microneedle array-based continuous glucose monitor

Abstract: The development of accurate, minimally invasive continuous glucose monitoring (CGM) devices has been the subject of much work by several groups, as it is believed that a less invasive and more user-friendly device will result in greater adoption of CGM by persons with insulin-dependent diabetes. This article presents the results of preliminary clinical studies in subjects with diabetes of a novel prototype microneedle-based continuous glucose monitor. In this device, an array of tiny hollow microneedles is applied into the epidermis from where glucose in interstitial fluid (ISF) is transported via passive diffusion to an amperometric glucose sensor external to the body. Comparison of 1396 paired device glucose measurements and fingerstick blood glucose readings for up to 72-hour wear in 10 diabetic subjects shows the device to be accurate and well tolerated by the subjects. Overall mean absolute relative difference (MARD) is 15% with 98.4% of paired points in the A+B region of the Clarke error grid. The prototype device has demonstrated clinically accurate glucose readings over 72 hours, the first time a microneedle-based device has achieved such performance.

Near-infrared LED based non-invasive blood glucose sensor

Abstract: Diabetes is a metabolic pathological condition of concern, which affects vital organs of body if not diagnosed and treated on time. Regular monitoring of blood glucose is important to avoid complication of diabetes. Commonly used glucose measurement methods are invasive which generally involves finger puncturing. These methods are painful and frequent pricking cause calluses on the skin and have risk of spreading infectious diseases. Therefore there is need to develop a non-invasive monitoring system which can measure blood glucose continuously without much problem. The present work is focused on development of non-invasive blood glucose measurement sensor system using Near-infrared (NIR) technique. Initially in-vitro glucose measurement prototype is developed using continuous wave (CW) from NIR LED (940 nm) to check the sensitivity of the system for different glucose concentrations. Later a Sensor patch was designed using LED and a photodiode to observe diffused reflectance spectra of blood from the human forearm. Diffused reflectance spectra of the subjects obtained with this technique was also compared with commercially available invasive finger tip gluco-meter. The results are promising and show the potential of using NIR for glucose measurement.

Automated control of an adaptive bihormonal, dual-sensor artificial pancreas and evaluation during inpatient studies.

Abstract: Automated control of blood glucose in patients with type-1 diabetes has not yet been fully implemented. The aim of this study was to design and clinically evaluate a system that integrates a control algorithm with off-the-shelf subcutaneous sensors and pumps to automate the delivery of the hormones glucagon and insulin in response to continuous glucose sensor measurements. The automated component of the system runs an adaptive proportional derivative control algorithm which determines hormone delivery rates based on the sensed glucose measurements and the meal announcements by the patient. We provide details about the system design and the control algorithm, which incorporates both a fading memory proportional derivative controller (FMPD) and an adaptive system for estimating changing sensitivity to insulin based on a glucoregulatory model of insulin action. For an inpatient study carried out in eight subjects using Dexcom SEVEN PLUS sensors, prestudy HbA1c averaged 7.6, which translates to an estimated average glucose of 171 mg/dL. In contrast, during use of the automated system, after initial stabilization, glucose averaged 145 mg/dL and subjects were kept within the euglycemic range (between 70 and 180 mg/dL) for 73.1% of the time, indicating improved glycemic control. A further study on five additional subjects in which we used a newer and more reliable glucose sensor (Dexcom G4 PLATINUM) and made improvements to the insulin and glucagon pump communication system resulted in elimination of hypoglycemic events. For this G4 study, the system was able to maintain subjects' glucose levels within the near-euglycemic range for 71.6% of the study duration and the mean venous glucose level was 151 mg/dL.

Coefficient of glucose variation is independently associated with mortality in critically ill patients receiving intravenous insulin

Abstract: Both patient- and context-specific factors may explain the conflicting evidence regarding glucose control in critically ill patients. Blood glucose variability appears to correlate with mortality, but this variability may be an indicator of disease severity, rather than an independent predictor of mortality. We assessed blood glucose coefficient of variation as an independent predictor of mortality in the critically ill. We used eProtocol-Insulin, an electronic protocol for managing intravenous insulin with explicit rules, high clinician compliance, and reproducibility. We studied critically ill patients from eight hospitals, excluding patients with diabetic ketoacidosis and patients supported with eProtocol-insulin for < 24 hours or with < 10 glucose measurements. Our primary clinical outcome was 30-day all-cause mortality. We performed multivariable logistic regression, with covariates of age, gender, glucose coefficient of variation (standard deviation/mean), Charlson comorbidity score, acute physiology score, presence of diabetes, and occurrence of hypoglycemia < 60 mg/dL. We studied 6101 critically ill adults. Coefficient of variation was independently associated with 30-day mortality (odds ratio 1.23 for every 10% increase, P < 0.001), even after adjustment for hypoglycemia, age, disease severity, and comorbidities. The association was higher in non-diabetics (OR = 1.37, P < 0.001) than in diabetics (OR 1.15, P = 0.001). Blood glucose variability is associated with mortality and is independent of hypoglycemia, disease severity, and comorbidities. Future studies should evaluate blood glucose variability.

Self-Monitoring of Blood Glucose: Impact of a Time Delay Between Capillary Blood Sampling and Glucose Measurement

Abstract: Several studies have drawn attention to frequent user-error sources in self-monitoring of blood glucose (SMBG), for example, obtaining an inadequate blood volume, neglecting hand washing, applying blood incorrectly onto the test strip, or using expired test strips.1-3 However, there is no sound scientific evidence as to whether the time the patient requires to apply the blood onto the test strip affects measurement results. We investigated, with 3 different SMBG systems, if a time delay between the generation of a blood drop and the application onto the test strip affects glucose measurement results. The investigation was performed by trained personnel at the Institut fur Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universitat Ulm, Ulm, Germany. The protocol was approved by the Ethics Committee, and the competent authority was notified. Glucose measurements on capillary blood samples from fingertips of 89 subjects (49 male, 40 female; 26 with type 1 diabetes mellitus, 43 with type 2 diabetes mellitus, 20 without diabetes; mean age 59, ranging from 21 to 76 years) were evaluated. Measurements with each system were consecutively performed on 4 blood drops with a diameter of approximately 1 mm. The first and the fourth drops were measured immediately (0 s); the second and third drops remained on the skin surface for 10 and 25 s, respectively, before being measured. The drift between the first and the fourth measurement was checked to be ≤0.56 mmol/L (≤10%) for blood glucose concentrations ≤5.6 mmol/L (>5.6 mmol/L). For each system, the relative deviations between the glucose value at 0 s (mean value of the first and the fourth measurement) and the glucose value after a delay of 10 and 25 s was calculated. All 3 systems showed increased glucose values after a time delay between the sampling and the measurement procedure with mean relative deviations between 0.7% and 2.1% after 10 s and between 0.1% and 4.7% after 25 s when compared to immediate measurements (Table 1). An additional evaluation based on linear interpolation between the glucose concentrations at immediate measurement was used to exclude a possible influence of glucose instability effects (data not shown). Table 1. Relative Deviations Between the Glucose Value Measured Immediately After Sample Collection (Time Delay of 0 s) and the Glucose Value Measured After a Delay of 10 and 25 s The amount of time that the blood drop is exposed to air can affect glucose measurements with some SMBG systems. The architecture and/or electrochemical composition of several test strips might also be prone to changes in the blood drop, for example, by evaporation, coagulation, or increase in pO2.4,5 Such changes in the blood drop over time might be particularly relevant in small drops with a higher surface-to-volume ratio (many systems require a sample volume less than 1 µL) or with long air-exposure times before the measurement, for example, when patients do not adequately prepare the measurement. Although further investigations are required to support the clinical relevance of our findings, patients should be advised to perform glucose measurements on capillary samples as quickly as possible.

Evaluation of Commercial Glucometer Test Strips for Potential Measurement of Glucose in Tears

Abstract: Tear glucose measurements have been suggested as a potential alternative to blood glucose monitoring for diabetic patients. While previous work has reported that there is a correlation between blood and tear glucose levels in humans, this link has not been thoroughly established and additional clinical studies are needed. Herein, we evaluate the potential of using commercial blood glucose test strips to measure glucose in tears. Of several blood glucose strips evaluated, only one brand exhibits the low detection limit required for quantitating glucose in tears. Calibration of these strips in the range of 0–100 μM glucose with an applied potential of 150 mV to the working electrode yields a sensitivity of 0.127 nA/μM and a limit of quantitation (LOQ) of 9 μM. The strips also exhibit ≤13% error (n = 3) for 25, 50, and 75 μM glucose in the presence of 10 μM acetaminophen, 100 μM ascorbic acid, and 100 μM uric acid. Measurements of glucose in tears from nine normal (nondiabetic) fasting human subjects using s...

An implantable continuous glucose monitoring microsystem in 0.18µm CMOS

Abstract: We present a fully implantable subcutaneous continuous glucose monitoring (CGM) microsystem on CMOS platform. The proposed design incorporates electrochemical sensing technique using an ultra-low-power potentiostatic system. It is wirelessly powered through an inductive coupling link at 900MHz and supports bidirectional data communication with an external reader. A low-power potentiostat and a dual-slope ADC record the on-chip sensor signal. Pt and Ag/AgCl on-chip electrodes are post-fabricated and functionalized in situ by glucose oxidase enzyme to enable glucose measurement. The 1.4×1.4×0.25mm 3 prototype fabricated in a 0.18μm CMOS technology was validated in glucose measurements. Total power consumption of the system is 6μW.

Accuracy of subcutaneous continuous glucose monitoring in critically ill adults: improved sensor performance with enhanced calibrations.

Abstract: Objective: Accurate real-time continuous glucose measurements may improve glucose control in the critical care unit. We evaluated the accuracy of the FreeStyle® Navigator® (Abbott Diabetes Care, Alameda, CA) subcutaneous continuous glucose monitoring (CGM) device in critically ill adults using two methods of calibration. Subjects and Methods: In a randomized trial, paired CGM and reference glucose (hourly arterial blood glucose [ABG]) were collected over a 48-h period from 24 adults with critical illness (mean±SD age, 60±14 years; mean±SD body mass index, 29.6±9.3 kg/m2; mean±SD Acute Physiology and Chronic Health Evaluation score, 12±4 [range, 6–19]) and hyperglycemia. In 12 subjects, the CGM device was calibrated at variable intervals of 1–6 h using ABG. In the other 12 subjects, the sensor was calibrated according to the manufacturer's instructions (1, 2, 10, and 24 h) using arterial blood and the built-in point-of-care glucometer. Results: In total, 1,060 CGM–ABG pairs were analyzed over the ...

Characterizing accuracy and precision of glucose sensors and meters.

Abstract: There is need for a method to describe precision and accuracy of glucose measurement as a smooth continuous function of glucose level rather than as a step function for a few discrete ranges of glucose. We propose and illustrate a method to generate a “Glucose Precision Profile” showing absolute relative deviation (ARD) and /or %CV versus glucose level to better characterize measurement errors at any glucose level. We examine the relationship between glucose measured by test and comparator methods using linear regression. We examine bias by plotting deviation = (test – comparator method) versus glucose level. We compute the deviation, absolute deviation (AD), ARD, and standard deviation (SD) for each data pair. We utilize curve smoothing procedures to minimize the effects of random sampling variability to facilitate identification and display of the underlying relationships between ARD or %CV and glucose level. AD, ARD, SD, and %CV display smooth continuous relationships versus glucose level. Estimates of MARD and %CV are subject to relatively large errors in the hypoglycemic range due in part to a markedly nonlinear relationship with glucose level and in part to the limited number of observations in the hypoglycemic range. The curvilinear relationships of ARD and %CV versus glucose level are helpful when characterizing and comparing the precision and accuracy of glucose sensors and meters.

Continuous glucose monitoring system and new era of early diagnosis of diabetes in high risk groups.

Abstract: Continuous glucose monitoring (CGM) systems are an emerging technology that allows frequent glucose measurements to monitor glucose trends in real time. Their use as a diagnostic tool is still developing and appears to be promising. Combining intermittent glucose self-monitoring (SGM) and CGM combines the benefits of both. Significant improvement in the treatment modalities that may prevent the progress of prediabetes to diabetes have been achieved recently and dictates screening of high risk patients for early diagnosis and management of glycemic abnormalities. The use of CGMS in the diagnosis of early dysglycemia (prediabetes) especially in high risk patients appears to be an attractive approach. In this review we searched the literature to investigate the value of using CGMS as a diagnostic tool compared to other known tools, namely oral glucose tolerance test (OGTT) and measurement of glycated hemoglobin (HbA1C) in high risk groups. Those categories of patients include adolescents and adults with obesity especially those with family history of type 2 diabetes mellitus, polycystic ovary syndrome (PCO), gestational diabetes, cystic fibrosis, thalassemia major, acute coronary syndrome (ACS), and after renal transplantation. It appears that the ability of the CGMS for frequently monitoring (every 5 min) glucose changes during real-life settings for 3 to 5 days stretches the chance to detect more glycemic abnormalities during basal and postprandial conditions compared to other short-timed methods.

Effects of Measurement Frequency on Analytical Quality Required for Glucose Measurements in Intensive Care Units: Assessments by Simulation Models

Abstract: BACKGROUND: Total error allowances have been proposed for glucose meters used in tight-glucose-control (TGC) protocols. It is unclear whether these proposed quality specifications are appropriate for continuous glucose monitoring (CGM). METHODS: We performed Monte Carlo simulations of patients on TGC protocols. To simulate use of glucose meters, measurements were made hourly. To simulate CGM, glucose measurements were made every 5 min. Glucose was measured with defined bias (varied from −20% to 20%) and imprecision (0% to 20% CV). The measured glucose concentrations were used to alter insulin infusion rates according to established treatment protocols. Changes in true glucose were calculated hourly on the basis of the insulin infusion rate, the modeled patient's insulin sensitivity, and a model of glucose homeostasis. We modeled 18 000 patients, equally divided between the hourly and every-5-min measurement schemas and distributed among 45 combinations of bias and imprecision and 2 treatment protocols. RESULTS: With both treatment protocols and both measurement frequencies, higher measurement imprecision increased the rates of hypoglycemia and hyperglycemia and increased glycemic variability (SD). These adverse effects of measurement imprecision were lower at the higher measurement frequency. The rate of hypoglycemia at an imprecision (CV) of 5% with hourly measurements was similar to the rate of hypoglycemia at 10% CV when measurements were made every 5 min. With measurements every 5 min, imprecision up to 10% had minimal effects on hyperglycemia or glycemic variability. Effects of simulated analytical bias on glycemia were unaffected by measurement frequency. CONCLUSIONS: Quality specifications for imprecision of glucose meters are not transferable to CGM.

In vitro glucose measurement using tunable mid-infrared laser spectroscopy combined with fiber-optic sensor.

Abstract: Because mid-infrared (mid-IR) spectroscopy is not a promising method to noninvasively measure glucose in vivo, a method for minimally invasive high-precision glucose determination in vivo by mid-IR laser spectroscopy combined with a tunable laser source and small fiber-optic attenuated total reflection (ATR) sensor is introduced. The potential of this method was evaluated in vitro. This research presents a mid-infrared tunable laser with a broad emission spectrum band of 9.19 to 9.77μm(1024~1088 cm−1) and proposes a method to control and stabilize the laser emission wavelength and power. Moreover, several fiber-optic ATR sensors were fabricated and investigated to determine glucose in combination with the tunable laser source, and the effective sensing optical length of these sensors was determined for the first time. In addition, the sensitivity of this system was four times that of a Fourier transform infrared (FT-IR) spectrometer. The noise-equivalent concentration (NEC) of this laser measurement system was as low as 3.8 mg/dL, which is among the most precise glucose measurements using mid-infrared spectroscopy. Furthermore, a partial least-squares regression and Clarke error grid were used to quantify the predictability and evaluate the prediction accuracy of glucose concentration in the range of 5 to 500 mg/dL (physiologically relevant range: 30~400 mg/dL). The experimental results were clinically acceptable. The high sensitivity, tunable laser source, low NEC and small fiber-optic ATR sensor demonstrate an encouraging step in the work towards precisely monitoring glucose levels in vivo.

Stability of glucose in plasma with different anticoagulants

Abstract: Background: People with hyperglycemia, especially those who are pregnant, depend on accurate blood glucose measurements for correct diagnosis of diabetes and monitoring. Glycolysis after blood draw, however, decreases glucose concentrations in blood that is collected at room temperature in the absence of a stabilizer. Cold temperatures (4 ° C) inhibit glycolysis; but prompt cooling and processing of each blood sample in the cold is difficult to achieve in routine clinical practice. Therefore, preservatives are used to stabilize glucose during blood collection and processing procedures that are performed at room temperature. This study examined the effect of different anticoagulants (EDTA, heparin, oxalate), with or without glycolysis inhibitors (NaF, citrate), on the stability of glucose in plasma samples – obtained from blood that was collected and stored at room temperature for up to 24 h. Methods: Venous blood was collected from 60 volunteers; each donor blood sample was divided into six tubes, each one containing a different anti-glycolysis – anticoagulant composition. Terumo VENOSAFE ™ Glycemia tubes contained NaF/citrate buffer)/Na 2 EDTA; NaF/Na-heparin; and NaF/K 2 oxalate. Sarstedt tubes contained NaF/citrate; NaF/Na 2 EDTA; and K 2 EDTA. At 0, 2, 8 and 24 h, plasma was obtained for glucose measurements using the Glucose Hexokinase and Glucose Oxidase methods, and the ADVIA ® 1800 Clinical Chemistry System. Results: Both methods demonstrated minimal glycolysis by 24 h ( < 3.8%) for the three Terumo VENOSAFE ™ Glycemia tubes, and the Sarstedt S-Monovette GlucoEXACT tube that contained NaF/citrate. Glycolysis was higher in tubes containing NaF/Na 2 EDTA-alone (11.7%) and K 2 EDTAalone (85%). Conclusions: Terumo VENOSAFE ™ Glycemia tubes (containing NaF/citrate buffer/Na 2 EDTA; NaF/Na-heparin; and NaF/K 2 oxalate) and the Sarstedt S-Monovette ® GlucoEXACT tubes (containing NaF/citrate) are suitable for shipping venous whole blood samples to the testing laboratory within 24 h at room temperature.

Glucose Control in the Intensive Care Unit by Use of Continuous Glucose Monitoring: What Level of Measurement Error Is Acceptable?

Abstract: BACKGROUND: Accuracy and frequency of glucose measurement is essential to achieve safe and efficacious glucose control in the intensive care unit. Emerging continuous glucose monitors provide frequent measurements, trending information, and alarms. The objective of this study was to establish the level of accuracy of continuous glucose monitoring (CGM) associated with safe and efficacious glucose control in the intensive care unit. METHODS: We evaluated 3 established glucose control protocols [Yale, University of Washington, and Normoglycemia in Intensive Care Evaluation and Surviving Using Glucose Algorithm Regulation (NICE-SUGAR)] by use of computer simulations. Insulin delivery was informed by intermittent blood glucose (BG) measurements or CGM levels with an increasing level of measurement error. Measures of glucose control included mean glucose, glucose variability, proportion of time glucose was in target range, and hypoglycemia episodes. RESULTS: Apart from the Washington protocol, CGM with mean absolute relative deviation (MARD) ≤15% resulted in similar mean glucose as with the use of intermittent BG measurements. Glucose variability was also similar between CGM and BG-informed protocols. Frequency and duration of hypoglycemia were not worse by use of CGM with MARD ≤10%. Measures of glucose control varied more between protocols than at different levels of the CGM error. CONCLUSIONS: The efficacy of CGM-informed and BG-informed commonly used glucose protocols is similar, but the risk of hypoglycemia may be reduced by use of CGM with MARD ≤10%. Protocol choice has greater influence on glucose control measures than the glucose measurement method.

In Vitro Evaluation of Fluorescence Glucose Biosensor Response

Abstract: Rapid, accurate, and minimally-invasive glucose biosensors based on Forster Resonance Energy Transfer (FRET) for glucose measurement have the potential to enhance diabetes control. However, a standard set of in vitro approaches for evaluating optical glucose biosensor response under controlled conditions would facilitate technological innovation and clinical translation. Towards this end, we have identified key characteristics and response test methods, fabricated FRET-based glucose biosensors, and characterized biosensor performance using these test methods. The biosensors were based on competitive binding between dextran and glucose to concanavalin A and incorporated long-wavelength fluorescence dye pairs. Testing characteristics included spectral response, linearity, sensitivity, limit of detection, kinetic response, reversibility, stability, precision, and accuracy. The biosensor demonstrated a fluorescence change of 45% in the presence of 400 mg/dL glucose, a mean absolute relative difference of less than 11%, a limit of detection of 25 mg/dL, a response time of 15 min, and a decay in fluorescence intensity of 72% over 30 days. The battery of tests presented here for objective, quantitative in vitro evaluation of FRET glucose biosensors performance have the potential to form the basis of future consensus standards. By implementing these test methods for a long-visible-wavelength biosensor, we were able to demonstrate strengths and weaknesses with a new level of thoroughness and rigor.

Retrospective evaluation of the accuracy of Roche AccuChek Inform and Nova StatStrip glucose meters when used on critically ill patients.

Abstract: Background: More stringent accuracy guidelines for hospital-use glucose meters have recently been published, but it remains unclear whether glucose meters can meet these accuracy guidelines when measurement is performed on critically ill patients with fresh whole blood samples. Materials and Methods: We performed a retrospective evaluation of a conventional (Roche Diagnostics [Indianapolis, IN] AccuChek® Inform) and a newer-generation (Nova Biomedical [Waltham, MA] StatStrip®) glucose system by comparing paired (drawn within 5 min of each other) whole blood glucose meter and laboratory serum glucose values obtained from intensive care unit (ICU) patients. We also performed a prospective evaluation of the accuracy of the Nova StatStrip. Results: The median (interquartile range) bias between Roche AccuChek Inform and serum laboratory glucose measurements was 11 (6–18) mg/dL, compared with a median bias between the Nova StatStrip and serum glucose measurements of 1 (−5 to 5) mg/dL. StatStrip met Int...

Accuracy of Point-of-Care Blood Glucose Measurements in Critically Ill Patients in Shock

Abstract: A widely used method in monitoring glycemic status of ICU patients is point-of-care (POC) monitoring devices. A possible limitation to this method is altered peripheral blood flow in patients in shock, which may result in over/underestimations of their true glycemic status. This study aims to determine the accuracy of blood glucose measurements with a POC meter compared to laboratory methods in critically ill patients in shock. POC blood glucose was measured with a glucose-1-dehydrogenase-based reflectometric meter. The reference method was venous plasma glucose measured by a clinical chemistry analyzer (glucose oxidase-based). Outcomes assessed were concordance to ISO 15197:2003 minimum accuracy criteria for glucose meters, bias in glucose measurements obtained by the 2 methods using Bland–Altman analysis, and clinical accuracy through modified error grid analysis. A total of 186 paired glucose measurements were obtained. ISO 2003 accuracy criteria were met in 95.7% and 79.8% of POC glucose values in the normotensive and hypotensive group, respectively. Mean bias for the normotensive group was –12.4 mg/dL, while mean bias in the hypotensive group was –34.9 mg/dL. POC glucose measurements within the target zone for clinical accuracy were 90.2% and 79.8% for the normotensive and hypotensive group, respectively. POC blood glucose measurements were significantly less accurate in the hypotensive subgroup of ICU patients compared to the normotensive group. We recommend a lower threshold in confirming POC blood glucose with a central laboratory method if clinically incompatible. In light of recently updated accuracy standards, we also recommend alternative methods of glucose monitoring for the ICU population as a whole regardless of blood pressure status.

Salivary alterations in type 1 diabetes mellitus patients: Salivary glucose could be noninvasive tool for monitoring diabetes mellitus

Abstract: Background: Diabetes mellitus (DM) is an endocrine disease characterized by hyperglycemia, the pathogenic mechanisms by which hyperglycemia arises differ widely. Monitoring people with diabetes involve repeated estimations of plasma glucose either by finger pricks or by intravenous blood sampling. Hence, a noninvasive procedure for glucose measurements would be most precious under the circumstances. Aims: (1) To evaluate salivary glucose, total protein and albumin in type 1 DM (T1DM) patients and to compare with healthy nondiabetic control group. (2) To compare and correlate serum and salivary glucose levels in patients with T1DM. Study Design: This study consisted of 30 T1DM patients and 30 controls. All subjects were subjected to the serum glucose, salivary glucose, and total protein and albumin estimations. Materials and Methods: Glucose estimations were done by glucose oxidase-peroxidase method, total protein estimations were done by Biuret method, end point and albumin estimations were done by bromocresol green dye method, end point. All the estimations were performed using an autoanalyzer. Statistical Analysis: Mean and standard deviation, Student's t-test and Karl Pearson correlation co-efficient were calculated. All these statistical analyses were performed by using SPSS 11.5 software. Results: The results showed elevated levels of salivary glucose, total protein and albumin in T1DM group compared to healthy controls. Further the levels of serum and salivary glucose in T1DM patients were significantly correlated. Conclusion: There are definite changes in salivary composition with increased levels of salivary glucose, total protein and albumin in T1DM patients compared with healthy controls. Salivary glucose could be used for monitoring of DM.

System and method for adjusting therapy based on risk associated with a glucose state

Abstract: The present disclosure relates to a system and method for determining a basal rate adjustment based on risk associated with a glucose state of a person with diabetes. A method may include detecting a glucose state of the person based on a received glucose measurement signal and determining a current risk metric associated with the detected glucose state. The method may include identifying a reference glucose state and a reference risk metric associated with the reference glucose state, and calculating an adjustment to a basal rate of a therapy delivery device based on the current risk metric associated with the detected glucose state and the reference risk metric associated with the reference glucose level.

Impact of Partial Pressure of Oxygen in Blood Samples on the Performance of Systems for Self-Monitoring of Blood Glucose

Abstract: Background: The partial pressure of oxygen (pO2) in blood samples can affect glucose measurements with oxygen-sensitive systems. In this study, we assessed the influence of different pO2 levels on blood glucose (BG) measurements with five glucose oxidase (GOD) systems and one glucose dehydrogenase (GDH) system. All selected GOD systems were indicated by the manufacturers to be sensitive to increased oxygen content of the blood sample. Materials and Methods: Venous blood samples of 16 subjects (eight women, eight men; mean age, 52 years; three with type 1 diabetes, four with type 2 diabetes, and nine without diabetes) were collected. Aliquots of each sample were adjusted to the following pO2 values: ≤45 mm Hg, approximately 70 mm Hg, and ≥150 mm Hg. For each system, five consecutive measurements on each sample were performed using the same test strip lot. Relative differences between the mean BG value at a pO2 level of approximately 70 mm Hg, which was considered to be similar to pO2 values in cap...

Glucose-measurement systems and methods presenting icons

Abstract: A glucose measurement system includes a display and a biosensor that provides a signal representative of a glucose level of a fluid sample. A processor determines glucose data values and a rate of change of blood glucose using the signal. The processor can determine a state band and a rate band using the values and rate, and display a state icon colored per the state band and a rate icon colored and shaped per the rate band. The processor does not display any other indication of the determined rate of change or of any of the stored glucose data values. The processor can also display a unified icon shaped per the rate of change, with a prevailing color determined using the values. The processor does not display any other indication of the determined rate of change or of any of the stored glucose data values. Corresponding methods are also described.

Application of the Reference Method Isotope Dilution Gas Chromatography Mass Spectrometry (ID/GC/MS) to Establish Metrological Traceability for Calibration and Control of Blood Glucose Test Systems:

Abstract: Self-monitoring of blood glucose (BG) by means of handheld BG systems is a cornerstone in diabetes therapy. The aim of this article is to describe a procedure with proven traceability for calibration and evaluation of BG systems to guarantee reliable BG measurements. Isotope dilution gas chromatography mass spectrometry (ID/GC/MS) is a method that fulfills all requirements to be used in a higher-order reference measurement procedure. However, this method is not applicable for routine measurements because of the time-consuming sample preparation. A hexokinase method with perchloric acid (PCA) sample pretreatment is used in a measurement procedure for such purposes. This method is directly linked to the ID/GC/MS method by calibration with a glucose solution that has an ID/GC/MS-determined target value. BG systems are calibrated with whole blood samples. The glucose levels in such samples are analyzed by this ID/GC/MS-linked hexokinase method to establish traceability to higher-order reference material. For method comparison, the glucose concentrations in 577 whole blood samples were measured using the PCA-hexokinase method and the ID/GC/MS method; this resulted in a mean deviation of 0.1%. The mean deviation between BG levels measured in >500 valid whole blood samples with BG systems and the ID/GC/MS was 1.1%. BG systems allow a reliable glucose measurement if a true reference measurement procedure, with a noninterrupted traceability chain using ID/GC/MS linked hexokinase method for calibration of BG systems, is implemented. Systems should be calibrated by means of a traceable and defined measurement procedure to avoid bias.

Dextrose 10% in the Treatment of Out-of-Hospital Hypoglycemia

Abstract: Introduction Prehospital first responders historically have treated hypoglycemia in the field with an IV bolus of 50 mL of 50% dextrose solution (D50). The California Contra Costa County Emergency Medical Services (EMS) system recently adopted a protocol of IV 10% dextrose solution (D10), due to frequent shortages and relatively high cost of D50. The feasibility, safety, and efficacy of this approach are reported using the experience of this EMS system. Methods Over the course of 18 weeks, paramedics treated 239 hypoglycemic patients with D10 and recorded patient demographics and clinical outcomes. Of these, 203 patients were treated with 100 mL of D10 initially upon EMS arrival, and full data on response to treatment was available on 164 of the 203 patients. The 164 patients’ capillary glucose response to initial infusion of 100 mL of D10 was calculated and a linear regression line fit between elapsed time and difference between initial and repeat glucose values. Feasibility, safety, and the need for repeat glucose infusions were examined. Results The study cohort included 102 men and 62 women with a median age of 68 years. The median initial field blood glucose was 38 mg/dL, with a subsequent blood glucose median of 98 mg/dL. The median time to second glucose testing was eight minutes after beginning the 100 mL D10 infusion. Of 164 patients, 29 (18%) required an additional dose of IV D10 solution due to persistent or recurrent hypoglycemia, and one patient required a third dose. There were no reported adverse events or deaths related to D10 administration. Linear regression analysis of elapsed time and difference between initial and repeat glucose values showed near-zero correlation. Conclusions In addition to practical reasons of cost and availability, theoretical risks of using 50 mL of D50 in the out-of-hospital setting include extravasation injury, direct toxic effects of hypertonic dextrose, and potential neurotoxic effects of hyperglycemia. The results of one local EMS system over an 18-week period demonstrate the feasibility, safety, and efficacy of using 100 mL of D10 as an alternative. Additionally, the linear regression line of repeat glucose measurements suggests that there may be little or no short-term decay in blood glucose values after D10 administration. Kiefer MV , Hern HG , Alter HJ , Barger JB . Dextrose 10% in the Treatment of Out-of-Hospital Hypoglycemia. Prehosp Disaster Med. 2014;29(2):1-5.

Determination and application of glucose sensor reliability indicator and/or metric

Abstract: Disclosed are a system and method for determining a metric and/or indicator of a reliability of a blood glucose sensor in providing glucose measurements. In one aspect, the metric and/or indicator may be computed based, at least in part, on an observed trend associated with signals generated by the blood glucose sensor.

What Are the Next Steps in Continuous Glucose Monitoring

Abstract: The development of glucose sensors for continuous glucose monitoring (CGM) is likely still in its early days. A number of novel approaches—along with many attempts to improve current CGM systems—are in development. The next generation of glucose sensors (NGGS) will also enable, for example, reliable glucose measurement in the low glycemic range. NGGS systems represent an important step forward for closed-loop systems. This commentary discusses a number of aspects that are relevant in this context.