Continuous subcutaneous glucose monitoring in children with type 1 diabetes mellitus: a single-blind, randomized, controlled trial

User Performance Evaluation and System Accuracy Assessment of Four Blood Glucose Monitoring Systems With Color Coding of Measurement Results

BACKGROUND

Blood glucose monitoring systems (BGMSs) are a cornerstone in diabetes management. They have to provide sufficiently accurate results in the hands of lay users, particularly in insulin-treated patients. The aim of this study was user performance evaluation and system accuracy assessment of four BGMSs with color coding of results.

METHODS

Study procedures were based on ISO 15197:2013. User performance evaluation included data from 100 participants, each of whom used every system with one reagent lot. Study personnel observed user techniques. For the system accuracy assessment, 100 capillary samples were obtained for measurement in duplicate with each of three reagent system lots per system, resulting in 600 results per system.

RESULTS

All assessed BGMSs exhibited a sufficient level of accuracy, with small differences between them. In the user performance evaluation, study personnel observed the smallest total number of user errors with Contour Next (Ascensia), followed by Accu-Chek Instant (Roche), Medisafe Fit Smile (Terumo), and OneTouch Ultra Plus Reflect (LifeScan). Approximately 90% of participants stated that a consistent color scheme, eg, for low blood glucose (BG) values, should be used across all BGMSs. There was no clear preference among the four tested BGMSs regarding the specific way of displaying color coding.

CONCLUSIONS

The four BGMSs assessed in this study showed only small differences in an overall sufficient level of accuracy. User handling errors, as observed by study personnel, differed between the systems.

Impact of Two Different Reference Measurement Procedures on Apparent System Accuracy of 18 CE-Marked Current-Generation Blood Glucose Monitoring Systems

BACKGROUND

Measurement accuracy has been assessed for many different blood glucose monitoring systems (BGMS) over the years by different study groups. However, the choice of the comparison measurement procedure may impact the apparent level of accuracy found in such studies.

MATERIALS AND METHODS

Measurement accuracy of 18 different BGMS was assessed in a setting based on ISO 15197 using two different comparison methods in parallel: a glucose oxidase (GOD)-based and a hexokinase (HK)-based method. Accuracy limits of ISO 15197 were applied, and additional analyses were performed, including bias, linear regression, and mean absolute relative difference (MARD) to assess the impact of possible differences between comparison methods on the apparent level of accuracy.

RESULTS

While ≈80% of BGMS met the accuracy criteria of ISO 15197 when compared with the respective manufacturers' reference measurement procedure, only two-thirds did so against both comparison methods. The mean relative bias ranged from -6.6% to +5.7% for the analysis against the GOD-based method and from -11.1% to +1.3% for the analysis against the HK-based method, whereas MARD results ranged from 3.7% to 9.8% and from 2.3% to 10.5%, respectively. Results of regression analysis showed slopes between 0.85 and 1.08 (GOD-based method) and between 0.81 and 1.01 (HK-based method).

CONCLUSIONS

The results of this study indicate that there are systematic differences between the reference measurement procedures used for BGMS calibration as well as for system accuracy assessment. Because of the potential impact on therapy of patients with diabetes resulting from these differences, further steps toward harmonization of the measurement procedures' results are important.

Effects of real-time continuous glucose monitoring in type 1 diabetes: a meta-analysis of randomized controlled trials

AIMS

Self-monitoring of blood glucose (SMBG) represented a major breakthrough in the treatment of type 1 diabetes. The aim of the present meta-analysis is to assess the effect of continues glucose monitoring (CGM) and flash glucose monitoring (FGM), on glycemic control in type 1 diabetes.

MATERIALS AND METHODS

The present analysis includes randomized clinical trials comparing CGM or FGM with SMBG, with a duration of at least 12 weeks, identified in Medline or clinicaltrials.gov. The principal endpoint was HbA1c at the end of the trial. A secondary endpoint was severe hypoglycemia. Mean and 95% confidence intervals for HbA1c and Mantel-Haenzel odds ratio [MH-OR] for severe hypoglycemia were calculated, using random effect models. A sensitivity analysis was performed using fixed effect models. In addition, the following secondary endpoints were explored, using the same methods: time in range, health-related quality of life, and treatment satisfaction. Separate analyses were performed for trials comparing CGM with SMBG, and those comparing CGM + CSII and SMBG + MDI and CGM-regulated insulin infusion system (CRIS) and CSII + SMBG.

RESULTS

CGM was associated with a significantly lower HbA1c at endpoint in comparison with SMBG (- 0.24 [- 0.34, - 0.13]%); CGM was associated with a significantly lower risk of severe hypoglycemia than SMBG. Treatment satisfaction and quality of life were not measured, or not reported, in the majority of studies. FGM showed a significant reduction in the incidence of mild hypoglycemia and an increased treatment satisfaction, but no significant results are shown in HbA1c. CGM + CSII in comparison with SMBG + MDI was associated with a significant reduction in HbA1c. Only two trials with a duration of at least 12 weeks compared a CRIS with SMBG + CSII; HbA1c between the two treatment arms was not statistically significant (difference in means: - 0.23 [- 0.91; 0.46]%; p = 0.52).

CONCLUSION

GCM compared to SMBG has showed a reduction in HbA1c and severe hypoglycemia in patient with type 1 diabetes. The comparison between CGM + CSII and SMBG + MDI showed a large reduction in HbA1c; it is conceivable that the effects of CSII + CGM on glycemic control additives. The only comparison available between FGM and SMBG was conducted in patients in good control.

A Systematic Review of Collective Evidences Investigating the Effect of Diabetes Monitoring Systems and Their Application in Health Care

INTRODUCTION

Diabetes monitoring systems (DMS) are a possible approach for regular control of glucose levels in patients with Type 1 or 2 diabetes in order to improve therapeutic outcomes or to identify and modify inappropriate patient behaviors in a timely manner. Despite the significant number of studies observing the DMS, no collective evidence is available about the effect of all devices.

GOAL

To review and consolidate evidences from multiple systematic reviews on the diabetes monitoring systems and the outcomes achieved.

MATERIALS AND METHODS

Internet-based search in PubMed, EMBASE, and Cochrane was performed to identify all studies relevant to the research question. The data regarding type of intervention, type of diabetes mellitus, type of study, change in clinical parameter(s), or another relevant outcome were extracted and summarized.

RESULTS

Thirty-three out of 1,495 initially identified studies, involving more than 44,100 patients with Type 1, Type 2, or gestational diabetes for real-time or retrospective Continuous Glucose Monitoring (CGMS), Sensor Augmented Pump Therapy (SAPT), Self-monitoring Blood Glucose (SMBG), Continuous subcutaneous insulin infusion (CSII), Flash Glucose Monitoring (FGM), Closed-loop systems and telemonitoring, were included. Most of the studies observed small nominal effectiveness of DMS. In total 11 systematic reviews and 15 meta-analyses, with most focusing on patients with Type 1 diabetes (10 and 6, respectively), reported a reduction in glycated hemoglobin (HbA1c) levels from 0.17 to 0.70% after use of DMS.

CONCLUSION

Current systematic review of already published systematic reviews and meta-analyses suggests that no statistically significant difference exists between the values of HbA1c as a result of application of any type of DMS. The changes in HbA1c values, number and frequency of hypoglycemic episodes, and time in glucose range are the most valuable for assessing the appropriateness and effectiveness of DMS. Future more comprehensive studies assessing the effectiveness, cost-effectiveness, and comparative effectiveness of DMS are needed to stratify them for the most suitable diabetes patients' subgroups.

System accuracy evaluation of 18 CE-marked current-generation blood glucose monitoring systems based on EN ISO 15197:2015

OBJECTIVE

Accuracy of 18 current-generation blood glucose monitoring systems (BGMS) available in Europe was evaluated applying criteria adapted from EN ISO 15197:2015 with one reagent system lot. BGMS were selected based on market research data.

RESEARCH DESIGN AND METHODS

The BGMS ABRA, Accu-Chek Guide, AURUM, CareSens Dual, CERA-CHEK 1CODE, ContourNext One, eBsensor, FreeStyle Freedom Lite, GL50 evo, GlucoCheck GOLD, GlucoMen areo 2K, GluNEO, MyStar DoseCoach, OneTouch Verio Flex, Pic GlucoTest, Rightest GM700S, TRUEyou, and WaveSense JAZZ Wireless were tested using capillary blood from 100 different subjects and assessing the percentage of results within ±15 mg/dL (0.83 mmol/L) or 15% of comparison method results for BG concentrations below or above 100 mg/dL (5.55 mmol/L), respectively. In addition, the minimal deviation from comparison method results within which ≥95% of results of the respective BGMS were found was calculated.

RESULTS

In total, 14 BGMS had ≥95% of results within ±15 mg/dL (0.83 mmol/L) or ±15% and 3 BGMS had ≥95% of results within ±10 mg/dL (0.55 mmol/L) or ±10% of the results obtained with the comparison method. The smallest deviation from comparison method results within which ≥95% of results were found was ±7.7 mg/dL (0.43 mmol/L) or ±7.7%; the highest deviation was ±19.7 mg/dL (1.09 mmol/L) or ±19.7%.

CONCLUSIONS

This accuracy evaluation shows that not all CE-labeled BGMS fulfill accuracy requirements of ISO 15197 reliably and that there is considerable variation even among BGMS fulfilling these criteria. This safety-related information should be taken into account by patients and healthcare professionals when making therapy decisions.

TRIAL REGISTRATION NUMBER

NCT03737188.

Clinical efficacy of Professional Continuous Glucose Monitoring in improving glycemic control among children with Type 1 Diabetes Mellitus: An Open-label Randomized Control Trial

Frequent self-monitoring of blood glucose (SMBG) is the only accurate method available for insulin dose titration in patients with T1DM. Professional continuous glucose monitoring (p-CGM) is blinded recording of glucose trends over 5–7 days and helps physicians to guide insulin titration to patient. This study was planned to assess efficacy of insulin dose adjustments, based on p-CGM plus SMBG in improving glycemic control compared to SMBG alone. We did an open-label, parallel design, randomized control trial among children (2–10 years) having T1DM for at least 6 months. Subjects in the intervention group were placed on p-CGM (iPRO 2™ Professional CGM, Medtronic, USA) for 3–5 days along with regular SMBG. Data from p-CGM was analyzed by physician and used to guide insulin titration along with SMBG over following 3 months. Control group had only SMBG records for titrating insulin doses. Primary outcome was change in HbA1c 3 months after intervention. A total of 68 eligible children were randomized, 34 each to either arms. Thirty children in intervention group and 33 in control group completed the study and were analyzed. It was found that there was more decreased unit change in HbA1c, percentage of low sugar records and total insulin requirement per day, after 3 months follow-up, in intervention group. However, difference was not significant except for total insulin Units/kg/day (p = 0.014). In sub-group analysis of children with baseline HbA1c >7.5%, there was a significant mean fall of HbA1c by 1.27% (p = 0.045). There were no major adverse events associated with p-CGM. We conclude that addition of p-CGM along with SMBG may help in adjusting insulin dose more effectively especially in children with higher baseline HbA1c.

Continuous glucose monitoring: a review of the evidence, opportunities for future use and ongoing challenges

The advent of devices that can track interstitial glucose levels, which are closely related to blood glucose levels, on a near continuous basis, has facilitated better insights into patterns of glycaemia. Continuous glucose monitoring (CGM) therefore allows for more intensive monitoring of blood glucose levels and potentially improved glycaemic control. In the context of the announcement on 1 April 2017 that the Australian Government will fund CGM monitoring for people with type 1 diabetes under the age of 21 years, this paper provides a review of the evidence for CGM and some of the ongoing challenges. There is evidence that real-time CGM in type 1 diabetes improves HbA1c and hypoglycaemia, while in type 2 diabetes, the evidence is less robust. Initial barriers to widespread implementation of CGM included issues with accuracy and user friendliness; however, as the technology has evolved, these issues have largely improved. Ongoing barriers include cost, and weaker evidence for their benefit in certain populations such as those with type 2 diabetes and less glycaemic variability. CGM has the potential to reduce healthcare costs, although real-world studies, including cost-effectiveness analyses, are needed in this area.

Practical implementation, education and interpretation guidelines for continuous glucose monitoring: A French position statement

The use by diabetes patients of real-time continuous interstitial glucose monitoring (CGM) or the FreeStyle Libre^® (FSL) flash glucose monitoring (FGM) system is becoming widespread and has changed diabetic practice. The working group bringing together a number of French experts has proposed the present practical consensus. Training of professionals and patient education are crucial for the success of CGM. Also, institutional recommendations must pay particular attention to the indications for and reimbursement of CGM devices in populations at risk of hypoglycaemia. The rules of good practice for CGM are the precursors of those that need to be enacted, given the oncoming emergence of artificial pancreas devices. It is necessary to have software combining user-friendliness, multiplatform usage and average glucose profile (AGP) presentation, while integrating glucose and insulin data as well as events. Expression of CGM data must strive for standardization that facilitates patient phenotyping and their follow-up, while integrating indicators of variability. The introduction of CGM involves a transformation of treatment support, rendering it longer and more complex as it also includes specific educational and technical dimensions. This complexity must be taken into account in discussions of organization of diabetes care.

Accuracy and Precision of Measured Blood Sugar Values by Three Glucometers Compared to the Standard Technique

INTRODUCTION

The prevalence of diabetes mellitus has magnified, globally. Being cost effective and user friendly, using the glucometer systems has become more widespread. However, despite their advantages, there are controversies regarding their accuracy and precision.

AIM

To determine the accuracy and precision of the common glucometers of Bionime, Accu-check, and Beurer compared with the laboratory technique.

MATERIALS AND METHODS

In a cross-sectional study, 257 patients of a general internal unit of Imam Reza hospital of Kermanshah were recruited. The blood sample of the subjects was transferred to the laboratory, then, two samples of capillary blood were tested by the three glucometers. The data was entered into a checklist, then entered to SPSS-16.0 software, and analyzed by descriptive and inferential statistics.

RESULTS

In this study, there was a positive correlation between the three blood glucose measurement methods with the standard approach, significantly, which indicates acceptable accuracy. However, this correlation was higher in the Beurer Glucometer (r=0.976, p<0.001). There were no significant differences in repeated measurements of blood glucose in the glucometers of Beurer (t=0.96, p=0.92), and Bionime (t=0.50, p=0.61) by paired t-test, but this test was significant for Accu-chek system (t=2.7, p=0.006).

CONCLUSION

With respect to the acceptable accuracy and precision of Beurer and Bionime glucometers, it is suggested to use these methods for diabetic patients at homes as well as in the hospital units.

Accuracy and Precision of Measured Blood Sugar Values by Three Glucometers Compared to the Standard Technique

INTRODUCTION

The prevalence of diabetes mellitus has magnified, globally. Being cost effective and user friendly, using the glucometer systems has become more widespread. However, despite their advantages, there are controversies regarding their accuracy and precision.

AIM

To determine the accuracy and precision of the common glucometers of Bionime, Accu-check, and Beurer compared with the laboratory technique.

MATERIALS AND METHODS

In a cross-sectional study, 257 patients of a general internal unit of Imam Reza hospital of Kermanshah were recruited. The blood sample of the subjects was transferred to the laboratory, then, two samples of capillary blood were tested by the three glucometers. The data was entered into a checklist, then entered to SPSS-16.0 software, and analyzed by descriptive and inferential statistics.

RESULTS

In this study, there was a positive correlation between the three blood glucose measurement methods with the standard approach, significantly, which indicates acceptable accuracy. However, this correlation was higher in the Beurer Glucometer (r=0.976, p<0.001). There were no significant differences in repeated measurements of blood glucose in the glucometers of Beurer (t=0.96, p=0.92), and Bionime (t=0.50, p=0.61) by paired t-test, but this test was significant for Accu-chek system (t=2.7, p=0.006).

CONCLUSION

With respect to the acceptable accuracy and precision of Beurer and Bionime glucometers, it is suggested to use these methods for diabetic patients at homes as well as in the hospital units.

Evaluation of a novel continuous glucose monitoring guided system for adjustment of insulin dosing - PumpTune: a randomized controlled trial

OBJECTIVE

Retrospective continuous glucose monitoring (CGM) can guide insulin pump adjustments, however, interpretation of data and recommending new pump settings is complex and subjective. We aimed to compare the safety and glycaemic profiles of children after their diabetologist or a novel algorithm (PumpTune) adjusted their insulin pump settings.

RESEARCH DESIGN AND METHODS

In a randomized cross-over trial of 22 patients aged 6-14 yr with type 1 diabetes with mean Hba1c 7.4% (57 mmol/mol) using CSII, CGM was used over two periods each of 6.5 d to assess percentage time glucose remained within, above and below 3.9-10.0 mmol/L. Before the start of one period pump settings were adjusted by the patient's diabetologist, and before the other insulin pump settings were adjusted by PumpTune.

RESULTS

A total of 63.4% of the sensor glucose levels were within target range with PumpTune settings and 57.4% were within range with the clinician settings (p = 0.016). The time spent above target range with PumpTune was 26.9% and with clinician settings was 33.5% (p = 0.021). The time spent below target range with PumpTune was 9.7% and with clinician settings was 9.2% (p = 0.77). The mean number of times when a sensor glucose level <2.75 mmol/L was recorded with PumpTune settings was 2.9 compared with 3.7 with clinician settings (p = 0.39). There were no serious adverse outcomes and no difference in parent-assessed satisfaction.

CONCLUSIONS

Automated insulin pump adjustment with PumpTune is feasible and warrants testing in a larger more varied population over a longer time. In this well-controlled group of children, PumpTune achieved a more favorable glucose profile.

Capillary bedside blood glucose measurement in neonates: missing a diagnosis of galactosemia

A number of factors may lead to inaccuracy in measurement of capillary blood glucose with a glucometer. Measurement of other carbohydrate molecules such as galactose and fructose along with glucose can potentially be a cause of error. We report a newborn patient who was referred to our hospital with conjugated bilirubinemia, hepatomegaly and high capillary blood glucose levels measured with a glucometer. Simultaneous biochemical measurements revealed normal blood glucose levels. Further investigation led to a diagnosis of classical galactosemia. Capillary blood glucose level measured with glucometer also dropped to normal values following cessation of breastfeeding and initiation of feeding with a lactose-free formula.

Effectiveness of 3-day continuous glucose monitoring for improving glucose control in type 2 diabetic patients in clinical practice

BACKGROUND

The aim of this study was to investigate whether adjusting diabetic treatment regimens according to the information obtained from a continuous glucose monitoring system (CGMS) might lead to improved glycemic control in patients with type 2 diabetes.

METHODS

We reviewed the medical charts of 172 patients who used the CGMS for 1 year starting in December 2008 and the records of 1,500 patients who visited their regular outpatient clinics during December 2008. Of these patients, a total of 65 CGMS patients and 301 regular outpatients (control group) were enrolled in the study after propensity score matching. There were no differences in baseline glycated hemoglobin (HbA1c), age, and duration of diabetes between the CGMS and the control groups after propensity score matching. The changes in the HbA1c levels from baseline to 6 months were calculated.

RESULTS

The CGMS group showed a significant improvement in the HbA1c level compared to the control group at 3 months (7.9%±1.6% vs. 7.4%±1.2%, P=0.001) and at 6 months (7.4%±1.2% vs. 7.9%±1.6%, P=0.010). There were significant differences in the treatment modality changes between the CGMS group and the control group.

CONCLUSION

Using a 3-day CGMS was advantageous for improving glucose control in patients with type 2 diabetes and may help these patients to optimize glycemic control in clinical practice.

Interstitium versus Blood Equilibrium in Glucose Concentration and its Impact on Subcutaneous Continuous Glucose Monitoring Systems

The relationship between both interstitial and blood glucose remains a debated topic, on which there is still no consensus. The experimental evidence suggests that blood and interstitial fluid glucose levels are correlated by a kinetic equilibrium, which as a consequence has a time and magnitude gradient in glucose concentration between blood and interstitium. Furthermore, this equilibrium can be perturbed by several physiological effects (such as foreign body response, wound-healing effect, etc.), with a consequent reduction of interstitial fluid glucose versus blood glucose correlation. In the present study, the impact of operating in the interstitium on continuous glucose monitoring systems (CGMs) will be discussed in depth, both for the application of CGMs in the management of diabetes and in other critical areas, such as tight glycaemic control in critically ill patients.

[Role of continuous subcutaneous glucose monitoring in intensive care]

Critical care associated with stress hyperglycaemia has gained a new view in the last decade since the demonstration of the beneficial effects of strong glycaemic control on the mortality in intensive care units. Strong glycaemic control may, however, induce hypoglycaemia, resulting in increased mortality, too. Pediatric population has an increased risk of hypoglycaemia because of the developing central nervous system. In this view there is a strong need for close monitoring of glucose levels in intensive care units. The subcutaneous continuous glucose monitoring developed for diabetes care is an alternative for this purpose instead of regular blood glucose measurements. It is important to know the limitations of subcutaneous continuous glucose monitoring in intensive care. Decreased tissue perfusion may disturb the results of subcutaneous continuous glucose monitoring, because the measurement occurs in interstitial fluid. The routine use of subcutaneous continuous glucose monitoring in intensive care units is not recommended yet until sufficient data on the reliability of the system are available. The Medtronic subcutaneous continuous glucose monitoring system is evaluated in the review partly based on the authors own results.

Continuous glucose monitoring in children with glycogen storage disease type I

BACKGROUND/OBJECTIVES

Glycogen storage disease type I (GSD I) is an autosomal recessive metabolic disorder caused by defects in the glucose-6-phosphatase complex. Deficient activity in the glucose-6-phosphatase-α catalytic unit characterizes GSD Ia and defects in the glucose-6-phosphate transporter protein characterize GSD Ib. Type Ia involves the liver, kidney and intestine (and Ib also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, severe fasting hypoglycemia within 3-4 h after a meal, hyperlactatemia, hyperuricemia and hyperlipidemia. The aim of the present study was to examine the safety and efficacy of a continuous subcutaneous glucose monitoring system to determine the magnitude and significance of hypoglycemia in GSD I and to evaluate the efficacy of the revised dietary treatment.

SUBJECTS/METHODS

Sixteen children with GSD I were studied over a 72-h period. Continuous glucose monitoring (CGM) was repeated in all patients 3-6 months after the first monitoring to examine the effects of revised dietary instructions on glycemic control.

RESULTS

All the patients completed the study without any major adverse events. Significant periods of asymptomatic hypoglycemia (below 4 mmol/l, 70 mg/dl) were noted. There was a close correlation between CGM sensor and capillary blood glucose values measured by a glucometer. CGM indicated a considerable reduction in duration of hypoglycemia, liver size and improvements in secondary metabolic derangements such as hyperlacticacidemia and hyperlipidemia.

CONCLUSIONS

CGM could be applied in the clinical setting to help the physician to identify hypoglycemic events, and repeated CGM may serve as a safe and useful tool for the assessment of the long-term management of patients with GSD I.

Continuous glucose monitoring: evidence and consensus statement for clinical use

Continuous glucose monitoring (CGM) is an essential tool for modern diabetes therapy. Randomized controlled studies have provided evidence that hemoglobin A1c (HbA1c) results can be improved in patients with type 1 diabetes with elevated baseline HbA1c when using CGM frequently enough and that the frequency and duration of hypoglycemic events can be reduced in patients with satisfactory baseline HbA1c. The CGM group within the Working Group Diabetes Technology (AGDT) of the German Diabetes Association (DDG) has defined evidence-based indications for the practical use of CGM in this consensus statement related to hypoglycemia (frequent, severe, or nocturnal) or hypoglycemia unawareness, insufficient metabolic control despite use of all possible therapeutic options and patient compliance, pregnancy associated with inadequate blood glucose results, and the need for more than 10 blood glucose measurements per day. Contraindications and defined preconditions for the successful use of CGM should be considered.

Continuous glucose monitoring in type 1 diabetes

Continuous glucose monitors (CGM), devices that can measure interstitial glucose in "real time," have become widely available particularly for use in patients with diabetes, and their accuracy and ease of use have greatly improved over the last decade. A number of large and well-controlled clinical trials have firmly established their usefulness in improving metabolic control (as measured by HbA1C) and decreasing time spent in hypoglycemia in adults; however, data have been less robust proving benefit in children and adolescents. Benefits are clearly linked to near-continuous wear. Insulin dosing algorithms based on CGM glucose trends have proven useful in dissecting the large volume of data generated daily by these devices, although these are imperfect tools, particularly in children. The technology is likely to be most useful when integrated with insulin pump delivery systems (sensor augmented). In this review, we concentrate on the analysis of published results of the largest trials in adults and children, including the very young, with diabetes.

Systematic review and meta-analysis of the effectiveness of continuous glucose monitoring (CGM) on glucose control in diabetes

Diabetes mellitus is a chronic disease that necessitates continuing treatment and patient self-care education. Monitoring of blood glucose to near normal level without hypoglycemia becomes a challenge in the management of diabetes. Although self monitoring of blood glucose (SMBG) can provide daily monitoring of blood glucose level and help to adjust therapy, it cannot detect hypoglycemic unawareness and nocturnal hypoglycemia which occurred mostly in T1DM pediatrics. Continuous glucose monitoring (CGM) offers continuous glucose data every 5 minutes to adjust insulin therapy especially for T1DM patients and to monitor lifestyle intervention especially for T2DM patients by care providers or even patients themselves. The main objective of this study was to assess the effects of continuous glucose monitoring (CGM) on glycemic control in Type 1 diabetic pediatrics and Type 2 diabetic adults by collecting randomized controlled trials from MEDLINE (pubmed), SCOPUS, CINAHL, Web of Science and The Cochrane Library up to May 2013 and historical search through the reference lists of relevant articles. There are two types of CGM device: real-time CGM and retrospective CGM and both types of the device were included in the analysis. In T1DM pediatrics, CGM use was no more effective than SMBG in reducing HbA1c [mean difference - 0.13% (95% CI -0.38% to 0.11%,]. This effect was independent of HbA1c level at baseline. Subgroup analysis indicated that retrospective CGM was not superior to SMBG [mean difference -0.05% (95% CI -0.46% to 0.35%)]. In contrast, real-time CGM revealed better effect in lowering HbA1c level compared with SMBG [mean difference -0.18% (95% CI -0.35% to -0.02%, p = 0.02)]. In T2DM adults, significant reduction in HbA1c level was detected with CGM compared with SMBG [mean difference - 0.31% (95% CI -0.6% to -0.02%, p = 0.04)]. This systematic review and meta-analysis suggested that real-time CGM can be more effective than SMBG in T1DM pediatrics, though retrospective CGM was not. CGM provided better glycemic control in T2DM adults compared with SMBG.

Continuous glucose monitoring in children and adolescents

Continuing glucose monitoring (CGM) is a relatively new and rapidly developing technology that shows promise for the future management of type 1 diabetes. When used with near-daily frequency, it has a significant effect on improvement of glucose metabolism as measured by HbA1C and reduction of hypoglycemia. It appears to be safe and actually reduces both DKA and severe hypoglycemia. Early studies indicate that it should be cost effective.

System accuracy evaluation of 43 blood glucose monitoring systems for self-monitoring of blood glucose according to DIN EN ISO 15197

BACKGROUND

The accuracy of systems for self-monitoring of blood glucose is important, as reliable measurement results are a prerequisite for therapeutic decisions.

METHODS

This system accuracy evaluation study was performed according to DIN EN ISO 15197:2003 for 43 Conformité Européenne (CE)-labeled blood glucose (BG) monitoring systems. Measurement results of each system were compared with results of the designated comparison method (manufacturer's measurement procedure): glucose oxidase method (YSI 2300 glucose analyzer) or hexokinase method (Hitachi 917/ cobas 501).

RESULTS

Complete assessment according to the International Organization for Standardization (ISO) standard was performed for 34 out of 43 systems, and 27 (79.4%) meet the requirements of the standard, i.e., ≥95% of their results showed at least the minimum acceptable accuracy. For 9 of the 43 systems, complete accuracy assessment was not performed due to an oxygen sensitivity (manufacturer's labeling). The bias (according to Bland and Altman) of all 43 evaluated systems ranged from -14.1% to +12.4%.

CONCLUSIONS

From the 34 systems completely assessed, 7 systems did not fulfill the minimal accuracy requirements of the ISO standard. The CE mark apparently does not guarantee that all BG systems provide accuracy according to the standard. Because inaccurate systems bear the risk of false therapeutic decisions, regular and standardized evaluation of BG meters and test strips should be requested in order to ensure adherence to quality standards.

Comparative analysis of the efficacy of continuous glucose monitoring and self-monitoring of blood glucose in type 1 diabetes mellitus

BACKGROUND

Self-monitoring of blood glucose (SMBG) and continuous glucose monitoring (CGM) have been proven effective in improving hemoglobin A1c (HbA1c) and in reducing hypoglycemia in patients with type 1 diabetes mellitus (T1DM). It is not clear, however, if CGM provides further efficacy and safety benefits beyond SMBG in the management of T1DM.

METHODS

MEDLINE (1966-November 2009), COCHRANE REGISTRY (all years), and EMBASE (1980-November 2009), and article bibliographies were searched for randomized controlled trials (RCTs) investigating the use of CGM in patients with T1DM, with clinical outcomes, including HbA1c and hypoglycemia and/or hyperglycemia.

RESULTS

Fourteen RCTs met eligibility criteria [n = 1188 patients, 97.4% with T1DM, age 29.0 ± 14.3 years, diabetes duration 11.7 ± 7.0 years, and baseline HbA1c 8.3 ± 0.8% (mean ± standard deviation)]. Compared with SMBG, the use of CGM was associated with a greater reduction in HbA1c [-0.3% (confidence interval: 0.4, -0.2), p < .0001]. The number of hypoglycemic events was not significantly different between the CGM and SMBG groups (0.52 ± 0.52 versus 0.52 ± 0.63 events/day, p = .5), but duration of hypoglycemia was shorter for the CGM group (75 ± 39 versus 89 ± 19 min/day), with an incremental reduction of hypoglycemia duration of -15.2 min/day, p < .0001. Continuous glucose monitoring also resulted in a shorter duration of hyperglycemia than SMBG (172 ± 125 versus 217 ± 152 min/day, p = .04).

CONCLUSIONS

The use of CGM is associated with improvement in metabolic control in T1DM, with significant short- and long-term reductions in HbA1c and reduction in the duration of periods of hypoglycemia and hyperglycemia versus SMBG.

Continuous glucose monitoring systems for type 1 diabetes mellitus

BACKGROUND

Self-monitoring of blood glucose is essential to optimise glycaemic control in type 1 diabetes mellitus. Continuous glucose monitoring (CGM) systems measure interstitial fluid glucose levels to provide semi-continuous information about glucose levels, which identifies fluctuations that would not have been identified with conventional self-monitoring. Two types of CGM systems can be defined: retrospective systems and real-time systems. Real-time systems continuously provide the actual glucose concentration on a display. Currently, the use of CGM is not common practice and its reimbursement status is a point of debate in many countries.

OBJECTIVES

To assess the effects of CGM systems compared to conventional self-monitoring of blood glucose (SMBG) in patients with diabetes mellitus type 1.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE and CINAHL for the identification of studies. Last search date was June 8, 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing retrospective or real-time CGM with conventional self-monitoring of blood glucose levels or with another type of CGM system in patients with type 1 diabetes mellitus. Primary outcomes were glycaemic control, e.g. level of glycosylated haemoglobin A1c (HbA1c) and health-related quality of life. Secondary outcomes were adverse events and complications, CGM derived glycaemic control, death and costs.

DATA COLLECTION AND ANALYSIS

Two authors independently selected the studies, assessed the risk of bias and performed data-extraction. Although there was clinical and methodological heterogeneity between studies an exploratory meta-analysis was performed on those outcomes the authors felt could be pooled without losing clinical merit.

MAIN RESULTS

The search identified 1366 references. Twenty-two RCTs meeting the inclusion criteria of this review were identified. The results of the meta-analyses (across all age groups) indicate benefit of CGM for patients starting on CGM sensor augmented insulin pump therapy compared to patients using multiple daily injections of insulin (MDI) and standard monitoring blood glucose (SMBG). After six months there was a significant larger decline in HbA1c level for real-time CGM users starting insulin pump therapy compared to patients using MDI and SMBG (mean difference (MD) in change in HbA1c level -0.7%, 95% confidence interval (CI) -0.8% to -0.5%, 2 RCTs, 562 patients, I(2)=84%). The risk of hypoglycaemia was increased for CGM users, but CIs were wide and included unity (4/43 versus 1/35; RR 3.26, 95% CI 0.38 to 27.82 and 21/247 versus 17/248; RR 1.24, 95% CI 0.67 to 2.29). One study reported the occurrence of ketoacidosis from baseline to six months; there was however only one event. Both RCTs were in patients with poorly controlled diabetes.For patients starting with CGM only, the average decline in HbA1c level six months after baseline was also statistically significantly larger for CGM users compared to SMBG users, but much smaller than for patients starting using an insulin pump and CGM at the same time (MD change in HbA1c level -0.2%, 95% CI -0.4% to -0.1%, 6 RCTs, 963 patients, I(2)=55%). On average, there was no significant difference in risk of severe hypoglycaemia or ketoacidosis between CGM and SMBG users. The confidence interval however, was wide and included a decreased as well as an increased risk for CGM users compared to the control group (severe hypoglycaemia: 36/411 versus 33/407; RR 1.02, 95% CI 0.65 to 1.62, 4 RCTs, I(2)=0% and ketoacidosis: 8/411 versus 8/407; RR 0.94, 95% CI 0.36 to 2.40, 4 RCTs, I(2)=0%).Health-related quality of life was reported in five of the 22 studies. In none of these studies a significant difference between CGM and SMBG was found. Diabetes complications, death and costs were not measured.There were no studies in pregnant women with diabetes type 1 and in patients with hypoglycaemia unawareness.

AUTHORS' CONCLUSIONS

There is limited evidence for the effectiveness of real-time continuous glucose monitoring (CGM) use in children, adults and patients with poorly controlled diabetes. The largest improvements in glycaemic control were seen for sensor-augmented insulin pump therapy in patients with poorly controlled diabetes who had not used an insulin pump before. The risk of severe hypoglycaemia or ketoacidosis was not significantly increased for CGM users, but as these events occurred infrequent these results have to be interpreted cautiously.There are indications that higher compliance of wearing the CGM device improves glycosylated haemoglobin A1c level (HbA1c) to a larger extent. 

Efficacy of continuous glucose monitoring in improving glycemic control and reducing hypoglycemia: a systematic review and meta-analysis of randomized trials

OBJECTIVE

We conducted a systematic review and meta-analysis to assess the efficacy of continuous glucose monitoring (CGM) in improving glycemic control and reducing hypoglycemia compared to self-monitored blood glucose (SMBG).

METHODS

We searched MEDLINE, EMBASE, Cochrane Central, Web of Science, and Scopus for randomized trials of adults and children with type 1 or type 2 diabetes mellitus (T1DM or T2DM). Pairs of reviewers independently selected studies, assessed methodological quality, and extracted data. Meta-analytic estimates of treatment effects were generated using a random-effects model.

RESULTS

Nineteen trials were eligible and provided data for meta-analysis. Overall, CGM was associated with a significant reduction in mean hemoglobin A1c [HbA1c; weighted mean difference (WMD) of -0.27% (95% confidence interval [CI] -0.44 to -0.10)]. This was true for adults with T1DM as well as T2DM [WMD -0.50% (95% CI -0.69 to -0.30) and -0.70 (95% CI, -1.14 to -0.27), respectively]. No significant effect was noted in children and adolescents. There was no significant difference in HbA1c reduction between studies of real-time versus non-realtime devices (WMD -0.22%, 95% CI, -0.59 to 0.15 versus -0.30%, 95% CI, -0.49 to -0.10; p for interaction 0.71). The quality of evidence was moderate due to imprecision, suggesting increased risk for bias. Data for the incidence of severe or nocturnal hypoglycemia were sparse and imprecise. In studies that reported patient satisfaction, users felt confident about the device and gave positive reviews.

CONCLUSION

Continuous glucose monitoring seems to help improve glycemic control in adults with T1DM and T2DM. The effect on hypoglycemia incidence is imprecise and unclear. Larger trials with longer follow-up are needed to assess the efficacy of CGM in reducing patient-important complications without significantly increasing the burden of care for patients with diabetes.

Use of continuous glucose monitoring systems in children with type 1 diabetes

Continuous glucose monitoring systems (CGMS) offer a recent technological solution to fear of hypoglycemia and reduction in hyperglycemia. With glucose readings every 5 minutes, and the alarm capabilities to signal rapid increases or decreases in blood glucose, they afford a sense of security for both children and parents. Although children and parents must continue to be vigilant in the treatment of diabetes, CGMS may effectively allow tight diabetes control with earlier detection of hypoglycemia onset. This article provides an overview of CGMS available at the time of publication; new generations of systems have been introduced annually with improvements in sensitivity and user friendliness.

Use of integrated real-time continuous glucose monitoring/insulin pump system in children and adolescents with type 1 diabetes: a 3-year follow-up study

BACKGROUND

Insulin pumps and real-time continuous glucose monitoring devices have recently been combined into the sensor-augmented pump (SAP) system. The objective of this study was the evaluation of the clinical use of SAP in a large series of children with type 1 diabetes using insulin pump therapy.

METHODS

A questionnaire was administered in all pediatric diabetologic centers in Italy; data were analyzed only regarding patients 18 years old or younger and using SAP for 6 months or more.

RESULTS

Among all patients using an insulin pump, 129 (13.5 ± 3.8 years old, with a disease duration of 6.3 ± 3.4 years) have been using SAP for 1.4 ± 0.7 years. Four hundred ninety-three patients (12.9 ± 3.4 years old, with a disease duration of 6.2 ± 3.3 years) using conventional insulin pump therapy for 1.7 ± 0.5 years have been evaluated as the control group. After 0.5-3 years of using SAP or conventional insulin pump therapy, glycosylated hemoglobin significantly improved (8.0 ± 1.5% vs. 7.4 ± 0.8% [P = 0.002] and 8.0 ± 1.6% vs. 7.7 ± 1.1% [P = 0.006], respectively); the improvement was higher with SAP (P = 0.005). Insulin requirement showed a significant decrease only in SAP patients (0.88 ± 0.25 vs. 0.7 ± 0.23 U/kg/day, P = 0.003). Body mass index did not change during the observation period. No diabetic ketoacidosis episodes were observed during the follow-up, and severe hypoglycemia significantly decreased in SAP patients (P = 0.04).

CONCLUSIONS

The increased availability of continuous glucose sensors is likely to have a significant impact on pediatric diabetes therapy and education in the near future. In daily settings, patients using SAP can achieve a better control than patients using conventional insulin pump.

Treatment of severe diabetic hypoglycemia with glucagon: an underutilized therapeutic approach

Tight glycemic control is important in reducing and delaying vascular complications in type 1 and 2 diabetes patients; however, the benefits achieved through strict metabolic control are counterbalanced by an increased risk of hypoglycemia. Glucagon is an effective therapy for treating severe hypoglycemia. Available as an emergency kit, glucagon is an essential tool for rapid response, but remains underappreciated and underused. This article reviews the role of glucagon in treating severe hypoglycemia and discusses the need for better education on glucagon for people with diabetes and their caregivers in order to alleviate fears of hypoglycemia and of administering glucagon in the event of an emergency.

Assessing glycaemic variability with continuous glucose monitoring system before and after continuous subcutaneous insulin infusion in people with Type 1 diabetes

We evaluated glycaemic variability with continuous glucose monitoring system in 31 people with Type 1 diabetes mellitus using multiple daily injections initially and after switching to continuous subcutaneous insulin infusion. There was a significant improvement in HbA1c, mean glucose, standard deviation of mean glucose and in hyperglycaemic excursions with CSII.

Use of a real-time continuous glucose monitoring system in children and young adults on insulin pump therapy: patients' and caregivers' perception of benefit

BACKGROUND

Real-time continuous glucose monitoring systems (RT-CGMS) are a recently introduced technology for type 1 diabetes and experience in children is limited.

OBJECTIVE

To assess patient and caregiver's perception of benefits and disadvantages of RT-CGMS in children or young adults with type 1 diabetes mellitus (DM) on insulin pump therapy.

SUBJECTS AND METHODS

Forty-three subjects (3-25 yr) on insulin pump therapy were included in the study. Thirty-four used RT-CGMS for a short-term trial (4 wk, ST group) and nine as a long-term tool (2-18 months, LT group). Forty subjects or their caregivers completed a questionnaire.

RESULTS

On the basis of the questionnaire responses, hypoglycemia prevention was the most common perceived benefit (88%), followed by elimination of hypoglycemia-related anxiety (83%), ease of pattern management (85%), improvement of diabetes control (80%), improvement of quality of life (78%), and ease of diabetes care (78%). Negative effects included irritation/annoyance from the sensor alarm (48%) and insertion site bruising, pain, or irritation (43%). A small percentage of patients who were interested in purchasing the device (12%) decided against using it LT after a 4-wk trial on RT-CGMS.

CONCLUSIONS

The most common perceived benefits of RT-CGMS are prevention of hypoglycemia and decrease in hypoglycemia-related anxiety. Negative effects are uncommon and seem to be unlikely to affect the decision to use RT-CGMS for a LT. A ST trial seems to be a valuable tool for the patient/caregiver in determining whether to purchase the device and in setting realistic expectations of its potential benefits.

An overview and commentary on retrospective, continuous glucose monitoring for the optimisation of care for people with diabetes

INTRODUCTION

Normoglycaemia in people with diabetes results in improved outcome. Continuous glucose monitoring provides detailed diagnostic information used to optimise therapy with the goal of achieving normoglycaemia. The objective of this study was to review the published literature evaluating the single device available for blinded, professional clinical use of continuous glucose monitoring; in particular all randomised controlled trials (RCTs) and relevant observational studies.

METHODS

Published studies (to 31 March 2009) using the Medtronic MiniMed Continuous Glucose Monitoring System (CGMS System Gold, Medtronic MiniMed, Inc., Northridge, CA) were identified using appropriate search terms in a series of clinical databases including: Medline, Pubmed, Google Scholar and Scientific Web of Knowledge. Other measures were also taken such as reviewing the reference lists.

FINDINGS

In addition to an extensive range of non-randomised studies using the device, seven randomised controlled trials were identified, of which five were in children. Although HbA1c was explicitly stated as the primary endpoint in four studies, the studies were only adequately powered to detect large, between-group minimum differences (range 0.5 to 1.0% HbA1c). Only two studies included subjects with type 2 diabetes. Other endpoints included the frequency of hypoglycaemia and hyperglycaemia. Within-group HbA1c decreases were observed in all but one study. The crude, weighted mean improvement in HbA1c across the studies using the device was 0.6% (range 0% to 0.8%). When compared to a control measure the weighted, mean marginal benefit in HbA1c was 0.2%. No studies recorded how the information was utilised to modify treatment, such as changes in dose titration or treatment regimen.

CONCLUSIONS

Devices such as the professional CGMS provide detailed diagnostic information. However, any consequent changes in care and outcome can only result from the appropriate application of this information. Although there was a notable improvement in glucose control (HbA1c), existing studies were largely underpowered and did not capture the resulting treatment changes that could lead to improved outcome.

Multicentre, randomised, controlled study of the impact of continuous sub-cutaneous glucose monitoring (GlucoDay) on glycaemic control in type 1 and type 2 diabetes patients

AIM

This randomised study was designed to investigate the impact of continuous glucose monitoring (CGM) for 48h on glycaemic control with a 3-month follow-up in patients with type 1 (T1D) or type 2 (T2D) diabetes.

METHODS

A total of 48 patients with poor glycaemic control (HbA(1c): 8-10.5%) underwent CGM for 48h using the GlucoDay((R)) system (A. Menarini Diagnostics), after which they were randomly assigned to treatment adjustments based on either their CGM profile (CGM group) or their usual self-monitoring of blood glucose (SMBG group). HbA(1c) measurement and 48-h CGM were repeated 3 months later.

RESULTS

Altogether, 34 patients with either T1D (n=9) or T2D (n=25) completed the study; seven patients chose to leave the study, and seven patients in the CGM group were excluded because their baseline CGM graphs were not interpretable. HbA(1c) levels decreased significantly in the CGM group (n=14, -0.63+/-0.27%; P=0.023), but not in the controls (n=20, -0.28+/-0.21%; P=0.30). In T2D patients, the improvement associated with CGM vs SMBG was due to HbA(1c) decreases (mean: -0.63+/-0.34%; P=0.05 vs -0.31+/-0.29%; P=0.18, respectively). However, HbA(1c) did not change significantly with CGM in T1D patients. Comparisons of CGM data at baseline and after 3 months showed no significant changes in glucose control, glucose variability or hypoglycaemia. No major adverse events related to the GlucoDay system were reported.

CONCLUSION

This is the first randomised study showing that CGM improves glycaemic control in patients with T2D.

TheClinical Research Tool: a high-performance microdialysis-based system for reliably measuring interstitial fluid glucose concentration

BACKGROUND

A novel microdialysis-based continuous glucose monitoring system, the so-called Clinical Research Tool (CRT), is presented. The CRT was designed exclusively for investigational use to offer high analytical accuracy and reliability. The CRT was built to avoid signal artifacts due to catheter clogging, flow obstruction by air bubbles, and flow variation caused by inconstant pumping. For differentiation between physiological events and system artifacts, the sensor current, counter electrode and polarization voltage, battery voltage, sensor temperature, and flow rate are recorded at a rate of 1 Hz.

METHOD

In vitro characterization with buffered glucose solutions (c(glucose) = 0 - 26 x 10(-3) mol liter(-1)) over 120 h yielded a mean absolute relative error (MARE) of 2.9 +/- 0.9% and a recorded mean flow rate of 330 +/- 48 nl/min with periodic flow rate variation amounting to 24 +/- 7%. The first 120 h in vivo testing was conducted with five type 1 diabetes subjects wearing two systems each. A mean flow rate of 350 +/- 59 nl/min and a periodic variation of 22 +/- 6% were recorded.

RESULTS

Utilizing 3 blood glucose measurements per day and a physical lag time of 1980 s, retrospective calibration of the 10 in vivo experiments yielded a MARE value of 12.4 +/- 5.7. Clarke error grid analysis resulted in 81.0%, 16.6%, 0.8%, 1.6%, and 0% in regions A, B, C, D, and E, respectively.

CONCLUSION

The CRT demonstrates exceptional reliability of system operation and very good measurement performance. The ability to differentiate between artifacts and physiological effects suggests the use of the CRT as a reference tool in clinical investigations.

Randomized controlled trial to assess the impact of continuous glucose monitoring on HbA(1c) in insulin-treated diabetes (MITRE Study)

AIMS

To determine whether continuous glucose information provided through use of either the GlucoWatch G2 Biographer or the MiniMed continuous glucose monitoring system (CGMS) results in improved glycated haemoglobin (HbA(1c)) for insulin-treated adults with diabetes mellitus, relative to an attention control and standard care group.

METHODS

Four hundred and four adults taking at least two daily insulin injections and with two consecutive HbA(1c) values > or = 7.5% were recruited to this randomized controlled trial (RCT). All were trained at baseline to use the same monitor for traditional capillary glucose testing throughout the 18-month study. The CGMS group were asked to wear the device three times during the first 3 months of the trial and on another three occasions thereafter. The GlucoWatch group wore the device a minimum of four times per month and a maximum of four times per week during the first 3 months and as desired for the remainder of the trial. Trained diabetes research nurses used downloaded data to guide therapy adjustments. Proportional reduction in HbA(1c) from baseline to 18 months was the primary outcome measure.

RESULTS

Neither an intention-to-treat nor per-protocol analysis showed improvement in HbA(1c) in the device groups compared with standard care. For the intention-to-treat analysis, when the standard care group was compared with each of the other groups, this equated to differences in mean relative HbA(1c) reduction (95% confidence interval) from baseline to 18 months of 3.5% (-1.3 to 8.3; GlucoWatch), 0.7% (-4.1 to 5.5; CGMS), and -0.1% (-4.6 to 4.3; attention control).

CONCLUSIONS

The additional information provided by these devices did not result in improvements in HbA(1c) in this population.

Study of glucose profiles with continuous glucose monitoring in adolescents with poorly controlled type 2 diabetes mellitus

AIM

To evaluate glycemic excursions in adolescents with poorly controlled type 2 diabetes mellitus (DM2).

METHODS

Seventeen adolescents (12 F/5 M) underwent glucose monitoring for 3 days using a continuous glucose monitoring system (CGMS). Glucose measurements were divided into periods of euglycemia, hyperglycemia, and hypoglycemia. The percentage of each period, average glucose concentration per 24 h, day and night, the number of excursions, and area under the curve (AUC) of glucose >150 mg/dl and <70 mg/dl were calculated.

RESULTS

On average, patients remained in euglycemia for 28.5%, hyperglycemia for 70%, and hypoglycemia 1.3% of the total day. Hyperglycemic excursions were more frequent during the day. Hypoglycemic events were more frequent during the night. 24-h average glucose, duration of glucose >150 mg/dl, and AUC >150 mg/dl correlate with HbA1c and fructosamine to varying degrees.

CONCLUSION

Continuous glucose monitoring provide valuable information on glucose excursions in adolescents with poorly controlled DM2 and may be helpful in improving metabolic control of poorly controlled adolescents with DM2.

[Is silent hypoglycemia part of ideal glycemic control in DM1 patients? - hypoglycemic state by CGMS vs. glycemic average]

BACKGROUND

To evaluate the impact of silent hypoglycemic state in glycemic control in type 1 diabetic patients (DM1) by CGMS.

METHODS

87 DM1 patients (45%M/55%F) submitted to a 72 h CGMS profile were classified in 4 groups. It was analyzed: unrecognized hypoglycemia (<70 mg/dL); duration time of silent hypoglycemia in which patients were classified into G1 (<5%), G2 (5-10%), G3 (10-20%) and G4 (>20%) of hypoglycemic state by CGMS; A1c and mean capillary glucose (MCG) in each group.

RESULTS

The silent hypoglycemia was detected in 64.5% of patients and nighttime episodes of hypoglycemia lasted longer (min) than daytime episodes in all groups (p<0.001). It was verified 41.4% of patients under than 5% of time in hypoglycemic state, 21.8% between 5-10%, 23% between 10-20% and 13.8% with more than 20% of CGMS in silent hypoglycemia. This data showed significant decreased in MCG when the duration time of silent hypoglycemia was longer (p=0.006).

CONCLUSION

The silent hypoglycemia is common in DM1 patients and most frequently in night time period. To take an average glycemia of 120-160 mg/dL in these patients, it was necessary a 10-20% of CGMS period in silent hypoglycemia in these patients.

A review of current evidence with continuous glucose monitoring in patients with diabetes

Devices that measure glucose on a near-continuous basis may provide a better insight into glycemic profiles, allowing patients with diabetes to make therapeutic adjustments to improve metabolic control, thereby reducing the risk of diabetic complications. Motivated and technologically adept patients with brittle diabetes, hypoglycemia unawareness, diabetic pregnancy, or who use pumps might benefit.Current evidence of continuous glucose monitoring (CGM) on health outcome in patients with diabetes is critically reviewed. No data are available on chronic complications or mortality. Therefore, surrogate endpoints need to be investigated, particularly HbA1c, number of hypo- and hyperglycemic episodes, time within normal, high, or low glucose concentrations, glycemic variability, and quality of life.Randomized controlled trials (RCTs) using CGM in a retrospective way did not show metabolic improvement. In contrast, most RCTs applying real-time CGM showed a decrease in HbA1c, reduced glycemic variability, and a diminished number and length of hypo- and hyperglycemic events. Using accurate, real-time CGM devices improves quality of life by reducing the fear of unexpected hypoglycemic events. These beneficial effects were observed despite the fact that in most studies no clear treatment algorithm based on CGM results was provided to the patients. However, most trials were too short in duration, with a variable use of CGM, and were performed in small study samples.In conclusion, real-time CGM systems can improve metabolic control, reduce hypoglycemic episodes, and improve quality of life. Whether this holds true for longer time periods and in the majority of patients remains to be proven. In the long term, CGM might help to reduce chronic diabetes complications and perhaps also mortality, thereby reducing health care costs.

The effect of continuous subcutaneous glucose monitoring (CGMS) versus intermittent whole blood finger-stick glucose monitoring (SBGM) on hemoglobin A1c (HBA1c) levels in Type I diabetic patients: a systematic review

BACKGROUND AND PURPOSE

Continuous glucose monitoring (CGMS) is a relatively new technology that measures interstitial glucose every 5 min for 72 h. The resulting profile provides a more comprehensive measure of glycemic excursions than intermittent self-blood finger-stick glucose monitoring (SBGM) and thus could potentially improve diabetes control. We performed a meta-analysis of randomized controlled trials comparing CGMS and SBGM in Type 1 diabetic patients. Our aim was to determine whether CGMS leads to better hemoglobin A1c (HBA1c) levels, a marker of long-term vascular risk.

METHODS

Randomized controlled trials comparing CGMS and SBGM in Type 1 diabetic patients were identified using both manual and electronic searches of the literature in MEDLINE, EMBASE, PUBMED and Cochrane Central Registry of Controlled Trials from 1996 to March 2007. Relevant studies were independently selected by two reviewers, who also extracted data on study design, quality and effect on HBA1c levels. Data from all trials were pooled using a random effects model.

RESULTS

Seven studies with a total of 335 patients fulfilled the inclusion criteria. Five studies were confined to the pediatric population (age<18 years). Study duration varied from 12 to 24 weeks. Compared with SBGM, CGMS was associated with a non-significant reduction in HBA1c (0.22%; 95% CI: -0.439% to 0.004%, p=0.055).

CONCLUSIONS

There is insufficient evidence to support the notion that CGMS provides a superior benefit over SBGM in terms of HBA1c reduction. There was some indication of improved detection of asymptomatic nocturnal hypoglycemia in the CGMS group.

[Insulin therapy for type 1 diabetes mellitus: past and present]

The discovery of insulin can be considered the milestone of diabetes mellitus history and a great achievement for its treatment. The first insulin available was the regular. Afterwards, Hagedorn added the protamine to the insulin, thus, creating the NPH insulin. In the 1950s an insulin free of protamine was synthesized: the lente insulin. With the advent of molecular biology, synthetic human insulin was synthesized using recombinant DNA technology. Most recently several types of insulin analogues were available, providing the patients with better metabolic control. Type 1 diabetes mellitus treatment includes plain substitution and individualization for short-acting plus long-acting insulin according to the physician's assistance, besides regular practice of physical activities and diet orientations. In type 1 diabetes mellitus the insulin of low variability is the best choice since basal/bolus insulin therapy or continuous subcutaneous insulin infusion pump can mimetize the physiological release of insulin by beta cells.

[Continuous glucose monitoring system (CGMS) in type 1 diabetic patients during 4 (96h) or 5 (120h) days: there is advantage?]

BACKGROUND

To evaluate the accuracy, complications and impact in glycemic control in type 1 diabetic patients (DM1) submitted to 4 or 5 days of CGMS.

METHODS

We studied 36 DM1 patients (44.5%M/55.5%F), in three groups without no difference about age, DM duration and A1c levels (p < 0.05), submitted to 72h (G1), 96h (G2) and 120h (G3) CGMS profile. It were analyzed: capillary glycemia (CG) and mean CGMS sensors glycemic value; correlation coefficient, median absolute percent difference (MAD%), number of sensor reading, complications (trauma, local infection, disconnection, dropped), postprandial hyperglycemia, unrecognized hypoglycemia (< 70 mg/dl). A1c levels were measured at the start (1 month before) and after 3 and 12 months in each group.

RESULTS

No technical difference were observed into 3 groups: correlation coefficient > 0.79 and MAD < 28% in 95% (p < 0.01). The use of CGMS sensor more than 72h was not related to signal error, trauma, local infection or disconnection. The mean capillary glucose values showed no difference by glucose CGMS sensor (p = 0.01) in all groups. The nighttime episodes of hypoglycemia lasted longer (min) than daytime episodes in all groups (p = 0.05). The postprandial hyperglycemia was statistically identified in groups 1 and 3. This data showed significant decreased A1c level three months after the CGMS in G1 (72h) and G3 (120h) (p < 0.001 and p = 0.002, respectively), which sustained after 1 year (p < 0.001 e p = 0.047, respectively).

CONCLUSIONS

The CGMS showed to be a very safety method, with high accuracy/technical efficacy in patients undergoing 96 h and 120 h of CGMS. We do not observed advantages in the use of CGMS during 96 h or 120 h against 72 h in decrease A1c levels after 3 and 12 months. It is possible the use of CGMS > 72h, with no technical damage. However, we do not observed significant clinical benefits of this conduct in DM1 patients.

Continuous glucose monitoring and diabetes health outcomes: a critical appraisal

This paper presents a critical review of continuous glucose monitoring studies that address accuracy, utility in assessing glucose variability, detection of hypoglycemia for improved metabolic control or reduced glucose variability, impact on quality of life, reduced fear of hypoglycemia, and applicability in helping patients to overcome their reluctance to intensify insulin therapy. This analysis can be used to delineate the evidence that is still missing when considering continuous glucose monitoring as an established tool in clinical practice and for reimbursement of the system and services.

[How the continuous glucose monitoring system can contribute to HbA1c interpretation in type 1 diabetes mellitus?]

The aim of the present study is a literature revision of the contribution of continuous glucose monitoring system (CGMS) in the interpretation of HbA1c levels in type 1 diabetes (T1DM). We performed a revision of the efficacy, benefits, interpretation of methods and experience with this system. The CGMS could be useful in T1DM patients that present great glycemic variability or severe hypoglycemia (mainly nocturnal) and postprandial hyperglycemia. The identification of altered patterns or the glycemic variability allows therapeutic adjustment and improvement of the metabolic control. CGMS is a safe method with a rare occurrence of side effects and it is well-tolerated by patients. The extension of the procedure for more days, over the 72h period recommended by the standard test, allows us to get important data to changes and adjustments on the insulin management of the type 1 diabetes mellitus patients.

Continuous Glucose Monitoring System in children with type 1 diabetes mellitus: a systematic review and meta-analysis

AIMS/HYPOTHESIS

We investigated the potential effects of the Continuous Glucose Monitoring System (CGMS), as compared with self-monitoring of blood glucose, on glycaemic control in children with type 1 diabetes.

METHODS

The following electronic databases were searched throughout June 2007: MEDLINE, EMBASE and The Cochrane Library. Additional references were obtained from reviewed articles. Only randomised controlled trials were included.

RESULTS

We included five trials involving 131 type 1 diabetic patients in the study. Combined data from all trials showed that the CGMS did not significantly reduce HbA1c levels compared with control groups. The pooled weighted mean difference was -0.02% (95% CI -0.29 to 0.25) with a fixed model and remained insignificant in the random effect model. Sensitivity analysis determined that the findings were stable. There was a trend towards a longer time under the CGMS curve for glucose <3.89 mmol/l in the CGMS group compared with the control group (mean difference 49.00 min, 95% CI -18.00 to 116.00). The CGMS significantly increased the number of insulin dose changes per patient per month for those managed with CGMS compared with the control groups (mean difference 6.3 changes, 95% CI 2.88-9.72).

CONCLUSIONS/INTERPRETATION

The Continuous Glucose Monitoring System is not better than self-monitoring of blood glucose with regard to improvement of metabolic control among type 1 diabetic children. However, due to the small number of participants and methodological limitations of the studies included, findings of this meta-analysis should be interpreted with caution.