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

Effectiveness of DialBetesPlus, a self-management support system for diabetic kidney disease: Randomized controlled trial

We evaluated the effectiveness of a mobile health (mHealth) intervention for diabetic kidney disease patients by conducting a 12-month randomized controlled trial among 126 type 2 diabetes mellitus patients with moderately increased albuminuria (urinary albumin-to-creatinine ratio (UACR): 30-299 mg/g creatinine) recruited from eight clinical sites in Japan. Using a Theory of Planned Behavior (TPB) behavior change theory framework, the intervention provides patients detailed information in order to improve patient control over exercise and dietary behaviors. In addition to standard care, the intervention group received DialBetesPlus, a self-management support system allowing patients to monitor exercise, blood glucose, diet, blood pressure, and body weight via a smartphone application. The primary outcome, change in UACR after 12 months (used as a surrogate measure of renal function), was 28.8% better than the control group's change (P = 0.029). Secondary outcomes also improved in the intervention group, including a 0.32-point better change in HbA1c percentage (P = 0.041). These improvements persisted when models were adjusted to account for the impacts of coadministration of drugs targeting albuminuria (GLP-1 receptor agonists, SGLT-2 inhibitors, ACE inhibitors, and ARBs) (UACR: -32.3% [95% CI: -49.2%, -9.8%] between-group difference in change, P = 0.008). Exploratory multivariate regression analysis suggests that the improvements were primarily due to levels of exercise. This is the first trial to show that a lifestyle intervention via mHealth achieved a clinically-significant improvement in moderately increased albuminuria.

Effectiveness of continuous glucose monitoring in maintaining glycaemic control among people with type 1 diabetes mellitus: a systematic review of randomised controlled trials and meta-analysis

AIMS/HYPOTHESIS

The aim of this work was to assess the effectiveness of continuous glucose monitoring (CGM) vs self-monitoring of blood glucose (SMBG) in maintaining glycaemic control among people with type 1 diabetes mellitus.

METHODS

Cochrane Library, PubMed, Embase, CINAHL, Scopus, trial registries and grey literature were searched from 9 June 2011 until 22 December 2020 for RCTs comparing CGM intervention against SMBG control among the non-pregnant individuals with type 1 diabetes mellitus of all ages and both sexes on multiple daily injections or continuous subcutaneous insulin infusion with HbA1c levels, severe hypoglycaemia and diabetic ketoacidosis (DKA) as outcomes. Studies also included any individual or caregiver-led CGM systems. Studies involving GlucoWatch were excluded. Risk of bias was appraised with Cochrane risk of bias tool. Meta-analysis and meta-regression were performed using Review Manager software and R software, respectively. Heterogeneity was evaluated using χ2 and I2 statistics. Overall effects and certainty of evidence were evaluated using Z statistic and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) software.

RESULTS

Twenty-two studies, involving 2188 individuals with type 1 diabetes, were identified. Most studies had low risk of bias. Meta-analysis of 21 studies involving 2149 individuals revealed that CGM significantly decreased HbA1c levels compared with SMBG (mean difference -2.46 mmol/mol [-0.23%] [95% CI -3.83, -1.08], Z = 3.50, p=0.0005), with larger effects experienced among higher baseline HbA1c >64 mmol/mol (>8%) individuals (mean difference -4.67 mmol/mol [-0.43%] [95% CI -6.04, -3.30], Z = 6.69, p<0.00001). However, CGM had no influence on the number of severe hypoglycaemia (p=0.13) and DKA events (p=0.88). Certainty of evidence was moderate.

CONCLUSIONS/INTERPRETATION

CGM is superior to SMBG in improving glycaemic control among individuals with type 1 diabetes in the community, especially in those with uncontrolled glycaemia. Individuals with type 1 diabetes with HbA1c >64 mmol/mol (>8%) are most likely to benefit from CGM. Current findings could not confer a concrete conclusion on the effectiveness of CGM on DKA outcome as DKA incidences were rare. Current evidence is also limited to outpatient settings. Future research should evaluate the accuracy of CGM and the effectiveness of CGM across different age groups and insulin regimens as these remain unclear in this paper.

PROSPERO REGISTRATION

Registration no. CRD42020207042.

FUNDING

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Correlation between short- and mid-term hemoglobin A1c and glycemic control determined by continuous glucose monitoring

BACKGROUND

Glucose monitoring is vital for glycemic control in patients with diabetes mellitus (DM). Continuous glucose monitoring (CGM) measures whole-day glucose levels. Hemoglobin A1c (HbA1c) is a vital outcome predictor in patients with DM.

METHODS

This study investigated the relationship between HbA1c and CGM, which remained unclear hitherto. Data of patients with DM (n = 91) who received CGM and HbA1c testing (1-3 months before and after CGM) were retrospectively analyzed. Diurnal and nocturnal glucose, highest CGM data (10%, 25%, and 50%), mean amplitude of glycemic excursions (MAGE), percent coefficient of variation (%CV), and continuous overlapping net glycemic action were compared with HbA1c values before and after CGM.

RESULTS

The CGM results were significantly correlated with HbA1c values measured 1 (r = 0.69) and 2 (r = 0.39) months after CGM and 1 month (r = 0.35) before CGM. However, glucose levels recorded in CGM did not correlate with the HbA1c values 3 months after and 2-3 months before CGM. MAGE and %CV were strongly correlated with HbA1c values 1 and 2 months after CGM, respectively. Diurnal blood glucose levels were significantly correlated with HbA1c values 1-2 months before and 1 month after CGM. The nocturnal blood glucose levels were significantly correlated with HbA1c values 1-3 months before and 1-2 months after CGM.

CONCLUSIONS

CGM can predict HbA1c values within 1 month after CGM in patients with DM.

Current treatment options and challenges in patients with Type 1 diabetes: Pharmacological, technical advances and future perspectives

Type 1 diabetes mellitus imposes a significant burden of complications and mortality, despite important advances in treatment: subjects affected by this disease have also a worse quality of life-related to disease management. To overcome these challenges, different new approaches have been proposed, such as new insulin formulations or innovative devices. The introduction of insulin pumps allows a more physiological insulin administration with a reduction of HbA1c level and hypoglycemic risk. New continuous glucose monitoring systems with better accuracy have allowed, not only better glucose control, but also the improvement of the quality of life. Integration of these devices with control algorithms brought to the creation of the first artificial pancreas, able to independently gain metabolic control without the risk of hypo- and hyperglycemic crisis. This approach has revolutionized the management of diabetes both in terms of quality of life and glucose control. However, complete independence from exogenous insulin will be obtained only by biological approaches that foresee the replacement of functional beta cells obtained from stem cells: this will be a major challenge but the biggest hope for the subjects with type 1 diabetes. In this review, we will outline the current scenario of innovative diabetes management both from a technological and biological point of view, and we will also forecast some cutting-edge approaches to reduce the challenges that hamper the definitive cure of diabetes.

Very Selective Detection of Low Physiopathological Glucose Levels by Spontaneous Raman Spectroscopy with Univariate Data Analysis

After decades of research on non-invasive glucose monitoring, invasive devices based on finger blood sampling are still the predominant reference for diabetic patients for accurately measuring blood glucose levels. Meanwhile, research continues improving point-of-care technology toward the development of painless and more accurate devices. Raman spectroscopy is well-known as a potentially valuable and painless approach for measuring glucose levels. However, previous Raman studies deal with glucose concentrations that are still order of magnitudes away with respect to human tissues’ physiological concentrations, or they propose enhancement methodologies either invasive or much complex to assure sufficient sensitivity in the physiological range. Instead, this study proposes an alternative non-enhanced Raman spectroscopy approach sensitive to glucose concentrations from 1 to 5 mmol/l, which correspond to the lowest physiopathological glucose level in human blood. Our findings suggest a very selective detection of glucose with respect to other typical metabolites, usually interfering with Raman spectroscopy’s glucose detection. We validate the proposed univariate sensing methodology on glucose solutions mixed with lactate and urea, the two most common molecules found in human serum with concentrations similar to glucose and similar features in the Raman spectra. Our findings clearly illustrate that reliable detection of glucose by Raman spectroscopy is feasible by exploiting the shifted peak at 1125 ± 10 cm–1 within physiopathological ranges.

Lessons from Use of Continuous Glucose Monitoring Systems in Digital Healthcare

We live in a digital world where a variety of wearable medical devices are available. These technologies enable us to measure our health in our daily lives. It is increasingly possible to manage our own health directly through data gathered from these wearable devices. Likewise, healthcare professionals have also been able to indirectly monitor patients' health. Healthcare professionals have accepted that digital technologies will play an increasingly important role in healthcare. Wearable technologies allow better collection of personal medical data, which healthcare professionals can use to improve the quality of healthcare provided to the public. The use of continuous glucose monitoring systems (CGMS) is the most representative and desirable case in the adoption of digital technology in healthcare. Using the case of CGMS and examining its use from the perspective of healthcare professionals, this paper discusses the necessary adjustments required in clinical practices. There is a need for various stakeholders, such as medical staff, patients, industry partners, and policy-makers, to utilize and harness the potential of digital technology.

Effect of Diabetes Education Through Pattern Management on Self-Care and Self-Efficacy in Patients with Type 2 Diabetes

This study investigated the effect of applying a customized diabetes education program through pattern management (PM), using continuous glucose monitoring system (CGMS) results, on individual self-care behaviors and self-efficacy in patients with type 2 diabetes mellitus. Patients with type 2 diabetes who had never received diabetes education, enrolled from March to September 2017, were sequentially assigned to either PM education or control groups. In the PM education group, the CGMS test was first conducted one week before diabetes education and repeated three times by PM in order to obtain data on self-care behaviors and self-efficacy. These results were then compared before and after education at three and six months. The control group received the traditional diabetes education. Self-efficacy showed statistically significant interactions between the two groups over time, indicating a significant difference in the degree of self-efficacy between the PM education and control groups. Diabetes education by PM using CGMS result analysis improved life habits with a positive influence on self-care behaviors and self-efficacy for diabetes management. Further studies are needed to further develop and apply individual diabetes education programs in order to sustain the effects of self-care behaviors and self-efficacy in patients with diabetes who experience a decrease in self-efficacy after three months of education.

Impact of Insulin Delivery Method on Hypoglycemia Incidence in Pediatric Type 1 Diabetes Mellitus Patients

Introduction

Insulin therapy of pediatric patients with type 1 diabetes mellitus (T1DM) is highly demanding due to their dynamic growth, development and different daily life activities.

Goal

To determine the optimal insulin delivery method for the prevention of hypoglycemia recorded by continuous monitoring of glucose in patients with insulin pump and PEN.

Material and Methods

The study included patients up to 18 years of age with diagnosed T1DM and treated with insulin pump and by insulin therapy with PEN at the Pediatric Clinic of the Clinical Center in Sarajevo. The study involved 149 patients, and lasted for 3 years. Patients were divided into two groups: group of patients on insulin pump therapy and group on insulin PEN.

Results

There were 73 patients (49.6%) on insulin pump therapy and 79 patients (52.4%) on the insulin PEN therapy. There was no significant difference in the age between genders nor groups with different insulin application methods. There were no significant differences in the number of anamnestic hypoglycemia in patients with a different mode of insulin application (83.56% vs. 81.58%, p=0.114, F=2.533 < Fk=3.919). The number of hypoglycemia episodes in history is higher with the PEN therapy than in the insulin pump group.

Conclusion

The number of anamnesis hypoglycemia as well as hypoglycemia from CGM records did not differ significantly in patients with IP and PEN therapy. The CGM record was significantly more valuable in the presentation of hypoglycemia compared to the history of hypoglycemia in all patients studied. Continuous monitoring of glycemia due to the ability to show glycemia variability and unrecognized hypoglycemia as well as predictive options for long-term metabolic control should be performed for all T1DM patients at least once a year.

Real-time continuous glucose monitoring in type 1 diabetes: a systematic review and individual patient data meta-analysis

BACKGROUND

Real-time continuous glucose monitoring (RTCGM) may help in the management of individuals with type 1 diabetes mellitus (T1DM); however, the evidence supporting its use is unclear. The available meta-analyses on this topic use aggregate data which weaken inference.

OBJECTIVE

Individual patient data were obtained from randomized controlled trials (RCTs) to conduct a meta-analysis and synthesize evidence about the effect of RTCGM on glycosylated haemoglobin (HbA1c), hypoglycaemic events and time spent in hypoglycaemia in T1DM.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, and Scopus through January 2015. We included RCTs that enrolled individuals with T1DM and compared RTCGM vs control group. A two-step regression model was used to pool individual patient data.

RESULTS

We included 11 RCTs at moderate risk of bias. Meta-analysis suggests that the use of RTCGM is associated with a statistically significant but modest reduction in HbA1c (-0·276; 95% confidence interval -0·465 to -0·087). The improvements in HbA1c were primarily seen in individuals over age 15 years. We were unable to identify a statistically significant difference in time spent in hypoglycaemia or the number of hypoglycaemic episodes although these analyses were imprecise and warrant lower confidence. There was no difference between males and females.

CONCLUSION

RTCGM in T1DM is associated with a reduction in HbA1c primarily in individuals over 15 years of age. We were unable to identify a statistically significant difference in the time spent in hypoglycaemia or the incidence of hypoglycaemic episodes.

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.

Modeling and Measurement of Correlation between Blood and Interstitial Glucose Changes

One of the most effective methods for continuous blood glucose monitoring is to continuously measure glucose in the interstitial fluid (ISF). However, multiple physiological factors can modulate glucose concentrations and affect the lag phase between blood and ISF glucose changes. This study aims to develop a compensatory tool for measuring the delay in ISF glucose variations in reference to blood glucose changes. A theoretical model was developed based on biophysics and physiology of glucose transport in the microcirculation system. Blood and interstitial fluid glucose changes were measured in mice and rats by fluorescent and isotope methods, respectively. Computer simulation mimicked curves were fitted with data resulting from fluorescent measurements of mice and isotope measurements of rats, indicating that there were lag times for ISF glucose changes. It also showed that there was a required diffusion distance for glucose to travel from center of capillaries to interstitial space in both mouse and rat models. We conclude that it is feasible with the developed model to continuously monitor dynamic changes of blood glucose concentration through measuring glucose changes in ISF with high accuracy, which requires correct parameters for determining and compensating for the delay time of glucose changes in ISF.

Use of continuous glucose monitoring to identify glucose dysregulation in growth hormone insensitivity syndrome

BACKGROUND/AIMS

Monogenic forms of growth hormone insensitivity (GHI) and its treatment with recombinant insulin-like growth factor-1 (rIGF-1) are both associated with glucose dysregulation. We used the information provided by continuous glucose monitoring systems (CGMS) for the clinical management of two children with monogenic GHI prior to the commencement of therapy as well as during the years when they received rIGF-1 treatment and continued to do so after the cessation of therapy.

METHODS

We evaluated the extent of hyper- and hypoglycaemia with CGMS.

RESULTS

In one patient, before treatment CGMS identified self-limiting nocturnal hypoglycaemia. Initiation of rIGF-1 treatment resulted in severe and persistent hypoglycaemia with an absence of spontaneous recovery. Corrective dietary measures were instituted. In a second patient, who had a poor growth response to rIGF-1 therapy, CGMS identified significant fluctuations in daytime glucose levels whilst on treatment with evidence of postprandial hyperglycaemia and both rebound and nocturnal hypoglycaemia. Given the lack of improved growth and the documented glucose dysregulation, treatment was stopped and repeat measurements with CGMS 1 month afterwards showed complete resolution.

CONCLUSIONS

We have demonstrated that CGMS is an effective tool to assess glucose dysregulation in patients with GHI and alters clinical management.

Evidence-informed clinical practice recommendations for treatment of type 1 diabetes complicated by problematic hypoglycemia

Problematic hypoglycemia, defined as two or more episodes per year of severe hypoglycemia or as one episode associated with impaired awareness of hypoglycemia, extreme glycemic lability, or major fear and maladaptive behavior, is a challenge, especially for patients with long-standing type 1 diabetes. Individualized therapy for such patients should include a composite target: optimal glucose control without problematic hypoglycemia. Therefore, we propose a tiered, four-stage algorithm based on evidence of efficacy given the limitations of educational, technological, and transplant interventions. All patients with problematic hypoglycemia should undergo structured or hypoglycemia-specific education programs (stage 1). Glycemic and hypoglycemia treatment targets should be individualized and reassessed every 3-6 months. If targets are not met, one diabetes technology-continuous subcutaneous insulin infusion or continuous glucose monitoring-should be added (stage 2). For patients with continued problematic hypoglycemia despite education (stage 1) and one diabetes technology (stage 2), sensor-augmented insulin pumps preferably with an automated low-glucose suspend feature and/or very frequent contact with a specialized hypoglycemia service can reduce hypoglycemia (stage 3). For patients whose problematic hypoglycemia persists, islet or pancreas transplant should be considered (stage 4). This algorithm provides an evidence-informed approach to resolving problematic hypoglycemia; it should be used as a guide, with individual patient circumstances directing suitability and acceptability to ensure the prudent use of technology and scarce transplant resources. Standardized reporting of hypoglycemia outcomes and inclusion of patients with problematic hypoglycemia in studies of new interventions may help to guide future therapeutic strategies.

Continuous glucose monitoring in insulin-treated patients in non-ICU settings

Inpatient hyperglycemia, in patients with and without a history of diabetes, is associated with increased risk of complications, mortality, and longer hospital stay in medicine and surgical patients. Bedside capillary point of care testing is widely recommended as the preferred method for glucose monitoring and for guiding glycemic management of individual patients; however, the accuracy of most handheld glucose meters is far from optimal. Recent studies in the hospital setting have reported that the use of continuous glucose monitoring (CGM) can provide real-time information about glucose concentration, direction, and rate of change over a period of several days. Because it provides glucose values every 5-10 minutes 24 hours a day, CGM may have an advantage over point of care testing with respect to reducing the incidence of severe hypoglycemia in acute care. Real-time CGM technology may facilitate glycemic control and to reduce hypoglycemia in insulin-treated patients. Recent guidelines, however, have recommended deferring the use of CGM in the adult hospital setting until further data on accuracy and safety become available. In this study, we review the advantages and disadvantages of the use of real-time CGM in the management of dysglycemia in the hospital setting.

Continuous glucose monitoring system: Is it really accurate, safe and clinically useful?

The continuous glucose monitoring system (CGM) has been used for constant checking of glucose level by measuring interstitial glucose concentrations, since the early days of the 21st century. It can potentially improve diabetes care if used carefully with the understanding of the characteristics of this system. Although there is a time lag of approximately 5–15 min between blood and interstitial glucose levels, the system is considered the most suitable device for meticulous glucose control and prevention of hypoglycemia. A large number of studies have examined its accuracy, safety and clinical effectiveness. The continuous glucose‐error grid analysis (CG‐EGA), designed by WL Clarke, evaluates the clinical accuracy of CGM. It examines ‘temporal’ characteristics of the data, analyzing pairs of reference and sensor readings as a process in time represented by a ‘bidimensional’ time series and taking into account inherent physiological time lags. Investment in CG‐EGA is clearly meaningful, even though there are other methodologies for evaluation. The use of each method complementarily is the most effective way to prove the accuracy of the device. The device has improved gradually, and real‐time CGM, which allows real‐time monitoring of blood glucose level, is already available commercially. The use of real‐time CGM could potentially lead to over‐ or undertreatment with insulin. Patient education through proper and effective handling of the new device is essential to improve diabetes care. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00197.x, 2012)

Recommendations for self-monitoring in pediatric diabetes: a consensus statement by the ISPED

A panel of experts of the Italian Society of Pediatric Endocrinology and Diabetology comprehensively discussed and approved the Italian recommendations regarding self-monitoring of blood glucose, continuous glucose monitoring and other measures of glycemic control in children and adolescents with type 1 diabetes. After an extensive review of the literature, we took these issues into account: self-monitoring blood glucose, continuous glucose monitoring, glycemic variability, glycosuria, ketonuria, ketonemia, glycated hemoglobin, fructosamine and glycated albumin, logbook, data downloading, lancing devices, carbohydrate counting, and glycemic measurements at school. We concluded that clinical guidelines on self-management should be developed in every country with faithful adaptation to local languages and taking into account specific contexts and local peculiarities, without any substantial modifications to the international recommendations. We believe that the National Health Service should provide all necessary resources to ensure self-monitoring of blood glucose and possibly continuous glucose monitoring of all children and adolescents with type 1 diabetes, according to the standards of care provided by these recommendations and internationally.

Relationship between HbA1c and continuous glucose monitoring in Chinese population: a multicenter study

Objective

Since there is a paucity of reference data in the literature to indicate the relationship between HbA1c, and 24 h mean blood glucose (MBG) from continuous glucose monitoring (CGM) in Chinese populations, we described the above relationship in adult Chinese subjects with different glucose tolerance status.

Methods

Seven-hundred-and-forty-two individuals without history of diabetes were included to the study at 11 hospitals in urban areas across China from 2007–2009 and data of 673 subjects were included into the final analysis. Oral glucose tolerance test (OGTT) classified the participants as nondiabetic subjects, including those with normal glucose regulation (NGR; n = 121) and impaired glucose regulation (IGR; n = 209), or newly diagnosed type 2 diabetes (n = 343). All participants completed testing for HbA1c levels and wore a CGM system for three consecutive days. The 24 h MBG levels were calculated. Spearman correlations and linear regression analyses were applied to quantify the relationship between glucose markers.

Results

The levels of HbA1c and 24 h MBG significantly increased with presence of glucose intolerance (NGR<IGR<type 2 diabetes; both, P<0.001). Analysis of the total population indicated that HbA1c was strongly correlated with 24 h MBG (r = 0.735). The correlation was also found to be significant for the subgroup of participants with newly diagnosed type 2 diabetes (r = 0.694, P<0.001). Linear regression analysis of the total study population yielded the following equation: 24 h MBG _mmol/L = 1.198×HbA1c–0.582 (24 h MBG _mg/dL = 21.564×HbA1c–10.476) (R² = 0.670, P<0.001). The model fit was not improved by application of exponential or quadratic modeling. When HbA1c was 6.5%, the calculated 24 h MBG was 7.2 (6.4–8.1) mmol/L (130 (115–146) mg/dL); and when HbA1c was 7.0%, the 24 h MBG was 7.8 (6.9–8.7) mmol/L (140 (124–157) mg/dL).

Conclusions

Our study provided the reference data of the relationship between HbA1c and CGM in Chinese subjects.

Continuous Glucose Monitoring Systems: A Review

There have been continuous advances in the field of glucose monitoring during the last four decades, which have led to the development of highly evolved blood glucose meters, non-invasive glucose monitoring (NGM) devices and continuous glucose monitoring systems (CGMS). Glucose monitoring is an integral part of diabetes management, and the maintenance of physiological blood glucose concentration is the only way for a diabetic to avoid life-threatening diabetic complications. CGMS have led to tremendous improvements in diabetic management, as shown by the significant lowering of glycated hemoglobin (HbA1c) in adults with type I diabetes. Most of the CGMS have been minimally-invasive, although the more recent ones are based on NGM techniques. This manuscript reviews the advances in CGMS for diabetes management along with the future prospects and the challenges involved.

The role of continuous glucose monitoring in the care of children with type 1 diabetes

Continuous glucose monitoring (CGM), while a relatively new technology, has the potential to transform care for children with type 1 diabetes. Some, but not all studies, have shown that CGM can significantly improve hemoglobin A1c levels and reduce time spent in the hypoglycemic range in children, particularly when used as part of sensor-augmented pump (SAP) therapy. Despite the publication of recent clinical practice guidelines suggesting CGM be offered to all children 8 years of age or older who are likely to benefit, and studies showing that younger children can also benefit, this technology is not yet commonly used by children with type 1 diabetes. Effects of CGM are enhanced when used on a near-daily basis (a use-dependent effect) and with insulin pump therapy. Therefore, coordinated strategies are needed to help children and their families initiate and continue to use this resource for diabetes care. This review introduces CGM to pediatric endocrinologists who are not yet familiar with the finer details of this technology, summarizes current data showing the benefits and limitations of CGM use in children, reviews specific case examples demonstrating when CGM can be helpful, and shows the value of both retrospective and real-time CGM. It is hoped that this information leads to discussion of this technology in pediatric endocrinology clinics as an important next step in improving the care of children with type 1 diabetes.

The lived experiences of young people (13-16 years) with Type 1 diabetes mellitus and their parents--a qualitative phenomenological study

AIMS

Within a programme of research aiming to develop a technology-based educational intervention for young people with Type 1 diabetes, this study aimed to explore adolescents' and parents' experiences of living with Type 1 diabetes from an interpretive phenomenological perspective.

METHODS

In-depth interviews were conducted with 20 adolescents with Type 1 diabetes from a diabetes clinic in North West England, and 27 of their parents.

RESULTS

Living with Type 1 diabetes in adolescence was characterized by three distinct stages: (1) adapting to the diagnosis; (2) learning to live with Type 1 diabetes; (3) becoming independent. Experiential learning was key to adolescents developing self-management skills and independence. Parents and health professionals were instrumental in facilitating environments that gave adolescents the freedom to learn through trial and error. They also provided the support, feedback and discussion necessary to facilitate such learning.

CONCLUSIONS

For adolescents to become independent in Type 1 diabetes self-management, they must develop capability through experiential learning. It is important that parents and health professionals understand the important role they play in this process and have the skills to support adolescents in this way. Data from this study have been used to develop an online interactive 'Adolescent Diabetes Needs Assessment Tool', which assesses individual learning and support needs to aid the process of feedback and discussion.

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.

Blood glucose monitoring: an overview

Glucose monitoring is done to obtain information on blood glucose levels to ensure a therapeutic regimen; the aim is to maintain consistent glucose levels and avoid hypoglycaemia and hyperglycaemia. Self-management is central to diabetes control. Diabetes is individual, so self-monitoring of blood glucose (SMBG) targets and frequency of testing must be decided to meet each patient's needs. Nurses have key roles in education and advocacy. They can educate patients on what affects glucose levels, why they need to carry out SMBG, and how to interpret and act on the results. Nurses also match glucose monitoring meters to patients' needs by considering ease of use, technical features and lifestyle. Access to testing supplies is sometimes restricted through blanket policies and nurses have an advocacy role here in challenging inappropriate restrictions.

Estimating average glucose levels from glycated albumin in patients with end-stage renal disease

PURPOSE

In patients with diabetic end stage renal disease (ESRD), glycated albumin (GA) reflects recent glycemic control more accurately than glycated hemoglobin (HbA1c). We evaluated the relationship between GA and average blood glucose (AG) level and developed an estimating equation for translating GA values into easier-to-understand AG levels.

MATERIALS AND METHODS

A total of 185 ESRD patients, including 154 diabetic and 31 non-diabetic participants, were enrolled (108 hemodialysis, 77 peritoneal dialysis). Patients were asked to perform four-point daily self-monitoring of capillary blood glucose (SMBG) at least three consecutive days each week for four weeks. Serum levels of GA, HbA1c and other biochemical parameters were checked at baseline, as well as at 4 and 8 weeks.

RESULTS

Approximately 74.3±7.0 SMBG readings were obtained from each participant and mean AG was 169.1±48.2 mg/dL. The correlation coefficient between serum GA and AG levels (r=0.70, p<0.001) was higher than that of HbA1c and AG (r=0.54, p<0.001). Linear regression analysis yielded the following equation: estimated AG (eAG) (mg/dL)=4.71×GA%+73.35, and with this formula, serum GA levels could be easily translated to eAG levels. Multivariate analysis revealed significant contributions of postprandial hyperglycemia (β=0.25, p=0.03) and serum albumin (β=0.17, p=0.04) in determining serum GA level, independent to other clinical parameters.

CONCLUSION

Compared to HbA1c, serum GA levels were better correlated with AG levels. Using the estimating equation, an average blood glucose level of 155-160 mg/dL could be matched to a GA value of 18-19% in patients with ESRD.

Beneficial effect of real-time continuous glucose monitoring system on glycemic control in type 1 diabetic patients: systematic review and meta-analysis of randomized trials

OBJECTIVE

Real-time continuous glucose monitoring (RT-CGM) provides detailed information on glucose patterns and trends, thus allowing the patients to manage their diabetes more effectively.

DESIGN

The aim of this study was to explore the potential beneficial effects of the use of RT-CGM on diabetes management compared with self blood glucose measurement (SBGM) in patients with type 1 diabetes mellitus (T1DM), by means of a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched through by two independent investigators for RCTs concerning the use of RT-CGM in patients with T1DM. Only studies with a similar insulin regimen in the experimental and control groups were included in the analysis.

RESULTS

Seven RCTs (n=948) met the inclusion criteria. Combined data from all studies showed better HbA1c reduction in subjects using RT-CGM compared with those using SBGM (mean difference (MD) -0.25; 95% confidence interval (95% CI): from -0.34 to -0.17; P<0.001). Patients treated with insulin pump and RT-CGM had a lower HbA1c level compared with subjects managed with insulin pump and SBGM (four RCTs, n=497; MD -0.26; 95% CI: from -0.43 to -0.10; P=0.002). The benefits of applying RT-CGM were not associated with an increasing rate of major hypoglycemic episodes. The use of RT-CGM for over 60-70% of time was associated with a significant lowering of HbA1c.

CONCLUSIONS

RT-CGM is more beneficial than SBGM in reducing HbA1c in patients with type 1 diabetes. Further studies are needed to evaluate the efficacy of this system in the pediatric population, especially in very young children.

Continuous glucose monitoring in children, adolescents, and adults with type 1 diabetes mellitus: analysis from the prospective DPV diabetes documentation and quality management system from Germany and Austria

OBJECTIVE

To determine frequency, duration, and relationship of continuous glucose monitoring (CGM) to glycemic control and rate of hypoglycemia in children and adults in Germany and Austria.

RESEARCH DESIGN AND METHODS

From 59,920 patients documented in the DPV (Diabetessoftware zur prospektiven Verlaufsdokumentation) database, 144,385 sensor days of 2874 patients using CGM between January 2008 and September 2010 were analyzed.

RESULTS

Overall, 4.8% of patients used CGM. In pediatric patients, study period (p = 0.0309), age (p = 0.0140), insulin dose (p < 0.0001), and use of insulin analogs (p < 0.0001) significantly influenced hemoglobin A1c (HbA1c), but duration of diabetes, sex, and CGM use did not. In contrast, adults with longer CGM use (>30 d) had significantly lower HbA1c (p < 0.0016). Severe hypoglycemia was not reduced in patients using CGM for <30 d.

CONCLUSIONS

CGM is still rarely used in Germany and Austria. CGM use is associated with a significant reduction of HbA1c in adults but not in children. Hypoglycemic events were not reduced, irrespective of age.

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. 

Deus ex machina: the use of technology in type 1 diabetes

Deus ex machina: in ancient Greek theatre, towards the end of a performance, a crane-like device was often used to lower an actor playing a god onto the stage in order to solve an apparently intractable problem in a plot-line. Nowadays, perceived wisdom believes that difficult clinical scenarios in diabetes can be alleviated by the introduction of technologies such as insulin pump therapy and glucose sensing. This "God from the Machine" approach to problem solving has been enthusiastically embraced by a small number of enthusiasts within the diabetes care community but access to these technologies is still very limited in the UK. The question is can the use of technology reduce or even eliminate the biological and psychological variables that prevent people living with diabetes achieving the standard of blood glucose control desired and if so should availability be more widespread?

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.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence-Based Laboratory Medicine Committee of the American Association for Clinical Chemistry jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (HbA(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of HbA(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence Based Laboratory Medicine Committee of the AACC jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (Hb A(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of Hb A(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Continuous glucose monitoring using a novel glucose/galactose binding protein: results of a 12-hour feasibility study with the becton dickinson glucose/galactose binding protein sensor

AIM

This study evaluated the performance characteristics of a prototype Becton Dickinson (BD) (Franklin Lakes, NJ) glucose/galactose binding protein (GGBP) sensor placed intradermally (BD-ID) or subcutaneously (BD-SC) for continuous glucose monitoring.

MATERIALS AND METHODS

The performance characteristics of the prototype BD GGBP sensor after intradermal or subcutaneous placement were assessed, and its accuracy was compared with that of a glucose oxidase (GOx)-based sensor and a standard laboratory method (YSI STAT2300 analyzer, Yellow Springs Instrument, Yellow Springs, OH) under glucose clamp conditions and during an off-clamp meal challenge in 40 patients with type 1 or 2 diabetes in a 12-h feasibility study.

RESULTS

BD-ID and BD-SC sensors performed as well as or better than the GOx-based sensor (differences in median absolute percentage error 2-4 points in hyperglycemic and euglycemic regions, ≥ 10 points in the hypoglycemic region). For glucose values ≤ 100 mg/dL, the percentage of measurement values in consensus error plot Zone A was substantially higher with the GGBP sensors than the GOx-based sensor.

CONCLUSIONS

The BD prototype sensor demonstrated competitive accuracy relative to a GOx-based sensor and a YSI blood standard with a single calibration and minimal warm-up. Current development work is focused on the design and manufacture of a commercially feasible device that will include marked enhancements to device robustness and longevity.

The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults

This article reviews the evidence and nutrition practice recommendations from the American Dietetic Association's nutrition practice guidelines for type 1 and type 2 diabetes in adults. The research literature was reviewed to answer nutrition practice questions and resulted in 29 recommendations. Here, we present the recommendations and provide a comprehensive and systematic review of the evidence associated with their development. Major nutrition therapy factors reviewed are carbohydrate (intake, sucrose, non-nutritive sweeteners, glycemic index, and fiber), protein intake, cardiovascular disease, and weight management. Contributing factors to nutrition therapy reviewed are physical activity and glucose monitoring. Based on individualized nutrition therapy client/patient goals and lifestyle changes the client/patient is willing and able to make, registered dietitians can select appropriate interventions based on key recommendations that include consistency in day-to-day carbohydrate intake, adjusting insulin doses to match carbohydrate intake, substitution of sucrose-containing foods, usual protein intake, cardioprotective nutrition interventions, weight management strategies, regular physical activity, and use of self-monitored blood glucose data. The evidence is strong that medical nutrition therapy provided by registered dietitians is an effective and essential therapy in the management of diabetes.

Effects of a novel short-term continuous subcutaneous insulin infusion program evaluated by continuous glucose monitoring on young adult type 1 diabetic patients in Taiwan

The aim of this study is to evaluate the effectiveness of blood sugar control by a short-course reinforcement program, consisting of using continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) for young adult type 1 diabetic patients. Twenty-six pump-naïve type 1 diabetic patients were successively enrolled in two years. The mean disease duration was 13 years and the mean HbA1c was 8.8 %. Initially, a 3-day course of CGM was used to evaluate the baseline glycemic status of the subjects, followed by 6-day intensive insulin adjustment by CSII therapy. Thereafter, a second course of CGM was performed to evaluate the effectiveness of our outcomes in comparison to the initial measurements. All participants received necessary education and instruction as required throughout the course of the program. The glucose variability as measured by standard deviation of plasma glucose and mean amplitude of glucose excursion decreased significantly (67.8 ± 2.7 to 52.0 ± 1.8 mg/dL and 140.4 ± 6.5 to 105.5 ± 5.3 mg/dL, p < 0.001). The hypoglycemic events noted per patient were reduced by 46.4% (p = 0.003) and occurred significantly less often during nocturnal periods (-63.2%, p = 0.002). Following the adjustment, the mean daily insulin requirement was reduced by 28.05% (from 0.82 to 0.59 IU/kg) and the new proportion of 40% as basal insulin was found. The short-term CSII program provided significant improvement in blood sugar control for type 1 diabetic patients, by reducing hypoglycemic events, glucose excursion, and insulin dosage in our examined subjects.

Pascal's wager: combining continuous glucose monitoring and continuous subcutaneous insulin infusion

Pascal's Wager is a suggestion posed by the French Philosopher, Blaise Pascal, that even though the existence of God cannot be determined through reason, a person should wager that God exists because he or she has everything to gain and nothing to lose. In the area of consideration here, the optimum experimental trial of the combined use of continuous subcutaneous insulin infusion and real-time continuous glucose monitoring in free-living individuals with type 1 diabetes providing rock-solid evidence of clinical benefit has not been performed. Nevertheless, there is considerable enthusiasm for combining the technologies among healthcare professionals, patients, and manufacturers based on the belief that this approach to diabetes care must be beneficial beyond the available evidence (i.e., reason).

Individualizing Care for the Many

Purpose

A generation of individuals with diabetes has come of age since the Diabetes Control and Complications Trial and the United Kingdom Prospective Diabetes Study, providing demonstrable evidence that optimal glycemic control, achieved early with intensive therapy, yields a durable beneficial effect. Yet realizing the full potential of intensive therapy requires more frequent glucose monitoring and accurate interpretation of data. Because patients typically check no more than 3 or 4 times per day and rarely during the night, glucose variability, including glycemic spikes and asymptomatic hypoglycemia, may be missed. Short-term use of a professional continuous glucose monitoring (CGM) device, worn by patients without access to real-time data, reveals patterns of high and low blood glucose undetectable by self-monitoring of blood glucose (SMBG) alone. Clinicians interpret the continuous profile retrospectively to identify and adjust components of the insulin regimen responsible for nocturnal hypoglycemia, postprandial hyperglycemia, and other glucose excursions. This supplement discusses how professional CGM, used as an adjunct to SMBG, can help patients understand the effects of their behavior on glycemic control and consider the potential utility of diabetes technology in transforming knowledge to action.

Conclusion

Strategic implementation of professional CGM may improve the time- and cost-effectiveness of diabetes care while advancing more personalized treatment in the course of everyday practice.

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.

Economic and clinical impact of inpatient diabetic hypoglycemia

OBJECTIVE

To assess the clinical and economic impact of hypoglycemia that develops during hospitalization of patients with diabetes.

METHODS

In this retrospective cohort study, data from 70 hospitals were used to identify the first inpatient encounter for adult patients with diabetes. Patients were included if all blood glucose measurements were 70 mg/dL or higher during the first 24 hours and their primary discharge diagnosis was for a condition other than hypoglycemia. Those who developed laboratory evidence of hypoglycemia (blood glucose <70 mg/dL after 24 hours) were compared with patients whose blood glucose values were all 70 mg/dL or higher. An alternative definition of hypoglycemia (blood glucose <50 mg/dL after 24 hours) was also evaluated. We adjusted for potential confounders with multivariate models.

RESULTS

Hypoglycemia had an adverse effect on all outcomes among more than 100,000 diabetic patients. After adjustment, patients with diabetes who developed hypoglycemia had higher charges (38.9%), longer lengths of stay (3.0 days), higher mortality (odds ratio, 1.07; 95% confidence interval, 1.02-1.11), and higher odds of being discharged to a skilled nursing facility (odds ratio, 1.58; 95% confidence interval, 1.48-1.69) than diabetic patients without hypoglycemia (P<.01 for all). In all cases, using the lower threshold (<50 mg/dL) to define hypoglycemia resulted in similar findings with a larger magnitude of differences.

CONCLUSIONS

Although a direct causal relationship cannot be inferred, these study findings suggest the importance of carefully maintaining euglycemia during hospitalizations. Whether the observed worse outcomes were due to hypoglycemia itself or whether they were a marker of worse outcomes due to other causes requires further research.

Exercise and glucose metabolism in persons with diabetes mellitus: perspectives on the role for continuous glucose monitoring

Exercise causes profound changes in glucose homeostasis. For people with type 1 diabetes, aerobic exercise usually causes blood glucose concentration to drop rapidly, while anaerobic exercise may cause it to rise, thereby making glycemic control challenging. Having the capacity to know their glucose levels and the direction of change during exercise increases self-efficacy in these persons who are prone to hypo- and hyperglycemia. For people with type 2 diabetes, learning first hand that regular exercise improves glucose levels may be a motivating factor in getting them to be more active. Continuous glucose monitoring is a potentially useful adjunct to diabetes management for the active person with either forms of diabetes. This review aims to guide the reader to use this technology to its maximum advantage by providing an overview of technical features, performance characteristics, and clinical utility, all balanced against the limitations that may be more prominent during physical activity.

Continuous glucose monitoring in youth with type 1 diabetes

Continuous glucose monitoring (CGM) is becoming increasingly popular and represents the third era of diabetes management. Currently available CGM devices have been studied in youth with type 1 diabetes and show similar accuracy across all age groups. Tolerability of these devices relates to alarm settings, sensor skin irritation, and durability of the device. Youth will be most successful on a CGM regimen if they have a personal investment in wearing the CGM device and have a stable support system for their diabetes care. Data indicate that glycemic control improves the most in youth who wear CGM devices >or=5 days per week, allowing for the ability to make more insulin dose changes. CGM has proven useful in alerting youth to hypoglycemia and may be a valuable tool with exercise. Further studies are needed to assess the utility of CGM for prevention of severe hypoglycemic events and increasing time spent in euglycemia. Fear of hypoglycemia may be ameliorated with CGM use; however, the potential for increased stress in families with continuous feedback must also be considered. In the future, CGM use in youth may couple with insulin pump technology to create a "closed-loop" system in which the CGM device will direct insulin administration without user input.

The correlation of hemoglobin A1c to blood glucose

The understanding that hemoglobin A1c (HbA1c) represents the average blood glucose level of patients over the previous 120 days underlies the current management of diabetes. Even in making such a statement, we speak of "average blood glucose" as though "blood glucose" were itself a simple idea. When we consider all the blood glucose forms-arterial versus venous versus capillary, whole blood versus serum versus fluoride-preserved plasma, fasting versus nonfasting-we can start to see that this is not a simple issue. Nevertheless, it seems as though HbA1c correlates to any single glucose measurement. Having more than one measurement and taking those measurements in the preceding month improves the correlation further. In particular, by having glucose measurements that reflect both the relatively lower overnight glucose levels and measurements that reflect the postprandial peaks improves not only our ability to manage diabetes patients, but also our understanding of how HbA1c levels are determined. Modern continuous glucose monitoring (CGM) devices may take thousands of glucose results over a week. Several studies have shown that CGM glucose averages account for the vast proportion of the variation of HbA1c. The ability to relate HbA1c to average glucose may become a popular method for reporting HbA1c, eliminating current concerns regarding differences in HbA1c standardization. Hemoglobin A1c expressed as an average glucose may be more understandable to patients and improve not only their understanding, but also their ability to improve their diabetes management.