Incremental value of continuous glucose monitoring when starting pump therapy in patients with poorly controlled type 1 diabetes: the RealTrend study

A new-generation continuous glucose monitoring system: improved accuracy and reliability compared with a previous-generation system

BACKGROUND

Use of continuous glucose monitoring (CGM) systems can improve glycemic control, but widespread adoption of CGM utilization has been limited, in part because of real and perceived problems with accuracy and reliability. This study compared accuracy and performance metrics for a new-generation CGM system with those of a previous-generation device.

SUBJECTS AND METHODS

Subjects were enrolled in a 7-day, open-label, multicenter pivotal study. Sensor readings were compared with venous YSI measurements (blood glucose analyzer from YSI Inc., Yellow Springs, OH) every 15 min (±5 min) during in-clinic visits. The aggregate and individual sensor accuracy and reliability of a new CGM system, the Dexcom(®) (San Diego, CA) G4™ PLATINUM (DG4P), were compared with those of the previous CGM system, the Dexcom SEVEN(®) PLUS (DSP).

RESULTS

Both study design and subject characteristics were similar. The aggregate mean absolute relative difference (MARD) for DG4P was 13% compared with 16% for DSP (P<0.0001), and 82% of DG4P readings were within ± 20 mg/dL (for YSI ≤ 80 mg/dL) or 20% of YSI values (for YSI >80 mg/dL) compared with 76% for DSP (P<0.001). Ninety percent of the DG4P sensors had an individual MARD ≤ 20% compared with only 76% of DSP sensors (P=0.015). Half of DG4P sensors had a MARD less than 12.5% compared with 14% for the DSP sensors (P=0.028). The mean absolute difference for biochemical hypoglycemia (YSI <70 mg/dL) for DG4P was 11 mg/dL compared with 16 mg/dL for DSP (P<0.001).

CONCLUSIONS

The performance of DG4P was significantly improved compared with that of DSP, which may increase routine clinical use of CGM and improve patient outcomes.

Novel molecular and nanosensors for in vivo sensing

In vivo sensors are an emerging field with the potential to revolutionize our understanding of basic biology and our treatment of disease. In this review, we highlight recent advances in the fields of in vivo electrochemical, optical, and magnetic resonance biosensors with a focus on recent developments that have been validated in rodent models or human subjects. In addition, we discuss major challenges in the development and translation of in vivo biosensors and present potential solutions to these problems. The field of nanotechnology, in particular, has recently been instrumental in driving the field of in vivo sensors forward. We conclude with a discussion of emerging paradigms and techniques for the development of future biosensors.

The effect of real-time continuous glucose monitoring in pregnant women with diabetes: a randomized controlled trial

OBJECTIVE

To assess whether intermittent real-time continuous glucose monitoring (CGM) improves glycemic control and pregnancy outcome in unselected women with pregestational diabetes.

RESEARCH DESIGN AND METHODS

A total of 123 women with type 1 diabetes and 31 women with type 2 diabetes were randomized to use real-time CGM for 6 days at 8, 12, 21, 27, and 33 weeks in addition to routine care, including self-monitored plasma glucose seven times daily, or routine care only. To optimize glycemic control, real-time CGM readings were evaluated by a diabetes caregiver. HbA1c, self-monitored plasma glucose, severe hypoglycemia, and pregnancy outcomes were recorded, with large-for-gestational-age infants as the primary outcome.

RESULTS

Women assigned to real-time CGM (n = 79) had baseline HbA1c similar to that of women in the control arm (n = 75) (median 6.6 [range 5.3-10.0] vs. 6.8% [5.3-10.7]; P = 0.67) (49 [34-86] vs. 51 mmol/mol [34-93]). Forty-nine (64%) women used real-time CGM per protocol. At 33 weeks, HbA1c (6.1 [5.1-7.8] vs. 6.1% [4.8-8.2]; P = 0.39) (43 [32-62] vs. 43 mmol/mol [29-66]) and self-monitored plasma glucose (6.2 [4.7-7.9] vs. 6.2 mmol/L [4.9-7.9]; P = 0.64) were comparable regardless of real-time CGM use, and a similar fraction of women had experienced severe hypoglycemia (16 vs. 16%; P = 0.91). The prevalence of large-for-gestational-age infants (45 vs. 34%; P = 0.19) and other perinatal outcomes were comparable between the arms.

CONCLUSIONS

In this randomized trial, intermittent use of real-time CGM in pregnancy, in addition to self-monitored plasma glucose seven times daily, did not improve glycemic control or pregnancy outcome in women with pregestational diabetes.

Real-time continuous glucose monitoring or continuous subcutaneous insulin infusion, what goes first?: results of a pilot study

BACKGROUND

Dual devices allow both continuous subcutaneous insulin infusion (CSII) and real-time (RT) continuous glucose monitoring (CGM). Patients usually start with CSII, adding RT-CGM later (CGM post-CSII). Lack of use of RT-CGM is the main limiting factor of dual device results. Initiating RT-CGM before CSII (CGM pre-CSII) could increase RT-CGM frequency use and further improve glycemic control.

SUBJECTS AND METHODS

In this 26-week pilot study, we randomly assigned, via sealed envelopes, 16 CSII and RT-CGM to naive patients 14 years of age or older with type 1 diabetes mellitus (T1DM) to CGM post-CSII or CGM pre-CSII. The Paradigm® Veo™ (Medtronic Inc., Northridge, CA) was the dual device used in all patients. The primary end point was frequency of use of RT-CGM between both groups at week 26.

RESULTS

We detected a significant higher RT-CGM frequency use in the CGM pre-CSII group at week 26 (78.4±10.9% vs. 56.0±40.8%; P=0.01), although we did not detect hemoglobin A1c level differences. In addition, CGM pre-CSII patients presented less time in hypoglycemia (average daily area under curve <70 mg/dL per 24 h, 0.87±1.02 mg/dL/day vs. 3.32±2.19 mg/dL/day; P=0.021), and no severe hypoglycemia events were detected during 26 weeks in this group.

CONCLUSIONS

CGM pre-CSII is effective in increasing RT-CGM frequency use in T1DM patients. This is accompanied by a significant reduction in time in hypoglycemia.

Detection of glycemic abnormalities in adolescents with beta thalassemia using continuous glucose monitoring and oral glucose tolerance in adolescents and young adults with β-thalassemia major: Pilot study

BACKGROUND

Both insulin deficiency and resistance are reported in patients with β-thalassemia major (BTM). The use of continuous blood glucose monitoring (CGM), among the different methods for early detection of glycemic abnormalities, has not been studied thoroughly in these adolescents.

MATERIALS AND METHODS

To assess the oralglucose tolerance (OGT) and 72-h continuous glucose concentration by the continuous glucose monitoring system (CGMS) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) was conducted in 16 adolescents with BTM who were receiving regular blood transfusions every 2-4 weeks and iron-chelation therapy since early childhood.

RESULTS

SIXTEEN ADOLESCENTS WITH BTM (AGE: 19.75 ± 3 years) were investigated. Using OGTT, (25%) had impaired fasting blood (plasma) glucose concentration (BG) (>5.6 mmol/L). 2-h after the glucose load, one of them had BG = 16.2 mmol/L (diabetic) and two had impaired glucose tolerance (IGT) (BG > 7.8 and <11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGMS,4 adolescents were diagnosed with diabetes (25%) (BG >11.1 mmol/L) and 9 with IGT (56%). HOMA and QUICKI revealed levels <2.6 (1.6 ± 0.8) and >0.33 (0.36 ± 0.03), respectively, ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B%) on one hand and the fasting and the 2-h BG (r=-0.6, and - 0.48, P < 0.01, respectively) on the other hand. Neither fasting serum insulin nor c-peptide concentrations were correlated with fasting BG or ferritin levels. The average and maximum blood glucose levels during CGM were significantly correlated with the fasting BG (r = 0.68 and 0.39, respectively, with P < 0.01) and with the BG at 2-hour after oral glucose intake (r = 0.87 and 0.86 respectively, with P < 0.001). Ferritin concentrations were correlated with the fasting BG and the 2-h blood glucose levels in the OGTT (r = 0.52, and r = 0.43, respectively, P < 0.01) as well as with the average BG recorded by CGM (r = 0.75, P < 0.01).

CONCLUSION

CGM has proven to be superior to OGTT for the diagnosis of glycemic abnormalities in adolescents with BTM. Defective β-cell function rather than insulin resistance appeared to be the cause for these abnormalities.

Routine sensor-augmented pump therapy in type 1 diabetes: the INTERPRET study

BACKGROUND

Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia.

SUBJECTS AND METHODS

A 12-month observational study in patients with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII), upon the introduction of continuous glucose monitoring (CGM), was conducted in 15 countries (in Europe and in Israel) to document the real-life use of SAP and assess which variables are associated with improvement in type 1 diabetes management.

RESULTS

Data from 263 patients (38% male; mean age, 28.0 ± 15.7 years [range, 1-69 years]; body mass index, 23.3 ± 4.9 kg/m(2); diabetes duration, 13.9 ± 10.7 years; CSII duration, 2.6 ± 3 years) were collected. Baseline mean glycated hemoglobin A1c (HbA1c) was 8.1 ± 1.4%; 82% had suboptimal HbA1c (≥ 7%). The average sensor use for 12 months was 30% (range, 0-94%), and sensor use decreased with time (first 3 months, 37%; last 3 months, 27%). Factors associated with improvement in HbA1c after 12 months in patients with baseline HbA1c ≥ 7% were high baseline HbA1c (P<0.001), older age group (P<0.001), and more frequent sensor use (P = 0.047). Significantly less hospitalization, increased treatment satisfaction, and reduced fear of hypoglycemia were reported after 12 months of SAP.

CONCLUSIONS

This is the largest and longest multicenter prospective observational study providing real-life data on SAP. These results are consistent with those of controlled trials showing the effectiveness of CGM in pump users.

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.

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.

Use of microneedle array devices for continuous glucose monitoring: a review

Microneedle array devices provide the opportunity to overcome the barrier characteristics of the outermost skin layer, the stratum corneum. This novel technology can be used as a therapeutic tool for transdermal drug delivery, including insulin, or as a diagnostic tool providing access to dermal biofluids, with subsequent analysis of its contents. Over the last decade, the use of microneedle array technology has been the focus of extensive research in the field of transdermal drug delivery. More recently, the diagnostic applications of microneedle technology have been developed. This review summarizes the existing evidence for the use of microneedle array technology as biosensors for continuous monitoring of the glucose content of interstitial fluid, focusing also on mechanics of insertion, microchannel characteristics, and safety profile.

[CGM-continuous glucose monitoring - statement of the Austrian Diabetes Association]

This position statement represents the recommendations of the Austrian Diabetes Association regarding the clinical diagnostic and therapeutic application, safety and benefits of continuous subcutaneous glucose monitoring systems in patients with diabetes mellitus, based on current evidence.

Continuous glucose monitoring: current clinical use

Four kinds of subcutaneous continuous glucose monitoring (CGM) machines have been currently introduced in clinical practice. These machines exhibit real-time glucose on the monitor every 5 minutes and have alarms to indicate hypoglycaemia and hyperglycaemia. However, thus far, there is no clear consensus about the clinical indications for CGM in actual clinical practice. CGM should be an ideal and powerful tool for monitoring glucose variability. Glycaemic variability has become a major concern over the years with growing evidence on its detrimental impact with respect to the risk of diabetic complications. Although the HbA1c level is ubiquitously measures in clinical practice, this level does not adequately represent glycaemic variability. Currently available evidence indicates that CGM aids in lowering the HbA1c level without increasing the incidence of severe hypoglycaemic episodes in patients with type 1 diabetes. Thus far, CGM has not been indicated for preventing severe hypoglycaemia or for treating type 2 diabetes because sufficient supporting evidence has not been obtained. Promising results have been obtained for the use of CGM for pregnant women with diabetes and for patients with hospital hyperglycaemia. Predictions regarding the feasibility of the closed-loop system have proven to be optimistic. CGM-integrated communication systems using information technology such as smart phone help controlling blood glucose more easily and effectively.

The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of this multicentre, randomised, controlled crossover study was to determine the efficacy of adding continuous glucose monitoring (CGM) to insulin pump therapy (CSII) in type 1 diabetes.

METHODS

Children and adults (n = 153) on CSII with HbA(1c) 7.5-9.5% (58.5-80.3 mmol/mol) were randomised to (CGM) a Sensor On or Sensor Off arm for 6 months. After 4 months' washout, participants crossed over to the other arm for 6 months. Paediatric and adult participants were separately electronically randomised through the case report form according to a predefined randomisation sequence in eight secondary and tertiary centres. The primary outcome was the difference in HbA(1c) levels between arms after 6 months.

RESULTS

Seventy-seven participants were randomised to the On/Off sequence and 76 to the Off/On sequence; all were included in the primary analysis. The mean difference in HbA(1c) was -0.43% (-4.74 mmol/mol) in favour of the Sensor On arm (8.04% [64.34 mmol/mol] vs 8.47% [69.08 mmol/mol]; 95% CI -0.32%, -0.55% [-3.50, -6.01 mmol/mol]; p < 0.001). Following cessation of glucose sensing, HbA(1c) reverted to baseline levels. Less time was spent with sensor glucose <3.9 mmol/l during the Sensor On arm than in the Sensor Off arm (19 vs 31 min/day; p = 0.009). The mean number of daily boluses increased in the Sensor On arm (6.8 ± 2.5 vs 5.8 ± 1.9, p < 0.0001), together with the frequency of use of the temporary basal rate (0.75 ± 1.11 vs 0.26 ± 0.47, p < 0.0001) and manual insulin suspend (0.91 ± 1.25 vs 0.70 ± 0.75, p < 0.018) functions. Four vs two events of severe hypoglycaemia occurred in the Sensor On and Sensor Off arm, respectively (p = 0.40).

CONCLUSIONS/INTERPRETATION

Continuous glucose monitoring was associated with decreased HbA(1c) levels and time spent in hypoglycaemia in individuals with type 1 diabetes using CSII. More frequent self-adjustments of insulin therapy may have contributed to these effects.

Sensor-augmented pump therapy at 36 months

BACKGROUND

This follow-up study investigates the metabolic and psychosocial effects of sensor-augmented pump (SAP) therapy in adults with type 1 diabetes 36 months after therapy start.

SUBJECTS AND METHODS

We invited all 24 Danish adults with type 1 diabetes who had previously participated in the European multicenter randomized controlled Eurythmics Trial. Thirteen of the 24 patients started SAP therapy during the Eurythmics Trial; 11 patients were controls but started using SAP immediately after completion of the trial. In the current study, we estimated the effects of SAP 36 months after therapy start by change in glycated hemoglobin (HbA1c) and diabetes questionnaire scores (Diabetes Treatment Satisfactions Questionnaire [DTSQs], Problem Areas in Diabetes [PAID] questionnaire, and Hypoglycemia Fear Survey [HFS]).

RESULTS

At 36 months, 16 of the 24 patients were still using SAP, 14 of them > 70% of time. The HbA1c level decreased from 8.7% at therapy start to 7.3% at 36 months (P < 0.0001). Similar reductions in HbA1c were obtained regardless of whether SAP therapy was initiated during or after the Eurythmics Trial. DTSQs, PAID questionnaire, and HFS scores improved by 9.0 (P < 0.0001), -10.8 (P = 0.013), and -5.5 (P = 0.152), respectively, in the 16 SAP users.

CONCLUSIONS

This study documents persisting beneficial effects of SAP on HbA1c, treatment satisfaction, magnitude of diabetes-related problems, and fear of hypoglycemia 36 months after therapy start. The follow-up is considerably longer than in other published studies; still, the results are in line with the positive short-term outcomes of larger studies of SAP use.

Can continuous glucose monitoring systems predict glycemia?

BACKGROUND

We investigated whether the arrow on a continuous glucose monitoring system (CGMS) screen predicts the course of the capillary glucose level 15 min later.

SUBJECTS AND METHODS

Twenty-three patients with type 1 diabetes (age, 40±13 years; diabetes duration, 19±12 years; hemoglobin A1c, 8.5±1.5%) admitted for education in the use of a CGMS performed 242 observations: the arrow was noted at time 0, and the interstitial and capillary glucose levels were noted at time 0 and 15 min later.

RESULTS

The capillary glucose courses were -15±28 mg/dL after a descending arrow (n=55), +1±23 mg/dL after a stable arrow (n=147) (P<0.001 vs. descending), and +2±23 mg/dL after an ascending arrow (n=40) (P<0.01 vs. descending), with similar findings for the 67 observations after an interstitial glucose level <100 mg/dL. There were 4.5% grossly erroneous arrows: six descending with later increasing and five ascending with later decreasing capillary glucose.

CONCLUSIONS

Although there is a large room for improvement, the arrow on the CGMS screen does predict the decline in capillary glucose 15 min later.

New technologies for diabetes: a review of the present and the future

This review summarizes the technologies in use and in the pipeline for the management of diabetes. The review focuses on glucose meters, continuous glucose monitoring devices, insulin pumps, and getting clinicians connected to technologies. All information presented can be found in the public domain, and was obtained from journal articles, websites, product review tables in patient publications, and professional conferences. The technology concerns, ongoing development and future trends in this area are also discussed.

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.

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.

The accuracy and efficacy of real-time continuous glucose monitoring sensor in Chinese diabetes patients: a multicenter study

BACKGROUND

The purpose of this multicenter study was to investigate the accuracy of a real-time continuous glucose monitoring sensor in Chinese diabetes patients.

SUBJECTS AND METHODS

In total, 48 patients with type 1 or 2 diabetes from three centers in China were included in the study. The MiniMed Paradigm(®) 722 insulin pump (Medtronic, Northridge, CA) was used to monitor the real-time continuous changes of blood glucose levels for three successive days. Venous blood of the subjects was randomly collected every 15 min for seven consecutive hours on the day when the subjects were wearing the sensor. Reference values were provided by the YSI(®) 2300 STAT PLUS™ glucose and lactate analyzer (YSI Life Sciences, Yellow Springs, OH).

RESULTS

In total, 1,317 paired YSI-sensor values were collected from the 48 patients. Of the sensor readings, 88.3% (95% confidence interval, 0.84-0.92) were within±20% of the YSI values, and 95.7% were within±30% of the YSI values. Clarke and consensus error grid analyses showed that the ratios of the YSI-sensor values in Zone A to the values in Zone B were 99.1% and 99.9%, respectively. Continuous error grid analysis showed that the ratios of the YSI-sensor values in the region of accurate reading, benign errors, and erroneous reading were 96.4%, 1.8%, and 1.8%, respectively. The mean absolute relative difference (ARD) for all subjects was 10.4%, and the median ARD was 7.8%. Bland-Altman analysis detected a mean blood glucose level of 3.84 mg/dL. Trend analysis revealed that 86.1% of the difference of the rates of change between the YSI values and the sensor readings occurred within the range of 1 mg/dL/min.

CONCLUSIONS

The Paradigm insulin pump has high accuracy in both monitoring the real-time continuous changes and predicting the trend of changes in blood glucose level. However, actual clinical manifestations should be taken into account for diagnosis of hypoglycemia.

Quality of care of patients with type 1 diabetes: population-based results in a French region

AIM

Although the incidence of type 1 diabetes (T1D) has been increasing, little is known of its quality of care. Thus, our survey was designed to retrospectively evaluate this issue in French patients.

METHODS

Patients with T1D living in northeastern France were identified thanks to the healthcare system (CPAM) database, and the resulting list reviewed by local diabetes specialists. All of the listed patients and their primary physicians were asked to fill in a questionnaire including clinical data, laboratory results and follow-up habits. The 'optimized results' included CPAM-based results plus any specialized care provided during hospitalizations in diabetes and non-diabetes units, according to questionnaire data.

RESULTS

A total of 227 individuals, for whom CPAM data were available, were identified as having T1D. From these patients, 174 questionnaires were answered, and optimized results (having both CPAM data and a completely filled-in questionnaire) were available for 149 patients. Of the 169 patients who responded, 71.3% reported at least a yearly visit with a diabetologist. This number reached 77.9% when optimized results were considered. Patients who received specialized care were younger, underwent HbA(1c) tests more often and were more frequently on optimal treatment; however, there was no difference in HbA(1c) values or in the prevalence of complications. Eye examinations and kidney tests had been performed at least once over the 2-year period in more than 87% of the patients, whereas around 30%, 21% and 23% had an eye exam, creatinine test and urinary albumin excretion measurement, respectively, only once over the same time period.

CONCLUSION

This is the first large-scale study of the quality of care in patients with T1DM in France, and it could serve as a preliminary survey for a national study. Although the follow-up was better than previously reported, there is still considerable room for improvement.

Insight into hypoglycemia in pediatric type 1 diabetes mellitus

Hypoglycemia is a common complication of insulin treatment in type 1 diabetes mellitus and can occur in any patient with diabetes when glucose consumption exceeds supply. Many studies have been done to elucidate those factors that predict severe hypoglycemia: younger age, longer duration of diabetes, lower HgbA1c, higher insulin dose, lower Body Mass Index, male gender, Caucasian race, underinsurance or low socioeconomic status, and the presence of psychiatric disorders. Hypoglycemia can affect patients' relationships, occupation, and daily activities such as driving. However, one of the greatest impacts is patients' fear of severe hypoglycemic events, which is a limiting factor in the optimization of glycemic control. Therefore, the importance of clinicians' ability to identify those patients at greatest risk for hypoglycemic events is two-fold: 1) Patients at greatest risk may be counseled as such and offered newer therapies and monitoring technologies to prevent hypoglycemic events. 2) Patients at lower risk may be reassured and encouraged to improve their glycemic control. Since the risk of long-term complications with poor blood glucose control outweighs the risks of hypoglycemia with good blood glucose control, patients should be encouraged to aim for glucose concentrations in the physiologic range pre- and post-prandially. Advancements in care, including multiple daily injection therapy with analog insulin, continuous subcutaneous insulin infusion, and continuous glucose monitoring, have each subsequently improved glycemic control and decreased the risk of severe hypoglycemia.

Is continuous glucose monitoring (CGM) for everyone? To whom should CGM be prescribed and how?

Are all type 1 diabetes (T1DM) patients potential candidates for continuous glucose monitoring (CGM)? Clearly, some patients improve their metabolic control with this tool, such as adults with poor metabolic control, especially those treated with continuous subcutaneous insulin infusion (CSII), and compliant patients with HbA(1c) levels <7%. There are also less good candidates for CGM, such as patients aged 8-18 years because they are reluctant to wear the sensors or those with new-onset T1DM. Other patient groups have not yet been evaluated, such as patients aged <8 years, women during pregnancy, and those with HbA(1c) >10% and/or severe hypoglycaemia. Beyond the indications, the mode of use of CGM is crucial. An appropriate patient selection, in order to choose those able to run the tool and motivated to use it, is necessary. How to prescribe the sensors is also an important question. Two approaches have been compared: patient-led and physician-driven prescription. Both modes of using CGM provide similar long-term metabolic improvement. However, physician-driven prescription is probably more cost-effective. The last key question is the education of patients by an experienced team. It can help them to translate the large amount of data from the monitor into effective self-management for optimalizing the CGM experience. However, elaboration of a validated algorithm is necessary to take full advantage of this device.

Advances in pump technology: insulin patch pumps, combined pumps and glucose sensors, and implanted pumps

This review discusses the most recent developments in insulin pump technology. The benefits of the insulin pump to patients with type 1 diabetes are recognized both for its metabolic effectiveness and its positive effects on quality of life. The current pumps are reliable, small and light, and are becoming more and more sophisticated. Nevertheless, there remain practical and psychological constraints for the patient. However, recent patch-pump advances should simplify the technical aspects of pump treatment and enhance patient comfort. Another advance combines the insulin pump with a glucose sensor. Such a combination is logical for optimizing pump use and, to that end, developing an automated or 'closed-loop'system that permits the delivery of subcutaneous insulin adjusted according to measured levels of subcutaneous glucose. Finally, implanted insulin pumps have proven their worth not only because of their simple use, but also for their contribution in the artificial pancreas project. Indeed, the prompt response with intraperitoneal administration of insulin makes it of interest for use in a closed-loop system.

Emergent technologies applied to diabetes: what do we need to integrate continuous glucose monitoring into daily practice? Where the long-term use of continuous glucose monitoring stands in 2011

The earliest continuous glucose monitoring (CGM) devices did not permit real-time readouts of glucose measurements. Instead, they were used to determine the glucose profile of patients in "real life" and as educational tools. In contrast, the latest real-time devices, whether linked or not to an insulin pump, give the patient access to glucose measurements and incorporate alarms that can be set. Thus, they are the newest self-management tools for patients with type 1 diabetes requiring an intensive insulin regimen. Some long-term studies in a selected population of patients with type 1 diabetes have shown improvement of glycaemic control as measured by HbA(1c). Although the characteristics of "responsive" patients have yet to be identified, the ability of the patient to use the system on a near-daily basis (about 80% of the time) is a key point. Initial training of the patient by a professional team with expertise in CGM is also of the utmost importance. To date, CGM is not reimbursed by Social Security in France.

How technology has changed diabetes management and what it has failed to achieve

Tremendous improvements have modified diabetes management from pure clinical diagnosis and the discovery of insulin to continuous subcutaneous insulin infusion (CSII) coupled with continuous glucose monitoring (CGM) to allow patients to adapt insulin delivery to glycaemia on a virtually "real-time" basis. Insulin was first discovered in 1923 and, in less than a century, it has been purified, humanized and now synthesized by genetically modified microorganisms. Insulin analogue, kinetics and reproducibility now allow near-normal glycaemia to be targeted without increasing hypoglycaemia, thus allowing greater flexibility in the patient's day-to-day life. In addition, advances have been made over the past few decades in the development of the necessary and complementary technologies for insulin infusion, glucose measurement, glucose insulin interaction and telemedicine. The major remaining limitations are the lack of glycaemic regulation on insulin administration and the burden of parenteral delivery. Thus, the dream of both patients and diabetologists is to close the loop and to build an artificial pancreas.

Personal continuous glucose monitoring (CGM) in diabetes management: review of the literature and implementation for practical use

AIM

Despite recent advances in diabetes therapy including the new long- and rapid-insulin analogs, insulin intensification strategies such as basal/bolus or pump therapy and sophisticated methods for insulin titration derived from the principles of functional insulin therapy, many patients fail to reach or maintain target glycosylated hemoglobin (HbA1c) values, putting them at increased risk for vascular complications. Continuous glucose monitoring (CGM) systems represent an important advance in diabetes technology that can facilitate optimal glucose control in type 1 diabetes.

METHOD

This review focuses on the efficacy and safety of CGM systems in diabetes management. The different CGM devices available are also described, as the way to use them and the educational approach to the patient in a step-by-step progression toward optimal glycemic control.

RESULTS

In type 1 diabetes, CGM systems are associated with 0.5-1% reduction in HbA1c without increased risk of hypoglycemia. CGM efficacy correlates with compliance to sensor wear, whatever the patient's age range.

CONCLUSION

Efficacy of CGM systems is now proven but indications, terms of use and educational issues of this new technology still need to be specified.

Assessment of patient-led or physician-driven continuous glucose monitoring in patients with poorly controlled type 1 diabetes using basal-bolus insulin regimens: a 1-year multicenter study

OBJECTIVE

The benefits of real-time continuous glucose monitoring (CGM) have been demonstrated in patients with type 1 diabetes. Our aim was to compare the effect of two modes of use of CGM, patient led or physician driven, for 1 year in subjects with poorly controlled type 1 diabetes.

RESEARCH DESIGN AND METHODS

Patients with type 1 diabetes aged 8-60 years with HbA(1c) ≥ 8% were randomly assigned to three groups (1:1:1). Outcomes for glucose control were assessed at 1 year for two modes of CGM (group 1: patient led; group 2: physician driven) versus conventional self-monitoring of blood glucose (group 3: control).

RESULTS

A total of 257 subjects with type 1 diabetes underwent screening. Of these, 197 were randomized, with 178 patients completing the study (age: 36 ± 14 years; HbA(1c): 8.9 ± 0.9%). HbA(1c) improved similarly in both CGM groups and was reduced compared with the control group (group 1 vs. group 3: -0.52%, P = 0.0006; group 2 vs. group 3: -0.47%, P = 0.0008; groups 1 + 2 vs. group 3: -0.50%, P < 0.0001). The incidence of hypoglycemia was similar in the three groups. Patient SF-36 questionnaire physical health score improved in both experimental CGM groups (P = 0.004). Sensor consumption was 34% lower in group 2 than in group 1 (median [Q1-Q3] consumption: group 1: 3.42/month [2.20-3.91] vs. group 2: 2.25/month [1.27-2.99], P = 0.001).

CONCLUSIONS

Both patient-led and physician-driven CGM provide similar long-term improvement in glucose control in patients with poorly controlled type 1 diabetes, but the physician-driven CGM mode used fewer sensors.

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.

Accuracy of the Enlite 6-day glucose sensor with guardian and Veo calibration algorithms

OBJECTIVE

This study investigates the accuracy of a newly developed, next-generation subcutaneous glucose sensor, evaluated for 6-day use.

RESEARCH DESIGN AND METHODS

Seventy-nine subjects (53 men, 26 women) with type 1 diabetes and 18 subjects (14 men, four women) with type 2 diabetes completed a three-center, prospective, sensor accuracy study. The mean age for the group was 42.2±15.0 years (mean±SD), ranging from 18 to 71 years, with a mean glycosylated hemoglobin level of 7.6±1.5%, ranging from 5.5% to 14%. Subjects wore Enlite™ sensors (Medtronic Diabetes, Northridge, CA) in the abdominal and buttocks region for two separate 7-day periods and calibrated with a home-use blood glucose meter. Subjects participated in an in-clinic testing day where frequent sampled plasma glucose samples were acquired every 15 min for 10 h. Sensor data was retrospectively processed with Guardian(®) REAL-Time (Medtronic) and Paradigm(®) Veo™ (Medtronic) calibration routines, and accuracy metrics were calculated for each algorithm and sensor location. Physiological time lag for each measurement site was calculated.

RESULTS

Based on 6,404 plasma-sensor glucose paired points, the Enlite sensor with Veo calibration algorithm produced a mean absolute relative difference of 13.86% with 97.3% of points within the A+B zones of the Clarke error grid. Threshold-only alarms detected 90.1% of hypoglycemia and 90% of hyperglycemia. Mean time lag measured at the abdominal region was 7.94±6.48 min compared with 11.70±6.71 min (P<0.0001) at the buttocks area.

CONCLUSIONS

The Enlite sensor accurately measures glucose when compared with gold standard laboratory measurements over its 6-day use. Sensors placed in the buttocks region exhibited greater time lags than sensors placed in the abdomen.

A randomized clinical trial to assess the efficacy and safety of real-time continuous glucose monitoring in the management of type 1 diabetes in young children aged 4 to <10 years

OBJECTIVE

Continuous glucose monitoring (CGM) has been demonstrated to improve glycemic control in adults with type 1 diabetes but less so in children. We designed a study to assess CGM benefit in young children aged 4 to 9 years with type 1 diabetes.

RESEARCH DESIGN AND METHODS

After a run-in phase, 146 children with type 1 diabetes (mean age 7.5 ± 1.7 years, 64% on pumps, median diabetes duration 3.5 years) were randomly assigned to CGM or to usual care. The primary outcome was reduction in HbA(1c) at 26 weeks by ≥0.5% without the occurrence of severe hypoglycemia.

RESULTS

The primary outcome was achieved by 19% in the CGM group and 28% in the control group (P = 0.17). Mean change in HbA(1c) was -0.1% in each group (P = 0.79). Severe hypoglycemia rates were similarly low in both groups. CGM wear decreased over time, with only 41% averaging at least 6 days/week at 26 weeks. There was no correlation between CGM use and change in HbA(1c) (r(s) = -0.09, P = 0.44). CGM wear was well tolerated, and parental satisfaction with CGM was high. However, parental fear of hypoglycemia was not reduced.

CONCLUSIONS

CGM in 4- to 9-year-olds did not improve glycemic control despite a high degree of parental satisfaction with CGM. We postulate that this finding may be related in part to limited use of the CGM glucose data in day-to-day management and to an unremitting fear of hypoglycemia. Overcoming the barriers that prevent integration of these critical glucose data into day-to-day management remains a challenge.

Health-related quality of life and treatment satisfaction in the Sensor-Augmented Pump Therapy for A1C Reduction 3 (STAR 3) trial

OBJECTIVE

This study assessed health-related quality of life (HRQOL) and treatment satisfaction in sensor-augmented pump therapy (SAPT) compared with optimal conventional therapy-multiple daily injection (MDI) therapy with self-monitoring of blood glucose (SMBG)-in adults and children with type 1 diabetes and children's caregivers. Patient acceptance of new therapies is essential to their adoption and effective use.

RESEARCH DESIGN AND METHODS

STAR 3, a randomized 12-month clinical trial, compared SAPT with MDI+SMBG in 485 adult and pediatric patients. Within- and between-treatment arm changes in generic HRQOL, diabetes-specific HRQOL (fear of hypoglycemia), and treatment satisfaction were assessed (significance criterion P<0.01).

RESULTS

In adults, children, and caregivers, there were no significant between-arm changes in generic HRQOL: SF-36 Physical Component Summary and Mental Component Summary scores in adults and the PedsQL Physical Health Summary and Psychosocial Health Summary scores in children or caregivers. Diabetes-specific HRQOL (Hypoglycemia Fear Survey Worry and Behavior subscale scores) improved more in SAPT than in MDI adults. Hypoglycemia Behavior scores improved more in SAPT caregivers. Key treatment satisfaction measures (Insulin Delivery System Rating Questionnaire measures of Convenience, Efficacy, and Overall Preference) improved more in SAPT adults, children, and caregivers (all P<0.001); all exceeded the criterion for minimal detectable difference.

CONCLUSIONS

In the first-ever large-scale study of SAPT compared with optimal conventional therapy, SAPT had significant advantages for hypoglycemia fear in adults and caregivers and for treatment satisfaction in adults, children, and caregivers.

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. 

Continuous glucose monitoring: coming of age?

In a recent issue of the Journal of Clinical Endocrinology and Metabolism, an Endocrine Society Clinical Practice Guideline on Continuous Glucose Monitoring (CGM) was published, co-sponsored by the European Society of Endocrinology. Such a guideline is a necessary step in the maturation of any new technology. This commentary tries to delineate where we stand some 10 years after the first retrospective CGM device entered the market from a European perspective.

Recent advances in the prevention of hypoglycemia in type 1 diabetes

Iatrogenic hypoglycemia is one of the chief barriers to optimal glycemic control in people with type 1 diabetes (T1D). As a common contributor to morbidity and mortality in T1D, severe hypoglycemia (SH) is also a major fear for people with T1D and their families. Consequently, fear of hypoglycemia and hypoglycemia-avoidant behaviors are predominant limiting factors in achieving euglycemia in people with T1D. Nocturnal SH and hypoglycemia unawareness are prevalent obstacles in the detection of hypoglycemia which further impair the prevention and treatment of SH. Various strategies and technologies have already been developed to help detect and prevent hypoglycemia, including improved patient education, frequent self-monitoring of blood glucose levels, the use of rapid-acting and basal insulin analogs, continuous subcutaneous insulin infusion therapy, exercise-related insulin modifications, and continuous glucose monitors. The efficacy of these methods is well established, but further advances are still needed. The purpose of this review is to describe these currently available methods and to emphasize recent progress related to the prevention of hypoglycemia in T1D.

Sensor-augmented pump therapy for A1C reduction (STAR 3) study: results from the 6-month continuation phase

OBJECTIVE To examine the effects of crossing over from optimized multiple daily injection (MDI) therapy to sensor-augmented pump (SAP) therapy for 6 months, and the effects of 18 months' sustained use of SAP. RESEARCH DESIGN AND METHODS The 6-month, single-crossover continuation phase of Sensor-Augmented Pump Therapy for A1C Reduction (STAR 3) provided SAP therapy to 420 subjects who completed the 1-year randomized study. The primary outcome was change in A1C in the crossover group. RESULTS A1C values were initially lower in the continuing-SAP group than in the crossover group (7.4 vs. 8.0%, P < 0.001). A1C values remained reduced in the SAP group. After 3 months on the SAP system, A1C decreased to 7.6% in the crossover group (P < 0.001); this was a significant and sustained decrease among both adults and children (P < 0.05). CONCLUSIONS Switching from optimized MDI to SAP therapy allowed for rapid and safe A1C reductions. Glycemic benefits of SAP therapy persist for at least 18 months.

Prevention of hypoglycemia by using low glucose suspend function in sensor-augmented pump therapy

BACKGROUND

Severe hypoglycemic episodes are a barrier for achieving optimal glycemic control. Sensor-augmented pump (SAP) therapy with insulin in combination with a novel mechanism of automatic insulin shutoff (low glucose suspend [LGS]) can be used to prevent and reduce hypoglycemia. In a prospective study, we investigated the effect of the LGS algorithm on the frequency of hypoglycemia in children and adolescents with type 1 diabetes under real-life conditions.

METHODS

Twenty-one patients with type 1 diabetes (10.8±3.8 years old, duration of diabetes 5.9±3.0 years, pump therapy for 3.7±1.7 years, glycated hemoglobin level 7.8±1.1%) from three pediatric centers used the Paradigm(®) Veo(™) system (Medtronic Minimed, Northridge, CA) during two subseqent time periods: SAP without LGS for 2 weeks and then SAP with LGS enabled for 6 weeks. The primary objective was to assess the frequency of hypoglycemic episodes when using the LGS feature with an insulin delivery shutoff of a maximum of 2 h at a sensor glucose level below 70 mg/dL (3.9 mmol/L).

RESULTS

In total, 1,298 LGS alerts occurred (853 shorter than 5 min). Forty-two percent of LGS activations (>5 min) lasted less than 30 min, whereas 24% had a duration of 2 h. The number of hypoglycemic excursions (average/day) was reduced during SAP+LGS (<70 mg/L, 1.27±0.75 vs. 0.95±0.49, P=0.010; ≤40 mg/dL, 0.28±0.18 vs. 0.13±0.14, P=0.005) as was the time spent in hypoglycemia (average minutes/day, 101±68 vs. 58±33, P=0.002) without significant difference in the mean glucose level (145±23 vs. 148±19 mg/dL). No episodes of severe hyperglycemia or diabetic ketoacidosis were observed following LGS activation.

CONCLUSIONS

The present investigation provides evidence that SAP with LGS reduces the frequency of hypoglycemia without compromising safety.

Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial

AIMS

To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes.

METHODS

In this investigator-initiated multi-centre trial (the Eurythmics Trial) in eight outpatient centres in Europe, we randomized 83 patients with Type 1 diabetes (40 women) currently treated with multiple daily injections, age 18-65 years and HbA(1c) ≥ 8.2% (≥ 66 mmol/mol) to 26 weeks of treatment with either a sensor-augmented insulin pump (n = 44) (Paradigm(®) REAL-Time) or continued with multiple daily injections (n = 39). Change in HbA(1c) between baseline and 26 weeks, sensor-derived endpoints and patient-reported outcomes were assessed.

RESULTS

The trial was completed by 43/44 (98%) patients in the sensor-augmented insulin pump group and 35/39 (90%) patients in the multiple daily injections group. Mean HbA(1c) at baseline and at 26 weeks changed from 8.46% (SD 0.95) (69 mmol/mol) to 7.23% (SD 0.65) (56 mmol/mol) in the sensor-augmented insulin pump group and from 8.59% (SD 0.82) (70 mmol/mol) to 8.46% (SD 1.04) (69 mmol/mol) in the multiple daily injections group. Mean difference in change in HbA(1c) after 26 weeks was -1.21% (95% confidence interval -1.52 to -0.90, P < 0.001) in favour of the sensor-augmented insulin pump group. This was achieved without an increase in percentage of time spent in hypoglycaemia: between-group difference 0.0% (95% confidence interval -1.6 to 1.7, P = 0.96). There were four episodes of severe hypoglycaemia in the sensor-augmented insulin pump group and one episode in the multiple daily injections group (P = 0.21). Problem Areas in Diabetes and Diabetes Treatment Satisfaction Questionnaire scores improved in the sensor-augmented insulin pump group.

CONCLUSIONS

Sensor augmented pump therapy effectively lowers HbA(1c) in patients with Type 1 diabetes suboptimally controlled with multiple daily injections.

Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk

OBJECTIVE

To evaluate a sensor-augmented insulin pump with a low glucose suspend (LGS) feature that automatically suspends basal insulin delivery for up to 2 h in response to sensor-detected hypoglycemia.

RESEARCH DESIGN AND METHODS

The LGS feature of the Paradigm Veo insulin pump (Medtronic, Inc., Northridge, CA) was tested for 3 weeks in 31 adults with type 1 diabetes.

RESULTS

There were 166 episodes of LGS: 66% of daytime LGS episodes were terminated within 10 min, and 20 episodes lasted the maximum 2 h. LGS use was associated with reduced nocturnal duration ≤2.2 mmol/L in those in the highest quartile of nocturnal hypoglycemia at baseline (median 46.2 vs. 1.8 min/day, P = 0.02 [LGS-OFF vs. LGS-ON]). Median sensor glucose was 3.9 mmol/L after 2-h LGS and 8.2 mmol/L at 2 h after basal restart.

CONCLUSIONS

Use of an insulin pump with LGS was associated with reduced nocturnal hypoglycemia in those at greatest risk and was well accepted by patients.

Continuous blood glucose monitoring in diabetes treatment

Continuous glucose monitoring system (CGMS) is a developing technology in the field of diabetes treatment since it enables patients to effectively control and adjust their insulin therapy. Clinical trials have shown its efficacy in lowering HbAlc significantly especially in adults with type 1 diabetes and those with HbAlc >8%. Improvement is sustained for at least one year. Conflicting data exist for children. Most recent studies agree that the nearly daily use of CGMS is accompanied by significant lowering of HbA1c independent of age. However, the randomized clinical trials have shown that the use of CGMS does not reduce significantly the number of severe hypoglycemic episodes as it is expected, but recent data indicate that it reduces the time spent in hypoglycemia. Accuracy remains a key issue for CGMS, particularly in children and adolescents who may have increased variability of blood glucose. CGMS cost is another barrier to the everyday use since reimbursement of CGM is limited to a few countries only. This review will focus on the present status of the use of CGMS in type 1 diabetes (T1D) patients.

Glycaemic control in type 1 diabetes during real time continuous glucose monitoring compared with self monitoring of blood glucose: meta-analysis of randomised controlled trials using individual patient data

OBJECTIVE

To determine the clinical effectiveness of real time continuous glucose monitoring compared with self monitoring of blood glucose in type 1 diabetes.

DESIGN

Meta-analysis of randomised controlled trials.

DATA SOURCES

Cochrane database for randomised controlled trials, Ovid Medline, Embase, Google Scholar, lists of papers supplied by manufacturers of continuous glucose monitors, and cited literature in retrieved articles. Studies reviewed Randomised controlled trials of two or more months' duration in men and non-pregnant women with type 1 diabetes that compared real time continuous glucose monitoring with self monitoring of blood glucose and where insulin delivery was the same in both arms. Analysis Two step meta-analysis of individual patient data with the primary outcome of final glycated haemoglobin (HbA(1c)) percentage and area under the curve of hypoglycaemia (glucose concentration <3.9 mmol/L) during either treatment, followed by one step metaregression exploring patient level determinants of HbA(1c) and hypoglycaemia.

RESULTS

Six trials were identified, consisting of 449 patients randomised to continuous glucose monitoring and 443 to self monitoring of blood glucose. The overall mean difference in HbA(1c) for continuous glucose monitoring versus self monitoring of blood glucose was -0.30% (95% confidence interval -0.43% to -0.17%) (-3.0, -4.3 to -1.7 mmol/mol). A best fit regression model of determinants of final HbA(1c) showed that for every one day increase of sensor usage per week the effect of continuous glucose monitoring versus self monitoring of blood glucose increased by 0.150% (95% credibility interval -0.194% to -0.106%) (1.5, -1.9 to -1.1 mmol/mol) and every 1% (10 mmol/mol) increase in baseline HbA(1c) increased the effect by 0.126% (-0.257% to 0.0007%) (1.3, -2.6 to 0.0 mmol/mol). The model estimates that, for example, a patient using the sensor continuously would experience a reduction in HbA(1c) of about 0.9% (9 mmol/mol) when the baseline HbA(1c) is 10% (86 mmol/mol). The overall reduction in area under the curve of hypoglycaemia was -0.28 (-0.46 to -0.09), corresponding to a reduction in median exposure to hypoglycaemia of 23% for continuous glucose monitoring compared with self monitoring of blood glucose. In a best fit regression model, baseline area under the curve of hypoglycaemia was only weakly related to the effect of continuous glucose monitoring compared with self monitoring of blood glucose on hypoglycaemia outcome, and sensor usage was unrelated to hypoglycaemia at outcome.

CONCLUSIONS

Continuous glucose monitoring was associated with a significant reduction in HbA(1c) percentage, which was greatest in those with the highest HbA(1c) at baseline and who most frequently used the sensors. Exposure to hypoglycaemia was also reduced during continuous glucose monitoring. The most cost effective or appropriate use of continuous glucose monitoring is likely to be when targeted at people with type 1 diabetes who have continued poor control during intensified insulin therapy and who frequently use continuous glucose monitoring.

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.

Continuous glucose monitoring for patients with diabetes: an evidence-based analysis

OBJECTIVE

To determine the effectiveness and cost-effectiveness of continuous glucose monitoring combined with self-monitoring of blood glucose compared with self-monitoring of blood glucose alone in the management of diabetes.

CLINICAL NEED

CONDITION AND TARGET POPULATION Diabetes is a chronic metabolic disorder that interferes with the body's ability to produce or effectively use insulin. In 2005, an estimated 816,000 Ontarians had diabetes representing 8.8% of the province's population. Type 1 or juvenile onset diabetes is a life-long disorder that commonly manifests in children and adolescents. It represents about 10% of the total diabetes population and involves immune-mediated destruction of insulin producing cells in the pancreas. The loss of these cells necessitates insulin therapy. Type 2 or "adult-onset" diabetes represents about 90% of the total diabetes population and is marked by a resistance to insulin or insufficient insulin secretion. The risk of developing type 2 diabetes increases with age, obesity and lack of physical activity. Approximately 30% of patients with type 2 diabetes eventually require insulin therapy.

TECHNOLOGY

Continuous glucose monitors (CGM) measure glucose levels in the interstitial fluid surrounding skin cells. These measurements supplement conventional self monitoring of blood glucose (SMBG) by monitoring the glucose fluctuations continuously over a stipulated period of time, thereby identifying fluctuations that would not be identified with SMBG alone. To use a CGM, a sensor is inserted under the skin to measure glucose in the interstitial fluid. The sensor is wired to a transmitter. The device requires calibration using a capillary blood glucose measurement. Each sensor continuously measures glucose every 5-10 seconds averaging these values every 5 minutes and storing this data in the monitors memory. Depending on the device used, the algorithm in the device can measure glucose over a 3 or 6 day period using one sensor. After the 3 or 6 day period, a new sensor is required. The device is equipped with alarms which warn the patient of impending hypo-or hyperglycemia. Two types of CGM are available: Systems that is stored in a monitor and can be downloaded later.Real time systems that continuously provide the actual glucose concentration on a display.

RESEARCH QUESTIONS

What is the effectiveness and cost-effectiveness of CGM combined with SMBG compared with SMBG alone in the management of diabetes?

RESEARCH METHODS

LITERATURE SEARCH

SEARCH STRATEGY

A literature search was performed on September 15, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2002 until September 15, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.

INCLUSION CRITERIA

English languageRandomized controlled trials (N>30 patients)Adults or pediatric patients with insulin dependent diabetes (type 1 or 2 or gestational)Studies comparing CGM plus SMBG versus SMBG alone

EXCLUSION CRITERIA

Case studiesStudies that did not compare CGM plus SMBG versus SMBG aloneStudies that did not report statistical analysis of outcomes or data was unextractable

OUTCOMES OF INTEREST

Change in glycosylated hemoglobin (HbA1c)Frequency or duration of hypo-or hyperglycemic episodes or euglycemiaAdverse effects

SUMMARY OF FINDINGS

Moderate quality evidence that CGM + SMBG: is not more effective than self monitoring of blood glucose (SMBG) alone in the reduction of HbA1c using insulin infusion pumps for Type 1 diabetes.is not more effective than SMBG alone in the reduction of hypoglycemic or severe hypoglycemic events using insulin infusion pumps for Type 1 diabetes.

Real-life utilization of real-time continuous glucose monitoring: the complete picture

BACKGROUND

Very few studies to date have analyzed the reasons why some people do not use real-time continuous glucose monitoring (RT-CGM) continuously, especially given its positive glycemic outcomes, or choose not to wear it at all, even after learning about its benefits.

METHODS

A questionnaire was designed to assess real-life use of and issues surrounding RT-CGM. Hemoglobin A1c (HbA1c) and duration of sensor use were also obtained from the patients' charts.

RESULTS

Fifty-eight subjects with type 1 diabetes (T1DM), average age 15.0 ± 4.8 years, T1DM duration 5.7 ± 3.8 years, HbA1c 8.8 ± 2.1%, 50% with RT-CGM, were included in the analysis. Hemoglobin A1c was lower with increased RT-CGM use. Real-time continuous glucose monitoring was ordered to improve control. Users liked the continuous data. The most disliked part was pain and discomfort. Occasional users described RT-CGM as annoying, a hassle, and interfering with their lives. Reasons for discontinuing RT-CGM included problematic equipment and inaccuracy (64%), intrusion in life (36%), and insurance issues (29%). Twenty-one percent of nonusers reported RT-CGM to be inconvenient or a hassle or just did not want it. Fifty-two percent of subjects continue to use RT-CGM despite reported problems.

CONCLUSION

Real-time continuous glucose monitoring is a beneficial tool for improving glycemic control, and many use it despite reported problems and hassles with current devices. However, this technology has not been wholeheartedly embraced by many individuals with T1DM, especially in youngsters, because of issues mentioned here. Based on the findings of this study, it is hoped that improvements will be made to RT-CGM technology so that more people with diabetes will embrace this beneficial tool.

Evolution of devices in diabetes management

Recent technological advancements in insulin administration and glucose monitoring have allowed patients with diabetes to become increasingly involved in their own care. Devices replacing the traditional vial and syringe, such as insulin pens, are gaining popularity and offer simple and convenient insulin administration. Pen devices are associated with improved dose accuracy, reducing the risk of hypo- or hyperglycemia, and are continually being updated with new safety features in order to optimize their performance. In patients for whom glucose variability remains a problem, continuous subcutaneous insulin infusion via an implanted canula or continuous intraperitoneal insulin infusion via an implanted pump is safe and effective when used correctly, although cost can be a limitation. More accurate retrospective and real-time continuous monitoring devices, which can better detect blood glucose excursions, have become standard components of modern-day diabetes management. The most recent devices have sensor-signaling capabilities with wireless data transmission, leading to reduced time delay and more accurate alerts. Ultimately, though, while self-management remains a critical factor in improving glycemic control at present, human error may undermine even the most accurate treatment interventions. A key long-term goal in diabetes management is, therefore, to develop an automated and accurate closed-loop system for blood glucose monitoring and insulin delivery to better reflect the physiological mechanisms of glucose homeostasis and remove the "human" element. This "artificial pancreas" would offer the most innovative intervention for diabetes management and has the potential to considerably reduce the patient's burden of self-care.