Glycaemic impact of patient-led use of sensor-guided pump therapy in type 1 diabetes: a randomised controlled trial

Continuous glucose monitoring: evidence and consensus statement for clinical use

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

Continuous glucose monitoring in type 1 diabetes

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

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.

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.

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.

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.

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.

Patient satisfaction and barriers to initiating real-time continuous glucose monitoring in early pregnancy in women with diabetes

AIM

To evaluate self-reported satisfaction and barriers to initiating real-time continuous glucose monitoring in early pregnancy among women with pregestational diabetes.

METHODS

Fifty-four women with Type 1 diabetes and 14 women with Type 2 diabetes were offered continuous glucose monitoring for 6 days at median 9 (range 6-14) gestational weeks and were asked to answer a semi-structured questionnaire on patient satisfaction.

RESULTS

Median HbA1c was 49 (range 34-86) mmol/mol) [6.6 (5.3-10.0) %] and duration of diabetes was 12 (0.5-37) years. Continuous glucose monitoring was used for 6 (0.5-7) days, with 43 (65%) women using continuous glucose monitoring for at least 5 days. The women experienced 2.7 (0-12) alarms per 24 h, of which approximately one third was technical alarms and one third disturbed their sleep. Sixteen women (24%) reported discomfort with continuous glucose monitoring during daytime and twelve (18%) during sleep. Many women reported improved diabetes understanding (52%) and would recommend continuous glucose monitoring to others (83%). Twenty-four patients (36%) had continuous glucose monitoring removed earlier than planned ( before the intended 6 days of initial monitoring). Ten women (15%) did not wish to use continuous glucose monitoring again in pregnancy. Main causes behind early removal of continuous glucose monitoring were self-reported skin irritation, technical problems and continuous glucose monitoring inaccuracy. No differences were found in continuous glucose monitoring use, inconvenience or compliance with respect to diabetes type.

CONCLUSIONS

The majority of pregnant women with diabetes found real-time continuous glucose monitoring useful and the intervention was equally tolerated regardless of diabetes type. Nevertheless, continuous glucose monitoring was frequently removed earlier than planned, primarily because of skin irritation, technical problems and inaccuracy.

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.

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. 

Short- and long-term effects of real-time continuous glucose monitoring in patients with type 2 diabetes

OBJECTIVE

To determine whether short-time, real-time continuous glucose monitoring (RT-CGM) has long-term salutary glycemic effects in patients with type 2 diabetes who are not on prandial insulin.

RESEARCH DESIGN AND METHODS

This was a randomized controlled trial of 100 adults with type 2 diabetes who were not on prandial insulin. This study compared the effects of 12 weeks of intermittent RT-CGM with self-monitoring of blood glucose (SMBG) on glycemic control over a 40-week follow-up period. Subjects received diabetes care from their regular provider without therapeutic intervention from the study team.

RESULTS

There was a significant difference in A1C at the end of the 3-month active intervention that was sustained during the follow-up period. The mean, unadjusted A1C decreased by 1.0, 1.2, 0.8, and 0.8% in the RT-CGM group vs. 0.5, 0.5, 0.5, and 0.2% in the SMBG group at 12, 24, 38, and 52 weeks, respectively (P = 0.04). There was a significantly greater decline in A1C over the course of the study for the RT-CGM group than for the SMBG group, after adjusting for covariates (P < 0.0001). The subjects who used RT-CGM per protocol (≥48 days) improved the most (P < 0.0001). The improvement in the RT-CGM group occurred without a greater intensification of medication compared with those in the SMBG group.

CONCLUSIONS

Subjects with type 2 diabetes not on prandial insulin who used RT-CGM intermittently for 12 weeks significantly improved glycemic control at 12 weeks and sustained the improvement without RT-CGM during the 40-week follow-up period, compared with those who used only SMBG.

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.

New-generation diabetes management: glucose sensor-augmented insulin pump therapy

Diabetes is one of the most common chronic disorders with an increasing incidence worldwide. Technologic advances in the field of diabetes have provided new tools for clinicians to manage this challenging disease. For example, the development of continuous subcutaneous insulin infusion systems have allowed for refinement in the delivery of insulin, while continuous glucose monitors provide patients and clinicians with a better understanding of the minute to minute glucose variability, leading to the titration of insulin delivery based on this variability when applicable. Merging of these devices has resulted in sensor-augmented insulin pump therapy, which became a major building block upon which the artificial pancreas (closed-loop systems) can be developed. This article summarizes the evolution of sensor-augmented insulin pump therapy until present day and its future applications in new-generation diabetes management.

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.

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.

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.

The effect of real-time continuous glucose monitoring on glycemic control in patients with type 2 diabetes mellitus

BACKGROUND

Real-time continuous glucose monitoring (RT-CGM) improves hemoglobin A1c (A1C) and hypoglycemia in people with type 1 diabetes mellitus and those with type 2 diabetes mellitus (T2DM) on prandial insulin; however, it has not been tested in people with T2DM not taking prandial insulin. We evaluated the utility of RT-CGM in people with T2DM on a variety of treatment modalities except prandial insulin.

METHODS

We conducted a prospective, 52-week, two-arm, randomized trial comparing RT-CGM (n = 50) versus self-monitoring of blood glucose (SMBG) (n = 50) in people with T2DM not taking prandial insulin. Real-time continuous glucose monitoring was used for four 2-week cycles (2 weeks on/1 week off). All patients were managed by their usual provider. This article reports on changes in A1C 0-12 weeks.

RESULTS

Mean (± standard deviation) decline in A1C at 12 weeks was 1.0% (± 1.1%) in the RT-CGM group and 0.5% (± 0.8%) in the SMBG group (p = .006). There were no group differences in the net change in number or dosage of hypoglycemic medications. Those who used the RT-CGM for ≥ 48 days (per protocol) reduced their A1C by 1.2% (± 1.1%) versus 0.6% (± 1.1%) in those who used it <48 days (p = .003). Multiple regression analyses statistically adjusting for baseline A1C, an indicator for usage, and known confounders confirmed the observed differences between treatment groups were robust (p = .009). There was no improvement in weight or blood pressure.

CONCLUSIONS

Real-time continuous glucose monitoring significantly improves A1C compared with SMBG in patients with T2DM not taking prandial insulin. This technology might benefit a wider population of people with diabetes than previously thought.

Real-time continuous glucose monitoring system for treatment of diabetes: a systematic review

AIMS

  This study reviews the effect of real-time continuous glucose monitoring systems in diabetes management.

METHODS

  A systematic search was performed in PubMed/MEDLINE and EMBASE for randomized controlled trials comparing real-time continuous glucose monitoring systems with self-monitoring blood glucose or non-real-time continuous glucose monitoring systems.

RESULTS

  Nine randomized controlled trials were identified. Two studies used a device which is not on the market any more. In this review we focus on the other seven studies. Performing a meta-analysis was not possible because of extensive clinical heterogeneity. Six of seven studies showed some positive effect of real-time continuous glucose monitoring systems on HbA(1c) (HbA(1c) decrease 0.3-0.7% or 3-8 mmol/mol). In some studies, this effect only was shown in subgroups (compliant adult patients). However, the size of effect may be underestimated by better-than-average results in the control group, as self-monitoring blood glucose measurements are carried out more frequently than in usual clinical practice. Despite the goal of lowering HbA(1c) , no more severe hypoglycaemic episodes were seen, except in one study. In contrast, no positive effect was shown with the real-time continuous glucose monitoring system on hypoglycaemia, but randomized controlled trials were not designed or powered to investigate this issue. Time in different glucose strata was assessed only in some trials: two of them showed a significant but small increase in time in euglycaemia.

CONCLUSIONS

  Current evidence shows that the real-time continuous glucose monitoring system has a beneficial effect on glycaemic control in adult diabetes patients, without an increase in the incidence of hypoglycaemia. Studies in well-selected patient groups (pregnancy, history of severe hypoglycaemias, Type 2 diabetes) are lacking.

Effect of continuous glucose monitoring on hypoglycemia in type 1 diabetes

OBJECTIVE

To assess the impact of continuous glucose monitoring on hypoglycemia in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In this randomized, controlled, multicenter study, 120 children and adults on intensive therapy for type 1 diabetes and a screening level of glycated hemoglobin A(1c) (HbA(1c)) <7.5% were randomly assigned to a control group performing conventional home monitoring with a blood glucose meter and wearing a masked continuous glucose monitor every second week for five days or to a group with real-time continuous glucose monitoring. The primary outcome was the time spent in hypoglycemia (interstitial glucose concentration <63 mg/dL) over a period of 26 weeks. Analysis was by intention to treat for all randomized patients.

RESULTS

The time per day spent in hypoglycemia was significantly shorter in the continuous monitoring group than in the control group (mean ± SD 0.48 ± 0.57 and 0.97 ± 1.55 h/day, respectively; ratio of means 0.49; 95% CI 0.26-0.76; P = 0.03). HbA(1c) at 26 weeks was lower in the continuous monitoring group than in the control group (difference -0.27%; 95% CI -0.47 to -0.07; P = 0.008). Time spent in 70 to 180 mg/dL normoglycemia was significantly longer in the continuous glucose monitoring group compared with the control group (mean hours per day, 17.6 vs. 16.0, P = 0.009).

CONCLUSIONS

Continuous glucose monitoring was associated with reduced time spent in hypoglycemia and a concomitant decrease in HbA(1c) in children and adults with type 1 diabetes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

An algorithm guiding patient responses to real-time-continuous glucose monitoring improves quality of life

OBJECTIVE

This study evaluated the impact on quality of life (QoL) of an algorithm guiding the responses of continuous subcutaneous insulin infusion (CSII)-treated type 1 diabetes (T1D) patients using real-time (RT)-continuous glucose monitoring (CGM).

RESEARCH DESIGN AND METHODS

Sixty CSII-treated T1D participants (13-70 years old, glycosylated hemoglobin [HbA1c] ≤ 9.5%), including adult and adolescent subgroups, were randomized in age-, gender-, and HbA1c-matched pairs. Phase 1 was an open 16-week multicenter randomized controlled trial; Group A received CSII/RT-CGM with the algorithm, and Group B received CSII/RT-CGM without algorithm. Phase 2 was the 16-32-week follow-up study; Group A returned to usual care (CSII without RT-CGM), and Group B was provided with algorithm at 16 weeks. QoL was assessed by DQOL (adults) and DQOLY (adolescents) questionnaires at baseline, 16 weeks, and 32 weeks. Higher scores (range 1-5) indicate poorer QoL. Analysis was by analysis of variance (between group for baseline-16 weeks) and paired two-tailed t tests (within group for baseline and 32 weeks) with significance at P < 0.05.

RESULTS

Withdrawals left 28 of 30 patients in Group A and 27 of 30 patients in Group B at 32 weeks. In Phase 1, QoL in Group A (2.16 [0.44] baseline to 1.86 [0.40] at 16 weeks) improved compared with Group B (2.03 [0.47] to 2.03 [0.50]) (P = 0.002). Change in QoL correlated with changes in HbA1c (R = 0.36; P = 0.007). In Phase 2, Group A QoL was better at 32 weeks compared with baseline (2.16 [0.44] vs. 2.02 [0.43]) (P = 0.04) but was not in Group B (2.03 [0.47] vs. 1.99 [0.51]) (P = not significant).

CONCLUSIONS

An algorithm guiding CSII-treated T1D responses to RT-CGM improved QoL, which persisted post-RT-CGM withdrawal. Algorithm provision at RT-CGM initiation was required to benefit QoL.

The SWITCH study (sensing with insulin pump therapy to control HbA(1c)): design and methods of a randomized controlled crossover trial on sensor-augmented insulin pump efficacy in type 1 diabetes suboptimally controlled with pump therapy

BACKGROUND

studies investigating the effect of real-time continuous glucose monitoring (CGM) combined with pump therapy on glycemic outcomes in type 1 diabetes are increasing. Pump therapy is well established as a "gold standard" for insulin delivery, offering improvements over multiple daily insulin injections. However, there is still a proportion of subjects using continuous subcutaneous insulin infusion in whom goals for metabolic control are far from achieved or benefits of this type of insulin therapy are transient. The SWITCH (Sensing With Insulin pump Therapy to Control HbA(1c) [hemoglobin A1c]) study is a multicenter, randomized, controlled, crossover study to evaluate if adding CGM to experienced pump patients with suboptimal metabolic control will provide additional insight enabling clinical and therapeutic benefit.

METHODS

subjects meeting the inclusion criteria were randomized to Sensor On or Sensor Off arms for 6 months, after a 1-month run-in period. Following a 4-month washout period, the subjects crossed over to the other study arm for 6 months. The primary end point was the between arm difference in HbA(1c) levels. Among others, additional end points include time spent in different glycemic ranges, percentage of patients with HbA(1c) <7%, number of hypoglycemic events, glucose variability parameters, safety outcomes, treatment satisfaction, and quality of life.

RESULTS

recruitment occurred between January 2008 and February 2009. A total of 153 patients were randomized. Study completion is anticipated in July 2010.

CONCLUSIONS

the results will establish if adding CGM to existing, capable, insulin pump users can enable better metabolic control.

Toward closing the loop: an update on insulin pumps and continuous glucose monitoring systems

This article reviews current pump and continuous glucose monitoring therapy and what will be required to integrate these systems into closed-loop control. Issues with sensor accuracy, lag time, and calibration are discussed as well as issues with insulin pharmacodynamics, which result in a delayed onset of insulin action in a closed-loop system. A stepwise approach to closed-loop therapy is anticipated, where the first systems will suspend insulin delivery based on actual or predicted hypoglycemia. Subsequent systems may control to range, limiting the time spent in hyperglycemia by mitigating the effects of a missed food bolus or underestimate of consumed carbohydrates, while minimizing the risk of hypoglycemia.

Psychosocial factors associated with use of continuous glucose monitoring

AIMS

To identify psychosocial factors associated with the use of continuous glucose monitoring by adults with Type 1 diabetes.

METHODS

Twenty adult patients (aged 45 +/- 15 years, diabetes duration 25 +/- 19 years, 50% female) followed at our site in the multi-centre Juvenile Diabetes Research Foundation continuous glucose monitoring trial were divided into three groups: Glycated haemoglobin (HbA(1c)) Responders who demonstrated an improvement in glycaemic control with continuous glucose monitoring (baseline HbA(1c)> or = 7.0%, HbA(1c) reduction greater than or equal to 0.5%), Hypoglycaemia Responders (baseline HbA(1c) < 7.0%) who demonstrated decreased time < 3.9 mmol/l while remaining within target HbA(1c), and HbA(1c) Non-Responders (baseline HbA(1c)> or = 7.0%, HbA(1c) reduction less than 0.5%). Subjects participated in semi-structured interviews focusing on their psychosocial experiences with continuous glucose monitoring.

RESULTS

Three major themes were identified that differentiated Responders (including both the HbA(1c) and Hypoglycaemia groups) from Non-Responders: (i) coping with frustrations-Responders used self-controlled rather than emotions-based coping when faced with continuous glucose monitoring frustrations; (ii) use of information-Responders used retrospective pattern analysis, not just minute-by-minute data analysis, in glycaemic management; (iii) 'significant other'/spousal involvement-Responders endorsed interest, encouragement and participation by their loved ones. Both Responders and Non-Responders expressed body image concerns when wearing continuous glucose monitoring devices.

CONCLUSIONS

This qualitative study points to the importance of coping skills, retrospective review of data, and 'significant other' involvement in the effective use of continuous glucose monitoring. These findings will inform clinical initiatives to improve patient selection and training in the use of this new technology and have served as the basis for development of quantitative surveys to be used in clinical practice.

Use of sensors in the treatment and follow-up of patients with diabetes mellitus

Glucose control is the cornerstone of Diabetes Mellitus (DM) treatment. Although self-regulation using capillary glycemia (SRCG) still remains the best procedure in clinical practice, continuous glucose monitoring systems (CGM) offer the possibility of continuous and dynamic assessment of interstitial glucose concentration. CGM systems have the potential to improve glycemic control while decreasing the incidence of hypoglycemia but the efficiency, compared with SRCG, is still debated. CGM systems have the greatest potential value in patients with hypoglycemic unawareness and in controlling daily fluctuations in blood glucose. The implementation of continuous monitoring in the standard clinical setting has not yet been established but a new generation of open and close loop subcutaneous insulin infusion devices are emerging making insulin treatment and glycemic control more reliable.

Evaluation of an algorithm to guide patients with type 1 diabetes treated with continuous subcutaneous insulin infusion on how to respond to real-time continuous glucose levels: a randomized controlled trial

OBJECTIVE

To evaluate an algorithm guiding responses of continuous subcutaneous insulin infusion (CSII)-treated type 1 diabetic patients using real-time continuous glucose monitoring (RT-CGM).

RESEARCH DESIGN AND METHODS

Sixty CSII-treated type 1 diabetic participants (aged 13-70 years, including adult and adolescent subgroups, with A1C <or=9.5%) were randomized in age-, sex-, and A1C-matched pairs. Phase 1 was an open 16-week multicenter randomized controlled trial. Group A was treated with CSII/RT-CGM with the algorithm, and group B was treated with CSII/RT-CGM without the algorithm. The primary outcome was the difference in time in target (4-10 mmol/l) glucose range on 6-day masked CGM. Secondary outcomes were differences in A1C, low (<or=3.9 mmol/l) glucose CGM time, and glycemic variability. Phase 2 was the week 16-32 follow-up. Group A was returned to usual care, and group B was provided with the algorithm. Glycemia parameters were as above. Comparisons were made between baseline and 16 weeks and 32 weeks.

RESULTS

In phase 1, after withdrawals 29 of 30 subjects were left in group A and 28 of 30 subjects were left in group B. The change in target glucose time did not differ between groups. A1C fell (mean 7.9% [95% CI 7.7-8.2to 7.6% [7.2-8.0]; P < 0.03) in group A but not in group B (7.8% [7.5-8.1] to 7.7 [7.3-8.0]; NS) with no difference between groups. More subjects in group A achieved A1C <or=7% than those in group B (2 of 29 to 14 of 29 vs. 4 of 28 to 7 of 28; P = 0.015). In phase 2, one participant was lost from each group. In group A, A1C returned to baseline with RT-CGM discontinuation but did not change in group B, who continued RT-CGM with addition of the algorithm.

CONCLUSIONS

Early but not late algorithm provision to type 1 diabetic patients using CSII/RT-CGM did not increase the target glucose time but increased achievement of A1C <or=7%. Upon RT-CGM cessation, A1C returned to baseline.

Assessment of different techniques for subcutaneous glucose monitoring in Type 1 diabetic patients during 'real-life' glucose excursions

AIMS

To compare the accuracy of two marketed subcutaneous glucose monitoring devices (Guardian RT, GRT; GlucoDay S, GDS) and standard microdialysis (CMA60; MD) in Type 1 diabetic patients.

METHODS

Seven male Type diabetic patients were investigated over a period of 26 h simulating real-life meal glucose excursions. Catheters of the three systems were inserted into subcutaneous adipose tissue of the abdominal region. For MD, interstitial fluid was sampled at 30- to 60-min intervals for offline glucose determination. Reference samples were taken at 15- to 60-min intervals. All three systems were prospectively calibrated to reference. Median differences, median absolute relative differences (MARD), median absolute differences (MAD), Bland-Altman plot and Clark Error Grid were used to determine accuracy.

RESULTS

Bland-Altman analysis indicated a mean glucose difference (2 standard deviations) between reference and interstitial glucose of -10.5 (41.8) % for GRT, 20.2 (55.9) % for GDS and 6.5 (35.2) % for MD, respectively. Overall MAD (interquartile range) was 1.07 (0.39; 2.04) mmol/l for GRT, 1.59 (0.54; 3.08) mmol/l for GDS and 0.76 (0.26; 1.58) mmol/l for MD. Overall MARD was 15.0 (5.6; 23.4) % (GRT), 19.7 (6.1; 37.6) % (GDS) and 8.7 (4.1; 18.3) % (MD), respectively. Total sensor failure occurred in two subjects using GRT and one subject using GDS.

CONCLUSIONS

The three investigated technologies had comparable performance. Whereas GRT underestimated actual blood glucose, GDS and MD overestimated blood glucose. Considerable deviations during daily life meal glucose excursions from reference glucose were observed for all three investigated technologies. Present technologies may require further improvement until individual data can lead to direct and automated generation of therapeutic advice in diabetes management.

Factors predictive of use and of benefit from continuous glucose monitoring in type 1 diabetes

OBJECTIVE

To evaluate factors associated with successful use of continuous glucose monitoring (CGM) among participants with intensively treated type 1 diabetes in the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Randomized Clinical Trial.

RESEARCH DESIGN AND METHODS

The 232 participants randomly assigned to the CGM group (165 with baseline A1C >or=7.0% and 67 with A1C <7.0%) were asked to use CGM on a daily basis. The associations of baseline factors and early CGM use with CGM use >or=6 days/week in the 6th month and with change in A1C from baseline to 6 months were evaluated in regression models.

RESULTS

The only baseline factors found to be associated with greater CGM use in month 6 were age >or=25 years (P < 0.001) and more frequent self-reported prestudy blood glucose meter measurements per day (P < 0.001). CGM use and the percentage of CGM glucose values between 71 and 180 mg/dl during the 1st month were predictive of CGM use in month 6 (P < 0.001 and P = 0.002, respectively). More frequent CGM use was associated with a greater reduction in A1C from baseline to 6 months (P < 0.001), a finding present in all age-groups.

CONCLUSIONS

After 6 months, near-daily CGM use is more frequent in intensively treated adults with type 1 diabetes than in children and adolescents, although in all age-groups near-daily CGM use is associated with a similar reduction in A1C. Frequency of blood glucose meter monitoring and initial CGM use may help predict the likelihood of long-term CGM benefit in intensively treated patients with type 1 diabetes of all ages.