Performance Comparison of CGM Systems: MARD Values Are Not Always a Reliable Indicator of CGM System Accuracy.

Background: The ongoing progress of continuous glucose monitoring (CGM) systems results in an increasing interest in comparing their performance, in particular in terms of accuracy, that is, matching CGM readings with reference values measured at the same time. Most often accuracy is evaluated by the mean absolute relative difference (MARD). It is frequently overseen that MARD does not only reflect accuracy, but also the study protocol and evaluation procedure, making a cross-study comparison problematic.

What Are the Next Steps in Continuous Glucose Monitoring?

The development of glucose sensors for continuous glucose monitoring (CGM) is likely still in its early days. A number of novel approaches-along with many attempts to improve current CGM systems-are in development. The next generation of glucose sensors (NGGS) will also enable, for example, reliable glucose measurement in the low glycemic range.

Current Trends in Continuous Glucose Monitoring.

The market introduction of systems for continuous glucose monitoring (CGM) some 15 years ago did not immediately revolutionize the treatment of diabetes; however, for a given group of patients, it would almost be inconceivable nowadays to imagine life without CGM. One day the development of insulin pumps together with CGM could culminate in an artificial pancreas system. The performance of the glucose sensors used for glucose measurement in the interstitial fluid in the subcutaneous tissue and the algorithms employed to analyze these data have improved so much over the past decade that current CGM systems by far outperform those of the first generations.

Assessing the analytical performance of systems for self-monitoring of blood glucose: concepts of performance evaluation and definition of metrological key terms.

Reliability of blood glucose (BG) measurements is a prerequisite for successful diabetes management. Publications on the evaluation of self-monitored glucose values, however, are frequently characterized by a confusion in terminology. We provide an inventory of key terms such as accuracy, trueness, precision, traceability, calibration, and matrix effect to avoid future misunderstanding.

Adiponectin in coronary heart disease and newly diagnosed impaired glucose tolerance.

Objective: Adiponectin is produced by adipose tissue and regarded as protective hormone for diabetes and coronary heart disease (CHD). Its role in heart failure is discussed controversially.

Methods: In this study, 1015 consecutive patients admitted for acute (n = 149) or elective (n = 866) coronary angiography were enrolled.

Accuracy in blood glucose measurement: what will a tightening of requirements yield?

Nowadays, almost all persons with diabetes--at least those using antidiabetic drug therapy--use one of a plethora of meters commercially available for self-monitoring of blood glucose. The accuracy of blood glucose (BG) measurement using these meters has been presumed to be adequate; that is, the accuracy of these devices was not usually questioned until recently. Health authorities in the United States (Food and Drug Administration) and in other countries are currently endeavoring to tighten the requirements for the accuracy of these meters above the level that is currently stated in the standard ISO 15197.

Oral glucose tolerance test and HbA₁c for diagnosis of diabetes in patients undergoing coronary angiography: [corrected] the Silent Diabetes Study.

Aims/hypothesis: The primary aim of this study was to compare the results of HbA(1c) measurements with those of an OGTT for early diagnosis of 'silent diabetes' in patients with coronary artery disease (CAD) undergoing angiography without prediagnosed diabetes. A secondary aim was to investigate the correlation between the extent of CAD and the glycaemic status of the patient.

Methods: Data from 1,015 patients admitted for acute (n = 149) or elective (n = 866) coronary angiography were analysed.

Are type 2 diabetes patients who self-monitor blood glucose special? The role of confounders in the observational ROSSO study.

Background: In the German multicenter, retrospective cohort study (ROSSO), those patients with type 2 diabetes who performed self-monitoring of blood glucose (SMBG) had a better long-term clinical outcome. We analyzed whether confounders accounted for the lower rate of clinical events in the SMBG cohort.

Methods: ROSSO followed 3268 persons from diagnosis of type 2 diabetes for a mean of 6.

Myocardial infarction and stroke in early years after diagnosis of type 2 diabetes: risk factors and relation to self-monitoring of blood glucose.

Background: The natural course of macrovascular events in patients with type 2 diabetes was analyzed: what are the risk factors, and what is the relationship to the use of self-monitoring of blood glucose (SMBG)?

Methods: Data were retrieved from ROSSO-a German retrospective observational study-which followed 3,268 patients from diagnosis of type 2 diabetes for 6.5 +/- 1.6 years.

[Analysis of the quality of health care for patients with type 2 diabetes enrolled in statutory or private health plans].

Background And Objective: Worldwide the quality of care of patients with type 2 diabetes has been investigated only by analysing within cross-sectional studies. But the quality of care in relation to statutory or private health plans in not known. It was the aim of this study to ascertain retrospectively, how in the course of time from first diagnosis the quality of medical care of patients with type 2 diabetes differed depending on the type of health insurance of the individual patient.

Interrelations between diabetes therapy, self-monitoring of blood glucose, blood glucose and non-fatal or fatal endpoints in patients with type 2 diabetes / results of a longitudinal cohort study (ROSSO 5).

The ROSSO study is a retrospective, longitudinal cohort study performed to obtain epidemiological data on self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes and to investigate the impact of SMBG on disease-related morbidity and mortality. 3,268 patients from 192 doctor's practices in Germany were included and their data from diabetes diagnosis (between 1995 and end of 1999) till drop-out (120 died, 17 drop-outs) or end of 2003 were collected from the medical records. The mean observational time was 6.

Cost impact of blood glucose self-monitoring on complications of type 2 diabetes: a Swiss perspective (ROSSO study No.11).

Question Under Study: despite the increasing prevalence of type 2 diabetes, its financial burden on the Swiss healthcare system remains unclear. Our aim was to determine the cost of self-monitoring of blood glucose (SMBG) in reducing diabetic complications by comparing the direct costs to the Swiss statutory health insurance system of diabetic complications in SMBG users vs. nonusers.

Epidemiology of complications and total treatment costs from diagnosis of Type 2 diabetes in Germany (ROSSO 4).

Objective: To determine the occurrence of complications and treatment costs in the first 6 years from diagnosis of Type 2 diabetes in the primary care level.

Design: The German multi-centre, retrospective epidemiological cohort study ROSSO observed patients from diagnosis in 1995-1999 until the end of 2003 or loss to follow-up.

Setting: 192 randomly contacted primary care practices and all patient records of newly diagnosed type 2 diabetes patients.

Self-measurement of blood glucose in patients with type 2 diabetes: a health economic assessment.

Background: The clinical role and the potential benefit of self-measurement of blood glucose (SMBG) for patients with type 2 diabetes are still under discussion. Even less information is available on the cost-effectiveness of performing SMBG by this patient group. The goal of this study was to establish cost-effectiveness ratios of performing SMBG by patients afflicted by this disease.

Altered disease course after initiation of self-monitoring of blood glucose in noninsulin-treated type 2 diabetes (ROSSO 3).

Background: Patients with noninsulin-treated type 2 diabetes were documented from diagnosis to determine whether patients taking up self-monitoring of blood glucose (SMBG) are distinct by baseline characteristics, exhibit a different natural disease course, and are treated differently.

Methods: The German multicenter, retrospective cohort study (ROSSO) followed 3268 persons from diagnosis of type 2 diabetes for a mean of 6.5 years.

Self-monitoring of blood glucose in type 2 diabetes and long-term outcome: an epidemiological cohort study.

Aims/hypothesis: The aim of this study was to obtain epidemiological data on self-monitoring of blood glucose (SMBG) in type 2 diabetes and to investigate the relationship of SMBG with disease-related morbidity and mortality.

Methods: The German multicentre Retrolective Study 'Self-monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes' (ROSSO) followed 3,268 patients from diagnosis of type 2 diabetes between 1995 and 1999 until the end of 2003. Endpoints were diabetes-related morbidity (non-fatal myocardial infarction, stroke, foot amputation, blindness or haemodialysis) and all-cause mortality.

Continuous glucose monitoring: reliable measurements for up to 4 days with the SCGM1 system.

Continuous glucose monitoring allows patients with diabetes to check their metabolic status throughout the day, including rarely monitored time periods, such as postprandial and nocturnal periods. The performance of a prototype of the novel SCGM1 System (Roche Diagnostics GmbH, Mannheim, Germany) employing the microdialysis technique was evaluated. Forty-two patients with type 1 diabetes participated in the study [29 males/13 females, age 34 +/- 9 years, duration of diabetes 16 +/- 11 years, glycated hemoglobin 7.

The SCGM1 System: subcutaneous continuous glucose monitoring based on microdialysis technique.

The SCGM1 System is designed to allow continuous glucose monitoring in the subcutaneous interstitial fluid for up to 120 h. The system is based on the microdialysis technique and is composed of three components: (1) a disposable Cassette, which contains the microdialysis catheter (with the necessary tubes), an electrochemical flow-through sensor for glucose measurement, and the fluid reservoirs for both the microdialysis perfusate and a reagent solution containing glucose oxidase; (2) the Sensor Unit, which houses the Cassette and is worn by the patient using a belt pack; and (3) the Data Manager, with an integrated blood glucose meter for the calibration of the glucose signal. The Data Manager also has the option of displaying the continuous glucose signal.

Continuous glucose monitoring with glucose sensors: calibration and assessment criteria.

Continuous glucose monitoring (CM) by means of minimally invasive or noninvasive glucose sensors can help to further optimize metabolic control in patients with diabetes without need for frequent capillary blood glucose measurements. Most glucose sensors measure glucose concentration in the interstitial fluid (ISF). Because of the varying conditions in this compartment, a general in vitro calibration ( = factory calibration) by the manufacturer appears not to be possible.

Hypoglycemia warning signal and glucose sensors: requirements and concepts.

Hypoglycemia is the most feared side effect of diabetes therapy with blood glucose-lowering agents. The fear of hypoglycemia often contributes to poor metabolic control of patients with diabetes. Therefore, integration of a hypoglycemia warning signal into continuous glucose monitoring systems represents an important additional help for patients with diabetes.