One in Five Laboratories Using Various Hemoglobin A(1c) Methods Do Not Meet the Criteria for Optimal Diabetes Care Management

Background: We assessed the reference change value (RCV) of currently available hemoglobin A(1c) (HbA(1c)) laboratory assays, which is defined as the critical difference between two consecutive HbA(1c) measurements representing a significant change in health status. Methods: We examined the individual laboratory coefficients of variation (CVs) in the Dutch/Belgian quality scheme based on 24 lyophilized samples and calculated the RCV per laboratory (n-220) and per assay method. In addition, two pooled whole blood samples were sent to the participating laboratories. The individual laboratory results were compared to the assigned value +/- an allowable total error (TEa) of 6%. Results: At HbA(1c) values of 41.0 mmol/mol (5.9%-Diabetes Control and Complications Trial [DCCT]) and 61.8 mmol/mol (7.8%-DCCT), 99% and 98%, respectively, of the laboratories reported a value within a TEa limit of 6%. The analytical CV of the HbA(1c) method used in 78% of the laboratories is Conclusions: The analytical performance of the majority of laboratory HbA(1c) methods is within the clinical requirements. However, based on the calculated RCV, 21.8% of the laboratories using different HbA(1c) methods are not able to distinguish an HbA(1c) result of 59 mmol/mol (7.5%-DCCT) from a previous HbA(1c) result of 53 mmol/mol (7.0%-DCCT). It can be presumed that differences in HbA(1c) results of 5 mmol/mol (0.5%-DCCT) do influence treatment decisions

Haemoglobin A1c:Historical overview and current concepts

<p>Since the discovery of the relation between increased concentrations of fast haemoglobin fractions in patients with diabetes mellitus compared to concentrations in subjects without diabetes mellitus by Samuel Rahbar and co-workers in 1969, glycated haemoglobin A1c (HbA1c) has become a "gold standard" for glucose management in patients with diabetes mellitus. Recently, HbA1c has been advocated as a diagnostic marker for diabetes mellitus, which further underlines the importance of HbA1c. There are currently more than 30 methods available on the market with an analytical performance ranging from poor to state of the art. This review describes the biochemistry of HbA1c and the concepts of analytical and biological variation with respect to the measurement of HbA1c. Subsequently, aspects regarding the discovery of HbA1c are described. In addition, an overview is given on the assays methods that are currently available for the measurement of HbA1c. Finally, recommendations for the minimally required analytical performance characteristics of the current HbA1c assays are presented. (C) 2012 Elsevier Ireland Ltd. All rights reserved.</p>

Haemoglobin A1c: Historical overview and current concepts

Since the discovery of the relation between increased concentrations of fast haemoglobin fractions in patients with diabetes mellitus compared to concentrations in subjects without diabetes mellitus by Samuel Rahbar and co-workers in 1969, glycated haemoglobin A1c (HbA1c) has become a "gold standard" for glucose management in patients with diabetes mellitus. Recently, HbA1c has been advocated as a diagnostic marker for diabetes mellitus, which further underlines the importance of HbA1c. There are currently more than 30 methods available on the market with an analytical performance ranging from poor to state of the art. This review describes the biochemistry of HbA1c and the concepts of analytical and biological variation with respect to the measurement of HbA1c. Subsequently, aspects regarding the discovery of HbA1c are described. In addition, an overview is given on the assays methods that are currently available for the measurement of HbA1c. Finally, recommendations for the minimally required analytical performance characteristics of the current HbA1c assays are presented. (C) 2012 Elsevier Ireland Ltd. All rights reserved

Repeat whole blood donors with a ferritin level of 30 mu g/L or less show functional iron depletion

BACKGROUND: Whole blood donors are screened for iron depletion through hemoglobin measurement alone or in combination with ferritin. Ferritin measurement gives the advantage of earlier detection of iron depletion. In a previous study we identified a ferritin level of 30 mu g/L or less as a possible indicator of suboptimal erythropoiesis. In this study, erythropoietic parameters were measured to determine if a ferritin level of 30 mu g/L or less is indicative of iron-deficient erythropoiesis in repeat whole blood donors. STUDY DESIGN AND METHODS: Twenty-one healthy male repeat whole blood donors were divided into two groups according to their predonation ferritin values: 30 mu g/L or less (low-ferritin group) and greater than 30 mu g/L (normal-ferritin group). Ferritin and erythropoietic parameters were measured before whole blood donation and weekly in the 8 weeks after donation. RESULTS: A significantly lower value was found for hemoglobin, mean corpuscular volume (MCV), reticulocytes, and reticulocyte hemoglobin content on at least three of the nine time points in the low-ferritin group compared to the normal-ferritin group (p <0.05). Of these parameters, MCV and reticulocyte hemoglobin content were significantly lower before donation as well as during all 8 weeks following donation (p <0.05). CONCLUSION: Based on the lower values of the erythropoietic parameters in the low-ferritin group, it can be concluded that repeat whole blood donors with a ferritin value of 30 mu g/L or less have iron-deficient erythropoiesis and therefore require a longer donation interval than the current 56 days

Pre- and Postoperative Accuracy and Safety of a Real-Time Continuous Glucose Monitoring System in Cardiac Surgical Patients: A Randomized Pilot Study

Background: Our objective was to evaluate the accuracy and safety of a real-time (RT) continuous glucose monitoring system (CGMS) in patients before and after cardiothoracic surgery and to investigate whether activation of the alarm function of the RT-CGMS had an effect on glucose control. Methods: Patients scheduled for elective cardiothoracic procedures, without a history of insulin-requiring diabetes, were perioperatively monitored with RT-CGMS for 72 h and were randomized into two groups: with or without the alarm function (set at 4 and 10 mmol/L) of the device activated. Sensor values were compared with capillary, arterial, and venous blood glucose values. Percentages of time spent in various glucose ranges were compared between groups. Results: There were no adverse effects of the RT-CGMS. Of the 1,001 sensor value comparisons with capillary or arterial measurements, 96.6% fell within Clarke Error Grid zones A and B, with relative absolute differences ranging from 15% (preoperative period) to 12% (intensive care unit period) to 14% (postoperative period on the ward). Seventeen (7.9%) arterial and 16 (2.0%) capillary comparisons fell within zone D or E. Whether or not the alarm function, as used in this pilot study, was activated did not affect time spent in different glucose ranges. Conclusions: Although the RT-CGMS is safe and accurate according to accepted standards, there are still small aberrations, which in our opinion preclude unlimited use in its present form in a clinical setting. The effect of the alarm function at different glucose levels remains to be investigated

In-Hospital Healthcare Utilization, Outcomes, and Costs in Pre-Hospital-Adjudicated Low-Risk Chest-Pain Patients

Background There is increasing evidence that in patients presenting with acute chest pain, pre-hospital triage can accurately identify low-risk patients. It is, however, still unclear which diagnostics are performed in pre-hospital-adjudicated low-risk patients and what the contribution is of those diagnostic results in the healthcare process. Objectives The aim of this study was to quantify healthcare utilization, costs, and outcomes in pre-hospital-adjudicated low-risk chest-pain patients, and to extrapolate to total costs in the Netherlands. Methods This was a prospective cohort study including 700 patients with suspected non-ST-elevation acute coronary syndrome in which pre-hospital risk stratification using the HEART score was performed by paramedics. Low risk was defined as a pre-hospital HEART scor

Clinical review: Consensus recommendations on measurement of blood glucose and reporting glycemic control in critically ill adults.

The management reporting and assessment of glycemic control lacks standardization. The use of different methods to measure the blood glucose concentration and to report the performance of insulin treatment yields major disparities and complicates the interpretation and comparison of clinical trials. We convened a meeting of 16 experts plus invited observers from industry to discuss and where possible reach consensus on the most appropriate methods to measure and monitor blood glucose in critically ill patients and on how glycemic control should be assessed and reported. Where consensus could not be reached, recommendations on further research and data needed to reach consensus in the future were suggested. Recognizing their clear conflict of interest, industry observers played no role in developing the consensus or recommendations from the meeting. Consensus recommendations were agreed for the measurement and reporting of glycemic control in clinical trials and for the measurement of blood glucose in clinical practice. Recommendations covered the following areas: How should we measure and report glucose control when intermittent blood glucose measurements are used? What are the appropriate performance standards for intermittent blood glucose monitors in the ICU? Continuous or automated intermittent glucose monitoring - methods and technology: can we use the same measures for assessment of glucose control with continuous and intermittent monitoring? What is acceptable performance for continuous glucose monitoring systems? If implemented, these recommendations have the potential to minimize the discrepancies in the conduct and reporting of clinical trials and to improve glucose control in clinical practice. Furthermore, to be fit for use, glucose meters and continuous monitoring systems must match their performance to fit the needs of patients and clinicians in the intensive care setting