Self-monitoring Of Blood Glucose Measurements Research Articles

High and low hemoglobin glycation phenotypes in type 1 diabetes: A challenge for interpretation of glycemic control

This study tested the hypothesis that there are consistent individual differences in the relationship between glycated hemoglobin (HbA1c) and mean blood glucose (MBG) levels in individuals with similar preceding blood glucose levels. Blood glucose data were collected for up to 2.3 years by 128 children and adolescents with type 1 diabetes. HbA1c values were date-matched with MBG levels calculated from an average of 85 self-monitored blood glucose measurements collected in the previous 30 days. There was significant linear correlation between MBG and HbA1c (HbA1c=0.027×MBG+5.8, n=682, r=.71, P<.0001) but also wide variability in the population HbA1c response to MBG. We calculated a hemoglobin glycation index (HGI=observed HbA1c−predicted HbA1c) to quantify the magnitude and direction of the difference between each patient's set of observed and predicted HbA1c results. Likelihood ratio tests and t statistics showed that mean HGI were significantly different among individuals, and that 29% of the patients had HbA1c levels that were statistically significantly higher or lower than predicted by the regression equation. The observed individual differences in the relationship between MBG and HbA1c were not related to erythrocyte age and there was no evidence of analytical artifact. We interpret these results as possible evidence of high and low hemoglobin glycation phenotypes within the population. We conclude that MBG and HbA1c are not necessarily interchangeable estimates of glycemic control and that hemoglobin glycation phenotype may be important for the clinical assessment of diabetic patients.

Clinical and technical evaluation of a new self-monitoring blood glucose meter: assessment of analytical and user error

Our study aimed to validate (against the standards of the American Diabetes Association and the International Organization for Standardization) the analytical and clinical accuracy of the new MediSense Precision Plus Electrodes on the QID system when compared with a reference method using the Abbott Vision glucose analyzer. Previous studies have shown that the overall accuracy of the device also depends on the proficiency of the operator, so we also assessed the ‘ease of use’ of the MediSense system, by comparing the results obtained by the patient and health care professional. Accuracy of the self-monitored blood glucose measurements was evaluated over a wide range of glucose readings (2.6–20.0 mmol/l). Between-run CVs (using the manufacturer's quality control material) were found to be 7% at 2.7 mmol/l and 4.8% at 15.5 mmol/l ( n=380). We used the error-grid analysis with target range blood glucose, then separated the data into different subsets. We found that 100% of all measurements were in the clinically acceptable zones of A and B. All measured values of the MediSense QID system complied with the requirements for ‘blood glucose monitoring meters’, as proposed by the International Organization for Standardization. The rating of the patient questionnaire showed a good to very good overall rating and acceptance with a short instruction time. The results indicate that that the MediSense QID/Precision Plus Electrodes is a reliable and easy to use device, which can be recommended for the majority of patients with diabetes mellitus.

Color Discrimination and Accuracy of Blood Glucose Self-Monitoring in Type I Diabetic Patients

To determine the importance of color discrimination ability regarding accuracy in the self-monitoring of blood glucose. Two hundred two insulin-dependent (type I) diabetic patients performed the Fansworth-Munsell 100-hue test and a second group of 159 type I diabetic patients performed a new Düsseldorf 26-hue test. Error scores in both tests were compared with error scores of patients' self-monitoring of blood glucose measurements with Chemstrip Haemoglucotest 20-800 strips. Color discrimination ability decreased with age, diabetes duration, and presence of retinopathy. It was independent of the degree of glycemia and accuracy of self-monitoring of blood glucose. Impaired color vision by itself is no reason to abandon self-monitoring of blood glucose with visually read strips.

Longitudinal relationship of asymptomatic hypoglycemia to cognitive function in IDDM.

Early-onset insulin-dependent diabetes mellitus (IDDM) is linked to subsequent learning deficits. To investigate the relationship of learning deficits to metabolic control, 23 children with IDDM (age at testing 71 +/- 21 mo, age at diagnosis 35 +/- 15 mo) diagnosed before 5 yr of age were followed for periods of 6-78 mo. Mean glycosylated hemoglobin (HbA1), episodes of severe hypoglycemia, and frequency of self-monitoring blood glucose (SMBG) measurements less than 2.8 mM (50 mg/dl, asymptomatic hypoglycemia) were recorded every 3 mo. Six subjects entered the study 12.3 +/- 6.7 mo after diagnosis, and only severe hypoglycemia was present before entry. For the remaining 17 subjects, HbA1 and severe and asymptomatic hypoglycemia were present from the time of diagnosis of diabetes. Mean HbA1 level was 10.1 +/- 1.0%, and mean severe hypoglycemic episodes per patient was 2.9, but the frequency was highly skewed; one patient had 37 episodes, and 14 had none. The mean percentage of SMBG readings less than 2.8 mM was 2.4 +/- 2.1. On the revised Stanford-Binet Intelligence Scale there was no correlation between any subscale and severe hypoglycemia. However, the relative frequency of asymptomatic hypoglycemia correlated with scores on the abstract/visual reasoning scale (r = -.39, P = .037). This relationship was primarily accounted for by the relationship of asymptomatic hypoglycemia to performance on the copying subscale (r = -.42, P = .022). Children with frequent asymptomatic hypoglycemic episodes had lower mean copying scores and abstract reasoning scores than those with infrequent episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

New approach to technical and clinical evaluation of devices for self-monitoring of blood glucose.

Despite the wide distribution of devices for self-monitoring of blood glucose (SMBG), there is no internationally accepted agreement on a standardized procedure for their evaluation. This is due to incomplete or even inappropriate technical evaluation and to inadequate evaluation criteria for their clinical acceptability. To provide adequate information on the performance of these devices over the whole clinically relevant range for SMBG (30-350 mg/dl), a standardized test procedure has been established for technical (accuracy, precision, and total deviation) and clinical (acceptance analysis) evaluation. To demonstrate the potency of this new approach, the following SMBG devices and test strips were evaluated: Chemstrip bG batch (n = 10), Glucostix batch (n = 2), Accu-Check II (n = 5), Diascan (n = 5), Diascan strip batch (n = 4), Glucocheck SC (n = 4), and Glucometer II (n = 4). The devices and test strips were examined by trained technicians, and in addition, 1 Chemstrip bG batch and 2 Accu-Check II meters were examined by 10 and 5 trained diabetic patients, respectively. Even the best-performing device did not achieve the American Diabetes Association's goal that SMBG measurements should be within 15% of the reference value. Instead, the maximal total deviation within the clinically relevant blood glucose range reached values that equalled deviations from the reference value between 16 and 108%. Three of 36 devices were classified as good, 29 as acceptable, and 4 as unacceptable for clinical use. In conclusion, this new approach to the technical and clinical evaluation of devices for SMBG is easy to perform and provides more realistic and comparable information for clinical use and approval than commonly used methods.