Bogdan Solnica

Analytical performance of glucometers used for routine glucose self-monitoring of diabetic patients.

BACKGROUND Glucometry is an essential part of diabetes treatment, but so far, no standard quality control procedure verifying blood glucose meter results is available. In this study, we evaluated the analytical performance of eight glucose meters: GX and Esprit (Bayer Diagn.), MediSense Card Sensor, ExacTech (MediSense) with strips Selfcare (Cambridge Diagn), One Touch Basic, One Touch II, One Touch Profile (Lifescan) and Glucotrend (Boehringer Mannheim/Roche). METHODS The evaluation included within-run imprecision, linearity, comparison with the laboratory method and calculation of differences between individual glucometers. RESULTS Within-run imprecision ranged from 1.5% to 4.5%, linearity assessed as the correlation between measured and calculated glucose concentrations yielded r(2) values from 0.97 to 0.981. Analytical bias of glucose concentration values obtained by the glucometry amounted from 0.14% to 16.9% of values measured by the laboratory method. Bias higher than 5% was found for One Touch Basic, II and Profile meters (however, glucose concentrations in plasma obtained by the laboratory method One Touch meters showed analytical bias from 3.0% to 8.8%). The regression analysis yielded slope values from 0.77 to 1.09 and r(2) values from 0.86 to 0.98. The best correlations with the laboratory method were found for One Touch Basic, II Profile, Glucotrend and Esprit meters. The calculated differences between the individual glucose meters can constitute 0.02-1.49 mmol/l (0.96-26.9%) at glucose concentration 5.55 mmol/l, and 0.16-4.16 mmol/l (0.96-24.96%) at glucose concentration 16.67 mmol/l. Error grid analyses have shown that Glucometers One Touch Basic and One Touch Profile yielded all results in zone A (acceptable). The remaining glucometers yielded 1-7% of results in zones B (insignificant errors), C or D (lack of detection and treatment). CONCLUSIONS All studied glucometers had both small deviation from laboratory reference values (<10%) and high concurrence with results obtained by the laboratory method.

Factors associated with plasma lipids and lipoproteins in type 1 diabetes mellitus: the EURODIAB IDDM Complications Study.

Aim  To assess the determinants and prevalence of hyperlipidaemia in Type 1 diabetic patients in the EURODIAB IDDM Complications Study.

Increased nitric oxide availability attenuates high fat diet metabolic alterations and gene expression associated with insulin resistance

BackgroundHigh fat diet impairs nitric oxide (NO) bioavailability, and induces insulin resistance. The link between NO availability and the metabolic adaptation to a high fat diet is not well characterized. The purpose of this study was to investigate the effect of high fat diet on metabolism in mice with decreased (eNOS-/-) and increased (DDAH overexpressed) NO bioavailability.MethodseNOS-/- (n = 16), DDAH (n = 24), and WT (n = 19) mice were fed a high fat diet (HFD) for 13 weeks. Body weight, biochemical parameters, adipokines and insulin were monitored. The matrigel in vivo model with CD31 immunostaining was used to assess angiogenesis.Gene expression in adipose tissues was analyzed by microarray and Real Time PCR. Comparisons of the mean values were made using the unpaired Student t test and p < 0.05 were considered statistically significant.ResultseNOS-/- mice gained less weight than control WT and DDAH mice. In DDAH mice, a greater increase in serum adiponectin and a lesser increment in glucose level was observed. Fasting insulin and cholesterol levels remained unchanged. The angiogenic response was increased in DDAH mice. In adipose tissue of DDAH mice, genes characteristic of differentiated adipocytes were down-regulated, whereas in eNOS-/- mice, genes associated with adipogenesis, fatty acid and triglyceride synthesis were upregulated.ConclusionsOur results indicate that increased NO availability attenuates some HFD induced alterations in metabolism and gene expression associated with insulin resistance.

Quality Control of SMBG in Clinical Practice

We present results of quality control of self‐monitored blood glucose (SMBG) performed in diabetes outpatient clinic. The tests included: inspection of glucose meter, blood glucose self‐measurement by a patient, glucose measurement by point‐of‐care analyzer used in a clinic and with the laboratory method. In the study 158 glucose meters were controlled and compared with HemoCue glucose analyzer used in the clinic as the reference. 122 glucose meters readings were also compared with the reference laboratory method. Tested glucose meters included: Accutrend® {18}, Glucotrend® {59}, Precision QiD {39}, One Touch® {26} and Glucocard II {16}. Reference glucose assays were performed using glucose oxidase method on Hitachi 911 analyzer. Glucose concentrations measured by the controlled glucose meters ranged from 36 to 425 mg/dL. The analytical bias of the glucose meters amounted from 2.48% to 8.27%. Correlation coefficient between results obtained by the tested glucose meters and HemoCue analyzer ranged from 0.957 to 0.980 and between glucose meters and laboratory method from 0.955 to 0.985. Passing‐Bablok agreement test and Deming regression analysis indicated good concordance of results between all the tested glucose meters and HemoCue analyzer, whereas good agreement with the laboratory method was found for Accutrend®, Glucotrend®, Precision QiD and One Touch® glucose meters. In conclusion, good analytical performance of the employed glucose meters and a bias less than 10% from the reference values were found. Results of this study show the possibility for routine, convenient for the patient quality control of SMBG in an outpatient clinic.

The Evaluation of Analytical Performance of the Precision G Point-of-Care Glucometer

Abstract In this study analytical and functional performance of the Precision GTM “point-of-care” glucometer (MediSense Inc.) was evaluated. Studies were carried-out using capillary blood collected for routine monitoring of glycemia in diabetic patients. Each glucose test measurement with the glucometer was paralleled by the laboratory measurement of glucose on the same blood sample, using the GOD/PAP method. Mean accuracy error in the glucose concentration range of 1.1–33.3 mmol/l calculated for the glucometer vs. the laboratory method amounted to only 0.2%. However, for glucose concentrations below 4.4 mmol/l the mean accuracy error was 3.9%, and for the concentrations above 10.0 mmol/l it was 4.6%. Within-run CV for three concentration levels was 2.76%, 2.89%, and 4.22%, respectively. Linearity of the meter response in samples with glucose concentration ranging from 1.7 mmol/l to 16.7 mmol/l, expressed as the correlation coefficient r, yielded r=0.996 and linear regression equation [y1 = 0.996 y2–0.005], where y1 is the measured glucose concentration and y2 is the target glucose concentration calculated in diluted samples. Correlation studies on a set of 114 blood samples collected from patients and assayed by glucometer and by the laboratory method yielded a relationship expressed by the equation: y = 0.84x + 1.13 where y is glucometer read-out and x is glucose concentration obtained by the laboratory method. Passing-Bablok test showed a significant agreement between the glucometer measurements and the reference laboratory results in the studied glucose concentration range. The error grid analysis of series of the paired patients samples showed that 95% of results were in the clinically acceptable zone A and 1% of results in zone

Quality control of self-monitoring of blood glucose: why and how?

The control of analytical quality of self-monitoring of blood glucose (SMBG) is recommended as a routine procedure in diabetes management. This control procedure should be easily accessible to patients, convenient, not time-consuming, and provide a reliable assessment of glucose meter performance. Optimally it should be located in the diabetes outpatient clinic. Presently there are two approaches to carrying out SMBG quality control. The first is based on the comparison of results obtained by a controlled glucose meter and use of the laboratory method or point-of-care testing device as a surrogate reference analyzer. The second one is a traditionally organized external quality assessment scheme with use of a dedicated control material, which is distributed to all participants. The recommended allowable meter error in SMBG can be realistically set at 10%.

Markers of Antioxidant Defense in Patients with Type 2 Diabetes.

Aims. Diabetes is considered a state of increased oxidative stress. This study evaluates blood concentrations of selected markers of antioxidant defense in patients with type 2 diabetes. Methods. The study included 80 type 2 diabetes patients and 79 apparently healthy controls. Measured markers included ferric reducing ability of plasma (FRAP), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), γ-glutamyltransferase (GGT) and uric acid serum, and plasma and/or hemolysate levels. Results. FRAP, uric acid, CRP, and GGT levels were significantly higher in patients with diabetes. Plasma and hemolysate GR was significantly higher whereas GPx activity was significantly lower in patients with diabetes. There were no significant differences in antioxidant defense markers between patients with and without chronic diabetes complications. Fasting serum glucose correlated with plasma GPx, plasma and hemolysate GR, FRAP, and serum GGT, and HbA1c correlated with serum GGT. Only FRAP and serum uric acid were significantly higher in obese (BMI > 30 kg/m2) patients with diabetes than in nonobese patients. Conclusions. Some components of antioxidant defense such as GR, uric acid, and GGT are increased in patients with type 2 diabetes. However, the whole system cannot compensate for an enhanced production of ROS as reflected by the trend toward decreased erythrocytes GSH.

Prevalence of diabetes and impaired fasting glucose in Poland—the NATPOL 2011 Study

The aim of the analysis was to assess the prevalence of diabetes and impaired fasting glucose in Poland.

The effect of hematocrit on the results of measurements using glucose meters based on different techniques.

Abstract Background: The aim of the study was to evaluate the effect of hematocrit (HCT) on glucose meter assays based on different measurement techniques. Methods: This paper studied glucose meters utilizing the glucose dehydrogenase reaction and four measurement techniques: colorimetry (HemoCue), reflectometry (Accu-Chek Active), amperometry (Optium Xido) and coulometry (Optium Omega). The EDTA venous blood samples HCT were modified by adding or removing defined aliquots of plasma. Glucose concentration was measured using each meter in 27 batches of blood samples, with HCT ranging from 20% to 60% in 10% increments. The data were analyzed using repeated measures models and a linear random effects model. Results: A significant relationship between HCT and glucose reading in all meters was found and, for all meters except Optium Xido, there was a significant modification of this relationship by glucose level. The relative decrease in glucose concentration per 1% increase of the HCT value varied from 0.30% for Optium Omega in samples with glucose concentrations <5.55 mmol/L to 1.37% for Optium Xido in the same stratum (p<0.0001). The 5% glucose meter error (the ADA recommendation) was reached in the <5.55 mmol/L stratum after HCT change by 3.9%–16.7%. Conclusions: There is a significant continuous effect of HCT on measurement accuracy of glucose meters across its wide range of values and glucose concentrations. The most sensitive to the HCT interference was the system utilizing amperometric technique (Optium Xido) followed by the one with reflectometric technique (Accu-Chek Active), while the systems with the coulometric technique (Optium Omega) or colorimetric measurements in whole blood haemolysate (HemoCue) were less sensitive.

Prevalence of lipid abnormalities in Poland. The NATPOL 2011 survey.

BACKGROUND Poland represents a country of high cardiovascular (CV) risk. The association between lipid abnormalities and increased CV risk is well established. Therefore, it is important to monitor the prevalence and control of dyslipidaemia. AIM To evaluate serum lipids concentrations as well as the prevalence, awareness, and control of lipid abnormalities in a representative sample of adults in Poland. METHODS In 2011, in a national cross-sectional survey blood samples were collected from 1168 males and 1245 females, aged 18-79 years, for measurement of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and triglycerides (TG) in blood serum. Low density lipoprotein cholesterol (LDL-C) was calculated using Friedewalds formula. RESULTS Mean serum TC concentration was 197.1 mg/dL (95% CI 193.8-200.4) in males (M) and 198.6 mg/dL (95% CI 195.7-201.5) in females (F). Levels of LDL-C were 123.6 mg/dL (120.9-126.2) and 123.7 mg/dL (121.4-126.1), HDL-C - 45.8 mg/dL (44.7-47.0) and 54.1 mg/dL (53.1-55.1), TG - 140.9 mg/dL (133.0-148.8) and 104.0 mg/dL (99.8-108.2) for males and females, respectively. TC ≥ 190 mg/dL was found in 54.3% subjects (M 54.3%; F 54.4%). After adding patients on lipid-lowering treatment, hypercholesterolaemia was present in 61.1% of adults (M 60.8%; F 61.3%). LDL-C ≥ 115 mg/dL was detected in 57.8% of all subjects (M 58.3%; F 57.3%), while HDL-C < 40 mg/dL in 35.2% of males and < 45 mg/dL in 22% of females TG ≥ 150 mg/dL was found in 21.1% of subjects (M 28.4%; F 14.0%). The highest prevalence of elevated TC and LDL-C levels was present in the age group of 40-59-year-olds. Of those with hypercholesterolaemia 58.7% (M 61.5%, F 56.0%) were not aware of the condition; 22.0% (M 21.0%, F 24.5%) were aware but were not being treated; 8.1% (M 7.7%, F 8.5%) were treated but with TC ≥ 190 mg/dL; and only 10.9% (M 10.7%, F 11.0%) were being treated with TC < 190 mg/dL. CONCLUSIONS The prevalence of dyslipidaemia in Poland continues to be high--over 60% of adults have hypercholesterolaemia, and control remains poor. The results of the NATPOL 2011 survey call for urgent preventive measures.