BACKGROUND: Point-of-care testing (POCT) glucometers are widely being used for management of diabetes. We examined the analytical performance of the recently developed glucometer CareSens(R) N Glucometer (i-SENS Inc., Korea). METHODS: CareSens N was evaluated for linearity, precision, and the effect of hematocrit. Method comparison using the laboratory reference method, hexokinase method by Hitachi 7600 (Hitachi Co., Japan) was also performed. Other glucometers, Accu-Chek(R) inform (Roche Diagnostics LTD., Germany) and Onetouch(R) ultra(TM) (Lifescan Inc., USA) were evaluated for the same categories according to CLSI guidelines. RESULTS: CareSens N Glucometer showed a good linearity and precision. The linearity was r=0.9965. The coefficients of variations (CVs) of within-run precision were 0.73-1.98% and CVs of total precision were 1.65-2.71%. A high correlation (glucose by CareSens N = 0.9767 x glucose by Hitachi 7600 + 4.1734, r=0.9614) was also shown between the CareSens N glucometer and Hitachi 7600 in the central laboratory. Other glucometers showed a good linearity. The within-run and total-run CVs of other glucometers were within 10%. Although differences with the reference method were within allowable ranges, all glucometers showed variable bias compared with the reference method. Overestimation or underestimation of glucose values were observed by change of hematocrit in range of 31.1 to 51.2%. CONCLUSIONS: CareSens N showed good linearity, precision, and correlation with reference method. CareSens N provided reliable result of blood glucose and seems appropriate for clinical use in the management of diabetic patients.
Bias (Epidemiology) ; Blood Glucose ; Glucose ; Hematocrit ; Hexokinase ; Humans ; Korea

BACKGROUND: In our previous report, we observed the increaseed epidermal glucose concentrations and decreased hexokinase actiuities of diabetic patients which were ciimpared to those of normal individuals. And we considered that, there were some derrangement of lipid metabolism and glycolysis of diabetic epidermis. OBJECTIVES: This study wns planed to prove the above possible changes of lipid metabolism and glycolysis of diabetic epidermis. METHODS: The epidermal enzymatic activties of glucose-6-phophate dehydrogenase(G6PDH), phosphofructokinase(PFK), 1-glycerophosphate dehydrogenase(GOPDH) and b-hydroxybutyryl CoA dehydrogenase(HBDH) were assayed in the skin samples obtained friom diabetic patients and normal individuals by the fluorometric: method. RESULTS: Teh epidermal PFK activities of diabetic patients were decreased(3.49+1.35(mmole/hr/kg dry weight)) compared to that of normal individuals(5.00+0.56(mmcle/hr/kg dry weight))(p<0.05). The epidermal HBDH activities of diabetic patients were decreised(0.28+0.10(mole/hr/kg dry weight)) compared to that of normal individuals(0.49+0.20(mole/hr/kg dry weight)(p<0.01). The mean epidermal G6PDH activity of diabetic patients was decreasec. compased to that of normal individuals, but there was no statisical significance. The mean epidermal 3OPDH activittes of diabetic patients and normal individual; showed no significant difference. CONCLUSION: We consider that the decreased epidermal HBDH actiities of diabetic patients can decrease keton body formatiori, and the abnormal glycolysis can exist in the diabetic epidermis because the decreased enzymatic activities of diabetic epidermal PFK may decrease the velocity of glycolysis.
Diabetes Mellitus ; Epidermis ; Glucose ; Glycolysis ; Hexokinase ; Humans ; Lipid Metabolism ; Skin

The concentration of glucose in the vitreous humor serves as an important diagnostic marker for diabetic mellitus in post-mortem examinations, as the vitreous humor can be easily collected and the glucose test using vitreous humor is not significantly affected by cell autolysis and hemolysis. For a quick and effective glucose test, we suggest a dipstick test of the vitreous humor during autopsy. The results were evaluated and compared with other methods for significance testing. In this study, vitreous humor was analyzed from 257 autopsy cases. Qualitative concordance rate of the dipstick test for glucose and the hexokinase test was 98.7%, positive prediction rate was 89.6%, and negative prediction rate was 100%. However, there was no significant correlation between the dipstick glucose test and the hexokinase test. We conclude that the dipstick glucose test is effective and useful for post-mortem glucose screening testing and for additional post-mortem diabetes testing. Recently, the importance of post-mortem glucose testing has increased with the increase in deaths from diabetes complications. The use of the dipstick glucose test in autopsy practice can improve forensic medicine in Korea.
Autolysis ; Autopsy* ; Diabetes Complications ; Forensic Medicine ; Glucose* ; Hemolysis ; Hexokinase ; Korea ; Mass Screening ; Vitreous Body

BACKGROUND: Clinical experience with the continuous glucose monitoring systems (CGMS) is limited in Korea. The objective of this study is to evaluate the accuracy of the CGMS and the correlation between interstitial fluid and venous plasma glucose level in Korean healthy male subjects. METHODS: Thirty-two subjects were served with glucose solution contained same amount of test food's carbohydrate and test foods after separate overnight fasts. CGMS was performed over 3 days during hopitalization for each subjects. Venous plasma glucose measurements were carried out during 4 hours (0, 0.25, 0.5, 0.75, 1, 2, 4 hours) just before and after glucose solution and test food load. The performance of the CGMS was evaluated by comparing its readings to those obtained at the same time by the hexokinase method using the auto biochemistry machine (Hitachi 7600-110). Also, correlations between glucose recorded with CGMS and venous plasma glucose value were examined. RESULTS: CGMS slightly underestimated the glucose value as compared with the venous plasma glucose level (16.3 +/- 22.2 mg/dL). Correlation between CGMS and venous plasma glucose values throughout sensor lifetime is 0.73 (regression analysis: slope = 1.08, intercept = 8.38 mg/dL). Sensor sensitivity can deteriorate over time, with correlations between venous blood glucose and CGMS values dropping from 0.77 during 1st day to 0.65 during 2nd and 3rd day. CONCLUSION: The accuracy of data provided by CGMS may be less than expected. CGMS sensor sensitivity is decreased with the passage of time. But, from this study, CGMS can be used for glucose variability tendency monitoring conveniently to the Korean.
Biochemistry ; Blood Glucose ; Extracellular Fluid ; Glucose ; Hexokinase ; Humans ; Korea ; Male ; Plasma ; Reading

It is well estabilshed that the xerosis is closely related to diabeic pruritus. Although the causes of xerosis are thought to bie the abnormalities of sweating and autonomic nervous system, the exact mechanism of the xerosis in diabetic skin is still unknown. This study was designed to investigate the possible derangement of glucose metabolism in the skin of diabetes mellitus patients with xerosis. The epidemal glucose content and hexokonase activities were masured in the skin samples obtained from normal individuals and diabetes mellitus patients with xerosis The epidermal glucose content was measured by the enzymatic cycling method. The enzymatic activities of hexokinase were assayed by fluorometric method. The epidermal glucose content of diabetic patients increaed approximately twice [27.46+9.52 (mmole/kg /dry weight) that of normal individuals [13.90+4.79(mmole/kg /dry weight)] (p<0. 0001). The epidermal hexokinase activities of diabetes patients were significantly decreased [0.56+0.15(mole/hr/kg/dry weight)] compared to that of normal indivduals [0.96+0.24(mole/hr/kg dry weight)] (p<0.0001). There were no significant differences in the epidermal glucose content and enzyme activities of hexokinase between the diabetic patients with: erosis and diabetic patients without xerosis. These data indicated that decreased activities of hexokinase could reduce the glucose phopkiorylation and uptake into keratinocytes, and which could lead to accumulat. glucose in the interstitial space of diabetic epidermis. And the decreased hexokinase activities may exert on lipid metabolism and glycolysis of diabetic epiidermis, because hexokinase is a key enzyme of hexose monophosphate pathway and glycolysis.
Autonomic Nervous System ; Diabetes Mellitus ; Epidermis ; Glucose ; Glycolysis ; Hexokinase* ; Humans ; Keratinocytes ; Lipid Metabolism ; Metabolism ; Pruritus ; Skin ; Sweat ; Sweating

Positron Emission Tomography(PET) is a new imaging modality to make biochemical metabolic images. Because biochemical changes precede anatomical changes in most of diseases including cancer, PET can detect earlier changes of diseases than conventional anatomical imaging modalities. PET can also characterize biochemical property of diseases. A PET center is composed of a medical cyclotron, synthesis system of radiopharmaceuticals and scanner. For PET oncology, several positron-emitting radiopharmaceuticals have been developed. Among them, F-18-fluorodeoxyglucose (FDG) is most frequently used. Higher rate of glucose metabolism has been observed in cancer cells. Like glucose, FDG is transported into the cancer cells and converted to FDG-6-phosphate by hexokinase. FDG-6-phosphate is trapped in the cytoplasm, and emits gamma rays to make PET images. The current application of FDG PET in oncology is in detection, differentiation, and staging of the primary tumors, grading malignancy, monitoring therapeutic response, and early detection of recurrence. Nowadays, PET is an established procedure for staging the diseases and detecting the recurrence in many cancers, especially the lung, colorectal, and head and neck cancers, melanoma, and lymphoma. PET is a regular part of medical insurance reimbursement in many developed countries, and becomes a valuable research tool in oncology as well as an important imaging modality in managing cancer patients.
Cyclotrons ; Cytoplasm ; Developed Countries ; Electrons* ; Gamma Rays ; Glucose ; Head ; Hexokinase ; Humans ; Insurance ; Lung ; Lymphoma ; Melanoma ; Metabolism ; Neck ; Radiopharmaceuticals ; Recurrence

BACKGROUND: Red blood cell (RBC) sorbitol has been implicated in the pathogenesis of organic complications of diabetes mellitus. W8 investigated RBC sorbitol level as an indicator of glucose control or diabetic complications, and also evaluated whether RBC sorbitol/plasma glucose ratio is an indicator of diabetic complications. METHODS: RBC sorbitol levels were measured in 43 healthy persons and 133 diabetes mellitus (DM) patients by enzymatic method. We also tested linearity, inter- and intra- assay precisions. Plasma glucose and Hb Alc were measured by hexokinase method and HPLC, respectively. Hospital records were reviewed. RESULTS: The intra- and inter-assay coefficients of variation of RBC sorbitol test are 8.7% and 28.5%, respectively. Linearity is good. The RBC sorbitol level(3.60+/-1.00 ug/mL) and RBC sorbitol/plasma glucose ratio (2.37+/-0.98%) in diabetic patients are significantly higher than those in normal control (1.69+/-0.43 ug/mL, 1.85+/-0.49 per mill), respectively(p<0.0001). We can't observe correlation between RBC sorbitol and Hb Alc in BM patients, but observe that in non-treatment DM patients. We also observed correlation between Hb Alc and glucose and reverse correlation between RBC sorbitol ratio and Hb Alc. We can't find significant relation between diabetic complications and RBC sorbitol or RBC sorbitol/plasma glucose. CONCLUSIONS: We suggest that the reference range of normal RBC sorbitol level and RBC sorbitol/plasma glucose ratio by enzymatic method are 1.69+/-0.86 ug/mL and 1.85+/- 0.98%,. These Ire significantly different from DM patients and may be useful in diagnosis of DM.
Blood Glucose ; Chromatography, High Pressure Liquid ; Diabetes Complications ; Diabetes Mellitus* ; Diagnosis ; Erythrocytes ; Glucose ; Hexokinase ; Hospital Records ; Humans ; Reference Values ; Sorbitol*

BACKGROUND: Red blood cell (RBC) sorbitol has been implicated in the pathogenesis of organic complications of diabetes mellitus. W8 investigated RBC sorbitol level as an indicator of glucose control or diabetic complications, and also evaluated whether RBC sorbitol/plasma glucose ratio is an indicator of diabetic complications. METHODS: RBC sorbitol levels were measured in 43 healthy persons and 133 diabetes mellitus (DM) patients by enzymatic method. We also tested linearity, inter- and intra- assay precisions. Plasma glucose and Hb Alc were measured by hexokinase method and HPLC, respectively. Hospital records were reviewed. RESULTS: The intra- and inter-assay coefficients of variation of RBC sorbitol test are 8.7% and 28.5%, respectively. Linearity is good. The RBC sorbitol level(3.60+/-1.00 ug/mL) and RBC sorbitol/plasma glucose ratio (2.37+/-0.98%) in diabetic patients are significantly higher than those in normal control (1.69+/-0.43 ug/mL, 1.85+/-0.49 per mill), respectively(p<0.0001). We can't observe correlation between RBC sorbitol and Hb Alc in BM patients, but observe that in non-treatment DM patients. We also observed correlation between Hb Alc and glucose and reverse correlation between RBC sorbitol ratio and Hb Alc. We can't find significant relation between diabetic complications and RBC sorbitol or RBC sorbitol/plasma glucose. CONCLUSIONS: We suggest that the reference range of normal RBC sorbitol level and RBC sorbitol/plasma glucose ratio by enzymatic method are 1.69+/-0.86 ug/mL and 1.85+/- 0.98%,. These Ire significantly different from DM patients and may be useful in diagnosis of DM.
Blood Glucose ; Chromatography, High Pressure Liquid ; Diabetes Complications ; Diabetes Mellitus* ; Diagnosis ; Erythrocytes ; Glucose ; Hexokinase ; Hospital Records ; Humans ; Reference Values ; Sorbitol*

BACKGROUND/AIMS: Icodextrin (glucose polymer) is metabolized by a-amylase to oligosaccharides such as maltose and maltotriose. The presence of these metabolites could have an effect on the enzymatic glucose measurement especially the glucose dehydrogenase pyrroloquinolinequinone (GDH-PQQ) based method. Patients treated with icodextrin are at risk for inaccurate blood glucose measurements. In this study we measured the blood glucose with different methods and analyzed the results to determine the test accuracy. METHODS: The blood glucose was measured, in seven outpatients and in seven inpatients using icodextrin, by the glucose hexokinase laboratory technique method as well as the GDH-PQQ method (Accu Chek Active)at the same time. To estimate an icodextrin residual effect, after discontinuing icodextin, the blood glucose was measured by the two methods after 48 hours in 4 inpatients. RESULTS: In seven outpatients the blood glucose was overestimated by the Accu Chek Active method (mean difference 68 mg/dL, p value 0.012). In seven inpatients the mean difference in the glucose was 56 mg/dL at 6am, 52 mg/dL at 11am, 52 mg/dL at 4pm, and 50 mg/dL at 9pm by the two different methods. In the four inpatients after changing their dialysate, the mean difference in the glucose was 58 mg/dL after 10 hours, 45 mg/dL after 24 hours, 24 mg/dL after 34 hours, and 26 mg/dL after 48 hours. CONCLUSION: Blood glucose was overestimated by the GDH-PQQ method and the inaccuracies were observed for more than 48 hours.
Blood Glucose ; Glucans ; Glucose ; Glucose 1-Dehydrogenase ; Hexokinase ; Humans ; Hypoglycemia ; Inpatients ; Maltose ; Oligosaccharides ; Outpatients ; Peritoneal Dialysis, Continuous Ambulatory ; Trisaccharides

BACKGROUND: Portable glucometers are often utilized at the patient's bedside in the ICU or operating room for frequent measurements of the blood glucose concentration. Many of these devices are based on a glucose oxidase method that may be influenced by PO2. The aim of this study was to evaluate the influence of a high PO2 of arterial blood on measured glucose values compared with venous blood. METHODS: Forty adult patients who underwent surgery with general anesthesia were included in this study. Each patient had a cannula inserted into the radial artery and a central venous catheter through the right internal jugular vein. Two hours after the induction of anesthesia, we drew arterial and venous blood and measured the blood glucose concentration using both a bedside glucometer based on a glucose oxidase method and a laboratory glucometer based on a hexokinase method. We also measured blood gas, electrolyte, and hematocrit values. Statistical analyses were performed with repeated measure ANOVA, multiple linear regression, and Bland-Altman's analysis. Data is expressed as mean +/- SD. RESULTS: The arterial blood glucose concentration measured by the glucose oxidase method (119.5 +/- 25.0 mg/dl) was significantly lower than the venous blood (133.5 +/- 24.8 mg/dl) and hexokinase method (134.2 +/- 27.1 mg/dl). There was no significant difference between the venous blood glucose concentration by the glucose oxidase method and hexokinase method. When we used the correction formula: corrected glucose value = arterial glucose value by glucose oxidase method + 0.1053 X PaO2 - 5.414, the bias improved from - 14.6 mg/dl to 1.0 mg/dl. CONCLUSIONS: The blood glucose concentration measured by the glucose oxidase method is more accurate in venous blood than oxygenated arterial blood. When we measure the blood glucose level using the glucose oxidase method, we should consider the influence of high oxygen tension.
Adult ; Anesthesia ; Anesthesia, General ; Bias (Epidemiology) ; Blood Glucose* ; Catheters ; Central Venous Catheters ; Glucose Oxidase* ; Glucose* ; Hematocrit ; Hexokinase ; Humans ; Jugular Veins ; Linear Models ; Operating Rooms ; Oxygen* ; Radial Artery