The sample haematocrit value and other chemical substances aria known to interfere with the analysis results obtained by bedside blood glucose monitoring systems. In order to evaluate the accuracy of the Nova StatStrip point-of-care blood glucose meter compared to other patient self-test meters, we performed a laboratory bench test with routine venous blood samples at low, normal, and high blood glucose concentrations and with different haematocrit (HCT 24.7-64.9 %), spiked maltose (2.8/5.6mmol/l), acetaminophen (0.22/0.66 mmol/l), and ascorbic acid concentrations (0.29/0.59 mmol/l). A glucose oxidase method served as standard reference. All blood glucose meters with the exception of the StatStrip showed an inverse relation between the haematocrit value and the blood glucose levels (e. g, at a blood glucose level of 237 mg/dl, the mean deviations with increasing haematocrit were: StatStrip: +6.7 %, Accu-Chek Aviva: -8.8 %, Ascencia Contour(+): -36.8%, Freestyle: -25.6 %, OneTouch Ultra 2: -49.9 %). In addition, a strong interference was seen by increasing maltose, acetaminophen, and ascorbic acid concentrations, with many devices (e.g, at a blood glucose level of 237 mg/dl, the mean percentage deviations at 2.8/5.6 mmol/l maltose and 0.29/0.59 mmol/l ascorbic acid were: StatStrip: -0.5/-1.1 % and 1.2/2.8%, Accu-Chek: 24.5/49.9 % and 5.6/16.7 %, Ascencia: -8.8/-6.1 % and 6.2/23.7 %, Freestyle: 4.4/3.5 % and 4.0/13.7 %, Ultra2: -26.3/9.5 % and 70/23.8 %). The point-of-care StatStrip glucose meter technology shows no clinically significant interference from the agents tested, including changes in haematocrit.
Increased endothelial binding and emigration of monocytes play a dominant role in the pathogenesis of atherosclerosis in diabetes mellitus. Previous studies revealed that hyperlipidemia correlates with monocyte binding in vitro. The aim of this study was to characterize the monocyte-endothelial interaction of leucocytes of hyperglycemic patients with type 1 diabetes but lacking hyperlipidemia. We isolated monocytes from healthy controls and normolipidemic type 1 diabetes patients with elevated levels of HbA1c and quantified monocyte binding by an immunoilluminometric cell adhesion assay. Purity of isolated monocytes was at least 98%. Endothelial binding of monocytes from patients with type 1 diabetes was found to be significantly increased compared to controls (19.2 +/- 3.9% vs. 14.9 +/- 3.5%). This difference of monocyte binding remained unchanged if the endothelial cells were stimulated with 27.7 mmol/l glucose for seven days prior to adhesion studies (31.5 +/- 4.9% in diabetes patients vs. 25.8 +/- 4.1% in controls) whereby monocyte binding markedly increased under these hyperglycemic conditions. Furthermore, an increased CD11b expression could be demonstrated on monocytes of normolipidemic hyperglycemic type 1 diabetes patients. Thus, we suggest that hyperglycemia per se may contribute to increased monocyte binding to endothelial cells by promoting leucocyte integrin expression. Recently performed studies of our group strengthen the hypothesis that this monocyte activation is mediated by stimulation of the beta-isoform of proteinkinase C.
Summary.Technosphere/Insulin (TI) is a formulation of regular human insulin and Technosphere, a new drug delivery system for pulmonary administration. The formulation is designed for efficient transport of insulin across the intact respiratory epithelium into the systemic circulation. We have investigated the pharmacodynamic and pharmacokinetic properties of Technosphere/Insulin in five healthy, non-smoking volunteers. In an open, randomized, three-way crossover study, subjects received 5 IU regular human insulin (HI) intravenously, 10 IU HI subcutaneously; and 100 IU TI via inhalation using a small commercially available asthma inhaler. The time action profiles of all three insulin formulations were assessed by the euglycemic glucose clamp technique on three different study days. Glucose infusion rates were monitored from 2 h before until 6 h after insulin administration. Other study measures were serum insulin, serum C-peptide concentrations, and safety parameters. The inhalation of TI was well tolerated. The time to peak action was significantly shorter with both i.v. injection and inhalation, as compared to s.c. (14 +/- 6 min and 39 +/- 36 min vs. 163 +/- 25 min; p < 0.0002 and p < 0.007 (mean +/- SD)). The metabolic effect during the first 3 h after insulin administration was higher with inhaled TI than with HI s.c. (AUC0-180 for glucose infusion rate: 1.94 +/- 0.77 mg/kg * min vs. 1.15 +/- 0.50 mg/kg * min; p < 0.04). Relative and absolute bioavailability for the first 3 h were 26 +/- 12% and 15 +/- 5% respectively (6 h: 16 +/- 8 and 16 +/- 6%). We conclude that inhalation of TI leads to a rapid onset of metabolic action resembling the effect observed with i.v. administration of regular HI. Despite the use of a common asthma inhaler, bioavailability over the three hour prandial period was substantially greater than with other reported pulmonary systems. Therefore, inhalation of Technosphere/Insulin may become a suitable and attractive alternative for prandial insulin delivery, especially for patients with type 2 diabetes mellitus.
Morphological and immunohistochemical studies in diabetic subjects have shown a depletion of the neuropeptide substance P (SP) in the central and peripheral nervous system. This is the first study investigating serum levels of substance P in type 1 diabetes patients (n=50) and controls (n=75) by means of an enzyme immunoassay. The serum level of SP was significantly decreased in the diabetic group compared to the control group (10.12+/-0.29 vs. 12.25+/-0.38 pg/ml; p<0.0001). In diabetic patients, there was no correlation of substance P levels with age, serum creatinine, albuminuria, total cholesterol, HDL- or LDL-cholesterol, triglycerides, HbA1c, type or duration of diabetes and gender. Furthermore, there was no difference in serum levels of SP in patients with or without retinopathy, but SP was significantly decreased in patients with neuropathy (9.59+/-0.48 vs. 10.78+/-0.83 pg/ml; p=0.04). These data show that SP is decreased in serum of type 1 diabetes patients, especially in those with diabetic neuropathy. Subsequent and already ongoing prospective studies in well validated diabetic patients with neuropathy may characterize the impact of this neurogenic marker in the course of diabetic neuropathy.
Recent studies have demonstrated that a combination of GAD-antibody assays and IA-2 autoantibody assays show a high diagnostic specificity for Type 1 diabetes. For this reason there is increasing interest in the use of GAD-antibody measurement for Type 1 risk assessment. Since a number of different assays have been published and documented in the literature, the aim of this study was to evaluate four different anti-GAD test systems that are commercially available in Germany. We tested the anti-GAD prevalences in five patient groups with the different immunoassays and compared them with the values obtained by an immunoprecipitation test (IP-Test). All assays correlated well with the IP-test and showed high sensitivity and specificity in the group of patients with recent onset Type 1 diabetes and the control group. The groups tested consisted of 20 subjects with recent onset Type 1 diabetes (< 6 weeks) (sensitivity 70-90%), nine subjects with a Type 1 duration of more than 2 years (sensitivity 11-33%), 21 patients with pluriglandular insufficiency (sensitivity 28.5-47.5%), 10 patients with Type 2 (specificity: 90-100%), and 14 healthy control subjects (specificity: 93-100%). Our data show a high level of sensitivity and specificity of the tested, commercially available, assays. Since almost every laboratory should be able to establish one of these assays, this may facilitate the possibility of further large scale population studies with the aim of investigating GAD-antibody prevalences in screening for Type 1 diabetes. Increased measurement of the diabetes-associated antibodies will be helpful in the differential diagnosis of gestational diabetes mellitus (GDM) and latent autoimmune diabetes of the adult (LADA).
OBJECTIVE Insulin lispro is an analog of human insulin with a faster onset and a shorter duration of action than regular human insulin. Efficacy and tolerability of insulin lispro in continuous subcutaneous insulin infusion (CSII) treatment were assessed in an open randomized crossover trial comparing insulin lispro and regular human insulin, both applied with insulin pumps. RESEARCH DESIGN AND METHODS A total of 113 type 1 patients (60 male, 53 female, age [mean +/- SD] 37 +/- 12 years, duration of diabetes 19 +/- 9 years) participated in this open, randomized crossover study. Both insulins were applied for 4 months each with the appropriate intervals between the prandial insulin bolus and the meal (human insulin: 30 min; lispro: 0 min). Observation parameters were HbA1c, daily and postprandial blood glucose profiles, adverse events, rate of hypoglycemic and hyperglycemic events, number of catheter obstructions, and treatment satisfaction as assessed with an international validated questionnaire. RESULTS The patients were well controlled with a mean HBA1c of 7.24 +/- 1.0% at baseline. HbA1c decreased in both treatment periods, but it was better during insulin lispro treatment (insulin lispro: 6.8 +/- 0.9%, regular human insulin: 6.9 +/- 1.0%, Friedman's rank-sum test: P < 0.02). In addition, the 1-h and 2-h postprandial rises in blood glucose were significantly lower (P < 0.001 for each meal) with insulin lispro, resulting in smoother daily glucose profiles as compared with regular human insulin. No significant differences were reported for the rate of hypoglycemia (mean +/- SD [median]: insulin lispro 12.4 +/- 13.9 [8], regular human insulin 11.0 +/- 11.2 [8]), for the rate of catheter obstructions (42 events in each treatment arm), and for the number and type of adverse events. No severe case of ketoacidosis was seen during insulin lispro treatment, whereas one case was reported during therapy with regular human insulin. Treatment satisfaction was better when patients were treated with insulin lispro. CONCLUSIONS Insulin lispro is a suitable and very convenient pump insulin that may result in an improvement of long-term glucose control during CSII treatment. Its safety profile does not differ from that of regular human insulin.
Advanced glycation end products (AGEs) have been identified as relevant mediators of late diabetic complications such as atherosclerotic disease. The endothelial migration of monocytes is one of the first steps in atherogenesis and monocyte-endothelial interaction itself is linked to the express ion of adhesion molecules like vascular cell adhesion molecule-1 (VCAM-1). Recently, stimulation of VCAM-1 by AG Es has been demonstrated. Since endothelial stimulation by AGEs is followed by generation of oxygen free radicals with subsequent activation of nuclear transcription factor kappa B, we investigated the influence of alpha-lipoic acid on the expression of VCAM-1 and monocyte adherence to endothelial cells in vitro by means of cell-associated chemiluminescence assays and quantitative reverse transcriptase polymerase chain reaction using a constructed recombinant RNA standard. We found that alpha-lipoic acid was able to decrease the number of VCAM-1 transcripts from 41.0+/-11.2 to 9.5+/-4.7 RNA copies per cell in AGE-stimulated cell cultures. Furthermore, expression of VCAM-1 was suppressed in a time- and dose-dependent manner by alpha-lipoic acid as shown by chemiluminescence endothelial cell assay. Pretreatment of endothelial cells with 0.5 mM or 5 mM alpha-lipoic acid reduced AGE-induced endothelial binding of monocytes from 22.5+/-2.9% to 18.3+/-1.9% and 13.8+/-1.8% respectively. Thus, we suggest that extracellularly administered alpha-lipoic acid reduces AGE-albumin-induced endothelial expression of VCAM-1and monocyte binding to endothelium in vitro. These in vitro results may contribute to the understanding of a potential antioxidative treatment of atherosclerosis.
Advanced glycation endproducts (AGEs) possibly play a dominant role in the pathogenesis of macrovascular disease in diabetes. Recent studies could demonstrate that glycated albumin (AGE-BSA) was able to stimulate vascular cell adhesion molecule-1 (VCAM.1) on endothelial cells. The aim of this study was to find out if AGE-BSA was not only able to enhance the expression of vascular cell adhesion molecule-1, but also of intercellular adhesion molecule-1 (ICAM-1) and E-Selectin on human endothelial cells. Stimulation of endothelial cells with AGE-BSA for six hours predominantly increased the expression of VCAM-1, but ICAM-1 and E-Selectin were also upregulated as shown by immunoilluminometric assay (ILMA).
Advanced glycation endproducts (AGE) are supposed to increase endothelial expression of adhesion molecules like vascular cell adhesion molecule-1 (VCAM-1) by inducing an intracellular stress with subsequent activation of nuclear transcription factor NF-kappa-B. Quantitative analysis of VCAM-1-transcription has not been demonstrated concerning this topic. Thus, the aim of this study was to establish quantitative reverse transcription polymerase chain reaction (RT-PCR) assays using a spacer gene in order to measure the amounts of specific mRNA for VCAM-1 in human umbilical vein endothelial cells (HUVEC) which were stimulated with AGE-albumin (AGE-BSA). A recombinant RNA-standard was synthesized and used as internal RT-PCR standard. The amount of VCAM-1-mRNA in unstimulated HUVEC was found to be 2.2 +/- 2.7 copies per cell. After stimulation with AGE-BSA, mRNA-levels were elevated to 38.9 +/- 10.9 copies per cell. Positive controls (stimulated with lipopolysaccharide) revealed mRNA-levels of 78.7 +/- 27.5 copies per cell. We conclude that quantitative RT-PCR using the spacer gene technique is a valid and reliable method for the measurement of small amounts of specific