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INTRODUCTION: Patients in intensive care units (ICUs) frequently lose control over their fecal continence leading to fecal incontinence (FI). We provide an overview of existing medical devices, which are supposed to alleviate FI-related problems. AREAS COVERED: Fecal management systems (FMS) prevent infections and complications. They reduce the risk of pressure ulcers and fecal incontinence. The systems enhance patient comfort and mitigate emotional distress during illness. Furthermore, FMS facilitate nursing care by reducing the incontinence-related workload. Finally, these systems can help minimize treatment costs by preventing complications, and reduction of extended hospital stays and additional treatments. Several well accepted systems made of silicone are on the market. A polyurethane-based soft balloon FMS (hygh-tec® basic-plus) has also been introduced, offering more comfort to the patient, safer handling for the healthcare professionals, and provides reliable leakproof access to the patient's colon. In addition to contamination-free fecal diversion, the trans-anal sealing mechanism of the device also allows for irrigation and delivery of medication into the colon. EXPERT OPINION: FMS in ICUs are integral to patient care and dignity. Recognizing and prioritizing the importance of these systems is essential for providing the highest standard of care to critically ill patients in the ICU.
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Rapid and sensitive detection of pathogens is critical in interrupting the transmission chain of infectious diseases. Currently, real-time (RT-)PCR represents the gold standard for the detection of SARS-CoV-2. RNase HII-assisted amplification (RHAM) is a promising technology, enabling reliable point-of-care (PoC) testing; however, its diagnostic accuracy has not yet been investigated. The present study compared the Pluslife Mini Dock (RHAM technology), with Abbott ID Now and Cepheid GeneXpert IV. The positive percent agreement (PPA) and negative percent agreement (NPA) were determined in 100 SARS-CoV-2 positive and 210 SARS-CoV-2 negative samples. Further, the reliability of the Pluslife Mini Dock was investigated in different SARS-CoV-2 variants (Delta and Omicron subvariants). The PPA was 99.00% for Pluslife, 100.00% for Abbott ID Now, and 99.00% for Cepheid GeneXpert, with an NPA of 100.00%, 98.90%, and 93.72%, respectively. Abbott ID Now demonstrated the highest rate of invalid results. All SARS-CoV-2 analysed variants were detected by the Pluslife device. Altogether, the Pluslife Mini Dock demonstrated a PPA of 99.16% (235/237) for CT < 36 and an NPA of 100.00% (313/313), respectively. In conclusion, the Pluslife Mini Dock demonstrated better analytical performance than Abbott ID Now and Cepheid GeneXpert IV, representing a highly accurate and rapid PoC alternative to RT-PCR.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , COVID-19/diagnosis , COVID-19/virology , Retrospective Studies , Point-of-Care Testing , Sensitivity and Specificity , Nucleic Acid Amplification Techniques/methods , Reproducibility of Results , COVID-19 Nucleic Acid Testing/methods , Real-Time Polymerase Chain Reaction/methodsABSTRACT
New European medical device regulations require the performance of postmarketing surveillance evaluations for blood glucose meters (BGMs). We conducted an ISO15197:2015-conform system performance evaluation with the approved glucose dehydrogenase (GDH)-based Wellion NEWTON BGM. One hundred subjects were enrolled into the study (44 female, 56 male, 43 healthy subjects, 23 type 1 diabetes, 34 type 2 diabetes, age: 53.7 ± 15.8 years). In addition, manipulated heparinized whole blood was used for a laboratory interference test with ten selected substances (interference definition: substance-induced bias > 10%). The mean absolute relative difference (MARD) was 4.7%, and 100% of the values were in zones A (99.7%) and B (0.3%), respectively, of the consensus error grid. Interference was observed with xylose only, which is a known interfering substance for GDH-based BGMs.
ABSTRACT
The Sencell sensor uses glucose-induced changes in an osmotic pressure chamber for continuous glucose measurement. A final device shall have the size of a grain of rice. The size limiting factor is the piezo-resistive pressure transducers inside the core sensor technology (resulting chamber volume: 70 µL. To achieve the necessary miniaturization, these pressure transducers were replaced by small (4000 × 400 × 150 nm³) nano-granular tunneling resistive (NTR) pressure sensors (chamber volume: 750 nL). For benchmark testing, we filled the miniaturized chamber with bovine serum albumin (BSA, 1 mM) and exposed it repeatedly to distilled water followed by 1 mM BSA solution. Thereafter, we manufactured sensors with glucose testing chemistry (ConcanavalinA/dextran) and investigated sensor performance with dynamic glucose changes between 0 and 300 mg/dL. Evaluation of the miniaturized sensors resulted in reliable pressure changes, both in the BSA benchmark experiment (30-35 mBar) and in the dynamic in vitro continuous glucose test (40-50 mBar). These pressure results were comparable to similar experiments with the previous larger in vitro sensors (30-50 mBar). In conclusion, the NTR pressure sensor technology was successfully employed to reduce the size of the core osmotic pressure chamber by more than 95% without loss in the osmotic pressure signal.
Subject(s)
Biosensing Techniques , Blood Glucose , Osmotic Pressure , Blood Glucose Self-Monitoring , Glucose , Miniaturization , Nanotechnology , Biosensing Techniques/methodsABSTRACT
Background: We conducted a prospective placebo-controlled double-blind randomized Study to assess the impact of a single dose of a nutritional Supplement (AB001) on alcohol absorption in healthy subjects. Other objectives were the impact on breath alcohol content, cognitive function 1 hour after alcohol uptake and tolerability. Method: A total of 24 healthy volunteers were enrolled into the study (12 male, 12 female, age: 28.3 ± 10.8 years, BMI: 23.5 ± 5.7 kg/m²). On the experimental day, they ingested a light breakfast together with a single dose (2 capsules) of AB001 (or placebo) and drank 2 moderate glasses of spirit (a total of 0.6 g/kg body weight). Breath alcohol tests and blood draws for determination of blood alcohol levels were performed for up to 6 hours. After crossover, the experiment was repeated in the following week. Areas under the curves were calculated to determine alcohol absorption rates. Results: There was a significant reduction of blood alcohol by 10.1% (P < .001) with AB001, when compared to placebo. There was a less pronounced but also significant reduction of alcohol in the breath test by 7.2% (P < .05). No difference in the cognitive function test between AB001 and placebo could be observed 60 minutes after alcohol ingestion (22.6 ± 8.0 seconds vs 23.0 ± 11.2 seconds, n.s.). The supplement uptake was well tolerated and there were no adverse events related to the study intervention. Conclusion: Uptake of a single dose of AB001 shortly before drinking alcohol significantly reduced plasma alcohol and breath alcohol concentrations, but the effect was less pronounced compared to chronic uptake as shown previously.
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OBJECTIVES: The aim of this study was to validate an active matrix metalloproteinase (MMP-8) point-of-care diagnostic tool in COVID-19 patients with periodontal disease. SUBJECTS, MATERIALS, AND METHODS: Seventy-two COVID-19-positive and 30 COVID-19-negative subjects were enrolled in the study. Demographic data were recorded, periodontal examination carried out, and chairside tests run for evaluating the expression of active MMP-8 (aMMP-8) in the site with maximum periodontal breakdown via gingival crevicular fluid sampling as well as via a mouth rinse-based kit for general disease activity. In COVID-19-positive patients, the kits were run again once the patients turned COVID-19 negative. RESULTS: The overall (n = 102) sensitivity/specificity of the mouthrinse-based kits to detect periodontal disease was 79.41%/36.76% and that of site-specific kits was 64.71%/55.88% while adjusting for age, gender, and smoking status increased the sensitivity and specificity (82.35%/76.47% and 73.53%/88.24, respectively). Receiver operating characteristic (ROC) analysis for the adjusted model revealed very good area under the ROC curve 0.746-0.869 (p < .001) and 0.740-0.872 (p < .001) (the aMMP-8 mouth rinse and site-specific kits, respectively). No statistically significant difference was observed in the distribution of results of aMMP-8 mouth rinse test (p = .302) and aMMP-8 site-specific test (p = .189) once the subjects recovered from COVID-19. CONCLUSIONS: The findings of the present study support the aMMP-8 point-of-care testing (PoCT) kits as screening tools for periodontitis in COVID-19 patients. The overall screening accuracy can be further increased by utilizing adjunctively risk factors of periodontitis. The reported noninvasive, user-friendly, and objective PoCT diagnostic methodology may provide a way of stratifying risk groups, deciding upon referrals, and in the institution of diligent oral hygiene regimens.
Subject(s)
COVID-19 , Periodontal Diseases , Periodontitis , COVID-19/diagnosis , COVID-19 Testing , Humans , Matrix Metalloproteinase 8/metabolism , Mouthwashes , Periodontal Diseases/diagnosis , Periodontitis/diagnosis , Point-of-Care TestingABSTRACT
Background: Regular alcohol consumption, e.g. by social drinking, is a potential source of consecutive health problems in many countries worldwide. A probiotic nutritional supplement (AB001) has been developed to reduce alcohol absorption from the intestine tract and to mitigate potential health care risks. Methods: This randomized placebo-controlled double-blind crossover study was conducted with 24 healthy subjects (13 male, 11 female, age: 25.4 ± 7.7 years, BMI: 23.6 ± 2.5 kg/m²). The subjects were randomized to take 2 capsules/day of AB001 or placebo for 1 week prior to an alcohol exposure experiment. On the experimental day, they ingested a light breakfast and drank a moderate glass of spirit (0.3 g/kg body weight). Breath alcohol tests and blood draws for determination of blood alcohol levels were performed for up to 6 hours. After crossover, the experiment was repeated in the following week. Areas under the curves were calculated to determine alcohol absorption rates. Results: A significant reduction of blood alcohol levels by 70.3% (P < 0.005 vs. placebo) was seen with AB001, (breath test: -30.7%; P < 0.005 vs. placebo). No difference was seen in a cognitive function test performed 60 minutes after alcohol ingestion (22.4 ± 7.7 seconds vs. 22.7 ± 5.6 seconds, n.s.). There were no adverse events or serious adverse events reported in this study. Conclusions: One week of supplementation with AB001 resulted in a substantially reduced absorption of alcohol into the body. Regular uptake of AB001 may help to prevent liver and other organ damage, and may reduce the negative medical and economical impact of social drinking on the individual and the society.
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BACKGROUND: Testing the potential influence of interfering substances on the measurement performance of needle sensors for continuous glucose monitoring (CGM) is a challenging task. For proper function, the sensors need an almost stable fluidic environment. Previously published in vitro interference experiments were measuring under static concentration conditons. Our experimental setup allows for interference testing with dynamic changes of the interferent concentrations. METHODS: We designed a macrofluidic test stand that is fueled by several high-pressure liquid chromatography (HPLC) pumps generating programmable glucose and/or interferent gradients in phosphate-buffered saline (PBS). After optimizing experimental parameters (channel dimensions, temperature, flow rates, gradient slopes, buffer, pH etc.), we validated the setup using Dexcom G6 (G6) and Freestyle Libre 2 (L2) sensors with/without interferents, and using YSI 2300 Stat plus as the reference glucose device at room temperature. RESULTS: Both sensors tracked the programmed glucose changes. After calibration, G6 results closely matched glucose reference readings, while L2 routinely showed ~50% to 60% lower readings, most likely because of the factory-based calibration and temperature compensation. Gradients of maltose, acetaminophen, and xylose were employed to further validate the setup. As expected, both sensors were not affected by maltose. We confirmed previous findings regarding susceptibility of G6 readings to acetaminophen and L2 readings to xylose. Signals from both sensors are influenced by temperature in a linear fashion. CONCLUSIONS: Our experimental in vitro setup and protocol may provide a useful method to dynamically test CGM sensors for interfering substances. This may help to improve the accuracy of future CGM sensor generations.
Subject(s)
Diabetes Mellitus , Solid Waste , Diabetes Mellitus/therapy , Humans , Recycling , Solid Waste/analysis , TechnologySubject(s)
Coronavirus Infections/epidemiology , Diabetes Complications/diagnosis , Mouth/virology , Pneumonia, Viral/epidemiology , Saliva/virology , Adult , Age Factors , Aged , Angiotensin-Converting Enzyme 2 , Betacoronavirus , Biomarkers/metabolism , COVID-19 , Dentistry/trends , Diabetes Complications/epidemiology , Diabetes Complications/prevention & control , Endocrinology/trends , Gingiva/pathology , Humans , Middle Aged , Models, Theoretical , Oral Health/statistics & numerical data , Pandemics , Peptidyl-Dipeptidase A/metabolism , Periodontitis/complications , Prevalence , Risk Factors , SARS-CoV-2ABSTRACT
BACKGROUND: Increased intact proinsulin in plasma is a highly specific biomarker for a major disruption of insulin-processing in the pancreatic ß-cells with associated insulin resistance. Increased intact proinsulin in morning fasting plasma indicates not only incipient diabetes, but also increased risk of macrovascular events in the patient - of ten times before an actual diagnosis of diabetes - due to the convergence of ß-cell dysfunction, insulin resistance, and chronic systemic inflammation. This has raised the question as to whether a marked increase in intact proinsulin levels after oral glucose load in healthy subjects might be considered as indicative for ß-cell dysfunction and prediabetes. METHODS: A previous study from 2011 examined, inter alia, intact proinsulin levels in blood samples from twenty healthy study participants at baseline and two hours after an oral glucose tolerance test (OGTT) with 75 g glucose. Seventeen of the participants showed normal glucose levels at baseline and at two hours compared to 4 participants with normal intact proinsulin levels at baseline but increased intact proinsulin levels at two hours. RESULTS: All four patients went on to develop type 2 diabetes in the following 5 years. None of the other subjects from the previous investigation developed type 2 diabetes. CONCLUSIONS: As also confirmed by recent literature, intact proinsulin provides a powerful, easily measured biomarker for ß-cell dysfunction and insulin resistance in type 2 diabetes, as well as risk of future cardiovascular events regardless of the stage of diabetes.
Subject(s)
Diabetes Mellitus, Type 2 , Glucose Tolerance Test , Prediabetic State , Proinsulin/blood , Adult , Aged, 80 and over , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Female , Humans , Insulin/metabolism , Male , Prediabetic State/blood , Prediabetic State/metabolismABSTRACT
This is a summary report of the most important aspects discussed during the YSI 2300 Analyzer Replacement Meeting. The aim is to provide the interested reader with an overview of the complex topic and propose solutions for the current issue. This solution should not only be adequate for the United States or Europe markets but also for all other countries. The meeting addendum presents three outcomes of the meeting.
Subject(s)
Blood Chemical Analysis/instrumentation , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose/analysis , Lactic Acid/blood , Biomarkers/blood , Blood Chemical Analysis/standards , Blood Glucose Self-Monitoring/standards , Equipment Design , Humans , Observer Variation , Predictive Value of Tests , Reproducibility of ResultsABSTRACT
BACKGROUND: The pain associated with pricking the fingertip for blood glucose self-testing is considered to be a major burden in diabetes treatment. This study was performed to evaluate the system accuracy of the invasive TensorTip Combo Glucometer (CoG) device component in accordance with ISO15197:2015 requirements and to explore the accuracy of the noninvasive tissue glucose prediction component. METHODS: One hundred samples were obtained from people with type 1 and type 2 diabetes and healthy volunteers (43 females, 57 males; age: 53 ± 16 years), with glucose distribution as requested by the ISO standard. Three strip lots were tested twice by healthcare professionals in comparison to YSI 2300 Stat Plus reference method followed by a noninvasive tissue glucose reading (NI-CoG). Mean Absolute (Relative) Difference (MARD) was calculated and a consensus error grid (CEG) analysis was performed. RESULTS: The ISO system accuracy criteria were met with the invasive strip technology by 586/600 of the data points (97.1%) and for each strip lot separately. All invasive results (100%) were within CEG-zone A and total MARD was calculated to be 7.1%. With the noninvasive reading, 99% of raw data points were in A + B (91.1% and 7.8%), and the total MARD was calculated to be 18.1%. DISCUSSION: The invasive component of the CoG device was shown to be in full compliance with the current ISO15197 criteria. Good results were also obtained with the NI-CoG tissue glucose prediction. This noninvasive technology would potentially be suitable for frequent pain-free glucose monitoring in many people with diabetes.
Subject(s)
Blood Glucose Self-Monitoring/instrumentation , Blood Glucose/analysis , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 2/diagnosis , Reagent Strips , Adult , Aged , Biomarkers/blood , Case-Control Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Equipment Design , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Reproducibility of ResultsABSTRACT
Background: We evaluated the Wellion Galileo GLU/KET blood and ketone (ß-Hydroxybutyrate, ß-OHB) meter to demonstrate that it meets ISO15107:2015 regulatory approval criteria. Research Design and Methods: A total of 100 subjects (52 female, age: 30 to 84 years, diabetes: 10 type 1/90 type 2) with blood glucose levels distributed over the entire measurement range as required by the ISO15197 protocol were tested (double determinations with 3 strip lots and two devices). A similar test protocol was followed to test ß-OHB strip performance (reference devices: YSI 2300plus for glucose and STANBIO ß-HOB LiquiColor TestKit for ß-OHB). Precision was tested for glucose with 3 blood glucose concentrations (ß-OHB: 2 control solutions). Results: All glucose test-strip lots met the strict ISO acceptance criteria. Mean absolute relative difference (MARD) was 4.9% and all data pairs were in zone A of the consensus error grid. The ß-OHB test-strips also met the pre-defined acceptance criteria. Within-run and between-run precision was calculated to be 2.3% and 0.7% for the glucose strips (3.7%/0.8% for the ketone strips). Conclusions: When tested according to the ISO15197:2015 guideline, the device showed very accurate measurement performance for glucose and ß-OHB testing and fully met regulatory accuracy approval criteria.
Subject(s)
3-Hydroxybutyric Acid/blood , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose/analysis , Practice Guidelines as Topic , Adult , Aged , Aged, 80 and over , Blood Glucose Self-Monitoring/standards , Female , Humans , Male , Middle Aged , Reproducibility of ResultsABSTRACT
BACKGROUND: In recent randomized clinical trials, an unusual reporting pattern of glycemic data and hypoglycemic events potentially related to an internet enabled blood glucose meter (MyGlucoHealth, BGM) was observed. Therefore, this clinical study was conducted to evaluate the system accuracy of the BGM in accordance with the ISO15197:2015 guidelines with additional data collection. METHODS: To investigate system accuracy, 10 of 3088 devices and 6 of 23 strip lots, used in the trials, were selected by a randomization procedure and a standard repeatability assessment. YSI 2300 STAT Plus was used as the standard reference method. The samples were distributed as per the ISO15197:2015 recommendations with 20 additional samples in the hypoglycemic range. Each sample was tested with 6 devices and 6 strip lots with double determinations. RESULTS: Overall, 121 subjects with blood glucose values 26-423 mg/dL were analyzed, resulting in 1452 data points. In all, 186/1452 readings (12.8%) did not meet the ISO acceptance criteria. Data evaluated according to the FDA guidelines showed that 336/1452 (23.1%) readings did not meet the acceptance criteria. A clear bias toward elevated values was observed for BG <100 mg/dL (MARD: 11.0%). CONCLUSIONS: The results show that the BGM, although approved according to standard regulatory guidelines, did not meet the level of analytical accuracy required for clinical treatment decisions according to ISO 15197:2015 and FDA requirements. In general, caution should be exercised before selection of BGMs for patients and in clinical trials.
Subject(s)
Blood Glucose/analysis , Diabetes Mellitus/blood , Hypoglycemia/diagnosis , Internet Access , Randomized Controlled Trials as Topic , Wireless Technology/instrumentation , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose Self-Monitoring/standards , Clinical Trials as Topic , Data Collection/instrumentation , Data Collection/standards , Endocrinology/instrumentation , Endocrinology/methods , Endocrinology/standards , Equipment Design/standards , Equipment Failure Analysis , Female , Humans , Hypoglycemia/blood , Hypoglycemia/epidemiology , Male , Middle Aged , Practice Guidelines as Topic , Randomized Controlled Trials as Topic/standards , Randomized Controlled Trials as Topic/statistics & numerical data , Reproducibility of Results , Sensitivity and Specificity , Wireless Technology/standardsABSTRACT
BACKGROUND: In recent clinical trials, use of the MyGlucoHealth blood glucose meter (BGM) and electronic diary was associated with an unusual reporting pattern of glycemic data and hypoglycemic events. Therefore, the performance of representative BGMs used by the patients was investigated to assess repeatability, linearity, and hematocrit interference in accordance with regulatory guidelines. METHOD: Ten devices and 6 strip lots were selected using standard randomization and repeatability procedures. Venous heparinized blood was drawn from healthy subjects, immediately aliquoted and adjusted to 5 target blood glucose (BG) ranges for the repeatability and 11 BG concentrations for the linearity tests. For the hematocrit interference test, each sample within 5 target BG ranges was split into 5 aliquots and adjusted to hematocrit levels across the acceptance range. YSI 2300 STAT Plus was used as the laboratory reference method in all experiments. RESULTS: Measurement repeatability or precision was acceptable across the target BG ranges for all devices and strip lots with coefficient of variation (CV) between 3.4-9.7% (mean: 5.7%). Linearity was shown by a correlation coefficient of .991; however, a positive bias was seen for BG <100 mg/dL (86% measurements did not meet ISO15197:2015 acceptance criteria). Significant hematocrit interference (up to 20%) was observed for BG >100 mg/dL (ISO15197:2015 acceptance criteria: ±10%), while the results were acceptable for BG <100 mg/dL. CONCLUSIONS: The BGM met repeatability requirements but demonstrated a significant measurement bias in the low BG range. In addition, it failed the ISO15197:2015 criteria for hematocrit interference.
Subject(s)
Blood Glucose/analysis , Clinical Laboratory Techniques , Diabetes Mellitus/blood , Equipment and Supplies/standards , Internet Access , Artifacts , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose Self-Monitoring/standards , Clinical Laboratory Techniques/methods , Equipment Design , Equipment Failure Analysis , Hematocrit/instrumentation , Hematocrit/methods , Hematocrit/standards , Humans , Linear Models , Reagent Strips/standards , Reproducibility of ResultsABSTRACT
BACKGROUND: Frequent blood glucose readings are the most cumbersome aspect of diabetes treatment for many patients. The noninvasive TensorTip Combo Glucometer (CoG) component employs dedicated mathematical algorithms to analyze the collected signal and to predict tissue glucose at the fingertip. This study presents the performance of the CoG (the invasive and the noninvasive components) during a standardized meal experiment. METHODS: Each of the 36 participants (18 females and males each, age: 49 ± 18 years, 14 healthy subjects, 6 type 1 and 16 type 2 patients) received a device for conducting calibration at home. Thereafter, they ingested a standardized meal. Blood glucose was assessed from capillary blood samples by means of the (non)invasive device, YSI Stat 2300 plus, Contour Next at time points -30, 0, 15, 30, 45, 60, 75, 90, 120, 150, and 180 minutes. Statistical analysis was performed by consensus error grid (CEG) and calculation of mean absolute relative difference (MARD) in comparison to YSI. RESULTS: For the noninvasive (NI) CoG technology, 100% of the data pairs were found in CEG zones A (96.6%) and B (3.4%); 100% were seen in zone A for the invasive component and Contour Next. MARD was calculated to be 4.2% for Contour Next, 9.2% for the invasive component, and 14.4% for the NI component. CONCLUSIONS: After appropriate individual calibration of the NI technology, both the NI and the invasive CoG components reliably tracked tissue and blood glucose values, respectively. This may enable patients with diabetes to monitor their glucose levels frequently, reliably, and most of all pain-free.
Subject(s)
Blood Glucose/analysis , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Eating/physiology , Meals , Adult , Aged , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose Self-Monitoring/methods , Female , Humans , Male , Middle Aged , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/methods , Postprandial Period , Reference Standards , Young AdultABSTRACT
BACKGROUND AND OBJECTIVES: In advanced ß-cell dysfunction, proinsulin is increasingly replacing insulin as major component of the secretion product. It has been speculated that proinsulin has at least the same adipogenic potency than insulin, leading to an increased tendency of lipid tissue formation in patients with late stage ß-cell dysfunction. METHODS AND RESULTS: Mesenchymal stem cells obtained from liposuction material were grown in differentiation media containing insulin (0.01 µmol), proinsulin (0.01 µmol) or insulin+proinsulin (each 0.005 µmol). Cell culture supernatants were taken from these experiments and an untreated control at weeks 1, 2, and 3, and were stored at -80°C until analysis. Cell differentiation was microscopically supervised and adiponectin concentrations were measured as marker for differentiation into mature lipid cells. This experiment was repeated three times. No growth of lipid cells and no change in adiponectin values was observed in the negative control group (after 7/14/12 days: 3.2±0.5/3.3±0.1/4.4±0.5 ng/ml/12 h). A continuous differentiation into mature adipocytes (also confirmed by Red-Oil-staining) and a corresponding increase in adiponectin values was observed in the experiments with insulin (3.6±1.9/5.1±1.4/13.3±1.5 ng/ml/12 h; p<0.05 week 1 vs. week 3) and proinsulin (3.3±1.2/3.5±0.3/12.2±1.2 ng/ml/12 h; p<0.05). Comparable effects were seen with the insulin/proinsulin combination. CONCLUSIONS: Proinsulin has the same adipogenic potential than insulin in vitro. Proinsulin has only 10â¼20% of the glucose-lowering effect of insulin. It can be speculated that the adipogenic potential of proinsulin may be a large contributor to the increased body weight problems in patients with type 2 diabetes and advanced ß-cell dysfunction.
ABSTRACT
The pentose xylose is enriched in edible algae, and is increasingly used as a slowly metabolized carbohydrate in functional food. It is known to interfere with glucose-dehydrogenase-based (GDH) blood glucose measurement systems for patients self-testing. The aim of our study was to investigate the extent of xylose interference in commercially available blood glucose meters. A heparinized whole blood sample was manipulated to contain 3 different glucose concentrations (50-80 mg/dL, 130-160 mg/dL, and 250-300 mg/dL) and 4 different xylose concentrations (0 mg/dL, 25 mg/dL, 50 mg/dL, and 100 mg/dL). Each sample was measured 3 times with 2 different strip lots per test meter (AccuChek Aviva, AccuChek Connect, Contour Next, FreeStyle Freedom Lite, FreeStyle Insulinx, MyStar Extra, OneTouch Verio IQ, and Wellion Calla, reference: YSI GlucoStat analyzer). For analysis, we calculated the xylose capture rate, that is, the xylose amount wrongly displayed as glucose. No xylose interference was seen with 4 meters: AccuChek Aviva (mean capture rate 0%), AccuChek Connect (-2%), MyStar Extra (10%), and Wellion Calla (8%). In contrast, substantial interference was observed with Contour Next (100%), FreeStyle Freedom Lite (104%), FreeStyle Insulinx (120%), and OneTouch Verio IQ (162%). We observed xylose interference in several GDH-based meters. This may become important with increased use of xylose in dietary and functional food products, in particular in products designed for weight loss. Our findings may affect the meter selection for patients who are consuming such food products as part of their lifestyle treatment regimen.