临床研究

EZSCAN 临床研究

1.Sheng et al. Accuracy of a Novel Non-Invasive technology based EZSCAN system for the diagnosis of diabetes mellitus in Chinese.Diabetology& Metabolic Syndrome 2011, 3:36

Accuracy of a Novel Non-Invasive technology based EZSCAN system for the diagnosis of diabetes mellitus inChinese.

Sheng CS1, Zeng WF, Huang QF, Deslypere JP, Li Y, Wang JG.

Abstract

BACKGROUND:

A new simple technique based on iontophoresis technology (EZSCAN, Impeto Medical, Paris, France) has recently been developed for the screening of diabetes. In the present study, we investigated the accuracy of this system for the diagnosis of diabetes mellitus in Chinese.

METHODS:

We performed the EZSCAN test in diabetic and non-diabetic subjects. EZSCAN measures electrochemical conductance (EC) at forehead, hands and feet, and derives a diabetes index with a value ranging from 0 to 100. Diabetes mellitus was defined as a plasma glucose concentration of at least 7 mmol/l at fasting or 11.1 mmol/l at 2 hours after glucose load, or as the use of antidiabetic drugs.

RESULTS:

The 195 study participants (51% men, mean age 52 years) included 75 diabetic patients (use of antidiabetic drugs 81%) and 120 non-diabetic subjects. EC (micro Siemens, μSi) was significantly (P < 0.001) lower in diabetic patients at the hands (44 vs. 61) and feet (51 vs. 69) locations, but not at the forehead (15 vs. 17, P = 0.39). When a diabetes index of 40 (suggested by the manufacturer) was used as the threshold, the sensitivity and specificity for the diagnosis of diabetes mellitus was 85% and 64%, respectively. In 80 patients who underwent an oral glucose tolerance test, EC at hands and feet and the diabetes index were significantly (P < 0.001) associated with both 2-hour post-load plasma glucose and serum glycosylated haemoglobin.

CONCLUSIONS:

EZSCAN might be useful in screening diabetes mellitus with reasonable sensitivity and specificity.

 

2.Zhi Yang et al, Autonomic test by EZSCAN in the screening for prediabetes and diabetes. PLoS One. 2013;8(2):e56480.

PLoS One. 2013;8(2):e56480.

Autonomic test by EZSCAN in the screening for prediabetes and diabetes.

Yang Z1, Xu B, Lu J, Tian X, Li M, Sun K, Huang F, Liu Y, Xu M, Bi Y, Wang W.

Abstract

BACKGROUND:

Autonomic neuropathy is common in diabetics and may occur in prediabetes. A new and noninvasive autonomic test-EZSCANevaluates sudomotor function precisely. No generally accepted EZSCAN thresholds to screen for prediabetes and diabetes have been defined.

METHODOLOGY AND PRINCIPAL FINDINGS:

Cross-sectional study of 5, 824 Chinese adults aged 40 and older was conducted in Shanghai, China. We used EZSCAN to evaluate autonomic function in different glucose status and screen for prediabetes and diabetes. The prevalence ofprediabetes and diabetes were 21.9% and 17.5% respectively. Compared with the lowest quintile, the highest quintile of EZSCAN value had odds ratios for having dysglycemia (prediabetes or diabetes) of 2.08 (95% CI 1.67-2.58) in total population, 2.89 (95% CI 2.06-4.05) in men and 1.70 (95% CI 1.28-2.25) in women after adjustment for confounding factors. EZSCAN value improved the areas under ROC curve for detection of dysglycemiaordiabetes beyond the contribution of conventional risk factors by 0.8% and 12.9%. The cut-off point of EZSCAN value higher than 30% provided reasonable sensitivities (70.3-83.7%) to detect dysglycemia not only in total population regardless of sex but also in individuals with high risk of developing diabetes.

CONCLUSIONS AND SIGNIFICANCE:

EZSCAN value higher than 30% indicate an increased risk of prevalent prediabetes and diabetes, suggesting that subjects with EZSCAN ≥30% should be further evaluated by oral glucose tolerance test. The improvement of EZSCAN for diabetes detection was still of limited clinical relevance. Thus the clinical application value of EZSCAN is needed to be explored in future studies.

 

3.Sun K et al, Accessing autonomic function can early screen metabolic syndrome.PLoS One. 2012;7(8):e43449.

PLoS One. 2012;7(8):e43449.

Accessing autonomic function can early screen metabolic syndrome.

Sun K1, Liu Y, Dai M, Li M, Yang Z, Xu M, Xu Y, Lu J, Chen Y, Liu J, Ning G, Bi Y.

Abstract

BACKGROUND:

Clinical diagnosis of the metabolic syndrome is time-consuming and invasive. Convenient instruments that do not require laboratory or physical investigation would be useful in early screening individuals at high risk of metabolic syndrome. Examination of the autonomic function can be taken as a directly reference and screening indicator for predicting metabolic syndrome.

METHODOLOGY AND PRINCIPAL FINDINGS:

The EZSCAN test, as an efficient and noninvasive technology, can access autonomic functionthrough measuring electrochemical skin conductance. In this study, we used EZSCAN value to evaluate autonomic function and to detect metabolicsyndrome in 5,887 participants aged 40 years or older. The EZSCAN test diagnostic accuracy was analyzed by receiver operating characteristic curves. Among the 5,815 participants in the final analysis, 2,541 were diagnosed as metabolic syndrome and the overall prevalence was 43.7%. Prevalence of the metabolic syndrome increased with the elevated EZSCAN risk level (p for trend <0.0001). Moreover, EZSCAN value was associated with an increase in the number of metabolic syndrome components (p for trend <0.0001). Compared with the no risk group (EZSCAN value 0-24), participants at the high risk group (EZSCAN value: 50-100) had a 2.35 fold increased risk of prevalent metabolic syndrome after the multiple adjustments. The area under the curve of the EZSCAN test was 0.62 (95% confidence interval [CI], 0.61-0.64) for predicting metabolic syndrome. The optimal operating point for the EZSCAN value to detect a high risk of prevalent metabolic syndrome was 30 in this study, while the sensitivity and specificity were 71.2% and 46.7%, respectively.

CONCLUSIONS AND SIGNIFICANCE:

In conclusion, although less sensitive and accurate when compared with the clinical definition of metabolicsyndrome, we found that the EZSCAN test is a good and simple screening technique for early predicting metabolic syndrome.

 

4.Zeng Q , et al, Association of EZSCAN values with arterial stiffness in individuals without diabetes or cardiovascular disease.PLoS One. 2014 Mar 3;9(3):e90854.

PLoS One. 2014 Mar 3;9(3):e90854.

Association of EZSCAN values with arterial stiffness in individuals without diabetes or cardiovascular disease.

Zeng Q1, Dong SY1, Wang ML2, Xiang H1, Zhao XL3.

Abstract

BACKGROUND:

The EZSCAN test was recently developed to screen for early dysglycemia through an assessment of sudomotor function. Given the associations of dysglycemia and autonomic dysfunction with the development of arterial stiffness, EZSCAN may also detect early arterial stiffness. The aim of this study was to investigate the association of EZSCAN with arterial stiffness across blood glucose levels.

METHODOLOGY AND PRINCIPAL FINDINGS:

A total of 5532 participants without diabetes or established cardiovascular disease were evaluated with EZSCAN. Their central systolic blood pressure (cSBP), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) were also measured. Multivariate linear regression analyses were used to assess the association between the EZSCAN value and the cSBP, baPWV, and ABI measurements in all of the participants, with additional subgroup analysis that separated participants into a normal glucose tolerance (NGT) group and an impaired glucose regulation (IGR) group. The frequency of the IGRs increased with quartiles of the EZSCAN value (P for trend <0.0001). The levels of cSBP and baPWV increased while the levels of ABI decreased across quartiles of EZSCAN value in both NGT and IGR individuals (P for trend <0.0001 for all). In multivariable analyses, the EZSCAN value was positively associated with cSBP (log-transformed beta = 8.20, P<0.0001) and baPWV (log-transformed beta = 1.82, P<0.0001) but inversely associated with ABI (log-transformed beta = -0.043, P<0.0001) and was independent of conventional factors. Further adjustment for fasting and postprandial glucoses did not attenuate the associations. The results were also unchanged when stratified by IGR.

CONCLUSIONS AND SIGNIFICANCE:

The EZSCAN results were associated with arterial stiffness independent of conventional factors, blood glucose levels, and glucose tolerance status, suggesting a probable link between the EZSCAN value and arterial stiffness through autonomic dysfunction. The EZSCAN test may help us detect the development of arterial stiffness in high risk individuals to prevent unfavorable cardiovascularevents.

 

5.Sun J, Zhang Y,Ning G, et al, Autonomic dysfunction assessed by EZSCAN and subclinical atherosclerosis.J Diabetes. 2014 Sep;6(5):409-16.

J Diabetes. 2014 Sep;6(5):409-16. doi: 10.1111/1753-0407.12135. Epub 2014 Mar 27.

Autonomic dysfunction assessed by EZSCAN and subclinical atherosclerosis.

Sun J1, Zhang Y, Xu B, Lv X, Ding L, Chen Y, Sun W, Lu J, Xu M, Bi Y, Ning G.

Abstract

BACKGROUND:

The present study aimed to explore the association between autonomic dysfunction and measurements of atherosclerosis in a middle-aged and elderly Chinese population.

METHODS:

A population-based cross-sectional study was performed in Shanghai, China, from March to August 2010, with 5076 participants included in the analysis. Autonomic function was assessed by a novel EZSCAN test based on sudomotor function analysis. Carotid intima-media thickness (CIMT) was measured using B-mode ultrasonography and brachial-ankle pulse wave velocity (ba-PWV) was measured using an autonomic device. Participants were divided into three groups based on EZSCAN values: Group 1: EZSCAN 0-24; Group 2, EZSCAN 25-49; and Group 3, EZSCAN 50-100. These groups denoted autonomic dysfunction risk groups as follows: no risk, moderate risk and high risk, respectively.

RESULTS:

The prevalence of elevated CIMT and ba-PWV increased markedly with increasing EZSCAN values (elevated CIMT 7.4%, 17.5%, and 29.7%, elevated ba-PWV 3.2%, 19.7%, and 36.5%, in Groups 1, 2, and 3, respectively; both Ptrend< 0.0001). Logistic regressions revealed thatEZSCAN values ≥50 were associated with a non-significantly higher risk of elevated CIMT (odds ratio [OR] = 1.43; 95% confidence interval [CI] 0.98-2.07) and a significantly higher risk of elevated ba-PWV (OR = 2.16; 95% CI 1.25-3.71) compared with EZSCAN values <25, after controlling for conventional risk factors.

CONCLUSION:

A higher EZSCAN value (≥50), an index of high autonomic dysfunction risk, was associated with an increased risk of elevated ba-PWV and CIMT. Such associations were partially explained by traditional atherosclerotic risk factors.

© 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

KEYWORDS:

EZSCAN test; atherosclerosis; autonomic dysfunction; brachial-ankle pulse wave velocity; carotid intima-media thickness;

 

6.Chen L, Hu Dayi, et al.Evaluation of EZSCAN as a screening tool for impaired glucose metabolism.Diabetes Res ClinPract. 2013 May;100(2):210-4.

Diabetes Res Clin Pract. 2013 May;100(2):210-4.

Evaluation of EZSCAN as a screening tool for impaired glucose metabolism.

Chen L1, Chen X, Ding R, Shi Q Jr, Hu D.

Abstract

AIMS:

To evaluate the performance of EZSCAN as a screening tool for impaired glucose metabolism (IGM), including impaired glucose tolerance,impaired fasting glucose and undiagnosed diabetes in a Chinese population.

METHODS:

876 subjects participated in the study. All subjects underwent tests of EZSCAN, glycated hemoglobin, fasting plasma glucose (FPG), and oral glucose tolerance test (OGTT). Correlation of electrical skin conductance (ESC) with glucose level was evaluated by Pearson correlation coefficient. EZSCAN performance was assessed by receiver operating characteristic curve.

RESULTS:

Among the 876 subjects, 53% had normal glucose tolerance (NGT), and 47% had IGM. The ESC for the hands and feet was 72 ± 10 μS and 75 ± 7 μS, respectively, in NGT group; and 64 ± 13 μS and 67 ± 11 μS, respectively, in IGM group. The ESC at hands and feet was significantly correlated with both 2h-OGTT and FPG (p<0.001). NGT group demonstrated a EZSCAN score of 33 ± 11%, which is significantly lower than that of IGM group (44 ± 12%, p<0.001). The cut-off point of EZSCAN for IGM detection was 40% with a sensitivity of 80% and a specificity of 72%.

CONCLUSIONS:

EZSCAN is a useful screening tool for identifying subjects at increased risk for impaired glucose metabolism in prediabetes and diabetes. Diagnostic laboratory test should be performed in subjects with EZSCAN scores greater than 40%.

Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

 

7.P. Brunswick et al,Use of Ni electrodes chronoamperometry for improved diagnostics of diabetes and cardiac diseases. Proceedings of the 29th Annual International Conference of the IEEE EMBS CitéInternationale, Lyon, France August 23-26, 2007.

Proceedings of the 29th Annual International Conference of the IEEE EMBS CitéInternationale, Lyon, France August 23-26, 2007.

Use of Ni electrodes chronoamperometry for improved diagnostics of diabetes and cardiac diseases.

P. Brunswick, H. Mayaudon , V. Albin, V. Lair, A. Ringuede, M. Cassir

 

Abstract

Low DC active current through nickel electrodes applied on skin in places like hands, forehead and feet provides a novel non invasive diagnostic tool using reverse iontophoresis. This work describes the electrochemistry reactions involved and some medical applications, such as diagnostics of neuropathy, diabetes and cardiac diseases. Finally we provide evidence for the utility of this method through large clinical studies.

 

8.Ramachandran A, A new non-invasive technology to screen for dysglycaemia including diabetes. Diabetes Res ClinPract. 2010 Jun;88(3):302-6

Diabetes Res ClinPract. 2010 Jun;88(3):302-6

A new non-invasive technology to screen for dysglycaemia including diabetes.

Ambady Ramachandran a,*, Anand Moses b, Samith Shetty a,Chandragiri JanakiramanThirupurasundari a, Abraham Catherin Seeli a,ChamukuttanSnehalatha a, Sunil Singvi c, Jean-Paul Deslypere d

Objective: Assess the ability of a new device based on electrochemical principles using

iontophoresis (the EZSCAN) to detect impaired glucose tolerance (IGT) and type 2 diabetes

mellitus (DM).

Methods: Eligible Asian Indian subjects, n = 212, had anthropometric and blood pressureMeasurements, followed by an OGTT, HbA1c, serum lipids tests and EZSCAN measurement.

Results: Biochemically, 24 subjects were diagnosed with DM, 30 with IGT, 57 subjects hadnormal glucose tolerance (NGT) with metabolic syndrome (MS) and 101 had NGT without

MS. Fasting plasma glucose (FPG) and HbA1c levels were highest in theDMgroup( p<.0001for both). HDL-C levels were different (p = 0.015). FPG at a cut-off level of 7.0 mmol/L had alow sensitivity to detect DM (29%) EZSCAN1 had a 75% sensitivity to detect DM, 70% for IGTand 84% for NGT with MS at threshold >50%.

Conclusions: FPG had low sensitivity to detect DM in the study group. EZSCAN demonstratedgood sensitivity to detect IGT and DM and also identified NGT with MS. The conceptof measuring ion fluxes through the skin appears to be a powerful method for earlydetection of MS, IGT and DM.

 

9.A. Ramachandran,Assessment of Sudomotor Function to Predict Future Abnormalities of Glucose Tolerance in at Risk Population.J Diabetes Metab 2011;2(3):1–4

J Diabetes Metab 2011;2(3):1–4

Assessment of Sudomotor Function to Predict Future Abnormalities of Glucose Tolerance in at Risk Population.

A. Ramachandran1, A. Moses2, C. Snehalatha1, A. S. Shetty1, A. Catherin Seeli1, S. Singvi3, JP. Deslypere4, P. Brunswick5 and JH. Calvet5*

 

Abstract

Aims: This study done in subjects with an initial normal glucose tolerance (NGT) was to assess the ability ofEZSCAN, a new device developed to evaluate sudomotor function, to predict future abnormalities in glucose tolerance.

Methods: South Asian (Indian) subjects (n= 69, 48% male, mean age 42 ± 9 years, mean BMI 28 ± 5 kg/m2)diagnosed as NGT with a previous oral glucose tolerance test (OGTT, T0) underwent a frequently sampled OGTT(FSOGTT), 8 months later (T8). At both times EZSCAN tests were done. Using the AUCglucose and AUCinsulin measured bythe FSOGTT, subjects were categorised as normal, high AUCinsulin or isolated high AUCglucose. Odds ratio (OR) for havinghigh AUCinsulin or isolated high AUCglucose vs normal was computed by logistic regression analysis using EZSCAN riskclassification at T0 as independent variable (<50%=normal, no risk,50-65%=intermediate risk and >65%=high risk).

Results: At T8, 11 and 5 subjects developed impaired glucose tolerance and diabetes respectively. OR of havinghigh AUCinsulin or isolated high AUCglucose in the different risk groups was 6.19 (CI 95% 1.50 – 25.48, p = 0.0116) for highrisk vs no risk and 3.0 (CI 95% 0.98 – 9.19, p = 0.0545) for intermediate risk vs no risk. Sensitivity of EZSCAN for earlydetection of these abnormalities in glucose tolerance was 77% while it was 14% for fasting plasma glucose and 66%for HbA1C.

Conclusions: Assessment of sudomotor function by EZSCAN, a sensitive method when compared with the conventionalmethods may be very useful to identify and manage subjects at risk for developing glucose intolerance.

 

10.Risa Ozaki, et al, A New Tool to Detect Kidney Disease in Chinese Type 2 Diabetes Patients—Comparison of EZSCAN with Standard Screening Methods.Diabetes technology & therapeutics. 2011;13(9):937-43

Diabetes technology & therapeutics. 2011;13(9):937-43

A New Tool to Detect Kidney Disease in ChineseType 2 Diabetes Patients—Comparison of EZSCANwith Standard Screening Methods.

Risa Ozaki, MBChB, MRCP,1 Kitty K.T. Cheung, MBChB, MRCP,1 Enoch Wu, MBChB, MRCP,1

Alice Kong, MBChB, FRCP,1Xilin Yang, Ph.D.,1 Eric Lau, MPhil,1

Philippe Brunswick, Ph.D.,2 Jean-Henri Calvet, Ph.D.,2

Jean-Paul Deslypere, M.D.,2 and Juliana C.N. Chan, M.D., FRCP1

 

Abstract

Background: EZSCAN (Impeto Medical, Paris, France), a noninvasive device that assesses sweat gland dysfunctionusing reverse iontophoresis, also detects early dysglycemia. Given the interrelationships among dysglycemia,vasculopathy, and neuropathy, EZSCAN may detect kidney disease in diabetes (DKD).

Methods: An EZSCAN score (0–100) was calculated using a proprietary algorithm based on the chronoamperometryanalysis. We measured the score in 50 Chinese type 2 diabetes patients without DKD (urinaryalbumin–creatinine ratio [ACR] < 2.5mg/mmol in men or ACR < 3.5mg/mmol in women and estimated glomerularfiltration rate [eGFR] > 90mL/min/1.73m2) and 50 with DKD (ACR ‡ 25mg/mmol and eGFR< 60mL/min/1.73m2). We used spline analysis to determine the threshold value of the score in detecting DKD and itssensitivity and specificity.

Results: EZSCAN scores were highly correlated with log values of eGFR (r = 0.67, P < 0.0001) and ACR (r =- 0.66, P < 0.0001). Using a cutoff value of 55, the score had 94% sensitivity, 78% specificity, and a likelihood ratioof 4.2 to detect DKD with a positive predictive value of 81% and a negative predictive value of 93%. Onmultivariable analysis, DKD was independently associated with EZSCAN score (b= -0.72, P = 0.02), smokingstatus (1 = never, 0 = current/former) (b= -2.37, P = 0.02), retinopathy (1 = yes, 0 = no) (b = 3.019, P = 0.01), triglycerides(b = 2.56, P = 0.013), and blood hemoglobin (b= -0.613, P = 0.04). Patients without DKD but lowEZSCAN score (n = 10) had longer duration of disease (median [interquartile range], 13 [9–17] vs. 8 [4–16] years;P = 0.017) and were more likely to have retinopathy (36.7% vs. 5.1%, P = 0.02), lower eGFR (98 [95.00–103] vs. 106[98.5–115], P = 0.036), and treatment with renin–angiotensin system blockers (81.8% vs. 25.6%, P = 0.002) thanthose with a normal score.

Conclusion: EZSCAN may detect high-risk subjects for DKD in Chinese populations.

 

11.P. Schwarz, P. Brunswick, JH. Calvet.EZSCAN a new tool to detect diabetes risk. British Journal of Diabetes & Vascular diseases. 2011;11(4):204-9

British Journal of Diabetes & Vascular diseases. 2011;11(4):204-9

EZSCAN a new tool to detect diabetes risk.

P. Schwarz, P. Brunswick, JH. Calvet.

 

Abstract

Key to putting prevention of diabetes into practiceis finding the people with increased risk. Severaltools are currently in use: oral glucose tolerancetest, fasting glucose measurement and a number of questionnairesto identify those with increased risk. Each hasits own advantages and disadvantages. One new toolthat can identify those with increased diabetes risk is theEZSCAN™. This new diagnostic device developed byImpeto Medical uses the sweat gland function to detectrisk for insulin resistance and diabetes. The basic pathophysiologybehind this technology is supported by thegrowing number of clinical studies worldwide whichshow a strong association between small nerve neuropathiesto insulin resistance and diabetes risk. Because theEZSCAN™ test takes only three minutes to run, is noninvasiveand easy to operate, it is an ideal diagnostic toolfor both the medical and paramedical setting. Severalapplications are possible: the EZSCAN™ can be used tomonitor insulin resistance-based treatment, to diagnoseincreased diabetes risk and to aid proposing diabetesprevention programmes. EZSCAN™ has the potential tobecome a very useful tool in diabetes risk diagnostics.

Keywords: diabetes screening, EZSCAN™, non-invasive sweatfunction

 

12.Hanna Ayouba, et al, Ageing of nickel used as sensitive material for early detection of sudomotor dysfunction.Applied Surface Science. 2012; 258(7): 2724-2731

Applied Surface Science. 2012; 258(7): 2724-2731

Ageing of nickel used as sensitive material for early detection of sudomotor dysfunction.

Hanna Ayouba, b, VirginieLaira, Sophie Griveaub, AnoukGaltayriesc, , , Philippe Brunswickd, FethiBediouib, Michel Cassira,

 

Abstract

The surface ageing of nickel electrodes was studied in the frame of the development of non-invasive biomedical devices, dedicated to the detection of sudomotor dysfunction manifested by an alteration of the ionic balance in human sweat. In this kind of technology, low voltage potentials with variable amplitudes are applied to nickel electrodes, placed on skin regions with a high density of sweat glands, and the electrical responses are measured. The trick is that nickel electrodes play alternately the role of anode and cathode, thus the analysis of the temporal evolution of the physico-chemical properties of nickel is of prime importance to ensure the good performance of the device. Electrochemical measurements coupled to surface chemical characterizations (X-ray photoelectron spectroscopy (XPS), Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS)) were performed on pure Ni samples, immersed in buffered chloride solutions mimicking human sweat. The shapes of voltammograms, recorded in a restricted anodic potential range, show that the nickel surface was gradually passivated as a function of the number of scans. This was confirmed by XPS data, with the formation of a 1 nm thick duplex layer composed by nickel hydroxide (outermost layer) and nickel oxide (inner layer). In a negative extended potential range, though the electrochemical behavior of electrodes was not modified upon cycling the potential, XPS data show that the inner layer was thickening, indicating a surface degradation of the nickel electrode. Below pitting potentials, adsorbed chloride was only hardly detected by XPS, and the surface composition of the nickel samples was similar after treatments in chloride or chloride-free buffered solutions. In a larger potential range enabling to reach the breakdown potential, the highly chemically sensitive ToF-SIMS characterization pointed out that the surface concentration of adsorbed chloride was higher in pits than elsewhere on the surface sample.

13.Hanna Ayoub, et al,Electrochemical Kinetics of Anodic Ni Dissolution in Aqueous Media as a Function of Chloride Ion Concentration at pH Values Close to Physiological Conditions.Electroanalysis 2012; 24(2):386-391

Electroanalysis 2012; 24(2):386-391

Electrochemical Kinetics of Anodic Ni Dissolution in Aqueous Media as a Function of Chloride Ion Concentration at pH Values Close to Physiological Conditions.

Hanna Ayoub1,2, Virginie Lair1, Sophie Griveau2, Philippe Brunswick4, José H. Zagal3,*, Fethi Bedioui2,* andMichel Cassir1,*

Abstract

We have studied the electrochemical kinetics of anodic Ni dissolution as a function of chloride ion concentration, at pH 5, 6 and 7, in order to mimic the conditions of sweat samples. Our results show that the rate-determining step for Ni dissolution in the mentioned pH range is the transfer of one first electron, as suggested by the Tafel slopes close to 0.120 V/decade. However, the reaction order in chloride ion varies from ca. 2 at pH 7 to values close to unity for pH values between 5 and 6. This finding is very important for sensor applications in sweat fluids since the sensitivity of the Ni electrode to chloride ions is higher in neutral solutions (pH ca. 7) compared to that in slightly acid solutions (pH between 5 and 6). Small variations in pH in real samples are expected so this change in sensitivity should be considered when sensing chloride ions in sweat fluids.

Keywords:

Nickel;Electrochemical kinetics;Sensors;Chloride ions

 

14.H. Mayaudon, et al, A new simple method for assessing sudomotor function: Relevance in type 2 diabetes.Diabetes & Metabolism. 2010;36(6):450-4

Diabetes & Metabolism. 2010;36(6):450-4

A new simple method for assessing sudomotor function:Relevance in type 2 diabetes.

H. Mayaudon, PO. Miloche, B. Bauduceau.

Abstract

Aim. – The current sudomotor function tests are too time-consuming to be used for diabetic patients in daily practice. EZSCAN is a new, patentedtechnology that measures electrochemical skin conductance (ESC) through reverse iontophoresis and chronoamperometry. The aim of the presentstudy was to assess the sensitivity, specificity and reproducibility of the method in type 2 diabetic patients in comparison to control subjects withno risk of diabetes.

Methods. –Atotal of 133 type 2 diabetic patients and 41 control subjects were tested. Participants placed their hands and feet on nickel electrodes,and an incremental low direct current was applied to the anode for 2 min. ESC was calculated from the resulting voltage and generated current.ESC diagnostic accuracy was analyzed by ROC curve modeling, and reproducibility was assessed using Bland–Altman analysis.

Results. – The ESC of hands and feet was significantly reduced in diabetic patients (53±16μSi and 67±14μSi, respectively) compared with control subjects (68±16μSi and 80±7μSi, respectively; P < 0.0001). ESC values had a sensitivity of 75% and specificity of 100%, with an areaunder the ROC curve of 0.88 at a threshold of 50% on the EZSCAN scale. Coefficients of variation in hand and foot measurements were 15 and7%, respectively.

Conclusion. – The good sensitivity, specificity and reproducibility of EZSCAN make it a feasible alternative for assessing sudomotor dysfunction,a clinical manifestation of autonomic neuropathy in diabetic patients. The test takes < 3 min to perform, and requires neither special patientpreparation nor medical personnel training.

© 2010 Elsevier Masson SAS. All rights reserved.

Keywords: Type 2 diabetes; Sudomotor function; Electrochemical skin conductance; Autonomic nervous system; EZSCAN

 

15.G. Müller, et al, Assessment of small fiber neuropathy to predict future risk of type2 diabetes.Primary Care Diabetes 2013; 7(4):269-273

Primary Care Diabetes 2013; 7(4):269-273

Assessment ofsmallfiberneuropathytopredictfutureriskoftype2diabetes.

G. Müllera, E. Parfentyevab, J. Olschewskyb, S.R. Bornsteinb, P.E.H. Schwarzb, c,

Abstract

Objective

Sudomotor dysfunction due to small fiber neuropathy can be observed very early in pre-diabetes. The aim of this study was to assess the predictive power of EZSCAN, a non invasive, quick and simple measurement of sudomotor function to identify glucose impairment.

 

Research design and methods

The study was performed in 76 German subjects at risk of diabetes. Glucose metabolism was assessed by using, oral glucose tolerance test (OGTT) at baseline and after 2 year follow-up. Sudomotor function was evaluated by measuring hand and foot electrochemical sweat conductances to calculate a risk score.

 

Results

At baseline, 38 patients had normal glucose tolerance (NGT), 34 had pre-diabetes (impaired fasting glucose, IFG and/or impaired glucose tolerance, IGT) and 4 had newly diagnosed type 2 diabetes. The AUC values for FPG, 2 h-OGTT glucose, 1 h-OGTT glucose, HbA1C and EZSCAN score to predict pre-diabetes were 0.50, 0.65, 0.64, 0.72 and 0.76, respectively. Subjects having a moderate or high EZSCAN score (>50) at baseline had a substantially increased risk for having IFG and/or IGT at follow-up visit presented by an odds ratio of 12.0 [1.4–100.5], the OR for having 1 h-OGTT ≥ 8.6 mmol/L at follow-up was 9.8 [1.0–92.8] and for having HbA1C ≥ 5.7% was 15.7 [1.9–131.5] compared to subjects with low EZSCAN risk.

 

Conclusions

This preliminary study, which must be confirmed in a larger population, shows that EZSCAN risk score is associated with diabetes progression which have implications for prevention and disease management.

 

Keywords

Small fiber neuropathy; Prediction of type 2 diabetes; Diabetes progression; Diabetes risk

 

16.G. Müller et al, Non-invasive Screening of Diabetes Risk by Assessing Abnormalities of Sudomotor Function.ExpClinEndocrinol Diabetes 2013; 121: 1–5

ExpClinEndocrinol Diabetes2013; 121: 1–5

Non-invasive Screening of Diabetes Risk by AssessingAbnormalities of Sudomotor Function.

G. Müller 1 , J. Olschewski 1 , T. Stange 1 , S. Bornstein 1 , P. E. H. Schwarz 1 , 2

Abstract


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