Detection of invasive ductal carcinoma in quadrant breast areas by electrical impedance tomography implemented with gaussian relaxation-time distribution (EIT-GRTD).

Invasive ductal carcinoma (IDC) in breast specimens has been detected in the quadrant breast area: (I) upper outer, (II) upper inner, (III) lower inner, and (IV) lower outer areas by electrical impedance tomography implemented with Gaussian relaxation-time distribution (EIT-GRTD). The EIT-GRTD consists of two steps which are (1) the optimum frequencyfoptselection and (2) the time constant enhancement of breast imaging reconstruction.foptis characterized by a peak in the majority measurement pair of the relaxation-time distribution functionγ,which indicates the presence of IDC.γrepresents the inverse of conductivity and indicates the response of breast tissues to electrical currents across varying frequencies based on the Voigt circuit model. The EIT-GRTD is quantitatively evaluated by multi-physics simulations using a hemisphere container of mimic breast, consisting of IDC and adipose tissues as normal breast tissue under one condition with known IDC in quadrant breast area II. The simulation results show that EIT-GRTD is able to detect the IDC in four layers atfopt= 30, 170 Hz. EIT-GRTD is applied in the real breast by employed six mastectomy specimens from IDC patients. The placement of the mastectomy specimens in a hemisphere container is an important factor in the success of quadrant breast area reconstruction. In order to perform the evaluation, EIT-GRTD reconstruction images are compared to the CT scan images. The experimental results demonstrate that EIS-GRTD exhibits proficiency in the detection of the IDC in quadrant breast areas while compared qualitatively to CT scan images.

First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. METHODS: Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. RESULTS: Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2. CONCLUSIONS: EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. TRIAL REGISTRATION: Not applicable.

The Influence of the Energy Intake Variability During the Week on the Body Composition in an Adult Population.

Background: The regularity of eating, together with other nutritional factors, is one of the important determinants of health. According to previous studies, it is not clear if a greater fluctuation in energy intake is associated with higher body fat and weight gain, or if the weight of people is stable despite these fluctuations in the energy intake. The aim of the study was to verify if a higher variability in the energy intake each day of the week is related to the amount of body fat and other anthropometric parameters. Methods: A total of 220 (151 women, 69 men) individuals of Czech Caucasian origin with a BMI of 18.3-58 kg/m2, aged 21.7-79.7 were included in the study. Selected anthropometric characteristics were measured using a bioelectrical impedance analysis. 7-day food records were completed and analyzed using nutritional software. The measured values were statistically evaluated by multiple linear regression analysis. Results: The results of the multiple linear regression showed the statistically significant dependence of the percentage of body fat (p<0.01), BMI (p<0.01), and waist circumference (p<0.05) on the relative variability of the daily energy intake. Conclusions: The results of our study suggest that people with more regular energy intake also have better anthropometric parameters related to their cardiometabolic health.

Analysis of hemodynamics and impedance using bioelectrical impedance analysis in hypovolemic shock-induced swine model.

To treat hypovolemic shock, fluid infusion or blood transfusion is essential to address insufficient volume. Much controversy surrounds resuscitation in hypovolemic shock. We aimed to identify the ideal fluid combination for treating hypovolemic shock-induced swine model, analyzing bioelectrical impedance and hemodynamics. Fifteen female three-way crossbred pigs were divided into three different groups. The three resuscitation fluids were (1) balanced crystalloid, (2) balanced crystalloid + 5% dextrose water, and (3) balanced crystalloid + 20% albumin. The experiment was divided into three phases and conducted sequentially: (1) controlled hemorrhage (1 L bleeding, 60 min), (2) resuscitation phase 1 (1 L fluid infusion, 60 min), and (3) resuscitation phase 2 (1 L fluid infusion, 60 min). Bioelectrical impedance analysis was implemented with a segmental multifrequency bioelectrical impedance analyzer. A total of 61 impedance measurements were assessed for each pig at six different frequencies in five segments of the pig. Pulse rate (PR), mean arterial pressure (MAP), stroke volume (SV), and stroke volume variation (SVV) were measured using a minimally invasive hemodynamic monitoring device. The three-dimensional graph showed a curved pattern when infused with 1 L of balanced crystalloid + 1 L of 5% dextrose water and 1.6 L of balanced crystalloid + 400 ml of 20% albumin. The 1M impedance increased in all groups during the controlled hemorrhage, and continuously decreased from fluid infusion to the end of the experiment. Only balanced crystalloid + 20% albumin significantly restored MAP and SV to the same level as the start of the experiment after the end of fluid infusion. There were no significant differences in MAP and SV from the time of recovery to the initial value of 1M impedance to the end of fluid infusion in all groups. The change and the recovery of hemodynamic indices such as MAP and SV coincide with the change and the recovery of 1M impedance. Using balanced crystalloid mixed with 20% albumin in hypovolemic shock-induced swine model may be helpful in securing hemodynamic stability, compared with balanced crystalloid single administration.

Association between Physical Activity and Phase Angle Obtained via Bioelectrical Impedance Analysis in South Korean Adults Stratified by Sex.

This cross-sectional study aimed to examine the association of various aspects of physical activity, including intensity, duration, type, and purpose, with the phase angle (PhA), an objective indicator of health, in Korean adults after stratification by sex. Data from the 2022 Korean National Health and Nutrition Examination Survey, a nationwide, representative, population-based survey, were used. In total, 3996 participants were included in the study. Participants self-reported their weekly intensity, frequency, duration of engagement in physical activity. PhA was categorized into two groups on the basis of sex-specific averages. Multiple logistic regression analysis was used to investigate the relationship between physical activity and PhA, and proportional odds logistic regression analysis was performed to determine the association between physical activity and different subclasses of PhA. A positive association was found between sufficiently active aerobic physical activity and PhA compared with inactive physical activity (sufficiently active, male: odds ratio = 1.952, 95% confidence interval = 1.373-2.776; female: odds ratio = 1.333, 95% confidence interval = 1.019-1.745). This association was further strengthened when aerobic physical activity was accompanied by muscle-strengthening activity (sufficiently active with muscle-strengthening activity, male: aOR = 2.318, 95% CI = 1.512-3.554; female: aOR = 1.762, 95% CI = 1.215-2.556) and vigorous-intensity activities (sufficiently active with sufficient vigorous-intensity activity, male: aOR = 2.785, 95% CI = 1.647-4.709; female: aOR = 2.505, 95% CI = 1.441-4.356) and when there was more leisure-time physical activity than occupational physical activity (sufficiently active with more leisure-time physical activity, male: aOR = 2.158, 95% CI = 1.483-3.140; female: aOR = 1.457, 95% CI = 1.078-1.969). Furthermore, the inclusion of muscle-strengthening activity made a significant difference in the values of PhA for males with insufficiently active physical activity (aOR = 2.679, 95% CI = 1.560-4.602). For females with highly active physical activity (aOR = 1.521, 95% CI = 1.068-2.166), the inclusion of muscle-strengthening and vigorous-intensity activities were significantly associated with higher values for PhA. This study can be utilized to provide specific suggestions for better health programs and can change perception that only occupational physical activity is enough. This study also indicated that PhA can be used for personalized health assessments.

Usefulness of Body Fat and Visceral Fat Determined by Bioimpedanciometry versus Body Mass Index and Waist Circumference in Predicting Elevated Values of Different Risk Scales for Non-Alcoholic Fatty Liver Disease.

BACKGROUND: Obesity constitutes a public health problem worldwide and causes non-alcoholic fatty liver disease (MALFD), the leading cause of liver disease in developed countries, which progresses to liver cirrhosis and liver cancer. MAFLD is associated with obesity and can be evaluated by validated formulas to assess MAFLD risk using different parameters such as the body mass index (BMI) and waist circumference (WC). However, these parameters do not accurately measure body fat. As MAFLD is strongly associated with obesity, we hypothesize that measuring body and visceral fat by electrical bioimpedance is an efficient method to predict the risk of MAFLD. The objective of our work was to demonstrate that electrical bioimpedance is a more efficient method than the BMI or WC to predict an elevated risk of MAFLD. METHODS: A cross-sectional, descriptive study involving 8590 Spanish workers in the Balearic Islands was carried out. The study's sample of employees was drawn from those who underwent occupational medicine examinations between January 2019 and December 2020. Five MAFLD risk scales were determined for evaluating very high levels of body fat and visceral fat. The determination of body and visceral fat was performed using bioimpedanciometry. Student's t-test was employed to ascertain the mean and standard deviation of quantitative data. The chi-square test was used to find prevalences for qualitative variables, while ROC curves were used to define the cut-off points for body and visceral fat. The calculations included the area under the curve (AUC), the cut-off points along with their Youden index, sensitivity, and specificity. Correlation and concordance between the various scales were determined using Pearson's correlation index and Cohen's kappa, respectively. RESULTS: As both total body fat and visceral fat increase, the risk of MAFLD increases with a statistically significant result (p < 0.001), presenting a higher risk in men. The areas under the curve (AUC) of the five scales that assess overweight and obesity to determine the occurrence of high values of the different MAFLD risk scales were very high, most of them exceeding 0.9. These AUC values were higher for visceral and body fat than for the BMI or waist circumference. FLD-high presented the best results in men and women with the AUC at around 0.97, both for visceral fat and total body fat, with a high Youden index in all cases (women body fat = 0.830, visceral fat = 0.892; men body fat = 0.780, visceral fat = 0.881). CONCLUSIONS: In our study, all the overweight and obesity scales show a very good association with the scales assessing the risk of MAFLD. These values are higher for visceral and body fat than for waist circumference and the BMI. Both visceral fat and body fat are better associated than the BMI and waist circumference with MAFLD risk scales.

Design, Fabrication, and Evaluation of 3D Biopotential Electrodes and Intelligent Garment System for Sports Monitoring.

This study presents the development and evaluation of an innovative intelligent garment system, incorporating 3D knitted silver biopotential electrodes, designed for long-term sports monitoring. By integrating advanced textile engineering with wearable monitoring technologies, we introduce a novel approach to real-time physiological signal acquisition, focusing on enhancing athletic performance analysis and fatigue detection. Utilizing low-resistance silver fibers, our electrodes demonstrate significantly reduced skin-to-electrode impedance, facilitating improved signal quality and reliability, especially during physical activities. The garment system, embedded with these electrodes, offers a non-invasive, comfortable solution for continuous ECG and EMG monitoring, addressing the limitations of traditional Ag/AgCl electrodes, such as skin irritation and signal degradation over time. Through various experimentation, including impedance measurements and biosignal acquisition during cycling activities, we validate the system's effectiveness in capturing high-quality physiological data. Our findings illustrate the electrodes' superior performance in both dry and wet conditions. This study not only advances the field of intelligent garments and biopotential monitoring, but also provides valuable insights for the application of intelligent sports wearables in the future.

Cell-Electrode Models for Impedance Analysis of Epithelial and Endothelial Monolayers Cultured on Microelectrodes.

Electric cell-substrate impedance sensing has been used to measure transepithelial and transendothelial impedances of cultured cell layers and extract cell parameters such as junctional resistance, cell-substrate separation, and membrane capacitance. Previously, a three-path cell-electrode model comprising two transcellular pathways and one paracellular pathway was developed for the impedance analysis of MDCK cells. By ignoring the resistances of the lateral intercellular spaces, we develop a simplified three-path model for the impedance analysis of epithelial cells and solve the model equations in a closed form. The calculated impedance values obtained from this simplified cell-electrode model at frequencies ranging from 31.25 Hz to 100 kHz agree well with the experimental data obtained from MDCK and OVCA429 cells. We also describe how the change in each model-fitting parameter influences the electrical impedance spectra of MDCK cell layers. By assuming that the junctional resistance is much smaller than the specific impedance through the lateral cell membrane, the simplified three-path model reduces to a two-path model, which can be used for the impedance analysis of endothelial cells and other disk-shaped cells with low junctional resistances. The measured impedance spectra of HUVEC and HaCaT cell monolayers nearly coincide with the impedance data calculated from the two-path model.

Conductive Hydrogel Tapes for Tripolar EEG: A Promising Solution to Paste-Related Challenges.

Electroencephalography (EEG) remains pivotal in neuroscience for its non-invasive exploration of brain activity, yet traditional electrodes are plagued with artifacts and the application of conductive paste poses practical challenges. Tripolar concentric ring electrode (TCRE) sensors used for EEG (tEEG) attenuate artifacts automatically, improving the signal quality. Hydrogel tapes offer a promising alternative to conductive paste, providing mess-free application and reliable electrode-skin contact in locations without hair. Since the electrodes of the TCRE sensors are only 1.0 mm apart, the impedance of the skin-to-electrode impedance-matching medium is critical. This study evaluates four hydrogel tapes' efficacies in EEG electrode application, comparing impedance and alpha wave characteristics. Healthy adult participants underwent tEEG recordings using different tapes. The results highlight varying impedances and successful alpha wave detection despite increased tape-induced impedance. MATLAB's EEGLab facilitated signal processing. This study underscores hydrogel tapes' potential as a convenient and effective alternative to traditional paste, enriching tEEG research methodologies. Two of the conductive hydrogel tapes had significantly higher alpha wave power than the other tapes, but were never significantly lower.

A 3 MHz Low-Error Adaptive Howland Current Source for High-Frequency Bioimpedance Applications.

Bioimpedance is a diagnostic sensing method used in medical applications, ranging from body composition assessment to detecting skin cancer. Commonly, discrete-component (and at times integrated) circuit variants of the Howland Current Source (HCS) topology are employed for injection of an AC current. Ideally, its amplitude should remain within 1% of its nominal value across a frequency range, and that nominal value should be programmable. However, the method's applicability and accuracy are hindered due to the current amplitude diminishing at frequencies above 100 kHz, with very few designs accomplishing 1 MHz, and only at a single nominal amplitude. This paper presents the design and implementation of an adaptive current source for bioimpedance applications employing automatic gain control (AGC). The "Adaptive Howland Current Source" (AHCS) was experimentally tested, and the results indicate that the design can achieve less than 1% amplitude error for both 1 mA and 100 µA currents for bandwidths up to 3 MHz. Simulations also indicate that the system can be designed to achieve up to 19% noise reduction relative to the most common HCS design. AHCS addresses the need for high bandwidth AC current sources in bioimpedance spectroscopy, offering automatic output current compensation without constant recalibration. The novel structure of AHCS proves crucial in applications requiring higher ß-dispersion frequencies exceeding 1 MHz, where greater penetration depths and better cell status assessment can be achieved, e.g., in the detection of skin or breast cancer.

Microneedle Array Electrodes Fabricated With 3D Printing Technology for High-Quality Electrophysiological Acquisition.

Electrophysiological recordings are vital in assessing biological functions, diagnosing diseases, and facilitating biofeedback and rehabilitation. The applications of conventional wet (gel) electrodes often come with some limitations. Microneedle array electrodes (MAEs) present a possible solution for high-quality electrophysiological acquisition, while the prior technologies for MAE fabrication have been either complex, expensive, or incapable of producing microneedles with uniform dimensions. This work employed a projection stereolithography (P µ SL) 3D printing technology to fabricate MAEs with micrometer-level precision. The MAEs were compared with gel and flat electrodes on electrode-skin interface impedance (EII) and performances of EMG and ECG acquisition. The experimental results indicate that the P µ SL 3D printing technology contributed to an easy-to-perform and low-cost fabrication approach for MAEs. The developed MAEs exhibited promising EII and enabled a stable EMG and ECG acquisition in different conditions without inducing skin allergies, inflammation, or injuries. This research lies in the development of a type of customizable MAE with considerable biomedical application potentials for ultra-minimally invasive or non-invasive electrophysiological acquisition.

Sex differences in chest electrical impedance tomography findings.

Objective.Electrical impedance tomography (EIT) has been used to determine regional lung ventilation distribution in humans for decades, however, the effect of biological sex on the findings has hardly ever been examined. The aim of our study was to determine if the spatial distribution of ventilation assessed by EIT during quiet breathing was influenced by biological sex.Approach.219 adults with no known acute or chronic lung disease were examined in sitting position with the EIT electrodes placed around the lower chest (6th intercostal space). EIT data were recorded at 33 images/s during quiet breathing for 60 s. Regional tidal impedance variation was calculated in all EIT image pixels and the spatial distribution of the values was determined using the established EIT measures of centre of ventilation in ventrodorsal (CoVvd) and right-to-left direction (CoVrl), the dorsal and right fraction of ventilation, and ventilation defect score.Main results.After exclusion of one subject due to insufficient electrode contact, 218 data sets were analysed (120 men, 98 women) (age: 53 ± 18 vs 50 ± 16 yr (p= 0.2607), body mass index: 26.4 ± 4.0 vs 26.4 ± 6.6 kg m-2(p= 0.9158), mean ± SD). Highly significant differences in ventilation distribution were identified between men and women between the right and left chest sides (CoVrl: 47.0 ± 2.9 vs 48.8 ± 3.3% of chest diameter (p< 0.0001), right fraction of ventilation: 0.573 ± 0.067 vs 0.539 ± 0.071 (p= 0.0004)) and less significant in the ventrodorsal direction (CoVvd: 55.6 ± 4.2 vs 54.5 ± 3.6% of chest diameter (p= 0.0364), dorsal fraction of ventilation: 0.650 ± 0.121 vs 0.625 ± 0.104 (p= 0.1155)). Ventilation defect score higher than one was found in 42.5% of men but only in 16.6% of women.Significance.Biological sex needs to be considered when EIT findings acquired in upright subjects in a rather caudal examination plane are interpreted. Sex differences in chest anatomy and thoracoabdominal mechanics may explain the results.

Association of body composition indicators with colorectal cancer: a hospital-based case-control study.

PURPOSE: Colorectal cancer (CRC) is a common malignancy that affects adults worldwide, causing a high disease burden. Few studies have examined the relationship between body composition (BC) measures and the prevalence of CRC. Our purpose was to investigate the relationship between pertinent BC indicators and CRC. METHODS: Bioelectrical impedance analysis, laboratory test results, face-to-face questionnaire investigation, and nutritional risk assessment (Nutritional Risk Screening 2002 and Patient-Generated Subjective Global Assessment) were used in this case-control study. Bioelectrical impedance analysis in the case group was performed prior to antitumor therapy/surgery. RESULTS: From June 2018 to January 2019, a total of 303 cases and 286 controls were included. The results showed that low body fat percentage (BFP) and high visceral adiposity index (VAI) groups had a higher risk of developing CRC in comparison to the normal BFP and normal VAI groups. The risk of CRC decreased with the increase of BFP. The group with a normal BC had a lower risk of developing CRC compared to those with a greater VAI and a lower BFP, as indicated by the results of the pairwise and total combinations of VAI, fat-free mass index (FFMI), and BFP. Additionally, FFMI and VAI had positive correlations with prealbumin, serum albumin, and nutritional risk scores. CONCLUSION: Low BFP and high VAI are associated with higher CRC risk. FFMI and VAI are positively correlated with prealbumin, serum albumin, and nutritional risk scores in CRC patients.

Electric field and SAR reduction in high-impedance RF arrays by using high permittivity materials for 7T MR imaging.

In the field of ultra-high field MR imaging, the challenges associated with higher frequencies and shorter wavelengths necessitate rigorous attention to multichannel array design. While the need for such arrays remains, and efforts to increase channel counts continue, a persistent impediment-inter-element coupling-constantly hinders development. This coupling degrades current and field distribution, introduces noise correlation between channels, and alters the frequency of array elements, affecting image quality and overall performance. The goal of optimizing ultra-high field MRI goes beyond resolving inter-element coupling and includes significant safety considerations related to the design changes required to achieve high-impedance coils. Although these coils provide excellent isolation, the higher impedance needs special design changes. However, such changes pose a significant safety risk in the form of strong electric fields across low-capacitance lumped components. This process may raise Specific Absorption Rate (SAR) values in the imaging subject, increasing power deposition and, as a result, the risk of tissue heating-related injury. To balance the requirement of inter-element decoupling with the critical need for safety, we suggest a new solution. Our method uses high-dielectric materials to efficiently reduce electric fields and SAR values in the imaging sample. This intervention tries to maintain B1 efficiency and inter-element decoupling within the existing array design, which includes high-impedance coils. Our method aims to promote the full potential of ultra-high field MRI by alleviating this critical safety concern with minimal changes to the existing array setup.

Bioelectrical impedance and lung function-associations with gender and central obesity: results of the EpiHealth study.

BACKGROUND: Obesity is a major public health concern associated with various health problems, including respiratory impairment. Bioelectrical impedance (BIA) is used in health screening to assess body fat. However, there is no consensus in healthcare on how body fat should be assessed in relation to lung function. In this study, we aimed to investigate how BIA in relation to waist circumference contribute, using data from a large Swedish population study. METHODS: A total of 17,097 participants (aged 45-75 years) were included in the study. The relationships between fat mass, waist circumference, and lung function were analysed using weighted quantile sum regression. RESULTS: Increased fat mass was significantly associated with decreased lung function (FEV1, FVC) in both sexes. Also, the influence of trunk fat and waist circumference on FVC and FEV1 differed by sex: in males, waist circumference and trunk fat had nearly equal importance for FVC (variable weights of 0.42 and 0.41), whereas in females, trunk fat was significantly more important (variable weights 0.84 and 0.14). For FEV1, waist circumference was more important in males, while trunk fat was more significant in females (variable weights male 0.68 and 0.28 and 0.23 and 0.77 in female). CONCLUSIONS: Our results suggest that trunk fat should be considered when assessing the impact of adipose tissue on lung function and should potentially be included in the health controls.

Bioimpedance analysis for identifying new indicators of exercise-induced muscle damage.

A noninvasive, immediate, and convenient method for assessing muscle tissue status during exercise-induced muscle damage (EIMD) has not been established. This study was designed to assess and determine parameters suitable for measuring EIMD after eccentric exercise, using multi-frequency bioimpedance analysis (BIA). Thirty-five young male participants performed dumbbell exercises with their left arm, and their BIA parameters were measured at various time points up to 168 h post exercise using a multi-frequency BIA device. At all-time points, intra and extracellular water content was greater in the left arm than in the right arm, whereas the impedance, reactance, resistance, and phase angle were lower in the left arm than in the right arm. Established EIMD indices, such as maximal isometric voluntary contraction, were measured and used in correlational analyses. Only reactance was correlated with biomarkers, indicating muscle damage (r = - 0.56 to - 0.49). Furthermore, reactance was found to correlate well with indirect indicators of EIMD, suggesting that it may be a suitable marker for evaluating EIMD. However, the relationship with the limited evaluation indices employed in this study is constrained. Future studies should investigate the correlation between reactance and direct damage indicators, such as structural damage, observed in biopsies.

Impact of volume indices in bioelectrical impedance measurement on the assessment of cardiac function indices by echocardiography in hemodialysis patients.

INTRODUCTION: Cardiovascular events resulting from volume overload are a primary cause of mortality in hemodialysis patients. Bioelectrical impedance analysis (BIA) is significantly valuable for assessing the volume status of hemodialysis (HD) patients. In this article, we explore the correlation between the volume index measured by BIA and the cardiac function index assessed by echocardiography (ECG) in HD patients. METHODS: Between April and November 2018, we conducted a cross-sectional study involving randomly selected 126 maintenance HD patients. Comprehensive data on medical history and laboratory test results were collected. Subsequently, we investigated the correlation between volume indices measured by BIA and cardiac function parameters by ECG. RESULTS: We discovered a significant correlation between the volume indices measured by BIA and various parameter of cardiac function. The Left Ventricular Hypertrophy (LVH) group exhibited higher levels of the percentage of Extracellular Water (ECW%) and the percentage of Total Body Water (TBW%) compared to the Non-LVH group. Extracellular Water (ECW) and Third Interstitial Fluid Volume (TSFV) were identified as independent risk factors for Left Ventricular Mass (LVM), and both demonstrated a high predictive value for LVM. ECW% emerged as an independent risk factor for the Left Ventricular Mass Index (LVMI), with a high predictive value for LVMI. CONCLUSION: ECW and TSFV were found to be positively associated with cardiac function parameters in HD patients.

[Relationship between bioelectrical impedance analysis-derived fluid status and nutritional indicators and the prognosis in patients undergoing maintenance hemodialysis].

Objective: To explore the relationship between bioelectrical impedance analysis (BIA)-derived fluid status and nutritional indicators and the prognosis in patients undergoing maintenance hemodialysis (MHD). Methods: A retrospective cohort study was conducted. The clinical data of MHD patients in Jiangsu Province Hospital between January 2014 and December 2016 were analyzed. BIA data of healthy volunteers in Gulou District, Nanjing City, collected between April and October 2022, were used to determine the cut-off value of body cell mass index (BCMI). Referring to previous research, using 0.15 as the cut-off value for the ratio of overhydration and extracellular water (OH/ECW). The data were transformed into binary variables based on these cut-off values to categorize patients into different groups. Kaplan-Meier analysis was used to plot survival curves, and the Cox proportional hazards model was performed to analyze risk factors for all-cause mortality. Results: A total of 706 MHD patients (407 males and 299 females) were included, aged (54±15) years. MHD patients were classified into four groups based on whether BCMI was<5.4 kg/m2 and OH/ECW was≥0.15, which included non-overhydration and non-malnutrition group, overhydration group, malnutrition group, and overhydration and malnutrition group, with 269, 186, 151, and 100 patients, respectively. During a median follow-up of [M(Q1, Q3)] 33 (26, 37) months, 162 patients died. Kaplan-Meier analysis showed that the median survival periods of the four groups were 52 months (95%CI: 41-54 months), 46 months (95%CI: 44-49 months), 37 months (95%CI: 34-40 months), and 34 months (95%CI: 30-38 months), respectively, with a statistically significant difference (P<0.001). The 1-year survival rates were 95.5%, 93.5%, 92.1%, and 88.0% (P<0.001), respectively, and the 2-year mortality rates were 92.6%, 87.1%, 83.4%, and 77.0% (P<0.001), respectively. Multivariate Cox regression analysis showed that compared with non-overhydration and non-malnutrition group, the risk of all-cause mortality increased by 1.18 times in the malnutrition group (HR=2.18, 95%CI: 1.29-3.71, P=0.004), and by 1.59 times in the overhydration and malnutrition group (HR=2.59, 95%CI: 1.48-4.54, P=0.001). Conclusions: BIA-derived fluid status and nutritional indicators are associated with the prognosis of MHD patients. Compared with patients without fluid overload and malnutrition, patients with malnutrition and fluid overload have an increased risk of all-cause mortality.

Associated factors of low muscle mass in community-dwelling patients with type 2 diabetes.

This study aims to analyze the prevalence of low muscle mass (LMM) and its associated factors among community-dwelling patients with type 2 diabetes (T2D). A retrospective design was employed to analyze the body composition of 2404 adults with T2D aged 18 years and older. LMM was defined as a skeletal muscle index < 7.0 kg/m2 for males and skeletal muscle index < 5.7 kg/m2 for females by bioelectrical impedance analyzer (InBody 770, Korea). Multivariable logistic regression was used to identify the factors related to LMM. The overall prevalence of LMM was 28%. After adjusting for multivariate odds ratios, factors significantly associated with LMM in patients with diabetes include being older than 75 years, female, having a body mass index of <18 kg/m2, and increased percent body fat. We recommend regular LMM evaluations for T2D patients with the previously mentioned characteristics as part of diabetes care.

Effect of measurement procedure errors on assessing lung fluid via remote dielectric sensing system.

The study assessed the impact of procedural errors on the remote dielectric sensing system (ReDS), a non-invasive lung fluid assessment technology, in an Asian cohort. Healthy volunteers underwent ReDS measurements following manufacturer's instructions, with two consecutive measurements one minute apart. A subset of 20 participants had modified procedure settings. Reliability was measured using intraclass correlation coefficient (ICC). The study included 86 healthy volunteers, and all ReDS measurements fell within the recommended normal range. The intra-rater reliability of ReDS measurements was excellent, with an ICC of 0.968. Among the subset of 20 subjects, deviations in height and weight did not significantly affect ReDS values. However, deviations in chest size by ± 3 cm had a noticeable impact on ReDS measures, and incorrect station selection led to fluctuations in ReDS readings. In conclusion, the ReDS system demonstrated excellent intra-rater reliability and applicability in an Asian cohort. Procedural errors, such as chest size measurement and station selection, significantly influenced ReDS measurements. Adherence to standardized operating procedures is crucial to ensure accurate and consistent results. These findings highlight the importance of adherence to manufacturer instructions when utilizing ReDS for lung fluid assessment, thereby enhancing its reliability and clinical applicability.