Bioimpedance Device Research Articles

Bioimpedence to Assess Breast Density as a Risk Factor for Breast Cancer in Adult Women and Adolescent Girls.

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast DensitometerTM (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were 230±52 and 226±50 Ω and 23.7±15.1 and 24.2±15.2%, respectively. The EBD measurements were inversely correlated with PD (rSpearman=-0.52, p<0.0001); the correlation was stronger in Caucasians (rSpearman=-0.70, p<0.0001) than Asians (rSpearman=-0.54, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders (rSpearman=-0.34, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were 256±32, 249±41, 202±46, and 178±43 Ω (p<0.0001). In girls, the mean EBD values in the left and right breast were 148±40 and 155±54 Ω; EBD values decreased from Tanner stages 1 to 4 (204±14, 154±79, 136±43, and 119±16 Ω for stages 1-4, respectively) but were higher at Tanner stage 5 (165±30 Ω). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

DETERMINATION OF VOLUME OVERLOAD BY BIOELECTRICAL IMPEDANCE ANALYSIS AND NT-PROBNP IN DIABETIC PRE-DIALYSIS PATIENTS.

Diabetic chronic kidney disease has more fatal clinical progresses and this situation can be related to volume overload, which is seen more commonly in diabetic chronic kidney disease patients than in non-diabetic chronic kidney disease patients. Therefore, we examined the effect of diabetes mellitus on volume overload in newly diagnosed stage 5 chronic kidney disease patients whose volume overloads were not showing signs of improvement from renal replacement therapy. One hundred and five patients (46 diabetic, 59 non-diabetic) with end-stage chronic kidney disease, who had glomerular filtration rate (GFR) under 15 mL/min for at least three months were enrolled in this prospective study. We determined the body volume overload and configuration using a bioimpedance device. NT-proBNP levels were recorded. There was a statistically significant difference between diabetic and non-diabetic groups according to overhydration (OH, p=0.003), extracellular water (ECW, p=0.045), intracellular water (ICW, p<0.001) and OH/ECW (p=0.003). In addition, there was a statistically significant difference between groups in terms of N-terminal Pro-brain Natriuretic Peptide (NT-proBNP levels, p=0.008). We compared diabetic and non-diabetic end-stage chronic kidney disease patients who were not in renal replacement therapy yet. We found more volume overload and extracellular fluid volume in the diabetic group.

Patterns of Obesity and Lymph Fluid Level during the First Year of Breast Cancer Treatment: A Prospective Study.

Obesity is one of the risk factors for developing lymphedema following breast cancer treatment. We prospectively enrolled 140 women and followed the participants for 12 months after surgery to investigate patterns of obesity and lymph fluid level in the first year of cancer treatment. Electrical bioimpedance devices were used to measure weight, BMI, and percent of body fat as well as lymph fluid level. General instructions were given to the participants on maintaining pre-surgery weight. Among the 140 participants, 136 completed the study with 2.9% attrition. More than 60% of the participants were obese (30.8%) or overweight (32.4%), while only two participants were underweight and about 35% had normal weight. This pattern of obesity and overweight was consistent at 4–8 weeks and 12 months post-surgery. At 12 months post-surgery, the majority of the women (72.1%) maintained pre-surgery weight and 15.4% had >5% weight loss; 12.5% of the women increase >5% of their weight. Significantly more patients in the obesity group had lymphedema defined by L-Dex ratio >7.1 than those in the normal/underweight and overweight group at pre-surgery and 4–8 weeks post-surgery. There was a trend of more patients in the obesity group had L-Dex ratio >7.1 at 12 months post-surgery. Obesity and overweight remain among women at the time of cancer diagnosis and the patterns of obesity and overweight continue during the first year of treatment. General instructions on having nutrition-balanced and portion-appropriate diet and physical activities daily or weekly can be effective to maintain pre-surgery weight.

A Temperature-Based Bioimpedance Correction for Water Loss Estimation During Sports.

The amount of total body water (TBW) can be estimated based on bioimpedance measurements of the human body. In sports, TBW estimations are of importance because mild water losses can impair muscular strength and aerobic endurance. Severe water losses can even be life threatening. TBW estimations based on bioimpedance, however, fail during sports because the increased body temperature corrupts bioimpedance measurements. Therefore, this paper proposes a machine learning method that eliminates the effects of increased temperature on bioimpedance and, consequently, reveals the changes in bioimpedance that are due to TBW loss. This is facilitated by utilizing changes in skin and core temperature. The method was evaluated in a study in which bioimpedance, temperature, and TBW loss were recorded every 15 min during a 2-h running workout. The evaluation demonstrated that the proposed method is able to reduce the error of TBW loss estimation by up to 71%, compared to the state of art. In the future, the proposed method in combination with portable bioimpedance devices might facilitate the development of wearable systems for continuous and noninvasive TBW loss monitoring during sports.

The Effects of Dynamic Stretching on Hemodynamics and Metabolic Functions

INTRODUCTION: The application of warm-up prior to exercise is commonly used to prepare the body for exercise demands. Dynamic stretching remains a controversial topic regarding the impact on human performance and the applicability in competition and overall influence on physical activity. There appears to be little evidence on the variables responsible for metabolic improvements associated with dynamic stretching. PURPOSE: To determine if a specific, lower body dynamic stretching protocol will have any effect on metabolic functioning and how cardiac variables may influence that while performing a submaximal cycle protocol. METHODS: Twenty-four participants consisting of both healthy males (25.11.2 years, 179.8 30.1 pounds) and females (24.7 1.1 years, 147.5 13.9 pounds) were tested twice, with and without prior stretching exercises. The inclusion of 4 lower extremity dynamic stretches on the first day of testing was randomly assigned. All participants underwent a submaximal lower extremity cycle ergometer protocol for 10 minutes with workload increasing by 20 watts every minute. A 3 minute warm-up and cool-down were completed prior to and after the cycle protocol. Hemodynamic variables were monitored using thoracic bioimpedance device and metabolic variables were collected with a ParvoMedics metabolic cart. RESULTS: When stretching was compared to non-stretching condition, significant differences were found only in the VO2 (8.7 1.9 vs. 7.8 2.0 ml/kg/min, p < 0.05) and minute ventilation (VE) (19.1 3.0 vs 16.6 3.7 L/min, p < 0.05) prior to warm up. No significant difference was revealed among genders based on condition. Linear regression analyses indicated cardiac index as the single best predictor for VO2 (R2 = 0.16, p<0.05) and ejection fraction and heart rate the predictors for VE (R2 = 0.18, p<0.05). CONCLUSION: Dynamic stretching had minimal effect on metabolic variables during and after the performance of a submaximal exercise test, however, higher baseline VO2 and VE were seen. These elevations were likely due to an increased intramuscular temperature and improved efficiency of muscle contraction shortly after the dynamic stretching protocol. It is possible that the stretching was not intense or long enough to perpetuate the benefits into the exercise routine.

Preprocessing and parameterizing bioimpedance spectroscopy measurements by singular value decomposition

In several applications of bioimpedance spectroscopy, the measured spectrum is parameterized by being fitted into the Cole equation. However, the extracted Cole parameters seem to be inconsistent from one measurement session to another, which leads to a high standard deviation of extracted parameters. This inconsistency is modeled with a source of random variations added to the voltage measurement carried out in the time domain. These random variations may originate from biological variations that are irrelevant to the evidence that we are investigating. Yet, they affect the voltage measured by using a bioimpedance device based on which magnitude and phase of impedance are calculated.By means of simulated data, we showed that Cole parameters are highly affected by this type of variation. We further showed that singular value decomposition (SVD) is an effective tool for parameterizing bioimpedance measurements, which results in more consistent parameters than Cole parameters. We propose to apply SVD as a preprocessing method to reconstruct denoised bioimpedance measurements. In order to evaluate the method, we calculated the relative difference between parameters extracted from noisy and clean simulated bioimpedance spectra. Both mean and standard deviation of this relative difference are shown to effectively decrease when Cole parameters are extracted from preprocessed data in comparison to being extracted from raw measurements.We evaluated the performance of the proposed method in distinguishing three arm positions, for a set of experiments including eight subjects. It is shown that Cole parameters of different positions are not distinguishable when extracted from raw measurements. However, one arm position can be distinguished based on SVD scores. Moreover, all three positions are shown to be distinguished by two parameters, R0/R∞ and Fc, when Cole parameters are extracted from preprocessed measurements. These results suggest that SVD could be considered as an effective technique for overcoming the variability of bio-impedance spectroscopy measurements.

Does the presence of an arteriovenous fistula alter changes in body water following hemodialysis as determined by multifrequency bioelectrical impedance assessment?

Multifrequency bioelectrical impedance assessments (MFBIAs) aid clinical assessment of hydration status for hemodialysis (HD) patients. Many MFBIA devices are restricted to whole body measurements and as many patients dialyze using arteriovenous fistulas (AVFs), we wished to determine whether AVFs affected body water measurements. We reviewed pre- and post-HD segmental MFBIA measurements in 229 patients attending for midweek HD sessions. Up to 144 were dialyzed with a left arm AVF (L-AVF), 42 with a right arm AVF (R-AVF), and 43 by central venous access catheter (CVC). Water content and lean tissue were greater in the left compared to right arm in those patients with L-AVFs both pre and post dialysis (pre 2.1 ± 0.7 vs. 2.0 ± 0.7 L, and post 1.9 ± 0.6 vs. 1.8 ± 0.6 L and pre 2.65 ± 0.9 vs. 2.56 ± 0.8 kg, and post 2.34 ± 0.8 vs. 2.48 ± 0.8 vs. 2.34 ± 0.8 kg, respectively) and were also greater in the right compared to left arm for those patients dialyzing with R-AVFs (pre-HD 1.92 ± 0.5 vs. 1.86 ± 0.6 L and post-HD 1.79 ± 0.5 vs. 1.7 ± 0.5 L, and pre-HD 2.47 ± 0.6 vs. 2.38 ± 0.7 kg and post-HD 2.3 ± 0.74 vs. 1.28 ± 0.7 kg, respectively), all Ps < 0.05. There were no significant differences in arm volumes or composition pre or post dialysis in those dialyzing with CVCs. Segmental MFBIA detects differences in arm water and lean mass in patients with AVFs. The presence on an AVF increases the water content in the ipsilateral arm both pre and post HD. This increased water content of the fistula arm will not be detected by whole body bioimpedance devices.

Bioimpedance at the bedside: current applications, limitations, and opportunities.

The loss of muscle mass is a defining characteristic of malnutrition, and there is ongoing interest in the assessment of lean tissue at the bedside. Globally, bioimpedance techniques have been widely appreciated for their noninvasiveness, safety, ease of use, portability, and relatively low cost compared with other clinically available methods. In this brief update, we review the 3 primary types of commercially available bioimpedance devices (single- and multiple-frequency and spectroscopy) and differentiate the underlying theory and current applications of each. We also address limitations and potential opportunities for using these devices at the bedside for clinical assessment. Mixed reports in the validation literature for all bioimpedance approaches have raised questions about absolute accuracy to estimate whole body composition in clinical populations, particularly those with abnormal fluid status and/or body geometry in whom underlying method assumptions may be violated. Careful selection of equations can improve whole body estimates by single- and multiple-frequency techniques; however, not all devices will allow for this approach. Research is increasing on the use of bioimpedance variables including phase angle and impedance ratio as potential markers of nutrition status and/or clinical outcomes; consensus on reference cut-points for interpreting these markers has yet to be established. Novel developments in the bioimpedance spectroscopy approach are allowing for improved fluid management in individuals receiving dialysis; these developments have implications for the clinical management of other conditions associated with fluid overload and may also provide enhanced whole body estimates of lean tissue through new modeling procedures.

Estimation of Body Composition and Normal Fluid Status Using a Calf Bioimpedance Technique

The aims of this study in hemodialysis (HD) patients were: 1. To evaluate the relationship of calf bioimpedance with total body composition and fluid status as measured by gold standard methods. 2. To investigate the ability of calf normalized resistivity (CNR) to predict the normal fluid status (dry weight: DW) in a prospective study. In the body composition study (n = 41), fluid status (ECV_Br/FFM_MRI), muscle mass (MM_MRI), and total adipose tissue (TAT_MRI) were measured by dilution (D₂O and Br) and MRI methods three hours prior to HD treatment. Calf extracellular and intracellular resistance, resistivity, and CNR were measured with a multi-frequency bioimpedance device (Hydra 4200). In the fluid status study (n = 32 with 429 measurements), a nonlinear model based on the differences in CNR between patients and healthy subjects was established to predict DW_cBIS previously determined by a separate continuous calf bioimpedance spectroscopy (cBIS) method. CNR significantly correlated with a gold standard hydration marker (ECV_Br/FFM_MRI). Calf body composition models were highly correlated with MM_MRI (R² = 0.85) and TAT_MRI (R² = 0.85). DW_cBIS prediction was validated with a CNR model in the degree of differences of 0.94 ± 0.18, 0.39 ± 0.7 and -0.02 ± 0.8 kg from DW_cBIS when post HD fluid overload was 1.8 ± 1.2, 1.15 ± 0.8 and 0.54 ± 0.5 kg, respectively. These differences are not considered to be clinically significant. Conclusion: This practical method of calf bioimpedance is useful to predict body composition and normal fluid status in dialysis patients.

Stress and inflammatory biomarkers and symptoms are associated with bioimpedance measures.

This large cross-sectional, multi-centre study evaluated the association of body composition measurements by a novel dual frequency bioimpedance device (BIA-ACC) with chronic stress/inflammation biomarkers and the presence of medically unexplained symptoms (MUS). Participants were adult Caucasians of both sexes and included 10,416 lean subjects with no MUS (Group A), 58,710 lean subjects with MUS (Group B) and 30,445 overweight/obese subjects with no MUS and excessive fat mass (FM) (Group C). Total body extracellular water (ECW) was higher, while intracellular water (ICW) was lower in Group B than both other groups (P < 0.01). Group A had significantly lower FM and higher skeletal mass (SK) and phase angle (PA) than Group B and lower circulating high sensitivity (hs) CRP levels than both other groups. hsCRP was higher in Group C than Group A though (P < 0.01). Salivary cortisol in Group B was lower in the morning and higher in the evening than both other groups (P < 0.001), indicating circadian rhythm obliteration or reversal in this group. ECW correlated positively with serum hsCRP and 8 p.m. salivary cortisol, but negatively with 8 a.m. salivary cortisol, while PA correlated positively with 8 a.m. and negatively with 8 p.m. salivary cortisol and serum hsCRP. Both 8 a.m. and 8 p.m. salivary cortisol and serum hsCRP were associated with the presence of MUS and BIA-ACC measurements, including ECW, ICW, FM, SK and PA. MUS is an index of chronic stress and inflammation and BIA-ACC may provide a useful, bloodless and rapid tool in the clinical setting, distinguishing patients with chronic stress/inflammation from healthy subjects and monitoring their response to treatment.

Energy balance of triathletes during an ultra-endurance event.

The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

A Thorax Simulator for Complex Dynamic Bioimpedance Measurements With Textile Electrodes.

Bioimpedance measurements on the human thorax are suitable for assessment of body composition or hemodynamic parameters, such as stroke volume; they are non-invasive, easy in application and inexpensive. When targeting personal healthcare scenarios, the technology can be integrated into textiles to increase ease, comfort and coverage of measurements. Bioimpedance is generally measured using two electrodes injecting low alternating currents (0.5-10 mA) and two additional electrodes to measure the corresponding voltage drop. The impedance is measured either spectroscopically (bioimpedance spectroscopy, BIS) between 5 kHz and 1 MHz or continuously at a fixed frequency around 100 kHz (impedance cardiography, ICG). A thorax simulator is being developed for testing and calibration of bioimpedance devices and other new developments. For the first time, it is possible to mimic the complete time-variant properties of the thorax during an impedance measurement. This includes the dynamic real part and dynamic imaginary part of the impedance with a peak-to-peak value of 0.2 Ω and an adjustable base impedance (24.6 Ω ≥ Z0 ≥ 51.6 Ω). Another novelty is adjustable complex electrode-skin contact impedances for up to 8 electrodes to evaluate bioimpedance devices in combination with textile electrodes. In addition, an electrocardiographic signal is provided for cardiographic measurements which is used in ICG devices. This provides the possibility to generate physiologic impedance changes, and in combination with an ECG, all parameters of interest such as stroke volume (SV), pre-ejection period (PEP) or extracellular resistance (Re) can be simulated. The speed of all dynamic signals can be altered. The simulator was successfully tested with commercially available BIS and ICG devices and the preset signals are measured with high correlation (r = 0.996).

Proactive approach to lymphedema risk reduction: a prospective study.

Advances in cancer treatments continue to reduce the incidence of lymphedema. Yet, many breast cancer survivors still face long-term postoperative challenges as a result of developing lymphedema. The purpose of this study was to preliminarily evaluate The Optimal Lymph Flow program, a patient-centered education and behavioral program focusing on self-care strategies to enhance lymphedema risk reduction by promoting lymph flow and optimize body mass index (BMI). A prospective, longitudinal, quasi-experimental design with repeated-measures was used. The study outcomes included lymph volume changes by infrared perometer, and BMI by a bioimpedance device at pre-surgery baseline, 2-4 weeks after surgery, 6-month and 12-month follow-up. A total of 140 patients were recruited and participated in The Optimal Lymph Flow program; 134 patients completed the study with 4% attrition rate. Fifty-eight percent of patients had axillary node dissection and 42% had sentinel lymph node biopsy (SLNB). The majority (97%) of patients maintained and improved their preoperative limb volume (LV) and BMI at the study endpoint of 12 months following cancer surgery. Cumulatively, two patients with SLNB and two patients with axillary lymph node dissection had measurable lymphedema (>10% LV change). At the 12-month follow-up, among the four patients with measurable lymphedema, two patients' LV returned to preoperative level without compression therapy but by maintaining The Optimal Lymph Flow exercises to promote daily lymph flow. This educational and behavioral program is effective in enhancing lymphedema risk reduction. The study provided initial evidence for emerging change in lymphedema care from treatment-focus to proactive risk reduction.

Influence of high-intensity interval training on peripheral and central blood pressure at rest and during a cold pressor test

Despite the progress of antihypertensive drug treatment, only about 30% of the treated patients achieve blood pressure control. These poor results could be partially due to the fact that the selection of antihypertensive agents is often done regardless of the hemodynamic profile of the patient. The purpose of our study is identification of the hemodynamic modulators (volemia, inotropy and vasoactivity) and hemodynamic status (medium arterial pressure MAP and stroke index SI) in uncontrolled hypertensive patients. We enrolled 25 uncontrolled hypertensive patients with essential hypertension treated with at least 2 antihypertensive drugs prescribed at optimal dose amounts. We implemented a thoracic electrical bioimpedance device (HOTMAN ) for noninvasive assessment of hemodynamic modulators and evaluation of the hemodynamic status of the patients. Systolic and diastolic BP averaged 155.62/93.04 mmHg. Among the whole study group, 52% were diagnosed as normodynamic, while 28% as hyperdynamic and 20% as hypodynamic. Modulators distribution: one abnormal hemodynamic modulator for 24%, two for 36% and three for 40% of the patients. Different combinations of hemodynamic modulators were present, the most common being concomitant hypervolemy, hypoinotropy and vasoconstriction in 32% of the patients. Two hemodynamic states correspond to this subgroup: hypodynamic in 50% and normodynamic in the other 50%. Antihypertensive drug distribution was: 68% used beta -blockers, 64 ACEI, 56% diuretics, 28% dihydropyridine CCB, 24% ARB. Careful analysis of all hemodynamic modulators should precede pharmacological treatment modification in order to achieve a normohemodynamic status. The clinical benefits potentially offered by a larger use of this technique in the daily management of patients require testing in future longitudinal outcome studies.

Volume overload correlates with cardiovascular risk factors in patients with chronic kidney disease

Volume overload is a predictor of mortality in dialysis patients. However, the fluid status of patients with chronic kidney disease (CKD) but not yet on dialysis has not been accurately characterized. We used the Body Composition Monitor, a multifrequency bioimpedance device, to measure the level of overhydration in CKD patients, focusing on the association between overhydration and cardiovascular disease risk factors. Overhydration was the difference between the amount of extracellular water measured by the Body Composition Monitor and the amount of water predicted under healthy euvolemic conditions. Volume overload was defined as an overhydration value at and above the 90th percentile for the normal population. Of the 338 patients with stages 3-5 CKD, only 48% were euvolemic. Patients with volume overload were found to use significantly more antihypertensive medications and diuretics but had higher systolic blood pressures and an increased arterial stiffness than patients without volume overload. In a multivariate analysis, male sex, diabetes, pre-existing cardiovascular disease, systolic blood pressure, serum albumin, TNF-α, and proteinuria were independently all associated with overhydration. Thus, volume overload is strongly associated with both traditional and novel risk factors for cardiovascular disease. Bioimpedance devices may aid in clinical assessment by helping to identify a high-risk group with volume overload among stages 3-5 CKD patients.

Thoracic bioelectrical impedance assessment of the hemodynamic reactions to recorded road-traffic noise in young adults

Noise exposure increases blood pressure in both experimental and field studies. The underlying mechanisms may be evaluated by thoracic bioelectrical impedance. The aim of this experimental study was to assess changes in blood pressure, cardiac and hemodynamic parameters provoked by recorded traffic noise in young adults. The study included 130 participants (42 men and 88 women), aged 24.88±2.67 years. Thoracic electrical bioimpedance device was applied to monitor cardiac parameters, hemodynamic parameters, heart rate variability, blood pressure and heart rate. The testing procedure consisted of three phases. Participants were exposed to recorded road-traffic noise (Leq=89dBA) for 10min and relaxed in quiet conditions (Leq=40dBA) before and after noise exposure. Listening to recorded noise resulted in significant decrease of stroke volume and cardiac output, and an increase of vascular resistance. Heart rate variability and the overall sympathovagal balance remained similar through all experimental conditions. During noise exposure, systolic pressure increased by 2mmHg among women (95% confidence interval=0.97–2.73mmHg), and by 4mmHg among men (95% confidence interval=2.16–5.00mmHg). Similarly, diastolic pressure increased by 2mmHg among women (95% confidence interval=0.95–2.47mmHg), and by 4mmHg among men (95% confidence interval=2.46–5.28mmHg). Once noise ceased, both pressures returned to pre-exposure levels. Experimental exposure to recorded road-traffic noise of 89dBA for 10min provoked significant hemodynamic changes in young adults, including vasoconstriction (increase of vascular resistance), and hypodynamics (decrease of global heart flow). The interaction of these effects resulted in the elevation of blood pressure during noise exposure.

Abstract P2-10-05: Lymphatic and pro-inflammatory candidate gene variations and breast-cancer related lymphedema

Abstract Background Traditionally, breast cancer-related lymphedema is considered to be mainly due to the mechanical injury from cancer surgery. Recent research identified that inflammation-infection may be one of the important predictors for breast cancer-related lymphedema. This pilot study aimed to explore the associations between lymphatic and pro-inflammatory candidate gene variations and lymphedema following breast cancer treatment. Methods A prospective, longitudinal, repeated-measure, and comparative design was used to recruit a sample of 178 breast cancer survivors. To ensure the accuracy of lymphedema phenotype, lymphedema was classified into two phenotypes: lymphedema of arm and breast. Arm lymphedema refers to swelling in the affected arm that must have been validated by infra-red perometer-S350 and a bioimpedance device. Breast lymphedema refers to swelling in the affected breast validated by self-report and an observational scale since no objective measure is available. Saliva samples were collected for DNA extraction from all the 178 participants. Candidate Gene Association Research Method was used to examine the eight genes known for inflammation and lymphatic specific growth factors, including candidate genes for inflammation, cytokines (IL1A, IL6, IL8, IL10, IL13) and PTGS2 (COX2), and lymphatic specific growth factors [VEGF-C &amp; D]. Descriptive statistics, Chi-Squared tests for contingency tables and one-way analysis of variance for continuous variables were used to compare the genotypes for each of these genes in patients with and without lymphedema. Odds ratios of developing lymphedema are estimated. Results Among 178 survivors, 39 women were confirmed to have arm lymphedema by infra-red perometer-S350 and a bioimpedance device and 43 women had breast lymphedema. Five genes were significantly associated with breast cancer-related lymphedema. Specific single nucleic polymorphisms (SNPs) for lymphatic specific growth factors VEGF-C (rs4604006) and cytokine IL13 (rs1800925) were related to arm lymphedema. Specific SNPs of cytokine IL1A (rs1800587) and PTGS2 (COX2) (rs20417) were associated with breast lymphedema. Conclusion Our findings provided preliminary data on genetic susceptibility as a risk factor for breast cancer-related lymphedema. Findings of our study may serve as a preliminary foundation for a priori recognition of genetic risk that may facilitate lymphedema risk prediction prior to surgery and raises the potential for early intervention for a high-risk group. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-10-05.

Lymphatic and proinflammatory candidate gene variations and lymphedema.

9 Background: Traditionally, breast cancer-related lymphedema is considered to be mainly due to the mechanical injury from cancer surgery. Recent research identified that inflammation-infection may be one of the important predictors for lymphedema. This pilot study aimed to explore the associations between lymphatic and pro-inflammatory candidate gene variations and lymphedema. Methods: A prospective, longitudinal, repeated-measure, and comparative design was used to recruit 178 breast cancer survivors. To ensure the accuracy of lymphedema phenotype, lymphedema was classified into lymphedema of arm and breast. Arm lymphedema must have been validated by infra-red perometer and a bioimpedance device. Breast lymphedema was validated by an observational scale since no objective measure is available. Saliva samples were collected for DNA extraction. Candidate Gene Association Research Method was used to examine the eight genes known for inflammation and lymphatic specific growth factors: cytokines (IL1A, IL6, IL8, IL10, IL13) and PTGS2 (COX2), and lymphatic specific growth factors [VEGF-C and D]. Descriptive statistics, Chi-Squared tests for contingency tables and one-way analysis of variance for continuous variables were used to compare the genotypes for each of these genes in patients with and without lymphedema. Odds ratios of developing lymphedema are estimated. Results: Among 178 survivors, 39 women were confirmed to have arm lymphedema and 43 women had breast lymphedema. Five genes were significantly associated with breast cancer-related lymphedema. Specific single nucleic polymorphisms (SNPs) for lymphatic specific growth factors VEGF-C (rs4604006) and cytokine IL13 (rs1800925) were related to arm lymphedema. Specific SNPs of cytokine IL1A (rs1800587) and PTGS2 (COX2) (rs20417) were associated with breast lymphedema. Conclusions: Our findings provided preliminary data on genetic susceptibility as a risk factor for breast cancer-related lymphedema. Findings of our study may serve as a preliminary foundation for a priori recognition of genetic risk that may facilitate lymphedema risk prediction prior to surgery and raises the potential for early intervention for a high-risk group.

Cardiac index assessment: Validation of a new non-invasive very low current thoracic bioimpedance device by thermodilution

Introduction. The accuracy of impedance cardiography for cardiac index assessment is matter of debate, with available studies reporting inconsistent results. Our study aimed at evaluating the agreement between measurements of cardiac index provided by a new-generation thoracic electrical bioimpedance device (Hotman System) and an invasive approach based on thermodilution in humans. Methods. Cardiac index was assessed simultaneously with thoracic electrical bioimpedance and conventional thermodilution through comparison of five consecutive measurements in 51 cardiac patients, hospitalized in an intensive care unit (mean± SD age: 60 ± 11 years; 68% males). The agreement between cardiac index values measured by both methods was assessed by the Bland–Altman approach, adjusted for repeated measures. The repeatability coefficient and the intraclass correlation coefficient were used to assess reproducibility of replicates. Results. Average (± SD) cardiac index was 3.05 ± 0.91 l/min/m2 with Hotman System and 3.14 ± 1.12 l/min/m2 with thermodilution. The bias of precision was −0.09 ± 0.41. The coefficients of repeatability and intraclass correlation coefficients were high and similar for the two techniques (0.95 l/min/m2 and 0.91 for Hotman System vs 0.78 l/min/m2 and 0.90 for thermodilution). Conclusions. Cardiac index values yielded by Hotman system compares favorably with that obtained with thermodilution in cardiac patients.

Evaluation of Nutritional Status in Renal Transplant Recipients in Accordance with Changes in Graft Function

Introduction and AimsRenal transplantation (RT) is the ultimate treatment modality for end-stage renal disease (ESRD) patients. Malnutrition is a strong predictor of cardiovascular disease among ESRD patients. Body composition analysis using bioimpedance devices (BIA) is a useful noninvasive tool to detect malnutrition in this population. We investigated the impact of graft function on nutritional status and reliability of BIA to detect malnutrition in RT recipients. MethodsWe evaluated retrospectively 189 RT recipients including 59 females, and of overall mean age of 38.3 ± 10.6 years who had a minimum posttransplant follow-up of 12 months. Body Composition Analyzer (Tanita BC-420MA) determinations were complemented with monthly assessments of biochemical parameters. Patients were divided into 3 groups according to glomerular filtration rate (GFR) levels: normal graft function/high GFR group (group 1, normal creatinine levels, no proteinuria and GFR ≥ 90 mL/min; n = 59); low renal function/low GFR group (normal or high creatinine levels with low GFR levels; group 2; GFR 89–60 mL/min; n = 87) and group 3, (GFR < 60 mL/min; n = 43). ResultsGroup 3 patients displayed significantly lower as well as hemoglobin albumin and calcium concentrations, with higher phosphorus and parathyroid hormone levels (P = .0001). They also showed significantly lower body weight (P = .0001), body mass index (P = .002), fat (P = .002) and muscle (P = .0001) contents as well as fat-free mass (P = .0001). Group 2 patients had significantly lower values compared with group 1 and higher values than group 3. GFR values positively correlated with albumin, fat, muscle, and fat-free mass (r = 0.337, 0.299, 0.281, 0.278, respectively; P = .0001). GFR values positively correlated with visceral fat ratio (r = 0.170; P = 0.02), body mass index (r = 0.253; P = .0001), and waist-hip ratio (r = 0.218; P = .006). ConclusionLoss of muscle and fat mass is an early sign of malnutrition among RT recipients. It is closely associated with loss of GFR. BIA is a noninvasive and reliable diagnostic tool that should be included in the follow-up of these patients for an early diagnosis of malnutrition-related complications.