Bioelectrical Impedance Analysis Phase Angle Research Articles

Nutritional Status of Coronary Artery Disease Patients-Preliminary Results.

Malnutrition is a condition that negatively impacts the clinical outcomes of numerous diseases. The aim of this study was to assess the nutritional status of coronary artery disease (CAD) patients and to investigate its relationship with the main clinical aspects of CAD. 50 CAD patients undergoing coronary angiography were enrolled in this study. The nutritional status assessment was based on Nutritional Risk Score 2002 (NRS 2002), body mass index (BMI), and bioelectrical impedance analysis (BIA) measurements. The analysis showed a moderate inverse correlation between NRS 2002 and BIA phase angle measured at 50 kHz (R: -0.31; p = 0.03) and Z200/5 parameter (R: 0.34; p = 0.02). The analysis of CAD clinical parameters showed a significant correlation between NRS 2002 and Canadian Cardiovascular Society (CCS) class (R: 0.37; p = 0.01). Left ventricle ejection fraction (LVEF) was correlated with BMI (R: 0.38; p = 0.02), however further BIA revealed hydration changes as LVEF was correlated to intracellular (ICF) and extracellular fluid (ECF) proportion: positively with ICF (R: 0.38; p = 0.02) and negatively with ECF (R: -0.39; p = 0.02). NRS 2002 and BIA are valuable tools for nutritional status assessment in CAD patients. Malnutrition is related to the severity of CAD symptoms, particularly in women. Maintaining proper nutritional status can have a potentially important role in this group of patients.

Obesity Affects the Association of Bioelectrical Impedance Phase Angle With Mortality in People Living With HIV.

Bioelectrical impedance analysis phase angle (BIA-PA) is a valid indicator of mortality risk in people living with HIV; however, it is not known whether BIA-PA is valid for people living with HIV who are overweight or obese. We assessed whether BIA-PA differentially predicted mortality by body mass index category in participants receiving clinical care at a single site between 2000 and 2012. Change in BIA-PA from the highest versus last available phase angle was assessed using multivariate logistic regression models. Eight hundred ninety participants were included in the final analyses, with 102 deaths recorded during the study period. Decline in BIA-PA was associated with mortality in underweight and normal weight participants but not in overweight or obese participants. Additional investigation is warranted to determine the appropriate clinical BIA-PA equations and parameters to identify overweight and obese patients with increased mortality risk.

SUN-P126: Bioelectrical Impedance Analysis Phase Angle as a Prognostic Marker for Outcome in Patients Admitted in Hospital with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

SUN-P126: Bioelectrical Impedance Analysis Phase Angle as a Prognostic Marker for Outcome in Patients Admitted in Hospital with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Malnutrition Assessment in Hemodialysis Patients: Role of Bioelectrical Impedance Analysis Phase Angle

To determine the most potent bioelectrical impedance analysis (BIA) marker of malnutrition and to adjust its application to hemodialysis (HD) patients. An observational study. A total of 99 patients on maintenance HD were enrolled in the study. The nutritional state of the patients was examined before and after the HD procedure using Subjective Global Assessment Scale (SGA), serum albumin, body mass index and BIA-derived fat-free mass index, reactance, resistance, and phase angle (PA). Malnutrition defined by the SGA questionnaire was used to detect the most potent marker of malnutrition. This marker was further analyzed and corrected for the excess fluid, age, and gender producing the nutritional state-specific cutoffs. The SGA rates of nutritional state were as follows: 57.6% (57) well nourished, 28.3% (28) moderately malnourished, and 14.1% (14) severely malnourished. Multivariate forward logistic regression analysis of the nutrition markers revealed PA as the most potent malnutrition predictor (odds ratio=3.69; 95% confidence interval [CI]: 1.59-8.62; P=.002). PA was adjusted for the excess fluid (5.00±0.97 vs 4.87±1.08 P< .001). Patients were assigned into groups with adjusted PA values below the 5th through the 50th percentile of the mean PA reference value. The moderately malnourished patients were most accurately identified by the percentile group of <25th (area under the curve=0.70; 95% CI: 0.60-0.81; P=.001), and the severely malnourished patients were most accurately identified by the percentile group of <15th (area under the curve=0.74; 95% CI: 0.62-0.85; P=.005). Malnutrition is present almost in a half of the HD patients. BIA-provided PA is the most potent predictor of malnutrition. PA can be adjusted for the excess fluid after HD, age, and gender and used accordingly.

Correlation of bioelectrical impedance analysis phase angle with changes in oxidative stress on end-stage renal disease patients, before, during, and after dialysis

Chronic kidney disease is a condition that promotes oxidative stress. There are conflicting evidence about the role of hemodialysis on oxidative stress, that are mostly related with the various types of membrane materials used, the quality and type of dialysate, the method used, etc. The phase angle (PhA), which is determined with bioelectrical impedance analysis (BIA), measures the functionality of cell membranes. In this study, the correlation of the PhA with parameters of oxidative stress is attempted for the first time. We evaluated parameters of oxidative status as total antioxidant capacity (TAC) in erythrocytes (RBCs) and plasma of patients with ESRD undergoing hemodialysis with low flux synthetic polysulfone membranes. Measurements were recorded from 30 patients (16 men and 14 women) aged 64 ± 14 years before, during, and after dialysis, and in 15 healthy volunteers aged 56 ± 12 years The PhA was obtained by BIA. The plasma TAC increased significantly (41%, p < 0.05). Intracellular TAC noted a non-significant increase. Total antioxidant capacity of the patients before and after hemodialysis was significantly lower from the healthy volunteers (p < 0.05) showing that ESRD patients are at the state of increased oxidative stress. The PhA increased in significantly positive correlation with plasma TAC at the end of hemodialysis. The process of hemodialysis with biocompatible synthetic membranes and bicarbonate dialysate improved plasma TAC. The positive correlation of PhA with extracellular TAC could evolve to a method of oxidative stress estimation by BIA but further research is needed.

Preoperative risk factors of malnutrition for cardiac surgery patients.

Background.Malnutrition (MN) is prevalent in cardiac surgery, but there are no specific preoperative risk factors of MN. The aim of this study is to assess the clinically relevant risk factors of MN for cardiac surgery patients.Materials and methods.The nutritional state of the patients was evaluated one day prior to surgery using a bioelectrical impedance analysis phase angle (PA). Two groups of patients were generated according to low PA: malnourished and well nourished. Risk factors of MN were divided into three clinically relevant groups: psychosocial and lifestyle factors, laboratory findings and disease-associated factors. Variables in each different group were entered into separate multivariate logistic regression models.Results.A total of 712 patients were included in the study. The majority of them were 65-year old men after a CABG procedure. Low PA was present in 22.9% (163) of patients. The analysis of disease-related factors of MN revealed the importance of heart functions (NYHA IV class OR: 3.073, CI95%: 1.416–6.668, p = 0.007), valve pathology (OR: 1.825, CI95%: 1.182–2.819, p = 0.007), renal insufficiency (OR: 4.091, CI95%: 1.995–8.389, p < 0.001) and body mass index (OR: 0.928, CI95%: 0.890–0.968, p < 0.001). Laboratory values related to MN were levels of haemoglobin (OR: 0.967, CI95%: 0.951–0.983, p < 0.001) and C-reactive protein (OR: 1.015, CI95%: 1.002–1.028, p = 0.0279). The lifestyle variables that qualified as risk factors concerned the intake of food (OR: 3.030, CI95%: 1.353–6.757, p = 0.007) and mobility (OR: 2.770, CI95%: 1.067–7.194, p = 0.036).Conclusions.MN risk factors comprise three different clinical groups: psychosocial and lifestyle factors, laboratory findings and disease-associated factors. The patients who are most likely to be malnourished are those with valve pathology, severe imparted heart function, insufficient renal function and high inflammatory markers. Also these patients have decreased mobility and food intake.

Estimating GFR Among Participants in the Chronic Renal Insufficiency Cohort (CRIC) Study

Glomerular filtration rate (GFR) is considered the best measure of kidney function, but repeated assessment is not feasible in most research studies. Cross-sectional study of 1,433 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study (ie, the GFR subcohort) to derive an internal GFR estimating equation using a split-sample approach. Adults from 7 US metropolitan areas with mild to moderate chronic kidney disease; 48% had diabetes and 37% were black. CRIC GFR estimating equation. Urinary (125)I-iothalamate clearance testing (measured GFR [mGFR]). Laboratory measures, including serum creatinine and cystatin C, and anthropometrics. In the validation data set, the model that included serum creatinine level, serum cystatin C level, age, sex, and race was the most parsimonious and similarly predictive of mGFR compared with a model additionally including bioelectrical impedance analysis phase angle, CRIC clinical center, and 24-hour urinary creatinine excretion. Specifically, root mean square errors for the separate models were 0.207 versus 0.202, respectively. Performance of the CRIC GFR estimating equation was most accurate for the subgroups of younger participants, men, nonblacks, non-Hispanics, those without diabetes, those with body mass index <30 kg/m(2), those with higher 24-hour urine creatinine excretion, those with lower high-sensitivity C-reactive protein levels, and those with higher mGFRs. Urinary clearance of (125)I-iothalamate is an imperfect measure of true GFR; cystatin C level is not standardized to certified reference material; lack of external validation; small sample sizes limit analyses of subgroup-specific predictors. The CRIC GFR estimating equation predicts mGFR accurately in the CRIC cohort using serum creatinine and cystatin C levels, age, sex, and race. Its performance was best in younger and healthier participants.

Phase angle, an alternative physiological tool to assess wound treatment in chronic nonhealing wounds.

This exploratory study was conducted in an effort to demonstrate that bioelectrical impedance analysis (BIA) phase angle measurement is a novel tool for monitoring the effectiveness of a wound care regimen at a regional level and is valuable in comparing that status with the overall metabolic health of the patient. Isolating and measuring the extent to which nutritional supplementation contributes to the healing process is difficult and confounded by the many treatment modalities patients undergo. The authors conducted a limited exploratory study to determine whether regional phase angle measurements accurately reflected the status of chronic nonhealing wounds. This information would potentially provide the ability to quantitatively evaluate of the role of nutritional supplementation in wounds of varying etiologies by comparing regional BIA phase angle measurement with overall BIA phase angle measurement. Eleven patients with wounds of varying etiologies were selected to participate. Each patient underwent a treatment regimen specific to his or her condition, and all patients were given JUVEN(®) nutritional supplement. In all patients, the BIA phase angle measurement mirrored the health of the wound and provided an accurate tool for assessing the regional tissue health, a valuable insight in measuring the effectiveness of a systemic treatment.

Strong Association between Nutritional Markers and Arterial Stiffness in Continuous Ambulatory Peritoneal Dialysis Patients

Background: Malnutrition is a predictor of cardiovascular disease in dialysis patients, but the mechanisms remain unknown. We investigated links between nutritional markers and arterial stiffness in continuous ambulatory peritoneal dialysis patients. Methods: We evaluated the relationship between arterial stiffness evaluated by pulse-wave velocity (PWV) and four estimates of nutritional status (serum albumin, handgrip strength [HGS], subjective global assessment [SGA], and bioelectrical impedance analysis phase angle [PA]) in 124 PD patients. Results: Malnourished patients exhibited a significantly higher PWV than those classified as well-nourished by SGA (p < 0.05). Furthermore, PWV correlated negatively with albumin, HGS and PA (p < 0.001, respectively). PWV was also correlated with age, systolic blood pressure, and C-reactive protein. In multivariate regression analysis, albumin, HGS, SGA and PA were each independently associated with PWV after adjustment. Conclusions: The significant association between each nutritional marker and PWV in PD patients was independent of inflammation and diabetic state, suggesting that malnutrition may contribute to vascular dysfunction.