Phase Angle as a Marker of Muscular Strength in Breast Cancer Survivors

Association of skeletal muscle quantity and quality with mortality in women with nonmetastatic breast cancer

Women with breast cancer are predisposed to muscle mass loss, to compromised muscle quality, and to decreased strength, and these abnormalities may serve as important predictors of adverse outcomes, including mortality. The aim of this study was to evaluate the possible associations between muscle mass markers, assessed by computed tomography with the phase angle (PhA) obtained by Bioelectrical impedance analysis (BIA), and health outcomes in women with breast cancer.

METHODS

retrospective study with 54 women newly diagnosed with breast cancer, aged ≥ 18 years and < 65 years; histologically confirmed diagnosis of early breast cancer (stage I-III range), and in the first chemotherapy-cycled treatment. Measurements performed: anthropometric assessments, BIA, third lumbar vertebra by computed tomography (CT) and physical function (handgrip strength, gait speed test 4 m, fatigue assessment), and blood biochemical analysis.

RESULTS

Lower skeletal muscle index were correlated with reduced PhA values (R² = 0.222, p = 0.0047), suggesting a worse prognosis. Logistic regression analysis showed that individuals with low muscle mass had a significantly lower likelihood of survival compared to those with normal muscle mass regardless of age and cancer stage.

CONCLUSION

low muscle mass negatively affected patient survival and was associated with lower PhA values. Phase angle emerges as a promising marker of overall health and could be a valuable clinical tool in assessing prognosis.

Phase Angle and Ultrasound Assessment of the Rectus Femoris for Predicting Malnutrition and Sarcopenia in Patients with Esophagogastric Cancer: A Cross-Sectional Pilot Study

BACKGROUND

Disease-related malnutrition (DRM) and sarcopenia are prevalent conditions in gastrointestinal cancer patients, whose early diagnosis is essential to establish a nutritional treatment that contributes to optimizing adverse outcomes and improving prognosis. Phase angle (PhA) and rectus femoris ultrasound measurements are considered effort-independent markers of muscle wasting, which remains unrecognized in oncology patients.

OBJECTIVE

This study aimed to evaluate the potential utility of PhA, rectus femoris cross-sectional area (RFCSA), and rectus femoris thickness (RF-Y-axis) in predicting malnutrition and sarcopenia in patients with esophagogastric cancer (EGC).

METHODS

This was a cross-sectional study of patients diagnosed with EGC. PhA was obtained using bioelectrical impedance vector analysis (BIVA) along with ASMMI. The RFCSA and RF-Y-axis were measured using nutritional ultrasound (NU®). Muscle capacity was assessed using handgrip strength (HGS), and functionality by applying the Short Physical Performance Battery (SPPB). Malnutrition and sarcopenia were determined according to the GLIM and EWGSOP2 criteria, respectively.

RESULTS

Out of the 35 patients evaluated, 82.8% had malnutrition and 51.4% had sarcopenia. The RFCSA (r = 0.582) and RF-Y-axis (r = 0.602) showed significant, moderate correlations with ASMMI, unlike PhA (r = 0.439), which displayed a weak correlation with this parameter. However, PhA (OR = 0.167, CI 95%: 0.047-0.591, p = 0.006), RFCSA (OR = 0.212, CI 95%: 0.074-0.605, p = 0.004), and RF-Y-axis (OR = 0.002, CI 95%: 0.000-0.143, p = 0.004) all showed good predicting ability for sarcopenia in the crude models, but only the RF-Y-axis was able to explain malnutrition in the regression model (OR = 0.002, CI 95%: 0.000-0.418, p = 0.023).

CONCLUSIONS

The RF-Y-axis emerged as the only independent predictor of both malnutrition and sarcopenia in this study, likely due to its stronger correlation with ASMMI compared to PhA and RFCSA.

Phase angle as a potential tool to evaluate chronic inflammatory state and predict quality of life deterioration in women with breast cancer and obesity: A narrative review

The interaction between lifestyle--defined more specifically in health care as the personal exposome--and its implications on obesity and breast cancer development highlights the critical role of body composition and inflammation in these patients. There is clear evidence that the personal and internal exposome triggers biochemical, inflammatory, and metabolic reprogramming, which might favor ectopic lipid accumulation within the body, such as muscles. Additionally, the presence of excessive adipose tissue exacerbates these alterations in the internal exposome, resulting in cell damage and modifying body composition. Understanding the nexus between these lifestyle-induced exposome modifications, such as inflammation, and the resultant changes in body composition is crucial to assess the association with breast cancer progression and treatment responses. Various techniques can be used to evaluate body composition; one of those most used currently is bioelectrical impedance analysis. This analysis provides parameters, including phase angle (PhA), by which cellular health and metabolic activity can be assessed. In addition, PhA is a potential indicator of nutritional status and disease prognosis, as it has been linked to survival and quality of life in patients with cancer. Therefore, PhA might be used in daily oncology practice to implement an accurate nutritional intervention, reducing side effects and complications of oncology management, and improving quality of life during treatment and survival, even in patients with breast cancer with obesity or overweight. The aim of this review is to analyze the existing information on the current application of PhA in patients with breast cancer and its potential use as a tool to assess inflammatory response, identify malnutrition, and predict the deterioration of quality of life so that it could be proposed as an early indicator for nutritional interventions in this group of patients.

Maximal Running Speed and Critical Speed Are Positively Related to Phase Angle in Healthy Young Adults

Phase Angle (PhA), derived from bioelectrical impedance analysis, is a measurement of cellular resistance to electrical current and a non-invasive tool to monitor neuromuscular performance. The relationship between PhA and components of athletic performance is not fully understood. The purpose of this study was to determine if maximal running speed, critical speed (CS), and/or D prime (D') derived from a 3-minute all-out-test (3MAOT) correlates to PhA, reactance (Xc), or resistance (R). Sixty-one (male n=35, female n=26) healthy young adults (23.4±3.9 years) completed bioelectrical impedance analysis (Inbody770) and a 3MAOT. The correlations between PhA, Xc, and R and 3MAOT results were evaluated using correlations. Simple and multiple linear-regressions were used to test if results from the 3MAOT (maximum running speed, CS, D') could predict PhA. Linear regression analysis indicated that maximum running speed and CS alone explained 32% and 9% of the variance in PhA, respectively (R2=0.32, p<0.05; R2=0.09, p<0.05). Multiple linear regression indicated that maximum running speed, CS, and D' explained 35% of the variance in PhA (R2=0.35; p<0.05). Only maximum running speed remained a significant predictor of PhA after controlling for age (β=0.45; p<0.05), but not after controlling for both age and sex (β=0.14; p>0.05). Since maximum running speed was a stronger predictor of PhA compared to CS (proxy for endurance performance), practitioners should use discernment when using PhA as a readiness tool to monitor endurance performance.

Limb-specific isometric and isokinetic strength in adults: The potential role of regional bioelectrical impedance analysis-derived phase angle

BACKGROUND & AIMS

It is not yet known whether regional bioelectrical impedance (BIA) phase angle (PhA) may be informative of different types of strength performed by the lower and upper limbs, independently of lean soft tissue mass (LSTM). Using a sample of healthy adults, we aimed to examine the association and relevance of regional PhA relative to isometric and isokinetic strength of each limb.

METHODS

A total of 57 participants (32.7 ± 12.9 years; 24.7 ± 3.5 kg/m2) were included in the present investigation. Regional raw BIA variables were determined using a phase-sensitive BIA device. Dual-energy X-ray absorptiometry was used to evaluate LSTM. Absolute isometric and isokinetic (i.e., 60°/s and 180°/s) strength of each limb (extension and flexion) was assessed using an isokinetic dynamometer and used to calculate relative strength.

RESULTS

In absolute strength, only dominant leg PhA was associated with isometric extension strength (β = 0.283) and isokinetic 180°/s flexion strength (β = 0.354), regardless of LSTM (p < 0.05). In relative strength, a significant association of regional PhA was found for dominant arm flexion isometric strength (β = 0.336), and non-dominant arm and dominant leg extension isometric strength (β = 0.377, β = 0.565, respectively; p < 0.05), independently of LSTM. Similarly, for isokinetic 180°/s strength, regional PhA significantly explained the variance in the relative strength of both arms and dominant leg (β = 0.350 to 0.506), regardless of LSTM (p < 0.05). Relative isokinetic 60°/s strength was not consistently associated with regional PhA (p ≥ 0.05).

CONCLUSIONS

Regional PhA significantly explained relative (isometric and 180°/s isokinetic strength of both arms and dominant leg), but not absolute muscle strength, independently of regional LSTM. Thus, after accounting for body size, regional PhA seems to have its own characteristics that explain relative strength independently of LSTM.

Phase angle is related to physical function and quality of life in preoperative patients with lumbar spinal stenosis

Lumbar spinal stenosis (LSS) can interfere with daily life and quality of life (QOL). Evaluating physical function and QOL and helping patients to improve is the focus of rehabilitation. Phase angle (PhA) assessment is widely used to measure body composition and is considered an indicator of physical function and QOL. This study investigated the relationship between PhA and physical function, physical activity, and QOL in patients with LSS. PhA, handgrip strength, walking speed, Timed Up and Go test (TUG), Life Space Assessment (LSA), Prognostic Nutritional Index (PNI), Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and EQ-5D were assessed and statistically analyzed. The study included 133 patients with LSS. Multiple regression analysis of PhA adjusted for age, sex, and body mass index (Model 1) and for Model 1 + PNI (Model 2) showed significant correlations (P < 0.05) with handgrip strength, walking speed, TUG, and LSA. Regarding QOL, PhA was significantly correlated (P < 0.05) with lumbar function in JOABPEQ. PhA was associated with physical function and QOL in patients with LSS and might be a new clinical indicator in this population.

Association between Phase Angle and Subjective Perceptions of Health Variables in Cancer Patients

The phase angle, an increasingly studied healthcare tool, was studied to explore its relationship with psychological factors in cancer patients. The aim of this study was to investigate the relationship between the phase angle (PhA), obtained by the bioimpedance analysis of body composition, and psychological factors measured by questionnaire in cancer patients. The study included 311 patients who underwent bioimpedance testing to determine their PhA value; their psychological profiles were assessed using SF-36, FACIT, QLQ-C30, and GHQ-12 questionnaires. Mixed linear regression models were used to analyze the relationship between PhA and the psychological tests. The results showed a statistical correlation between PhA and the GHQ-12, FACIT, and SF-36 questionnaires, with higher PhA values associated with better results on the questionnaires. In the QLQ-C30 questionnaire, a correlation was observed between PhA and the functioning scales (p < 0.001), except for emotional and cognitive functioning (p = 0.148 and p = 0.544, respectively), but not in most of the symptom scales. The PhA is a useful tool for assessing the subjective health perception of cancer patients, especially with regard to psychological factors. While there is a statistically significant correlation, further research is required before confidently applying it in clinical practice. The current predictive value of this predictor for certain psychological aspects is limited, underscoring the need for additional research.

Differences in the Relationships Between Muscle Strength, Muscle Mass, Balance Function, and Quality of Life for Middle-Aged and Older Breast Cancer Survivors

PURPOSE

The purpose of this study was to investigate the differences in muscle strength, muscle mass, balance function, and quality of life (QOL) among middle-aged breast cancer survivors (BCSs) and older BCSs.

METHODS

The study included 53 middle-aged (<65 years old) BCSs and 49 older (≥65 years old) BCSs. Muscle strength was evaluated via handgrip and knee extensor strength, and muscle mass was assessed using a body composition test. Balance function was assessed using the Timed Up and Go test and the body sway test. QOL was assessed using the Medical Outcome Study 36-item Short-Form Health Survey.

RESULTS

The older BCSs had significantly lower right grip strength, right knee extension strength, and muscle mass (P < .05) than the middle-aged BCSs. In addition, the body sway test showed that older BCSs had a significant increase in the length of center of pressure compared to middle-aged BCSs (P < .05). Older BCSs showed significantly lower physical functioning subscales in QOL compared to middle-aged BCSs (P < .05). The associations among muscle strength, muscle mass and QOL were more significantly observed in the older BCSs (P < .05). Furthermore, a significant correlation between QOL and balance function was observed in the older BCSs, but not in the middle-aged BCSs (P < .05).

CONCLUSION

There may be associations among muscle strength, muscle mass, balance and QOL in older BCSs, but not in middle-aged BCSs. We believe that the findings of this study will be relevant in the context of planning rehabilitation for older BCSs.

Exercise-Based Cancer Rehabilitation Program Improves Phase Angle in Breast Cancer Survivors

Phase angle (PhA) is an index of cell membrane integrity and prognostic indicator of survival and quality of life in cancer survivors. The efficacy of exercise-based cancer rehabilitation programs (ExCR) on PhA is unknown. To assess the effect of ExCR on PhA in breast cancer survivors. Fifty-nine female breast cancer survivors (61 ± 9 years) were referred to the ExCR by their oncologist and participated in one-on-one exercise-based training for 90 minutes, 3 times a week, for 12 weeks. Training sessions included 45 minutes of resistance training at intensities between 40-85% of 1-repetition maximum with a rate of perceived exertion (RPE) between 3-8, 30 minutes of cardiorespiratory training at intensities between 40-85% of heart rate reserve with an RPE between 3-8, and 15 minutes of flexibility training. Participants completed pre- and post-measurements of body composition, cardiorespiratory endurance, flexibility, muscular endurance, muscular strength, and PhA (Inbody 770). PhA significantly increased (p < 0.05) after ExCR (PhApre = 4.56; PhApost = 4.64; Δ = 1.8%). Changes in measures of muscular strength have a weak but significant positive relationship (r = 0.20-0.39; p < 0.05) with changes in PhA. There was no relationship between changes in PhA and changes in cardiorespiratory endurance or muscular endurance. A 12-week ExCR significantly improves PhA in breast cancer survivors. Training muscular strength may be an integral component of ExCR with the objective of improving PhA.

Phase angle of bioimpedance at 50 kHz is associated with cardiovascular diseases: systematic review and meta-analysis

The phase angle of bioimpedance is an important prognostic tool in clinical practice. The aim of this study was to investigate the association between phase angle and cardiovascular diseases. Electronic searches were carried out on MEDLINE, EMBASE, Cochrane, SCIELO, LILACS, CINAHL, Scopus, and the Web of Science. The PECO was "P" adults over 18 years of age, "E" the presence of cardiovascular disease, "C" absence of cardiovascular disease, and "O" phase angle values. The phase-angle means difference (MD) was analyzed separately by sex. Subgroup metanalysis with age, body mass index, and heart failure disease and meta-regressions were analyzed with random-effects models. Sensitivity analysis was performed considering only studies with high quality. The heterogeneity among studies was assessed using the Q-Cochran test and I² statistics. Four-hundred-thirty-nine articles were identified, and 22 studies were included in this systematic review, totaling 10.010 participants. Eight studies met the criteria for the meta-analysis, involving 2164 participants. The phase angle (PA) was measured at 50 kHz frequency in all studies. Individuals with cardiovascular disease had a smaller PA compared to the control group, for both males (MD -0.70; 95% CI -1.01 to -0.39) and females (MD -0.76; 95% CI -1.39 to -0.13). In the sensitivity analysis, in men, the quality of studies (P < 0.01), and in women, heart failure (P < 0.01) was significantly different between groups.The values of the phase angle were lower in individuals with cardiovascular disease than in control subjects. This result reinforces the importance of this tool in clinical practice, highlighting its potential to assess health status. Registration: The systematic review protocol was registered in the PROSPERO database as CRD42020164178.

Bioelectrical Phase Angle in Patients with Breast Cancer: A Systematic Review

Simple Summary

Breast cancer (BC) patients suffer from loss of muscle tissue and fluid alterations during the whole trajectory of the disease. Such alterations might be reflected by phase angle (PhA) measures, but its use in the oncologic setting is still limited. Therefore, the aim of this systematic review was to assess PhA in BC patients, since it has been proven to be a reliable index for predicting nutritional status and survival. Findings reveal that PhA decreases after chemotherapy in BC patients, with high results in women with a better nutritional status, and these changes may persist even after five years. However, PhA remains stable, or can increase in some cases, when patients are supported by targeted lifestyle interventions. Thus, PhA can be useful to identify and monitor changes in body compartments and the nutritional status of BC patients over time.

Abstract

Breast cancer (BC) is the most common cancer diagnosed among women worldwide. Phase angle (PhA), a proxy measure of membrane integrity and function, has gained relevance in clinical practice and it has been suggested to be a prognostic and nutritional indicator. This systematic review aimed to explore PhA and its relationship with nutritional status and survival in BC patients. Four databases (PubMed, EMBASE, Web of Science, and CINAHL) were systematically searched until September 2021 for studies evaluating PhA in BC patients. A total of 16 studies met the inclusion criteria, where 11 were observational studies and 5 were interventional studies. Baseline PhA-value varied from 4.9 to 6.30 degrees, showing a great variability and heterogeneity across the selected studies. Available data suggested that PhA decreased by 5–15% after completing chemotherapy, and those effects might persist in the long term. However, the use of tailored nutritional and/or exercise programs during and after therapy could prevent PhA reduction and body derangement. High PhA values were found in women displaying a better nutritional status, while inconsistent data were found on survival. Therefore, further studies are needed to focus on the clinical relevance of PhA in BC patients, evaluating its association with disease outcomes and survival.

Can Phase Angle Be Associated With Muscle Strength in Healthy Male Army Cadets?

INTRODUCTION

Phase angle (PhA) determined by bioelectrical impedance (BIA) is related to body fluid balance and cell membrane integrity. Handgrip strength (HGS) is used to assess muscle strength and as an indicator of health. We aimed to determine the relationship between PhA and HGS in healthy young males and to verify whether this relationship is dependent on body components.

MATERIALS AND METHODS

Hundred and sixty-three healthy male army cadets (18.8 ± 0.6 years old) participated in the study. PhA was determined by BIA, HGS was assessed by a hydraulic dynamometer, and dual-energy X-ray absorptiometry determined: fat mass (FM), bone mineral content (BMC), and lean soft tissue (LST). Participants were divided according to the PhA tertile (first tertile: PhA < 7.14°, second tertile: 7.14° ≤ PhA < 7.83°, and third tertile: PhA ≥ 7.83°).

RESULTS

Youth from the first tertile of PhA had lower BMC (2.8 kg vs. 3.0 kg and vs. 3.1 kg) and LST (51.7 vs. 53.8 kg and vs. 57.6 kg) compared to youth from the second and third tertile of PhA (P < .001), respectively. Additionally, lower HGS (83.0 kg vs. 93.1 kg) was found in the first tertile compared to the third tertile of PhA (P < .001). PhA explained 3% of the HGS variation (R2 = 0.029), while LST and BMC explained 39% (R2 = 0.385) and 22% (R2 = 0.221), respectively. Furthermore, the correlation between PhA and HGS was dependent on LST (P = .567) and BMC (P = .182).

CONCLUSION

In this sample, PhA showed a small relationship with HGS, remaining dependent on BMC and LST values. These results reinforce the importance of maintaining a physically active lifestyle with great lean mass and muscle strength values.

Effect of exercise on phase angle in cancer patients: a systematic review

INTRODUCTION

Body composition is one of the main variables of interest in clinical practice in cancer patients. Specific markers from bioelectrical impedance analysis, such as phase angle (PhA), have been assuming increasing relevance in this population. The aim of the present systematic review was to study and systematise the effect of exercise on PhA in cancer survivors, as compared to control conditions, namely usual care, with no exercise. The effect of exercise on PhA in the population of cancer survivors is not yet established. EVIDENCE ACQUISITIONː This systematic review was conducted on October 13, 2021, through PubMed, Web of Science, Wiley Online Library, Directory of Open Access Journals, Science Direct and JSTOR, following PRISMA guidelines and PICOS model that include: cancer survivors with ≥18 years; intervention of any exercise program for the target group; comparison between intervention group and control group that followed control conditions, namely usual care, with no exercise; outcome related to PhA; and studies of randomized control trials.

EVIDENCE SYNTHESIS

We founded a total of 1244 publications, using selected keywords. Eight studies were included in this systematic review, after inclusion/exclusion criteria considered. Compared with the control conditions, exercise training programs seem associated with a positive effect on PhA, both in solid tumours and haematologic cancer types, but only when using resistance exercise alone. According to the best evidence synthesis criteria, we could not conclude the superiority of any exercise program analysed in the value of the PhA.

CONCLUSIONS

There were several exercise details that may have potential to be beneficial for PhA in cancer patients, including an early start of the exercise intervention (during treatment and immediately after discharge from hospital), the use of resistance exercise or/and aerobic exercise, and mainly a long follow-up period (≥ 4 months) to verify the structural effects of exercise on the PhA. However, there were no effects on the PhA value immediately after the intervention, regardless of the type of protocol and the intervention time.

Association of phase angle with muscle strength and aerobic fitness in different populations: A systematic review

OBJECTIVES

The aim of this study was to summarize the evidence on the association of phase angle (PhA) with muscle strength and aerobic fitness in different populations.

METHODS

A systematic search on this topic was performed in nine electronic databases (CINAHL, LILACS, PubMed, SciELO, Scopus, SPORTDiscus, ScienceDirect, MEDLINE, and Web of Science) in January 2021. Studies with different designs that permitted extraction of information about the relationships between PhA and muscle strength and between PhA and aerobic fitness were included. A total of 4446 studies were initially identified; 34 were included after reading of the title, abstract, full text, and references. Four of the studies included had a longitudinal design, with samples consisting of participants ages 6 to 92 years. Thirty-two of the 34 studies evaluated the relationship between PhA and muscle strength, two cross-sectional studies investigated only PhA and aerobic fitness, and three cross-sectional studies evaluated both components (muscle strength and aerobic fitness).

RESULTS

PhA was directly associated with muscle strength in 30 cross-sectional studies and two longitudinal studies; the two studies that did not find a direct relationship had a cross-sectional design. For aerobic fitness, the five studies identified reported a direct relationship with PhA.

CONCLUSIONS

PhA is directly associated with muscle strength and aerobic fitness in different age groups (children, adolescents, adults, and older adults) and in people with different health conditions (human immunodeficiency virus, Crohn's disease, chronic obstructive pulmonary disease, bariatric surgery, kidney transplant, cancer, hemodialysis, and sarcopenia).

Physical Activity for Health and Wellness

Regular physical activity (PA) is both a preventive measure and a cure for non-communicable diseases (NCDs) [...].

Phase angle as a marker for muscle abnormalities and function in patients with colorectal cancer

BACKGROUND AND AIMS

Considering the applicability of phase angle (PhA) as a marker of muscle mass and function, we aimed to investigate whether PhA is a predictor of muscle abnormalities and function in patients with cancer.

METHODS

In a sample of patients with colorectal cancer (CRC), PhA was obtained from measurements of resistance and reactance from bioelectrical impedance analysis. Computerized tomography imaging at the third lumbar vertebra was used to evaluate muscle abnormalities by quantifying skeletal muscle index (SMI) and skeletal muscle radiodensity (SMD). Muscle function was assessed by handgrip strength (HGS) and gait speed (GS).

RESULTS

This cross-sectional study included 190 participants (X±SD), mean age 60.5 ± 11.3 years; 57% men; 78% had cancer stages III to IV. PhA was highly correlated with SMI (r = 0.70) and moderately correlated with HGS (r = 0.54). PhA explained 48% of the SMI variability (R² = 0.485), 21% of the SMD variability (R² = 0.214), 26% of HGS (R² = 0.261) and 9.8% of GS (R² = 0.098). In the multivariate model adjusted for age, sex, body mass index, performance status, comorbidities and cancer stage, 1-degree decrease in PhA was associated with low SMI (Odds Ratio (OR) = 6.56, 95% CI: 2.90-14.86) and with low SMI and HGS combined (OR = 11.10, 95% CI: 2.61-47.25). In addition, Receiving Operating Characteristics curve analysis showed that PhA had a good diagnostic accuracy for detecting low SMI, low SMI and SMD combined, low SMD and HGS and low SMI and HGS combined (AUC = 0.81, 95% CI: 0.74-0.88; AUC = 0.88, 95% CI: 0.81-0.95; AUC = 0.80, 95% CI: 0.70-0.91; AUC = 0.82, 95% CI: 0.74-0.89; respectively).

CONCLUSIONS

PhA was a predictor of muscle abnormalities and function and had a good diagnostic accuracy for detecting low muscle mass, low muscle mass and radiodensity, low muscle radiodensity and strength, and low muscle mass and strength in patients with CRC.

Phase angle cutoff value as a marker of the health status and functional capacity in breast cancer survivors

Accurate predictive tools are key factors for cancer care. Phase angle (PhA) has been proposed as a marker of cellular health, particularly of cell-membrane integrity. Cutoff values have been proposed, including for cancer survivors. This study aimed to assess the usefulness of the proposed PhA cutoff, as a marker of bioelectrical impedance analysis (BIA) assessed health-status, and functional capacity in breast cancer (BC) survivors. This cross-sectional study included 25 women (50.6 ± 8.6 yrs) survivors of BC, divided into two groups according to the PhA reference value of 5.6° (group 1 [G1]: PhA ≤ 5.6° [n=13]; group 2 [G2]: PhA > 5.6° [n=12]) (Gupta et al. 2008). BIA-assessed health status parameters included: extracellular water (ECW), intracellular water (ICW), total body water (TBW), PhA, body mass, fat-free mass, muscle mass, body cell mass (BCM). Four functional tests were performed: 30 s chair-stand test, timed up and go test, ball throw test and 6-minute walking test. Results showed G2 had lower ECW/ICW ratio (p=0.001; ES=1.2), ECW/BCM ratio (p=0.001; ES=3.2) and ECW/TBW ratio (p=0.001; ES=4.8). There was no difference in functional capacity between groups. The results of the present study show that patients with higher PhA values have a higher ICW values and preservation in the ECW/ICW ratio, suggesting it's a better cell membrane quality and integrity. Relation of both PhA and cell membrane integrity with functional capacity warrants further research.

Bioelectrical Impedance Vector Analysis: A Valuable Tool to Monitor Daily Body Hydration Dynamics at Altitude

Bioelectrical impedance vector analysis (BIVA) is a method used to estimate variation in body hydration. We assessed the potential of BIVA for monitoring daily body hydration fluctuations in nine healthy, normally active males under matching normoxic (NX) and hypobaric hypoxic (HH) experimental conditions. Furthermore, we aimed to investigate whether changes in BIVA may correspond with the development of acute mountain sickness (AMS). Subjects were exposed in a hypobaric chamber to both NX (corresponding to an altitude of 262 m) and HH conditions corresponding to an altitude of 3500 m during two four-day sojourns within which food, water intake and physical activity were controlled. Bioimpedance and body weight measurements were performed three times a day and medical symptoms were assessed every morning using the Lake Louise score (LLS). Total body water (TBW) was also assessed on the last day of both sojourns using the deuterium dilution technique. We detected circadian changes in vector length, indicating circadian body water variations that did not differ between NX and HH conditions (ANOVA effects: time: p = 0.018, eta2 = 0.149; interaction: p = 0.214, eta2 = 0.083; condition: p = 0.920, eta2 = 0.001). Even though none of the subjects developed AMS, four subjects showed clinical symptoms according to the LLS during the first 24 hours of HH conditions. These subjects showed a pronounced (Cohen's d: 1.09), yet not statistically significant (p = 0.206) decrease in phase angle 6 hours after exposure, which may indicate fluid shift from the intracellular to the extracellular compartment. At the end of each sojourn, vector length correlated with deuterium dilution TBW "gold standard" measurements (linear regression: NX: p = 0.002 and r2 = 0.756, HH: p < 0.001 and r2 = 0.84). BIVA can be considered a valuable method for monitoring body hydration changes at altitude. Whether such changes are related to the development of clinical symptoms associated with AMS, as indicated in the present investigation, must be confirmed in future studies.

Segmental Phase Angle and Body Composition Fluctuation of Elite Ski Jumpers between Summer and Winter FIS Competitions

(1) Background: The purpose of this study was to observe segmental phase angle (PhA) and body composition fluctuation of elite ski jumpers. (2) Methods: In the study, 12 professional ski jumpers took part. Body composition was estimated with segmental multi-frequency bioelectrical impedance analysis. Repeated ANOVA was used to check the parameters' variability in time. The symmetry between the right and left side of the body was verified with the t-test for dependent samples. Pearson's linear correlation coefficient was calculated. (3) Results: The most stable parameter was body weight. An increase in the visceral fat area was noted, the fat-free mass dropped, and significant changes were noted in the internal and external cell water parameters. Parameters connected with water between the right and left side of the body were symmetrical. Significant correlation between PhA values and body parameters with regard to fat tissue and PhA values of the legs was noticed when PhA was measured at 50 kHz. (4) Conclusions: PhA could be considered as a ski jumper body symmetry monitoring tool. The described relationship may be useful for the assessment of body fat change, which, in the case of jumpers, is crucial. Moreover, our data suggest that segmental PhA evaluation could be a good solution for ski jumpers as a confirmation if lowered body mass and low BMI are still healthy and increase the chance for longer jumps and good performance.