Association between phase angle from bioelectrical impedance analysis and level of physical activity: Systematic review and meta-analysis

The use of bioelectrical impedance analysis to predict post-operative complications in adult patients having surgery for cancer: A systematic review

BACKGROUND

Patients undergoing surgery for cancer are at particular risk of post-operative complications. The pre-operative period is an opportunity to identify and mitigate risk factors and improve outcome. Bioelectrical impedance analysis (BIA) may offer an additional means of identifying patients at risk of post-operative morbidity.

AIMS

The aim of this systematic review was to assess the use of measures and estimates of body composition determined by BIA as markers of peri-operative risk in adult patients undergoing elective surgery for cancer.

METHODS

This review was performed in accordance with the PRISMA guidelines. The electronic databases of MEDLINE, EMBASE, CINAHL, CENTRAL and the Web of Science were searched from inception. Studies of adult participants having elective surgery for cancer were included if participants underwent BIA in the peri-operative period and were assessed for post-operative complications.

RESULTS

2578 studies were identified, of which 12 were eligible for inclusion. In total the studies report data from 1508 subjects. Five studies examined phase angle or standardized phase angle, six examined derived measures and one examined both. Eight of the 12 demonstrated an association between phase angle and/or body composition and an increased risk of post-operative complications.

CONCLUSIONS

Bioelectrical impedance analysis in the peri-operative period may be useful in predicting the risk of complications following elective cancer surgery. Phase angle more consistently demonstrates an association than derived estimates. Further high quality studies are needed and should report the raw impedance values, standardized phase angle and the equations used to derive body composition.

Phase angle association with metabolic profile in adults: A population-based study

OBJECTIVE

This study assesses the association of the phase angle (PhA) with the metabolic profile in adults of both sexes.

METHODS

This is a cross-sectional, population-based study including 949 adults 20 to 59 y of age living in the Viçosa, Minas Gerais, Brazil - urban zone. The PhA was measured based on electrical bioimpedance analysis. The metabolic profile comprised the following components: waist circumference, glucose, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides, C-reactive protein, homeostatic model assessment index-insulin resistance (HOMA-IR), serum uric acid, systolic blood pressure, and diastolic blood pressure. Linear regression models (crude and adjusted) were used to determine the association between each independent and dependent variable; statistical significance was analyzed at 5%.

RESULTS

Multiple analyses showed that the increase in the values of waist circumference (β: -0.01; 95%CI: -0.03; -0.01) represented lower values in the PhA. For the glucose, non-HDL-C, triglycerides, CRP, HOMA-IR and uric acid there was no association with PhA in the adjusted models. .

CONCLUSION

Low PhA was directly associated with grater values of the waist circumference, even after adjustments were made in the sociodemographic, lifestyle variables and body mass index; this outcome suggests that PhA is a promising cardiometabolic profile biomarker in adults.

The Predictive Role of Raw Bioelectrical Impedance Variables in Disordered Eating Attitudes in Female Ballet Dance Students

The present study used receiver operating characteristic (ROC) curve analysis to investigate the accuracy of body composition and raw bioelectrical impedance analysis (BIA) in correctly classifying disordered eating attitudes (DEA) in dance students. Participants were 81 female dancers assigned in two groups: beginner training (BT; age (mean ± SD) = 10.09 ± 1.2 years, n = 32) and advanced training (AT; age = 15.37 ± 2.1 years, n = 49). Fat mass (FM) was estimated by Slaughter's equation and skeletal muscle with Poortman's equation. Impedance (Z), resistance (R), reactance (Xc) and phase angle (PhA) were obtained through multifrequency BIA at a frequency of 50 kHz. Fat-free mass (FFM) was assessed using Sun's equation. For evaluation of DEA, the Eating Attitudes Test-26 (EAT-26) questionnaire was performed. We defined an EAT-26 score ≥ 20 as positive for DEA. Comparisons between groups were performed by a one-way ANOVA test or Kruskall-Wallis test. Spearman's rank correlation coefficients were performed to assess associations between variables. ROC curve analysis was utilized to test the accuracy of body composition and BIA variables in predicting DEA. In the BT group, Xc and PhA demonstrated high accuracy in predicting DEA with an area under the curve (AUC) of 0.976 (95% confidence interval (CI): 0.85-1.00) and 0.957 (95% CI: 0.82-0.99), respectively, (both p < 0.0001). FFM Sun had an AUC of 0.836 (95% CI: 0.66-0.94) (p < 0.0001) in the BT group and FFM Slaughter was 0.797 (95% CI: 0.66-0.90) (p < 0.001) in the AT group. Reactance and Phase angle were excellent and useful predictors of DEA in the BT group.

Bioelectrical impedance analysis (BIA) -derived phase angle in sarcopenia: A systematic review

BACKGROUND & AIMS

Bioelectrical impedance analysis-derived phase angle (PhA) has been gaining attention in the clinical evaluation of nutritional status because it is thought to be a proxy of water distribution and body cell mass; it is also associated to muscle strength and is an effective predictor of different clinical outcomes. Since an association may be expected between PhA and sarcopenia (defined by low skeletal muscle mass and impaired muscle function), the aim of this systematic review was to evaluate: a) changes in PhA due to sarcopenia; b) prevalence of sarcopenia according to PhA values; c) derivation of phase angle cut-offs for detecting sarcopenia; d) sarcopenia and PhA as predictors of clinical outcomes.

METHODS

A systematic research on electronic databases (PubMed, Embase, Scopus and Web of Science) from inception to January 31st, 2020 was performed according to PRISMA checklist. Using PICOS strategy, "P" corresponded to participants of any age, gender or ethnicity, "I" designated diagnosis of sarcopenia, "C" indicated subjects without sarcopenia, "O" corresponded to PhA, and "S" selected all study types. Methodological quality was assessed using the National Institute of Health (NIH) quality assessment tool.

RESULTS

Through the initial literature search and after removing duplicates and excluding papers by screening titles and abstracts, 79 potentially relevant studies were examined. Thirteen studies (7668 subjects) met the inclusion criteria. The overall risk of bias was low. Sarcopenia was associated with a significant lower PhA in seven studies out of eight, while five studies out of six reported a high prevalence of sarcopenia was in patients with low PhA. Different cut-off point values from 4.05 to 5.05° have been derived for the identification of sarcopenia. PhA and sarcopenia were independent predictors of survival in cancer patients and geriatric hospitalized patients.

CONCLUSIONS

Data from the selected papers demonstrate that PhA is decreased in sarcopenic subjects and the prevalence of sarcopenia is higher in subjects with low PhA. Further studies are needed to determine to what extent PhA may be valuable in detecting low muscle quality and/or identifying sarcopenia.

The associations of phase angle with the structural severity and quadriceps strength among patients with hip osteoarthritis: the SPSS-OK study

INTRODUCTION/OBJECTIVES

This study examined whether phase angle (PhA) is associated with hip osteoarthritis (HOA) severity and quadriceps strength in patients with HOA.

METHOD

A series of 549 patients with HOA, obtained from the Screening for People Suffering Sarcopenia in the Orthopedic cohort of Kobe study, were analyzed. PhA and quadriceps strength were measured using bioelectrical impedance analysis and a handheld dynamometer, respectively. The HOA severity was graded using the Kellgren-Lawrence radiographic scale. We estimated (1) mean differences in PhA by differences in HOA severity and (2) mean differences in quadriceps strength by differences in PhA using general linear models.

RESULTS

The patients' mean age was 64.9 years, and 85% were women. A decreasing trend of PhA associated with increasing HOA severity was observed (P for trend < 0.001). PhA was statistically associated with a decrease in HOA grade 4 compared with that associated with HOA grade 1 (mean difference, - 0.40°; 95% confidence interval (CI), - 0.51° to - 0.30°). PhA per leg was associated with greater quadriceps strength per leg independent of age, sex, leg muscle mass, and HOA severity (mean difference per 1° increase, 3.80 Nm; 95% CI, 0.93 to 6.66). There was insufficient evidence of any difference in the association between PhA and quadriceps strength by HOA severity and sex (P for interaction = 0.07 and 0.06, respectively).

CONCLUSIONS

PhA gradually decreased with increasing HOA severity, especially in patients with end-stage HOA. Paying close attention to PhA might provide a key to increasing quadriceps strength, regardless of HOA severity. Key Points • PhA gradually decreased with progression of HOA, particularly in patients with end-stage HOA. • PhA was positively associated with quadriceps strength, regardless of HOA severity. • PhA could be one of the indicators of quadriceps strength in patients with HOA.

Body Water Content and Morphological Characteristics Modify Bioimpedance Vector Patterns in Volleyball, Soccer, and Rugby Players

Background: Bioimpedance vector analysis (BIVA) is a widely used method based on the interpretation of raw bioimpedance parameters to evaluate body composition and cellular health in athletes. However, several variables contribute to influencing BIVA patterns by militating against an optimal interpretation of the data. This study aims to explore the association of morphological characteristics with bioelectrical properties in volleyball, soccer, and rugby players. Methods: 164 athletes belonging to professional teams (age 26.2 ± 4.4 yrs; body mass index (BMI) 25.4 ± 2.4 kg/m²) underwent bioimpedance and anthropometric measurements. Bioelectric resistance (R) and reactance (Xc) were standardized for the athlete's height and used to plot the vector in the R-Xc graph according to the BIVA approach. Total body water (TBW), phase angle (PhA), and somatotype were determined from bioelectrical and anthropometric data. Results: No significant difference (p > 0.05) for age and for age at the start of competition among the athletes was found. Athletes divided into groups of TBW limited by quartiles showed significant differences in the mean vector position in the R-Xc graph (p < 0.001), where a higher content of body fluids resulted in a shorter vector and lower positioning in the graph. Furthermore, six categories of somatotypes were identified, and the results of bivariate and partial correlation analysis highlighted a direct association between PhA and mesomorphy (r = 0.401, p < 0.001) while showing an inverse correlation with ectomorphy (r = -0.416, p < 0.001), even adjusted for age. On the contrary, no association was observed between PhA and endomorphy (r = 0.100, p = 0.471). Conclusions: Body fluid content affects the vector length in the R-Xc graph. In addition, the lateral displacement of the vector, which determines the PhA, can be modified by the morphological characteristics of the athlete. In particular, higher PhA values are observed in subjects with a high mesomorphic component, whereas lower values are found when ectomorphy is dominant.

Independent Association of Phase Angle with Fasting Blood Glucose and Hemoglobin A1c in Korean Type 2 Diabetes Patients

The relationship between phase angle (PhA) of bioelectrical impedance analysis (BIA) and glycemic parameters in diabetes mellitus (DM) patients has not been well studied. To evaluate the prognostic value of the PhA from BIA as a glycemic marker, we investigated the relationship of PhA with various variables such as age, body mass index (BMI), and glycemic parameters in Korean patients with type 2 DM (T2DM). We evaluated the anthropometric data, body composition, glycemic parameters, and PhA of 321 T2DM patients aged 30–83 years. The patients were classified by sex into men (n = 133) and women (n = 188). General linear models identified the independent effects of PhA after covarying for age, sex and BMI. The PhA, body cell mass (BCM), extracellular mass (ECM), lean body mass, intracellular water (ICW), extracellular water (ECW), total body water (TBW), fasting blood glucose, and hemoglobin A1c (HbA1c) of T2DM Korean patients were significantly higher in men than in women. However, fat mass, ECM/BCM, ECW/ICW, ECW/TBW, and serum insulin were significantly higher in women than in men. Statistically significant independent associations were observed between PhA and age, BCM, ECM, ECM/BCM, ICW, ECW, ECW/ICW, and ECW/TBW for both sexes. There was no significant association between PhA and BMI the patients. Glycemic parameters, such as HbA1c and fasting blood glucose were independently associated with PhA. These results suggest that PhA could be an indicator for assessing ability to control fasting blood glucose in T2DM patients in Korea.

Phase angle associated with different indicators of health-related physical fitness in adults with obesity

In obese populations, the exacerbated increase in adipose tissue results in a significant reduction of health-related physical fitness and can affect the phase angle (PhA), a promising health indicator of cell health and integrity. The aim of this study was to investigate the association of PhA with health-related physical fitness indicators in obese adults. This cross-sectional study had a non-probabilistic sample and was conducted from April to June 2018. The PhA was obtained by a bioelectrical impedance analysis, and the health-related physical fitness indicators evaluated were percentage of body fat (%BF), lower- and upper-body maximal strength, cardiorespiratory fitness (relative V̇O2peak), and flexibility. Pearson and Spearman´s linear correlations, crude and adjusted linear regression analyses were performed. A total of 69 obese adults (60.8% female; BMI = 33.5 ± 2.8 kg/m²) with a mean age of 34.6 ± 7.1 years were studied. The PhA means were 5.8 (±0.6º) and had an inverse correlation with %BF (r=-0.74; p<0.001) and positive correlation with V̇O2peak (r=0.50; p<0.001), lower- and upper-body maximal strength (r=0.65; r=0.70; p<0.001, respectively). After adjustment, %BF (β=-0.065, adjusted R²=0.53; p<0.001), lower- and upper-body maximal strength (β=0.004; adjusted R²=0.46; p<0.001, and β=0.024; adjusted R²=0.50; p<0.001, respectively) were predictors of PhA. Our results suggest the favorable role of PhA as a clinically viable tool to screen and identify the physical fitness variables and functional status of obese adults.

Nutritional Status Plays More Important Role in Determining Functional State in Older People Living in the Community than in Nursing Home Residents

The aim of this study was to verify whether the relationship between nutritional and functional status differs between seniors in the community and those in long-term care institutions. One hundred nursing home (NH) residents aged 60 years and above and 100 sex- and age-matched community-dwelling (CD) older adults were examined. Functional status was assessed using the Comprehensive Geriatric Assessment (CGA) and nutritional status using anthropometric measures, the Mini Nutritional Assessment questionnaire (MNA) and bioimpedance analysis (BIA). Significant environmental interactions were observed with resting metabolic rate (RMR), extracellular water (ECW) and intracellular water (ICW) ratio, skeletal muscle mass (SMM), skeletal muscle index (SMI) and impedance (Z) and resistance (R) to the results of the Timed Up and Go (TUG) test. The two groups demonstrated different relationships between Z and R and handgrip strength and between Geriatric Depression Scale (GDS) score and fat free mass (FFM), body density, total body water (TBW) and phase angle (PhA). Nutritional status seems to be more important for functional state in CD older people than in NH residents. Therefore, to ensure the functional independence of seniors living in the community, it is crucial to maintain the correct nutritional parameters. Further studies are necessary to account for the fact that this relationship is less significant among NH residents and to identify other factors that may contribute to these discrepancies between community and institutional environments.

Phase Angle from Bioelectric Impedance and Maturity-Related Factors in Adolescent Athletes: A Systematic Review

Phase angle (PhA) is a body composition (BC) parameter from bioelectrical impedance analysis that is suggested as a marker of cell integrity and general health. In adolescent athletes, PhA values are used to monitor the effects of training and competitions and seem to vary according to age, having an upward trajectory during puberty. Since adolescence is a period composed of maturation stages, the aim of this systematic review was to investigate the relationship between PhA and maturation stage in adolescent athletes. A search was conducted in PubMed/MEDLINE, BVS, Web of Science (WOS), Scopus, Science Direct, and Academic Search Complete (EBSCO) databases up to May 2020. Eligibility criteria followed the PICOS strategy and studies with healthy athletes aged 10–19 years of any level of competition were included. Six cross-sectional studies and two longitudinal studies met the inclusion criteria. Results showed that early and mature athletes have higher PhA than those who are non-matured or maturated late. Thus, PhA is influenced by the pubertal status. Considering BC is one of the factors influencing sports performance together with its growth-related changes, practitioners may use PhA values in BC analysis of adolescent athletes.

Impact of Vigorous-Intensity Physical Activity on Body Composition Parameters, Lipid Profile Markers, and Irisin Levels in Adolescents: A Cross-Sectional Study

In adolescence, health status is influenced by several factors, including dietary pattern and physical activity (PA) which are crucial elements of lifestyle in terms of prevention and treatment of metabolic and chronic diseases. The current study aimed to explore the impact of the different intensity levels of PA along with the adherence to a Mediterranean diet (MD), on body composition indices and metabolic parameters in a cohort of adolescents, thereby investigating potential predictors of health behavior in youth. This cross-sectional study was carried out among 92 participants (44 girls and 48 boys, aged 14 to 17 years), which were divided into the following three groups according to intensity levels of PA: Group A (physical inactivity), Group B (moderate PA), and Group C (vigorous-intensity PA). The Questionnaire of Adherence to the Mediterranean Diet (KIDMED test) was used to assess both diet composition and adherence to a MD. All subjects underwent anthropometric measurements, bio-impedentiometric analysis for body composition parameters, and biochemical and hormonal measurements. The majority of adolescents (60.87%) had a medium adherence to the MD, and even a better distribution of food rates was found in adolescents performing vigorous-intensity PA. A comparison of anthropometric measurements and body composition parameters among groups showed that body mass index and fat mass (FM) were significantly lower while body cell mass (BCM), free fat mass (FFM), phase angle (PhA), and total body water (TBW) were higher in Group C adolescents as compared with those of Group A. In Group C, insulin resistance (HOMA-IR) was reduced and insulin levels were inversely associated with FFM (r = −0.454 and p = 0.004) and directly correlated with FM (r = 0.331 and p = 0.003). In the same Group C, we observed elevated serum irisin levels and lower lipid profile markers as compared with Group A. Interestingly, irisin negatively correlated with both total cholesterol (r = −0.428 and p = 0.04) and LDL (r = −0.468 and p = 0.02) in Group C. Finally, a receiver operator characteristic curve (ROC) analysis revealed irisin, LDL, HDL, and body composition variables (FFM, BMC, PhA, and TBW) as the most predictive measures for vigorous-intensity PA. Our results highlight the importance of developing healthy lifestyle programs that include improving the intensity of PA among a young population as a superior strategy for ensuring a better quality of life.

Classic Bioelectrical Impedance Vector Reference Values for Assessing Body Composition in Male and Female Athletes

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R–Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes.

Bioelectrical impedance phase angle in sport: a systematic review

BACKGROUND

Phase angle (PhA) is a raw BIA variable that has been gaining attention in recent years because it is supposed to be an index of the ratio between extracellular and intracellular water, body cell mass, and cellular integrity. The aim of this systematic review was to evaluate the variability of PhA between different sports and its relationships with sport performance. Additionally, we investigated whether PhA depends on gender or age, and analyzed the differences between athletes and controls.

METHODS

A systematic research using PubMed, Scopus and Web of Science up to June 2019 was performed. Selection criteria included studies on subjects who practice sports in planned and continuous modality at competitive or elite level.

RESULTS

Thirty-five papers met the inclusion criteria (twenty-one cross-sectional data, fourteen longitudinal data). A few but convincing studies have shown that mean PhA is higher in athletes vs. controls. PhA increases with age and is likely to be higher in male than female athletes. A large variability in PhA is observed for the same sport, while it is still uncertain to what extent PhA differs between various sports. There are no clear relationships of PhA with sport performance or training/untraining.

CONCLUSION

It is still to be defined to what extent PhA varies between different sports and changes with training/untraining. It can be argued that for a given sport much more data should be collected in a systematic way and for a period of time appropriate in order to determine changes and trends. This is even more crucial in the case of intervention studies.