Phase angle by bioelectrical impedance vector analysis as predictor of prolonged hospital stay

Background: Little is known on the clinical relevance of the nutritional status and body composition of patients hospitalized with SARS-CoV-2 infection. The aim of our study was to assess the prevalence of malnutrition in patients with COVID-19 pneumonia using bioelectrical impedance vector analysis (BIVA), and to evaluate the relationship of their nutritional status with the severity and outcome of disease. Methods: Among 150 consecutive patients who were hospitalized with COVID-19 pneumonia, 37 (24.3%) were classified as malnourished by BIVA, and were followed-up for 60 days from admission. Outcome measures were differences in the need for invasive mechanical ventilation, in-hospital mortality, and the duration of hospital stay in survivors. Results: During 60 days of follow-up, 10 (27%) malnourished patients and 13 (12%) non-malnourished patients required invasive mechanical ventilation (p = 0.023), and 13 (35%) malnourished patients and 9 (8%) non-malnourished patients died (p < 0.001). The average duration of the hospital stay in survivors was longer in patients with malnutrition (18.2 ± 15.7 vs. 13.2 ± 14.8 days, p < 0.001). In survival analyses, mechanical ventilation free (log-rank 7.887, p = 0.050) and overall (log-rank 17.886, p < 0.001) survival were significantly longer in non-malnourished than malnourished patients. The Cox proportional ratio showed that malnutrition was associated with an increased risk of mechanical ventilation (HR 4.375, p = 0.004) and death (HR 4.478, p = 0.004) after adjusting for major confounders such as age, sex, and BMI. Conclusions: Malnutrition diagnosed with BIVA was associated with worse outcomes in hospitalized patients with COVID-19 pneumonia.

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Identifying Athlete Body Fluid Changes During a Competitive Season With Bioelectrical Impedance Vector Analysis

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2019-0285 ◽

2020 ◽

Vol 15 (3) ◽

pp. 361-367 ◽

Cited By ~ 14

Author(s):

Francesco Campa ◽

Catarina N. Matias ◽

Elisabetta Marini ◽

Steven B. Heymsfield ◽

Stefania Toselli ◽

...

Keyword(s):

Phase Angle ◽

Body Fluid ◽

Bioelectrical Impedance ◽

Impedance Analysis ◽

Fat Free Mass ◽

Vector Analysis ◽

Bioelectrical Impedance Vector Analysis ◽

Competitive Season ◽

Impedance Vector ◽

Total Body

Purpose: To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes. Methods: A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW–ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre–post, increase or decrease) according to sex. Results: Significant mean vector displacements in the postgroups were observed in both sexes. Specifically, reductions in vector length (Z/H) were associated with increases in TBW and ICW (r = −.718, P < .01; r = −.630, P < .01, respectively) and decreases in ECW:ICW ratio (r = .344, P < .05), even after adjusting for age, height, and sex. Phase-angle variations were positively associated with TBW and ICW (r = .458, P < .01; r = .564, P < .01, respectively) and negatively associated with ECW:ICW (r = −.436, P < .01). Phase angle significantly increased in all the postgroups except in women in whom TBW decreased. Conclusions: The results suggest that bioelectrical impedance vector analysis is a suitable method to obtain a qualitative indication of body fluid changes during a competitive season in athletes.

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Phase angle and bioelectrical impedance vector analysis in the evaluation of body composition in athletes

Clinical Nutrition ◽

10.1016/j.clnu.2019.02.016 ◽

2020 ◽

Vol 39 (2) ◽

pp. 447-454 ◽

Cited By ~ 25

Author(s):

Elisabetta Marini ◽

Francesco Campa ◽

Roberto Buffa ◽

Silvia Stagi ◽

Catarina N. Matias ◽

...

Keyword(s):

Body Composition ◽

Phase Angle ◽

Bioelectrical Impedance ◽

Vector Analysis ◽

Bioelectrical Impedance Vector Analysis ◽

Impedance Vector

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Ethnic differences in fat and muscle mass and their implication for interpretation of bioelectrical impedance vector analysis

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2018-0276 ◽

2019 ◽

Vol 44 (6) ◽

pp. 619-626 ◽

Cited By ~ 8

Author(s):

Björn Jensen ◽

Takashi Moritoyo ◽

Martha Kaufer-Horwitz ◽

Sven Peine ◽

Kristina Norman ◽

...

Keyword(s):

Skeletal Muscle ◽

Body Composition ◽

Muscle Mass ◽

Phase Angle ◽

Ethnic Differences ◽

Bioelectrical Impedance ◽

World Health ◽

Vector Analysis ◽

Bioelectrical Impedance Vector Analysis ◽

Impedance Vector

According to the World Health Organization Expert Consultation, current body mass index (BMI) cut-offs should be retained as an international classification. However, there are ethnic differences in BMI-associated health risks that may be caused by differences in body fat or skeletal muscle mass and these may affect the interpretation of phase angle and bioelectrical impedance vector analysis (BIVA). Therefore, the aim of this study was to compare body composition measured by bioelectrical impedance analysis among 1048 German, 1026 Mexican, and 995 Japanese adults encompassing a wide range of ages and BMIs (18–78 years; BMI, 13.9–44.3 kg/m2). Regression analyses between body composition parameters and BMI were used to predict ethnic-specific reference values at the standard BMI cut-offs of 18.5, 25, and 30 kg/m2. German men and women had a higher fat-free mass per fat mass compared with Mexicans. Normal-weight Japanese were similar to Mexicans but approached the German phenotype with increasing BMI. The skeletal muscle index (SMI, kg/m2) was highest in Germans, whereas in BIVA, the Mexican group had the longest vector, and the Japanese group had the lowest phase angle and the highest extracellular/total body water ratio. Ethnic differences in regional partitioning of fat and muscle mass at the trunk and the extremities contribute to differences in BIVA and phase angle. In conclusion, not only the relationship between BMI and adiposity is ethnic specific; in addition, fat distribution, SMI, and muscle mass distribution vary at the same BMI. These results emphasize the need for ethnic-specific normal values in the diagnosis of obesity and sarcopenia.

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