Multifrequency Bioelectrical Impedance Analysis Research Articles

Relationship of the Degree of Sarcopenia with the Severity of Nonalcoholic Fatty Liver Disease and Cardiometabolic Risk in Adolescents

The association between nonalcoholic fatty liver disease (NAFLD) and sarcopenia has been suggested. We investigated sarcopenia’s impact on NAFLD severity and its relationship with cardiometabolic risk in adolescents. We conducted a retrospective study on 122 patients aged 13–18 years and diagnosed with both NAFLD and sarcopenia by laboratory tests, abdominal ultrasound (US), and multifrequency bioelectrical impedance analysis. Sarcopenia was stratified into tertiles based on the skeletal muscle-to-fat ratio (MFR), NAFLD severity was established by the US, and cardiometabolic risk was assessed by the triglyceride–glucose (TyG) index and the atherogenic index of plasma (AIP). Compared with the other patients, those in the lower MFR tertiles exhibited a greater severity of NAFLD (p < 0.001) and significantly higher TyG index and AIP. The independent effect of MFR was observed to have a negative correlation with the severity of NAFLD (p < 0.001). Based on the aforementioned results, the degree of sarcopenia can be considered as one of the risk factors of severe NAFLD and might be an indicator of cardiometabolic risk in adolescents. Weight training to reach the amount of muscle mass could be included in the treatment strategies to improve or prevent NAFLD in adolescents with sarcopenia.

Segmental phase angles as predictors of functional recovery and activities of daily living in patients after stroke.

This study investigated the association between segmental phase angles and functional outcomes in patients after stroke, hypothesizing that increased segmental phase angle correlates with improved functional status. A retrospective cohort study of 1012 patients after stroke was conducted. Whole body and segmental phase angles were measured using bioelectrical impedance analysis within 3 days of admission. Our exposure of interest was segmental phase angle measured via a multifrequency bioelectrical impedance analyzer and calculated as phase angle = arctangent (Xc/R) × (180/π), where R is the resistance of the right half of the body and Xc is the reactance measured at 50 kHz. The primary outcomes were the motor subscale of the functional independence measure (FIM) at discharge and FIM change between admission and discharge. Secondary outcomes included FIM scores for specific activities. Multiple linear regression analysis was performed to assess associations. Phase angles of the healthy upper and lower limbs demonstrated stronger associations with discharge FIM motor scores (β = 0.175 and β = 0.105, respectively) and FIM motor gain (β = 0.242 and β = 0.092, respectively) compared with whole body or paretic limb phase angles. Upper limb phase angles were more closely related to grooming and toileting abilities, whereas lower limb phase angles were associated with both toileting and locomotion at discharge. Segmental phase angles, particularly those of the nonparetic limbs, are promising predictors of functional outcomes in patients after stroke. Assessing segmental phase angles may guide targeted interventions and rehabilitation strategies for improving specific activities of daily living.

Ultrasonographic Evaluation of Systemic Venous Congestion in Maintenance Hemodialysis Patients During Fluid Removal.

Fluid overload is a frequent and serious complication in hemodialysis patients. The combination of multiple point of care ultrasound (POCUS) measurements can identify significant venous congestion but its usefulness to determine ultrafiltration (UF) requirements and dry weight is unknown. Therefore, we evaluated prospectively patients in maintenance hemodialysis to establish the correlations between changes in venous congestion parameters and fluid removal. This was a prospective, single-center, observational study. POCUS venous congestion measurments were performed in 22 patients during 32 online post-dilutional hemodiafiltration sessions and findings were correlated with UF volume, central venous pressure and body water composition determined by multifrequency bioelectric impedance analysis (BIA). The pre dialysis weight was on average 1.9 kg above the BIA estimated dry weight, the average initial IVC diameter was <2 cm. An initial abnormal Hepatic Vein (HV) waveform was present in 26% (8) of the measurements. The average UF volume was 2084 ± 655 ml and correlated with changes in inferior vena cava (IVC) diameter (R= 0.34, CI 95% (0.18, 0.56) p < 0.05) but not with any other POCUS venous congestion parameters. Normalization of the IVC diameter and HV waveform was observed during the first UF hour in all initially altered measurements. Diameter reduction in the IVC correlated with total body water volume reduction estimated with BIA when measured immediately after fluid removal (R= 0.34, CI 95% (0.08, 0.56) p<0.05) Conclusion. Reduction in IVC diameter had a modest but significant correlation with UF volume in our patients on maintenance hemodiafiltration. POCUS may be used to monitor patients during UF.

Standardization of transthoracic impedance values for estimating heart failure and its utility

Abstract Background The use of intrathoracic impedance for examining pleural effusion in heart failure patients has been explored previously. However, due to concerns about its accuracy and complexity, transthoracic impedance values have had limitations in quantifying extravascular lung water. Our dual objectives were to clarify the relationship between intrathoracic conditions and percutaneous transthoracic impedance values, and to establish a basic model for a new machine learning-based estimation system for assessing intrathoracic conditions in patients with heart failure. Methods First, we developed a live porcine congested lung model that induced pleural effusion by substantial fluid loading, and then longitudinally evaluated its correlation with percutaneous transthoracic impedance values. Second, we conducted multi-frequency bioelectrical impedance analysis to simultaneously collect electrical, physical, and hematological data from 63 hospitalized heart failure patients and 82 healthy volunteers Results In the porcine model, pleural effusion correlated with a concurrent decrease in SpO2 and a gradual decrease in impedance. We indexed and generated features from the measured values and developed an intrathoracic estimation model based on electrical measurements and clinical findings using a decision tree-based machine learning approach. Among the 286 features collected per individual, the model used 16 features. Notably, the model demonstrated high accuracy in discriminating patients with pleural effusion, achieving an AUC of 0.905 (95% CI: 0.870-0.940) in cross-validation, significantly outperforming the conventional frequency-based method. Conclusions Transthoracic impedance values, when indexed, reflect intrathoracic conditions and improve estimation. Our results highlighted the potential of machine learning and thoracic impedance measurement for accurate estimation of pleural effusion. This approach provides an effective means of assessing intrathoracic conditions. Figure: The upper figure shows the relationship between impedance values and pleural effusion in the congested lung model. On these results, human data were collected to construct the estimation model. The lower illustrates the accuracy of the model and provides a comprehensive view of the system.

Anthropometric Profile and Position-Specific Changes in Segmental Body Composition of Professional Football Players Throughout a Training Period.

Body and anthropometric profiles of football players vary depending on the physiological and technical demands imposed by different positions. The aim of this study was to evaluate the body composition of professional soccer players in relation to their position on the field during a training macrocycle. The Direct Segmental Multi-Frequency Bioelectrical Impedance Analysis method was used to analyze 58 players at six key moments of the macrocycle. The results show that body profiles are adjusted to the specific demands of each position. Midfielders showed the lowest muscle mass, while defenders showed many notable changes. In general, as the season progressed, all field players experienced an increase in trunk body fat. Fat and lean mass values of goalkeepers differed greatly from the rest. The greatest variations in body composition were observed during pre-season and transition in relation to variations in training load and competitive intensity. The results suggest that the phase of the macrocycle has a greater influence on these variations, although the physical characteristics of each position are relevant. Understanding these dynamics allows for the design of more personalized and efficient training programs to optimize the performance of footballers according to their roles and each stage of the season.

Appendicular skeletal muscle mass is associated with metabolic dysfunction-associated steatotic liver disease severity in young men: a cross-sectional and longitudinal study.

Although appendicular skeletal muscle mass (ASM) has been linked to the severity of hepatic steatosis, investigations of its correlation among younger age groups are lacking. We aimed to elucidate the role of ASM in determining the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) in younger patients. Retrospective data were collected from patients younger than 35years who visited the Armed Forces Goyang Hospital between June 2022 and February 2024. Steatosis presence was determined by a controlled attenuation parameter score ≥ 250dB/m, and significant fibrosis was identified with liver stiffness measurement > 8.0kPa. ASM was measured using multifrequency bioelectrical impedance analysis (InBody 620). Of 910 participants, 630 were diagnosed with MASLD. Patients with MASLD had lower ASM/fat mass (ASM/F) (1.02 vs. 1.91; p < 0.001), ASM/body mass index (BMI) (0.91 vs. 1.04/m2; p < 0.001), and ASM/body weight (ASM/W) (29.5% vs. 33.8%; p < 0.001) than non-MASLD patients. Additionally, ASM/F, ASM/BMI, and ASM/W significantly decreased with worsening steatosis severity and were notably lower in patients with significant fibrosis. Among 107 patients with MASLD who underwent two examinations with a median interval of 6.0months, those with increased ASM/F showed a higher proportion of steatosis regression and a lower proportion of steatosis worsening than those with decreased ASM/F (steatosis regression, 43.1% vs. 22.9%; worsening, 11.1% vs. 28.6%; p = 0.031). All three ASM indices were significant factors in steatosis regression during the study period. ASM is associated with the severity of steatosis and significant fibrosis in MASLD in young adults < 35years.

Accuracy Of Multifrequency BIA Measurements Compared To DXA In African American Cancer Survivors

Accuracy Of Multifrequency BIA Measurements Compared To DXA In African American Cancer Survivors

Comparison of Four Body Composition Methods: Circumference Measurements, Eight-Point Bioelectrical Impedance Analysis up to 500 and 1000 kHz to Dual-Energy X-Ray Absorptiometry to Measure Body Fat Percentage

ABSTRACT Introduction A comparison of body composition assessments using military circumferences to bioelectrical impedance analysis (BIA) and the reference standard dual-energy X-ray absorptiometry (DEXA) can gauge effectiveness of assessments. High-frequency (500 KHz) direct segmental multifrequency bioelectrical impedance analysis (DSM-BIA) accurately calculates total water mass and body fat% (BF%), but it is unknown whether higher frequencies (1,000 KHz) increase measurement accuracy. The purpose was to compare DSM-BIA 500, DSM-BIA 1000, the DoD Circumference Method (CM), and the reference-standard DEXA. Materials and Methods Design: Cross sectional, observational study. Participants/Setting: A total of 62 participants from the military healthcare system (n = 25 males, 38.8 ± 11.4 years, n = 37 females 43.7 ± 15.95 years) were measured in an outpatient clinic setting. Statistical Analysis: BF% was estimated via DEXA, DSM-BIA 500, DSM-BIA 1000, and CM to identify the relationship between methods using Pearson correlation, intraclass correlation coefficients (ICCs), and Bland-Altman plots. The study was approved by the IRB from Walter Reed National Military Medical Center at Bethesda and Concordia University Chicago. Results Circumference Method BF% was moderately correlated with DSM-BIA 500 (males r = 0.63, ICC = 0.76; females r = 0.77, ICC = 0.85), DSM-BIA 1000 (males r = 0.59, ICC = 0.74; females r = 0.77, ICC = 0.85), and DEXA (males r = 0.62, ICC = 0.62; females r = 0.73, ICC = 0.82). DSM-BIA 500 BF% was strongly correlated with DSM-BIA 1000 (males r = 0.99, ICC = 0.99; females r = 0.99, ICC = 0.99) and DEXA (males r = 0.93, ICC = 0.94; females r = 0.89, ICC = 0.89). Lastly, DSM-BIA 1000 BF% was also strongly correlated with DEXA (males r = 0.93, ICC = 0.94; females r = 0.84, ICC = 0.90) (P for each reported r &amp;lt; 0.01). Bland-Altman analysis confirmed an overall mean bias of −1.72% CM vs. DEXA in females, indicating the tendency of CM to underestimate BF% compared to DEXA limits of agreement from −14.24 to 10.8. There was an upward slope of the linear relationship between the bias and mean of the measures (Beta = 0.34, P = 0.01). In the full cohort, there was an overall mean bias of 1.14% of CM vs. DSM BIA 1000, with CM tending to overestimate BF% compared to DSM BIA 1000 with limits of agreement −11.13 to 13.41%. There is an upward slope line of the linear relationship between the bias and the mean of the measures (Beta = 0.17, P = .03). Conclusion This study found that CM BF% was moderately correlated with DSM-BIA 500 kHz, DSM-BIA 1,000 kHz BIA, and DEXA. Both DSM-BIA 500 and DSM-BIA 1,000 kHz strongly correlated well with DEXA implying that there was no further increase in correlation with increased frequency. Additionally, there was proportional bias in BF% in the female group between CM and DEXA and in the total group between CM and DSM BIA 1000.

Effects of muscle quantity, muscle quality, and phase angle on whole-body reaction time in 5164 adults aged 20-91years.

Muscle quantity, defined as appendicular lean mass (ALM); muscle quality, defined as the ratio of muscle strength to ALM; and bioelectrical impedance analysis (BIA)-derived phase angle (PhA) are determinants of physical performance. We examined whether muscle quality indices were significant predictors of the whole-body reaction time (WBRT) in healthy female and male adults aged 20-91years. Data from 5164 adults (2869 women and 2295 men; mean age ± standard deviation, 60.9 ± 15.6years) were analyzed. Height and weight were measured, and body mass index was calculated. ALM was estimated using a previously validated 8-electrode multi-frequency BIA. PhA was measured at 50kHz using a BIA device. Knee extension strength (KES), leg extension power (LEP), and flexibility were examined. The ALM to weight (ALM/weight), KES to ALM (KES/ALM), and LEP to KES (LEP/KES) ratios were calculated. In the WBRT test, participants were asked to stand on a force plate and jump upright as quickly as possible in response to a light stimulus. The WBRT was divided into the response initiation and motion execution phases. ALM/weight, KES/ALM, LEP/KES, PhA, and flexibility were significant independent predictors of WBRT and the time of the motion execution phase (p < 0.001). However, PhA was not a significant predictor of the time of response initiation phase. Muscle quantity (ALM/weight), muscle quality (KES/ALM and LEP/KES), PhA, and flexibility are determinants of WBRT test performance, particularly in the motion execution phase.

Motor function is related to the lower phase angle than to muscle mass of the lower limbs in older females with hip osteoarthritis: a cross-sectional observational study

BackgroundMuscle mass and phase angle (PhA) can be measured using multi-frequency bioelectrical impedance analysis (BIA). Osteoarthritis of the hip (OAhip) causes decreased muscle mass and PhA in the deformed lower limb. However, previous studies have not accounted for the influence of sex, and thus, the relationship between muscle mass, PhA, and motor function remains unclear. This study aimed to elucidate the relationship between PhA, an index of muscle mass and quality measured using BIA, and motor function during gait and standing in female patients with OAhip.MethodsMuscle mass and PhA of patients with OAhip were measured using BIA. Motor function was evaluated using the Timed Up and Go test, ground reaction/weight, rate of force development/weight, and load ratio between the osteoarthritic (OA) and contralateral sides when standing up. The difference between the OA side and the contralateral lower limb was tested to clarify the characteristics of the deformed lower limb. The relationship between each motor function was determined using a partial correlation coefficient with age as a control variable and multiple regression analysis with each motor function as the dependent variable and age, OA-side muscle mass/body weight ratio, and PhA as independent variables.ResultsThis study involved 60 patients with OAhip (age 65.6 ± 7.6 years, height 154.2 ± 6.0 cm, weight 56.8 ± 10.5 kg) scheduled for unilateral total hip arthroplasty. Muscle mass, PhA, and lower limb load ratio were significantly decreased in the lower limbs on the OA side. Furthermore, using a partial correlation coefficient with age as a control variable, PhA showed significant correlations with motor functions related to standing up and walking, and multiple regression analysis revealed that PhA was independently related to each motor function. ConclusionsEvaluation and interventions that consider muscle quality rather than muscle mass are important.

Does high-frequency resistance exercise offer additional benefits to older adults? learnings from a randomized controlled trial

ObjectiveResistance exercise is an effective strategy to improve muscle strength in older adults. A limited-load resistance would be flexible and suitable for community-based training. It was unclear whether high-frequency resistance exercise offer additional benefits to older adults. Here, we aimed to examine the effect of limited-load resistance exercise among different frequency on muscle parameters in older adults.MethodsThe current study was a single-blind, randomized controlled trial comparing the effectiveness of different-frequency resistance exercise in older adults. Change in skeletal muscle was estimated with a multi-frequency bioelectrical impedance analyzer. Demographics, physical examination, nutritional assessment, prealbumin and lymphocytes were also measured. Fisher’s precision probability test and baseline-adjusted generalized linear models were applied accordingly to analyze the influence of dose-different exercise on prevalence of sarcopenia, muscle parameters and body composition. A two-sided p value of < 0.05 was defined statistical significance.ResultsThe participants had a mean age of 71.96 years and close gender ratio. One hundred and twenty-seven participants (control 40; low-dose 46; high-dose 41) completed the 6-month exercise intervention. In contrast to control group, only high-dose exercise groups experienced improvements in muscle mass (0.66 kg, p < 0.001) and max grip strength (+ 2.17 kg, p < 0.001). There were significant dose-response effects of muscle mass (index), fat mass (index), max grip strength, 5-times sit to stand test, 6-minute walking test and visceral fat area (all ptrend <0.01).ConclusionsAs the proved dose-dependent effect, current findings supported high-frequency limited-load resistance exercise applied and extended among older adults in community.Trial RegistrationThis study was registered at Chinese Clinical Trial Registry Network (ChiCTR2200062007, Registered on 19 July 2022).

Segmental multi-frequency bioelectrical impedance analysis indicates dehydration status after exercise

AimHydration status monitoring is critical to help those in exercise training to avoid serious dehydration. Bioelectrical impedance analysis (BIA) is a convenient and timely method to monitor body composition in resting conditions. The study obtained bioelectrical impedance (BI) from different segments at multi-frequency before and after exercise aiming to evaluate whether segmental multi-frequency (SMF)-BIA can indicate exercise dehydration in humans. MethodsA total of 43 young adults were recruited. Body weight (BW) and segmental BI at frequencies of 1, 5, 50, 250, 500, and 1000 kHz from each subject were measured before and after each bout of exercise. Hydration status was assessed by body weight loss (BWL), indicated by changes in body weight (ΔBW) and the percentage of body weight change (ΔBW%). Each subject participated in 3 to 4 exercise sessions on different days. ResultsA total of 143 pieces of data were collected with various degrees of dehydration: BWL ranging from 0.2–4.2 kg (0.4 %–5.8 %) in participants (aged 24.40 ± 6.47). Correlation analysis revealed that the changes of BI (ΔZ) in arms and legs during exercise were correlated with the BWL. Multivariate regression and machine learning analysis showed that predicted values of dehydration were correlated with true values of dehydration (ΔBW: R2 = 0.4471, R2 = 0.5502; ΔBW%: R2 = 0.4469, R2 = 0.5073). When the diagnosis of dehydration is based on BWL > 1 %: the AUC of the SMF-BIA regression model was 0.7262 (p < 0.001) and the specificity and sensitivity were 85.19 %, 60 %. When the diagnosis of dehydration is based on BWL > 2 %: the AUC of the SMF-BIA regression model was 0.8757 (p < 0.0001) and the specificity and sensitivity were 77.22 %, 81 %. ConclusionThese results suggested that SMF-BIA can indicate exercise dehydration in humans.

Open, Active-Controlled Clinical Study to Evaluate the Correlation between Whole Body DEXA and BIA Muscle Measurements.

Dual energy X-ray absorptiometry (DXA) is the gold standard for diagnosing sarcopenia. However, comparative studies using bioelectrical impedance analysis (BIA) would be required in the Korean population. This study aimed to evaluate the correlation between total-body bone density measuring devices (Hologic and GE Lunar) and a bioelectrical impedance measurement device (InBody 970) as well as the correlation between upper body muscle mass. A total of 119 participants were involved in this study, aged 20 to 70 years, with specific body mass index ranges and no severe health conditions used both DXA (or DEXA) and BIA technologies to assess body composition. The participants were scanned using a Hologic QDR-4500W DXA scanner and GE-Lunar Prodigy DXA systems, and the InBody 970 type of multi-frequency BIA machine. Statistical analysis was performed to determine the correlation between the devices, with a coefficient of at least 0.8. The muscle mass measurement comparisons between the InBody 970 and Hologic devices demonstrated remarkably high correlation coefficients (exceeding 0.9) across all limbs. Similarly, the muscle mass comparison between the Inbody 970 and GE Lunar devices also revealed substantial correlation coefficients, ranging from 0.83 upwards, across all limbs. Limb muscle mass measurements using Hologic and GE Lunar whole-body DXA and Inbody 970 BIA demonstrated particularly high levels of concordance. In addition, a conversion formula that bridges limb muscle mass measurements from two widely used whole-body DXA machines and a BIA machine will facilitate sarcopenia research and patient management.

Comparing Device-Generated and Calculated Bioimpedance Variables in Community-Dwelling Older Adults.

Despite BIA emerging as a clinical tool for assessing older adults, it remains unclear how to calculate whole-body impedance (Z), reactance (Xc), resistance (R), and phase angle (PhA) from segmental values using modern BIA devices that place electrodes on both sides of the body. This investigation aimed to compare both the whole-body and segmental device-generated phase angle (PhADG) with the phase angle calculated using summed Z, Xc, and R from the left, right, and combined sides of the body (PhACalc) and to compare bioelectric variables between sides of the body. A sample of 103 community-dwelling older adults was assessed using a 50 kHz direct segmental multifrequency BIA device. Whole-body PhACalc values were assessed for agreement with PhADG using 2.5th and 97.5th quantile nonparametric limits of agreement and Spearman's rho. Bioelectrical values between sides of the body were compared using Wilcoxon rank and Spearman's rho. A smaller mean difference was observed between PhADG and right PhACalc (-0.004°, p = 0.26) than between PhACalc on the left (0.107°, p = 0.01) and on the combined sides (0.107°, p < 0.001). The sum of Z, R, and PhACalc was significantly different (p < 0.01) between the left (559.66 ± 99.55 Ω, 556.80 ± 99.52 Ω, 5.51 ± 1.5°, respectively) and the right sides (554.60 ± 94.52 Ω, 552.02 ± 94.23 Ω, 5.41 ± 0.8°, respectively). Bilateral BIA values do not appear to be interchangeable when determining whole-body measurements. Present data suggest that using right-sided segmental values would be the most appropriate choice for calculating whole-body bioelectrical variables.

Validation of Bioelectrical Impedance Devices for the Determination of Body Fat Percentage in Firefighters.

Jagim, AR, Luedke, J, Erickson, JL, Fields, JB, and Jones, MT. Validation of bioelectrical impedance devices for the determination of body fat percentage in firefighters. J Strength Cond Res 38(8): e448-e453, 2024-To cross-validate bioelectrical impedance devices for the determination of body fat percentage (BF%) in firefighters. Twenty-eight structural firefighters were evaluated (female, n = 2; male, n = 26 [mean ± SD] age: 38.2 ± 8.3 years; height: 180.2 ± 7.5 cm; body mass: 86.7 ± 20.8 kg; body mass index: 25.8 ± 7.8 kg·m-2) using multifrequency bioelectrical impedance analysis (MFBIA) hand-to-foot device, and single-frequency BIA foot scale (F2FBIA), and a single-frequency handheld BIA device (HHBIA). Dual X-ray absorptiometry served as the criterion. Validity metrics were examined to establish each method's performance. Body fat % values produced by MFBIA (r = 0.913), F2FBIA (r = 0.695), and HHBIA (r = 0.876) were strongly associated (p < 0.001) with criterion BF% measures. However, MFBIA, F2FBIA, and HHBIA all significantly (p < 0.001) underestimated BF% when compared with the criterion measure. Constant error ranged between 4.0 and 5.5% across all BIA devices. Despite strong associations between the BIA devices included in the current study and the criterion measure, all BIA devices underestimated BF%, which resulted in an overestimation of fat-free mass. In addition, proportional bias was observed in which BF% was overestimated at lower values and underestimated at higher values.

What About Water? Implications for Body Composition Assessment in Military Personnel.

Sergi, TE, Roberts, BM, and Heileson, JL. What About Water? Implications for Body Composition Assessment in Military Personnel. J Strength Cond Res 38(9): e534-e540, 2024-Body composition standards ensure service members maintain physical fitness, wellness, and support mission readiness. Anthropometric techniques (i.e., height/mass, circumference-based "tape test") have been the primary screening and percent body fat (%BF) assessment method in military personnel for about 4 decades. Recently, the Army and Marine Corps have implemented more advanced body composition assessment methods, such as air displacement plethysmography (ADP), multifrequency bioelectrical impedance analysis (MF-BIA), and dual-energy x-ray absorptiometry (DXA), to serve as supplemental %BF assessment after failing the tape test. Although supplemental assessments are intended to improve on the accuracy and precision of the tape test, preassessment standardization, specifically regarding acute water ingestion (AWI), is lacking. Thus, the purpose of this narrative review was to (a) summarize the available literature regarding the influence of AWI on body composition estimates derived from ADP, MF-BIA, and DXA and (b) provide evidence-based recommendations for researchers and practitioners. Studies indicate that AWI increases %BF estimates with ADP (4 of 6 [4/6] observations) and MF-BIA (6/7), whereas AWI increases muscle mass (6/6) and likely decreases %BF (2/3) when obtained by DXA. In conclusion, ADP, MF-BIA, and DXA are susceptible to confounding from AWI, leading to inaccurate body composition estimates that may negatively affect the careers of military personnel. Based on the findings from this narrative review, military practitioners and researchers should (a) follow manufacturer guidelines for calorie intake [food and fluid] and exercise avoidance, (b) conduct urine-specific gravity testing [if possible], and (c) limit AWI to <250 ml before assessment.

The correlation between hepatic controlled attenuation parameter (CAP) value and insulin resistance (IR) was stronger than that between body mass index, visceral fat area and IR

BackgroundHepatic controlled attenuation parameter (CAP) is a novel marker for quantifying hepatic fat accumulation. Insulin resistance (IR) plays a major role in the pathogenesis and natural history of hepatic steatosis. This study aimed to investigate the possible relationship between CAP value and IR.MethodsThis study included a total of 420 patients with overweight or obesity who came to the obesity clinic at Tianjin Union Medical Center. Vibration-controlled transient elastography examination was conducted to detect CAP and liver stiffness measurement (LSM) values. Body composition, including visceral fat area (VFA), and body fat mass (BFM), was evaluated by the direct segmental multi-frequency bioelectrical impedance analysis (BIA). The associations between CAP value, body mass index (BMI), VFA, BFM and homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed.ResultsCAP value was positively associated with HOMA-IR (r = 0.568, P < 0.001), the strength of which was much stronger than BMI, VFA, and BFM. In multivariate linear regression, CAP value and HOMA-IR showed a significant positive association (adjusted β = 0.015, 95% CI 0.007–0.022, P < 0.001). Subgroup analysis suggested no significant interaction between CAP value and HOMA-IR across age, BMI, LSM, hypertension, and sex groups (all P for interaction > 0.05).ConclusionsHepatic CAP value is more remarkably than other obesity markers associated with HOMA-IR in individuals with overweight or obesity, regardless of age, BMI, LSM, hypertension, and sex.

Analysis of hemodynamics and impedance using bioelectrical impedance analysis in hypovolemic shock-induced swine model

To treat hypovolemic shock, fluid infusion or blood transfusion is essential to address insufficient volume. Much controversy surrounds resuscitation in hypovolemic shock. We aimed to identify the ideal fluid combination for treating hypovolemic shock-induced swine model, analyzing bioelectrical impedance and hemodynamics. Fifteen female three-way crossbred pigs were divided into three different groups. The three resuscitation fluids were (1) balanced crystalloid, (2) balanced crystalloid + 5% dextrose water, and (3) balanced crystalloid + 20% albumin. The experiment was divided into three phases and conducted sequentially: (1) controlled hemorrhage (1 L bleeding, 60 min), (2) resuscitation phase 1 (1 L fluid infusion, 60 min), and (3) resuscitation phase 2 (1 L fluid infusion, 60 min). Bioelectrical impedance analysis was implemented with a segmental multifrequency bioelectrical impedance analyzer. A total of 61 impedance measurements were assessed for each pig at six different frequencies in five segments of the pig. Pulse rate (PR), mean arterial pressure (MAP), stroke volume (SV), and stroke volume variation (SVV) were measured using a minimally invasive hemodynamic monitoring device. The three-dimensional graph showed a curved pattern when infused with 1 L of balanced crystalloid + 1 L of 5% dextrose water and 1.6 L of balanced crystalloid + 400 ml of 20% albumin. The 1M impedance increased in all groups during the controlled hemorrhage, and continuously decreased from fluid infusion to the end of the experiment. Only balanced crystalloid + 20% albumin significantly restored MAP and SV to the same level as the start of the experiment after the end of fluid infusion. There were no significant differences in MAP and SV from the time of recovery to the initial value of 1M impedance to the end of fluid infusion in all groups. The change and the recovery of hemodynamic indices such as MAP and SV coincide with the change and the recovery of 1M impedance. Using balanced crystalloid mixed with 20% albumin in hypovolemic shock-induced swine model may be helpful in securing hemodynamic stability, compared with balanced crystalloid single administration.

The effect of regular chokeberry juice consumption on anthropometric and lipid parameters in women with overweight or obesity.

Aronia melanocarpa is nowadays valued for its high content of biologically active substances, the main group of which are polyphenols, which include anthocyanins, flavonols, flavanols, proanthocyanidins and phenolic acids. From the available sources, we can conclude that extracts and juices from black chokeberry have a great potential in human nutrition and influence on their health. The research was to evaluate the effect of regular consumption of 100% organic chokeberry juice on selected anthropometric and lipid parameters of overweight or obese women. A clinical study consisted of 19 women with overweight and obesity, age from 44 to 63. The probands consumed 50 ml of chokeberry juice daily for 8 weeks as part of their regular diet. Body composition and biochemical indicators were monitored before consumption, after 4 and 8 weeks of nutritional intervention. Body composition was determined using multifrequency bioelectrical impedance analysis (MFBIA) - InBody 720. Biochemical analyzes of blood serum were performed using standard methods in an accredited laboratory using automatic biochemical analyzer a BioMajesty JCA-BM6010/C. The monitored group of probands is characterized by menopausale and postmenopausale women, overweight or obese women with hypercholesterolemia without pharmacological treatment. Statistically significant differences (p<0.05) were observed when evaluating the amount of body fat (BFM) of the probands before the start of consumption and after the consumption of chokeberry juice. We noted a statistically significant reduction especially in the assessment of visceral fat (VFA) (p<0.001). There were no fundamentally significant changes in the lipid profile of women in this intervention study. With short-term consumption of chokeberry juice (after 4 weeks), we recorded an average reduction in total cholesterol and LDL-cholesterol, but without statistical significant. We also focused on the evaluation of the inflammatory marker CRP and noted a significant beneficial reduction of CRP (p˂0.05). In the research, we evaluated the effect of 8 weeks consumption of 100% chokeberry juice on selected anthropometric parameters, focusing on changes in visceral fat and total fat in overweight and obese women. In conclusion, we can state that the regular consumption of chokeberry juice has a beneficial effect on fat tissue in women of reproductive age, which can reduce the risk of cardiovascular diseases.

GDF-15 is associated with sarcopenia and frailty in acutely admitted older medical patients.

Growth differentiation factor-15 (GDF-15) has been associated with senescence, lower muscle strength, and physical performance in healthy older people. Still, it is not clear whether GDF-15 can be utilized as a biomarker of sarcopenia and frailty in the early stages of hospitalization. We investigated the association of plasma GDF-15 with sarcopenia and frailty in older, acutely admitted medical patients. The present study is based on secondary analyses of cross-sectional data from the Copenhagen PROTECT study, a prospective cohort study including 1071 patients ≥65years of age admitted to the acute medical ward at Copenhagen University Hospital, Bispebjerg, Denmark. Muscle strength was assessed using handgrip strength, and lean mass was assessed using direct segmental multifrequency bioelectrical impedance analyses and used to clarify the potential presence of sarcopenia defined according to guidelines from the European Working Group on Sarcopenia in Older People. Frailty was evaluated using the Clinical Frailty Scale. Plasma GDF-15 was measured using electrochemiluminescence assays from Meso Scale Discovery (MSD, Rockville, MD, USA). We included 1036 patients with completed blood samples (mean age 78.9±7.8years, 53% female). The median concentration of GDF-15 was 2669.3pg/mL. Systemic GDF-15 was significantly higher in patients with either sarcopenia (P<0.01) or frailty (P<0.001) compared with patients without the conditions. Optimum cut-off points of GDF-15 relating to sarcopenia and frailty were 1541 and 2166pg/mL, respectively. Systemic GDF-15 was higher in acutely admitted older medical patients with sarcopenia and frailty compared with patients without. The present study defined the optimum cut-off for GDF-15, related to the presence of sarcopenia and frailty, respectively. When elevated above the derived cutoffs, GDF-15 was strongly associated with frailty and sarcopenia in both crude and fully adjusted models.