Higher Phase Angle Research Articles

Raw bioelectrical data and physical performance in track and field athletes: Are there differences between the sexes in the relationship?

ObjectivesThe study aimed to investigate the relationship between raw bioelectrical data and physical performance in track and field athletes. Specifically, the objectives were to determine: 1) whether a regional bioelectrical impedance approach provides additional insights compared to whole-body analysis, 2) the reliability of the Levi Muscle Index (LMI) in this context, and 3) whether there are differences in these relationships between male and female athletes. DesignThis study utilized a cross-sectional design involving thirty-one female athletes (mean age 21.4 ± 3.8 years) and thirty male athletes (mean age 21.1 ± 2.6 years) from track and field. On a single day, participants underwent whole-body and regional bioelectrical impedance assessments focusing on the lower limbs, alongside strength and speed performance tests. ResultsThe study found no significant differences in the relationship between whole-body versus regional bioelectrical impedance and performance tests. Resistance (R) demonstrated an inverse correlation, while phase angle (PhA) and Levi Muscle Index (LMI) showed direct correlations with most performance variables in track and field athletes. Significant differences were observed between male and female athletes across all parameters, with male athletes exhibiting superior performance, higher PhA and LMI values, and stronger correlation coefficients compared to females. ConclusionsIn summary, this study highlights the intricate relationship between body composition and physical performance in athletes. It underscores the importance of considering sex differences and the reliability of raw bioelectrical data, whether obtained through regional or whole-body approaches, in assessing athletic performance.

Association between preoperative phase angle and all-cause mortality after cardiovascular surgery: A retrospective cohort study.

The importance of preoperative physical function assessment for post-operative intervention has been reported in older patients undergoing cardiovascular surgery. Phase angle (PhA), measured using bioelectrical impedance analysis, is an indicator of cellular health and integrity and is reported as a prognostic factor in several chronic diseases; however, its association with the long-term prognosis of cardiovascular surgery remains unclear. This study aimed to investigate the prognostic value of PhA for long-term mortality in patients undergoing cardiovascular surgery. This retrospective cohort study included consecutive patients who underwent elective cardiovascular surgery between October 2016 and March 2021 at Nagoya Heart Center, Japan. PhA was assessed using bioelectrical impedance analysis before surgery, and physical function measures (gait speed, grip strength and short physical performance battery [SPPB]) were measured synchronously. The association between PhA and all-cause mortality after discharge was assessed using Kaplan-Meier and multivariate Cox regression analyses. The incremental prognostic value of PhA was compared with other physical function measures using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). A total of 858 patients were included in the present analysis (mean age=68.4±11.9years, 67.6% male). PhA positively correlated with body mass index (ρ=0.38, P<0.001), skeletal muscle mass index (ρ=0.58, P<0.001), usual gait speed (ρ=0.44, P<0.001), grip strength (ρ=0.73, P<0.001) and SPPB (ρ=0.51, P<0.001). The mean follow-up period, within which 44 (4.7%) died, was 908.9±499.9days for the entire cohort. Kaplan-Meier survival curves based on the PhA tertiles showed that higher PhA was associated with better survival (log-rank test, P<0.001). The Cox regression analysis showed the independent association of PhA with mortality risk (hazard ratio: 0.91 per 0.1° increment; 95% confidence interval [CI]: 0.87-0.95; P<0.001). The NRI and IDI showed significant improvements in predicting mortality after adding PhA to the clinical model consisting of age, sex and cardiac and renal function (NRI: 0.426, 95% CI: 0.124-0.729, P=0.006; IDI: 0.037, 95% CI: 0.012-0.062, P=0.003). The predictive model consisting of the clinical model and PhA was superior to the model consisting of the clinical model and each of the other physical function indicators (P<0.05). PhA correlated with physical function and independently predicted long-term mortality after cardiovascular surgery. The additive prognostic value of PhA compared with the other physical function measures suggests the clinical usefulness of preoperative PhA for risk stratification in planning post-operative treatment and rehabilitation.

Plant-Based Emulsions as Dairy Cream Alternatives: Comparison of Viscoelastic Properties and Colloidal Stability of Various Model Products.

In the context of growing interest in plant-based food products for their potential health benefits and sustainability, this study investigates the effect of mono- and diglycerides of fatty acids application on physico-chemical properties of various plant-based cream products, compared to lecithin application in rice cream. Rheological and textural parameters, colour profile, and colloidal stability were analysed. The application of mono- and diglycerides modified the creams' viscoelastic behaviour, showing a decrease in viscoelasticity across the samples; although in oat-coconut cream resulted in a higher viscoelasticity, indicating the formation of a gel-like structure. Rice cream with lecithin emulsifier showed lower viscoelastic properties characterised by higher phase angle (tan δ). All samples behaved as pseudoplastic materials (with a flow behaviour index n < 1). For coconut and almond creams, the consistency coefficient increased and flow behaviour index decreased after emulsifier application. Interestingly, the emulsifier addition did not significantly affect the cream's colour profile, characterised by yellow hue angle (h*) as a dominant spectral component. The colloidal stability, indicated by a stability index (SI), was determined as well.

Somatotype and bioelectrical impedance vector analysis of Italian CrossFit® practitioners

ObjectivesCrossFit® is a high-intensity sport characterized by various workouts that require strength, speed, endurance, or agility, impacting participants' body composition. This observational study aimed to determine the morphological (anthropometrical and bioelectrical) profile of CrossFit® athletes and to compare them with other athletic populations. MethodsAnthropometrical measurements and bioelectrical vector analysis (classic and specific approaches) were performed on 145 CrossFit® practitioners (107 men aged 30.7 ± 8.4 years and 38 women aged 28.1 ± 6.7 years). Each participant's relative somatotype was calculated and compared between sexes and with a Spanish CrossFit® athletes' group. Resistance-reactance graphs and Hotelling's T2 test were applied to characterize the sample, compare them with an athletes' reference population, and identify differences between somatotype groups. ResultsThe most represented somatotype in both groups was the balanced mesomorph (male 3.5–5.2 - 1.7 and female 4.4–4.5 - 1.8). Compared with Spanish CrossFit® athletes, significant differences were denoted for men but not women (SAD = 2.3). The bioelectrical graphs indicated that the distribution of CrossFit® athletes is quite heterogeneous and within average values for the athlete's reference. The mesomorphic and endomorphic components were associated with a higher phase angle. ConclusionsCrossFit® practitioners predominantly present a mesomorphic component and show a body type like other power athletes, although with less pronounced characteristics. The somatotype may influence the vector's position in the RXc graphs. This study provided the bioelectrical tolerance ellipses for CrossFit® practitioners in classic and specific approaches for the first time.

The effect of aromatic side chains on the dilational rheological properties of N-acyltaurate amphiphiles at water-decane interfaces.

To elucidate the effect of aromatic side chains on dilational rheological properties of N-acyltaurate amphiphiles at the decane-water interface, the interfacial rheological properties of sodium N-2-(2-naphthoxy)-tetradecanoyltaurinate (12+N-T) and sodium N-2-(p-butylphenoxy)-tetradecanoyltaurinate (12+4B-T) were investigated utilizing the drop shape analysis method. The effects of adsorption time, interfacial pressure, oscillating frequency, and bulk concentration on the interfacial dilational modulus and phase angle were explored. The results show that the 12+4B-T molecule with a longer hydrophobic chain shows a higher ability for reducing the interfacial tension (IFT). In addition, the interfacial films of both 12+N-T and 12+4B-T are dominated by diffusion exchange at high concentrations. The rigidity of molecules controls the diffusion exchange at low concentrations, while the molecular hydrodynamic radius determines the diffusion exchange at high concentrations. Thus, at low concentrations, the stronger intermolecular interaction between 12+4B-T molecules results in higher dilational modulus values than 12+N-T. When approaching the CMC (critical micelle concentration) value, the rapid diffusion exchange of 12+4B-T between the sublayer micelles and the interface causes a significant decrease in the dilational modulus, while the relatively rigid structure of 12+N-T enables a higher dilational modulus than 12+4B-T. What's more, the longer hydrophobic chain allows 12+4B-T molecules to escape from the interface more easily, resulting in a higher phase angle at low concentrations. However, the diffusion exchange of 12+4B-T is slower than that of 12+N-T, which results in lower phase angles for 12+4B-T than 12+N-T at high concentrations. In general, the introduction of a rigid naphthalene ring in the molecular structure gives the interfacial film greater strength at high concentration. The research results in this paper provide a new technique for the strength regulation of interfacial surfactant adsorption films.

819 ELLIPSE: Electrical Impedance Analysis in Patients Undergoing Emergency Abdominal Surgery

Abstract Introduction An ageing population represents greater operative risk; therefore, preoperative risk stratification is required to allow patients to make an informed decision. One method of risk stratification is bioelectrical impedance analysis (BIA) which can provide information such as muscle and fat mass, providing a proxy for patient metabolic health. Aim Metabolic health is intrinsically linked to outcomes following surgery. We hypothesised that BIA is a feasible method of assessing patients undergoing emergency abdominal surgery and predicting postoperative outcomes. Method A BIA analyser was used to measure patients body composition. All adult patients who met the National Emergency Laparotomy Audit (NELA) inclusion criteria were prospectively recruited and followed up until 30 days postoperatively. These patients had serial BIA measurements and compared with a healthy population. The phase angle (PA) is a raw variable which can be standardised to a healthy reference population and matched for age and gender. In summary, a higher phase angle is associated with improved outcomes. Results 31 patients were recruited and BIA analysis in patients undergoing emergency abdominal surgery was feasible. Patients with a phase angle lower than the reference population had a greater incidence of complications (p = 0.03) and had more severe complications (p = 0.023). Furthermore, the same patients also had a significantly higher NELA morbidity percentage (p = 0.022). Conclusions Our study shows that conducting BIA analysis in patients undergoing emergency abdominal surgery is feasible. The presence and severity of complications correlates with the phase angle. This represents a successful proof of concept study of BIA to predict postoperative outcomes.

New bioelectrical impedance vector references and phase angle centile curves in 4,367 adults: The need for an urgent update after 30 years

The bioelectrical impedance vector analysis (BIVA) represents a qualitative analysis of body composition. The vector, defined by resistance (R) and reactance (Xc) standardized by stature, can be evaluated compared to the 50%,75%, and 95% tolerance ellipses representative of the reference populations. The tolerance ellipses for healthy adults have been provided in 1995 and were developed by mixing underage, adult, and elderly subjects, possibly misrepresenting the actual adult population. The current multicentric, cross-sectional study aimed to provide new tolerance ellipses specific for the general adult population and as a secondary aim to present centile curves for the bioelectrical phase angle. R, Xc, and phase angle were measured in 2137 and 2230 males and females using phase-sensitive foot-to-hand analyzers at 50kHz. A minimum of 35 subjects were included for each sex and age category from 18 to 65 years. The new mean vectors showed a leftward shift on the R-Xc graph with respect to the former reference values (males: F=75.3; p<0.001; females: F=36.6, p<0.001). The results provided new 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97th percentile curves for phase angle, identifying time point phases of decrement (males:-0.03° per year at 33.0-51.0 years and-0.05° per year after 51 years; females:-0.03° per year from 37.2 to 57.9 years). Compared to the original references, the new data are characterized by a different distribution within the R-Xc graph with a higher phase angle. Thirty years after the BIVA invention, the current study presents new tolerance ellipses and phase angle reference values for the adult population.

Skeletal muscle quality, measured via phase angle, and cardiorespiratory fitness in patients with obesity and heart failure with preserved ejection fraction

ObjectivesCardiorespiratory fitness (CRF) is influenced by body composition quantity and quality in heart failure with preserved ejection fraction (HFpEF) and obesity. Bioelectrical impedance analysis (BIA) provides a noninvasive quantitative and qualitative body composition assessment. The aim of this study was to determine the role of phase angle (PhA), a BIA-measure of skeletal muscle quality and body cell mass, on CRF in patients with obesity and HFpEF. MethodsFifty-nine consecutive outpatients with HFpEF underwent cardiopulmonary exercise testing to measure CRF. Single-frequency segmental BIA was used to measure PhA and body composition quantity. Resting Doppler echocardiography and biomarkers were measured to assess cardiac function and systemic inflammation. ResultsCompared with patients with lower PhA, patients with higher PhA (above mean 5.8°) presented a greater absolute peak oxygen consumption (VO2; 1.83 [1.3–2.1] versus 1.39 [1.1–1.6] L/min, P = 0.003), VO2 peak adjusted for body weight (17.5 [12.3–18.1] versus 13.3 [12.7–15.2] mL/kg/min, P = 0.040), and a lower edema index (48.7 [2.9] versus 51.4% [2.7], P < 0.001) and N-terminal pro-B-type natriuretic peptide (NT-proBNP; 64 [50–121] versus 183 [68–343.5] pg/dL, P < 0.001). In the overall sample, PhA was correlated with absolute VO2 peak (r = 0.468, P < 0.001), VO2 peak adjusted for body weight (r = 0.368, P = 0.004), VO2 peak adjusted for fat-free mass (r = 0.315, P = 0.015), edema index (r = –0.508, P < 0.001), and NT-proBNP (r = –0.579, P < 0.001). PhA remained a significant predictor for CRF even after adjustment for potential confounders and HFpEF severity. ConclusionIn patients with obesity and HFpEF, a greater PhA is an independent predictor for favorable CRF.

Association of 24-h movement behaviors with phase angle in community-dwelling older adults: a compositional data analysis.

Phase angle (PhA) is an indicator of cellular conditions. Recent studies have suggested that PhA supports healthy aging. Identifying modifiable lifestyle factors for PhA is important. The associations of PhA in 24-h movement behaviors, including physical activity (PA), sedentary behavior (SB), and sleep, have not been studied in older adults. We investigated the cross-sectional associations between 24-h movement behaviors and PhA in community-dwelling older adults while appropriately considering the co-dependent nature of daily time use using compositional data analysis. The participants were 113 healthy older adults. PhA was measured using a bioelectrical impedance device. Time spent in light-intensity PA (LPA), moderate- to vigorous-intensity PA (MVPA), and SB was measured using a tri-axial accelerometer. Sleep duration information was self-reported in a questionnaire. Compositional multiple linear regression and compositional isotemporal substitution were performed to examine the associations of 24-h movement behaviors with PhA and hypothetical time reallocation in movement behaviors with PhA, respectively. Even after adjusting for potential confounders, relative to other behaviors more time spent in MVPA was significantly associated with higher PhA (p < 0.001). The 30min/day of time reallocation from the other behaviors (SB, LPA, and sleep) to MVPA was predicted to be 0.12 higher PhA (corresponding to 2.3% increase; 95% CI 0.01, 0.24). Our results suggest that increasing or maintaining the daily time spent in MVPA is important for managing PhA in older adults, regardless of the other behaviors time consumed instead.

Modeling the Impact of Testing Mode on the Viscoelastic Behavior of Asphalt Concrete

The variations in the viscoelastic behavior of asphalt concrete due to testing mode is assessed and modeled in the present investigation. Asphalt concrete mixture was prepared at its optimum binder requirement and compacted in slab mold with the aid of roller compaction. Beam specimens of 62 mm width, 400 mm length, and 56 mm depth were extracted from the slab samples and tested using controlled stress and strain techniques under dynamic flexural stresses. The viscoelastic properties such as the cumulative dissipated energy, phase angle, flexural stiffness, micro strain, and permanent deformation were monitored and modeled among the two testing techniques. It was observed that higher permanent deformation and micro strain are detected when the test was conducted under constant strain mode. However, higher phase angle, flexural stiffness, and energy dissipation could be observed under constant stress mode of test.

The effects of a physical exercise program in Chinese kidney transplant recipients: a prospective randomised controlled trial.

Kidney transplant has become the preferred therapy for end-stage renal disease. However, kidney transplant recipients (KTRs) still face several challenges, such as physical inactivity. The purpose of this study was to explore the effects of a nurse-led physical exercise program in Chinese KTRs. A total of 106 participants were enrolled from the Third Xiangya Hospital of Central South University between July 2021 and June 2022 and randomly assigned to the control or intervention groups. Participants in the control group were provided with routine nursing care and participants in the intervention group received a nurse-led rigorous physical exercise program that was divided into two stages: the pre-discharge stage and the post-discharge stage. The pre-discharge stage included the non-ambulatory and ambulatory stages. The Chinese traditional exercise Baduanjin was incorporated into the physical exercise during the ambulatory stage. The post-discharge stage continued the same exercise as the ambulatory stage at home. After 3months of intervention, both groups received the same follow-up for 3months. The primary and secondary outcomes of all participants were collected. The data were analysed with repeated measures analysis of variance to examine the effectiveness of the intervention. Compared with the control group, the intervention group had less fatigue and more motivation to be active in primary outcomes. Moreover, patients in the intervention group had a higher phase angle, a longer 6-minute walk distance, more 30-second chair stand times and decreased anxiety and depression levels in secondary outcomes. No adverse events were observed during the intervention. There were no significant differences in all dimensions of the quality-of-life questionnaire between the intervention and the control group. Chinese KTRs could benefit from the nurse-led physical exercise program post-operatively. ChiCTR2100048755.

Cross‐sectional and longitudinal study of the relationship between phase angle and physical function in older adults

Although the validity of the assessment in older adults has been supported by several studies, cross-sectional and longitudinal relationships between phase angle (PhA) and physical function by sex have not been clarified. This study aimed to examine (i) cross-sectional relationships and (ii) longitudinal relationships between PhA and physical function in older adults. A total of 816 and 445 community-dwelling older adults were included in cross-sectional and longitudinal analyses, respectively. We evaluated their physical function using grip strength, 5-repetition sit-to-stand test (5-STS), 5-meter habitual walk, Timed Up and Go test (TUG), single-leg balance with eyes open, and sit-and-reach test. A multifrequency bioelectrical impedance analyzer was used to determine the PhA at 50 kHz as well as the participants' body composition. In the cross-sectional analysis, a higher PhA was significantly associated with higher grip strength, sit-and-reach, single-leg balance with eyes open, 5-STS and lower TUG in women, as well as higher grip strength, single-leg balance with eyes open, lower 5-STS and TUG in men, adjusting for age, body mass index and muscle mass. In the longitudinal analysis, there was a significant interaction between PhA and year in the TUG test (B=-0.08; 95% CI, -0.136 to -0.025; P=0.005) in men. There was no significant interaction between the PhA value and year for the other physical functions. The PhA is a useful indicator for assessing physical function in both older men and women. Furthermore, the PhA may be able to predict mobility limitation in older men. Geriatr Gerontol Int 2023; 23: 141-147.

Association between Phase Angle from Bioelectric Impedance and Muscular Strength and Power in Physically Active Adults.

Simple SummaryThis study compared muscle strength and power indicators in resistance-trained men by evaluating associations between phase angle and performance, while controlling for body composition. We evaluated dynamic muscle strength in bench press and back squat, and muscle power using the Wingate test and countermovement jump. Participants with higher phase angle displayed superior muscle strength of the upper limbs and greater muscle power of the lower limbs. Regarding countermovement jump and bench press, phase angle showed moderate association with performance, even after controlling for body composition. Still, lean soft tissue was the most important predictor of muscle strength and power.This study aimed to compare muscle strength and power indicators according to bioimpedance spectroscopy’s phase angle (PhA) values, in resistance-trained (RT) men, while exploring associations between PhA and performance. Forty-four men aged 18–45 years, engaged in RT, were allocated according to PhA tertiles. Lean soft tissue (LST) and fat mass (%FM) were assessed using dual-energy x-ray absorptiometry; dynamic muscle strength using 1 repetition maximum (1RM) of bench press (BP) and back squat (BS) and muscle power using Wingate test (WT) and countermovement jump (CMJ). For WT and CMJ, the 3rd tertile was significantly higher than the 1st tertile (p = 0.027 and p = 0.018, respectively). Regarding BP 1RM, the 3rd tertile was significantly higher than the 2nd tertile (p = 0.037). LST better explained the variability in the WT, BS and BP (p =< 0.001), while %FM better accounted for jump height in CMJ (p =< 0.001). PhA was a predictor of performance in both CMJ (p = 0.040) and BP (p = 0.012), independently of LST and %FM. Participants with higher PhA also displayed superior muscle strength of the upper limbs and greater muscle power of the lower limbs. PhA displayed significant moderate associations with performance in CMJ and BP, even after controlling for body composition. Still, LST was the most important predictor of muscle strength and power.

MO688: Peritoneal Protein Clearance, Inflammation, Nutrition and Overhydration in PD Patients: Looking for the Culprit

Abstract BACKGROUND AND AIMS Peritoneal protein loss has been for many years seen as a detrimental consequence of peritoneal dialysis (PD). Many studies correlated this leakage with mortality, malnutrition and inflammation. More recent knowledge has brought overhydration to this equation. This study aims to review classic and recent factors associated with peritoneal protein clearance and its consequences on overall mortality. METHOD Prevalent and incident PD patients were included. Interleukin 6 (IL-6; dialysate and serum) was obtained during a 3.86% glucose peritoneal equilibration test. Hydration and nutritional status was assessed by bioimpedance. Linear and Cox regression were performed. RESULTS A total of 78 patients were included (54 incident, 24 prevalent), the mean age was 54.6 ± 18.1 years, 65% were males, and the mean follow-up was 33.9 ± 29.3 months. The mean Charlson comorbidity index (CCI) was 4.4 ± 2.4. The residual GFR was 6.7 ± 3.6 mL/min/1.73 m2 and the D/P creatinine 0.65 ± 0.12. The IL-6 concentration in the dialysate was 24.9 ± 30.8 pg/mL and in serum was 37.3 ± 5.1 pg/mL. The phase angle was 5.4 ± 1.1°, overhydration 0.88 ± 0.94 L and peritoneal protein clearance 85.6 ± 54.7 mL/24 h. Overall, eight patients died. Linear univariable analysis showed positive associations between peritoneal protein clearance and (i) small solute transport, as measured by D/P creatinine, (ii) body composition, as measured by phase angle and overhydration and (iii) CCI. The peritoneal protein clearance also correlated positively with dialysate IL-6, but not with serum IL-6. By linear multivariable analysis, using the backward method, a significant positive association between peritoneal protein and overhydration (P &amp;lt; 0.001; IC:26.665–71.694) and also phase angle (P = 0.032; IC: 1.845–39.330) were validated. In the exploratory survival analysis, no relationship was found between mortality and peritoneal protein clearance. A univariable positive association was shown with serum IL-6 concentration, overhydration and CCI. A higher phase angle was associated with lower mortality. No relationship with dialysate IL-6 or D/P creatinine was found. In this early-stage PD population, with globally preserved residual kidney function, an effect of this variable on mortality was not evident. Cox regression, conditional backward method, showed CCI (OR: 1.896, IC: 1.235–2.913, P = 0.003), overhydration (OR: 10.034, IC: 1.426–70.587, P = 0.021) and peritoneal protein clearance (OR: 0.576, IC: 0.339–0.978, P = 0.041) were predictors for mortality. CONCLUSION A better nutrition status and overhydration are the major determinants of peritoneal protein clearance. The survival analysis showed that mortality is higher in overhydrated patients, with higher CCI, but not with higher peritoneal protein clearance. Inflammation, local or systemic, as assessed by IL-6 concentration, did not reveal to be such a strong prognosis predictor as overhydration in these PD patients.

A Higher Phase Angle Is Associated with Greater Metabolic Equivalents in Women 1 Year After Bariatric Surgery.

Phase angle (PhA), proposed as an indicator of the number, integrity, and function of cells and evaluated in some clinical situations, decreases after bariatric surgery (BS). In contrast, higher values are found in physically active or exercising individuals. We therefore evaluated the influence of physical activity on PhA after BS. The PhA and body composition (obtained by bioelectrical impedance analysis), physical activity level (obtained by International Physical Activity Questionnaire), and metabolic equivalents (METs) were evaluated in adult women submitted to BS. The PhA and body composition were evaluated at three time points: before and 6 and 12months after surgery. Physical activity level and METs were measured at the two postoperative time points. A reduction in PhA was observed 6 (p < 0.01) and 12months (p < 0.01) after BS, with no significant difference between time points. A moderate or high physical activity level was found in 81% of the volunteers after 6months and in 65% after 12months. METs were reduced after 12months compared to 6months. A positive correlation (p < 0.05) was observed between PhA and body cell mass after surgery. There was a significant positive correlation (p < 0.01) between PhA and METs after 12months. Physical activity may attenuate the PhA reduction that occurs after BS, with this parameter reflecting the engagement of these patients in this type of activity.

Bioimpedance Phase Angle as a Prognostic Tool in Late-Onset Pompe Disease: A Single-Centre Prospective Study With a 15-year Follow-Up.

Background: Late-onset Pompe disease (LOPD) is an autosomal-recessive metabolic myopathy caused by deficiency of the lysosomal enzyme Acid Alpha—Glucosidase (GAA), leading to glycogen accumulation in proximal and axial muscles, and in the diaphragm. Enzyme Replacement Therapy (ERT) with recombinant GAA became available in 2006. Since then, several outcome measures have been investigated for the adequate follow-up of disease progression and treatment response, usually focusing on respiratory and motor function. Prognostic factors predicting outcome have not been identified till now. Methods: In this single Centre, prospective study, we evaluate the response to enzyme replacement therapy in 15 patients (7 males) with LOPD in different stages of disease, aged 49.4 ± 16.1, followed-up for 15 years. Treatment response was measured by the 6-min walking test, vital capacity in supine and upright position, respiratory muscle strength, muscle MRI, manual muscle testing. We investigated the usefulness of Body Impedance Vectorial Analysis for serial body composition assessment. Results: Although most patients with LOPD benefit from long-term treatment, some secondary decline may occur after the first 3–5 years. Some nutritional (lower body mass index, higher fat free mass, higher phase angle) and disease parameters (higher creatinine and shorter disease duration at the beginning of treatment) seem to predict a better motor outcome. Lower Phase Angle, possibly reflecting loss of integrity of skeletal muscle membranes and thus treatment mis-targeting, seems to correlate with worse treatment response on long-term follow-up. Conclusion: Body Impedance Vectorial Analysis is a fast, easily performed and cheap tool that may be able to predict long-term treatment response in patients with LOPD. Low Phase angle may serve as a marker of muscle quality and may be used to predict the response to a muscle-targeted intervention such as ERT, thus improving the identification of patients needing a closer follow-up due to higher fragility and risk of deterioration.

Impact of β−hydroxy-β−methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT

Muscle wasting deteriorates life quality after critical illness and increases mortality. Wasting starts upon admission to intensive care unit (ICU). We aimed to determine whether β-hydroxy-β-methylbutyrate (HMB), a metabolite of leucine, can attenuate this process. Prospective randomized, placebo-controlled double blind trial. ICU patients depending on mechanical ventilation on day 3 having a functional gastrointestinal tract. They were randomized to HMB (3g/day) or placebo (maltodextrin) from day 4 on for 30 days. magnitude of loss of skeletal muscle area (SMA) of the quadriceps femoris measured by ultrasound at days 4 and 15. body composition, change in protein metabolism assessed by amino acids tracer pulse, and global health at 60 days. Data are mean [95% CI]. Statistics by ANCOVA with correction for confounders sex, age and/or BMI. Thirty patients completed the trial, aged 65 [59, 71] years, SAPS2 score 48 [43, 52] and SOFA 8.5 [7.4, 9.7]. The loss of total SMA was 11% between days 4 and 15 (p<0.001), but not different between the groups (p=0.86). In the HMB group, net protein breakdown (Δ Estimate HMB-Placebo:-153 [-242,-63]; p=0.0021) and production of several amino acid was significantly reduced, while phase angle increased more (0.66 [0.09, 1.24]; p=0.0247), and SF-12 global health improved more (Δ Estimate HMB-Placebo: 27.39 [1.594, 53.19], p=0.04). HMB treatment did not significantly reduce muscle wasting over 10 days of observation (primary endpoint), but resulted in significantly improved amino acid metabolism, reduced net protein breakdown, a higher phase angle and better global health. CLINICALTRIALS. NCT03628365.

Determination of rheological properties of bio-asphalt binders through experimental and multilayer feed-forward neural network methods

• Conventional properties and high-temperature rheological performance of CPO-modified bitumen in unaged and RTFO-aged conditions were investigated. • Bio-asphalt modified with 5% CPO showed almost similar high-temperature performance of base bitumen. • ANN approach was utilised to model G* and δ of bio-asphalt binders. • The proposed ANN technique is satisfactory for fast and accurate modeling of the G* and δ of bio-asphalt binders. This study seeks to determine the rheological properties of unaged and RTFO-aged bio-asphalt binders using experimental and modelling methods. Crude palm oil (CPO) was used as a bio-oil at varying percentages of 0, 5, 10 and 15% by total weight of asphalt binder. The dynamic shear rheometer (DSR) was used to investigate the rheological properties of bio-asphalt binders. The multilayer feed-forward neural network method was used to predict the complex modulus and phase angle of bio-asphalt binders by virtue of its ability to learn and adapt. Result of the DSR analysis showed that the complex modulus of bio-asphalt with 5% CPO is almost similar as that of the base asphalt binder, and that higher CPO content resulted in reduced complex modulus and higher phase angle. Result of the modelling shows that all models have an R 2 value greater than 0.99, thus indicating the good agreement between the predicted and the experimental results.

Phase angle: medical interpretations and applications

Specialists are interested in using bioimpedance technology to assess the rate of metabolic processes and body composition; thus, this study aimed to determine the possibilities of the clinical application of the phase angle, which is a parameter that is specific for the bioimpedance method to obtain body composition information. In nutrition assessment, the phase angle is used as an indirect characteristic of the protein fraction of the body and the rate of metabolic processes.&#x0D; In the early 2000s, low values of the phase angle in diseased catabolic orientation were shown to assess the survival rate whereas high values assess the muscular system fitness in athletes and other individuals who regularly experience physical exertion. Systematic reviews and Meta-analyzes of subsequent years have summarized the evidence based on these provisions and identified several new applications for sarcopenia, anorexia, and renal failure. Therefore, all the reviews presented in this study confirm that higher phase angle values correspond to a better state of the body and that phase angle can dynamically change in an individual patient. This feature of the parameter requires a detailed understanding of the variability of values depending on measurement conditions.&#x0D; The phase angle is recognized as a convenient diagnostic tool and a convenient parameter for screening examinations. At high values, it reflects the degree of muscular system fitness, and at low values, the severity of catabolic disorders due to existing diseases or immobilization.

Frequency and Risk Factors for Reverse Triggering in Pediatric Acute Respiratory Distress Syndrome during Synchronized Intermittent Mandatory Ventilation

Rationale: Reverse triggering (RT) occurs when respiratory effort begins after a mandatory breath is initiated by the ventilator. RT may exacerbate ventilator-induced lung injury and lead to breath stacking.Objectives: We sought to describe the frequency and risk factors for RT among patients with acute respiratory distress syndrome (ARDS) and identify risk factors for breath stacking.Methods: We performed a secondary analysis of physiologic data from children on synchronized intermittent mandatory pressure-controlled ventilation enrolled in a single-center randomized controlled trial for ARDS. When children had a spontaneous effort on esophageal manometry, waveforms were recorded and independently analyzed by two investigators to identify RT.Results: We included 81,990 breaths from 100 patient-days and 36 patients. Overall, 2.46% of breaths were RTs, occurring in 15/36 patients (41.6%). A higher tidal volume and a minimal difference between neural respiratory rate and set ventilator rate were independently associated with RT (P = 0.001) in multivariable modeling. Breath stacking occurred in 534 (26.5%) of 2,017 RT breaths and in 14 (93.3%) of 15 patients with RT. In multivariable modeling, breath stacking was more likely to occur when total airway Δpressure (peak inspiratory pressure - positive end-expiratory pressure [PEEP]) at the time patient effort began, peak inspiratory pressure, PEEP, and Δpressure were lower and when patient effort started well after the ventilator-initiated breath (higher phase angle) (all P < 0.05). Together, these parameters were highly predictive of breath stacking (area under the curve, 0.979).Conclusions: Patients with higher tidal volume who have a set ventilator rate close to their spontaneous respiratory rate are more likely to have RT, which results in breath stacking >25% of the time.Clinical trial registered with ClinicalTrials.gov (NCT03266016).