Muscle-to-fat ratio in children and adolescents with type 1 diabetes in predicting glycaemic control and partial clinical remission.

BACKGROUND: Advances in treatment could mitigate the expected adverse changes in the body composition of children and adolescents with type 1 diabetes (T1D). OBJECTIVES: To examine the evolution of weight status and body composition and their association with glycaemic control and partial clinical remission in youth with T1D. METHODS: Ninety-nine participants with T1D (median age 9.5 years [interquartile range 7.3, 12.9], 59.6% boys) were longitudinally followed for 3 years since diagnosis. Data at seven pre-determined time points were extracted from medical files. Outcome measures included body mass index (BMI) z-scores, muscle-to-fat ratio (MFR) z-scores, haemoglobin A1c (HbA1c) levels, continuous glucose monitoring metrics, and insulin dose-adjusted HbA1c (IDAA1c) levels. RESULTS: The BMI z-scores increased significantly (p < 0.001) for both sexes, with no significant change in MFR z-scores over time. The girls had higher BMI z-scores (p < 0.001) and lower MFR z-scores than the boys (p = 0.016). The mean HbA1c levels decreased during the first month and at 3 months since diagnosis (p < 0.001), then plateaued and achieved a median overall HbA1c of 7.1% for the entire cohort. At 12 months, 37 participants (37.6%) were in partial clinical remission, as evidenced by IDAA1c ≤ 9. The odds of partial clinical remission at 2 years increased by 2.1-fold for each standard deviation increase in the MFR z-score (p < 0.001). Higher MFR z-scores were associated with better metabolic control. CONCLUSIONS: Integration of body composition assessments could mitigate adverse body changes in paediatric patients with T1D.

Correlates of Body Composition in Children with Stunting: A Cross-sectional Study in Uganda.

BACKGROUND: Development of body composition (BC) may be disrupted in children with stunting. Such disruption may affect the later risk of excess adiposity and metabolic health, yet few studies have investigated correlates of BC in children with stunting. OBJECTIVES: We aimed to investigate nutritional status, infection and inflammation, breastfeeding behaviors, and other factors as correlates of BC in children with stunting. METHODS: Among Ugandan children with a height-for-age z-score <-2, BC was estimated using bioelectrical impedance analysis and compared with United Kingdom references. We used multiple linear regression analysis to identify correlates of fat mass (FM), fat-free mass (FFM), FM-index (FMI), and FFM index (FFMI) and height, adjusting for gender and age. RESULTS: In 750 children aged 1-5 y, FMI was 0.46 (95% confidence interval [CI]: 0.38, 0.54] and FFMI 0.18 [95% CI: 0.11, 0.26) z-scores lower than United Kingdom references. Elevated serum α1-acid glycoprotein was associated with 1.14 [0.76, 1.52] cm lower height, 0.50 [0.35, 0.65] kg/m2 less FFMI, and 0.48 [0.31, 0.66] kg/m2 greater FMI. Similar, weaker, associations for elevated serum C-reactive protein were detected. A positive malaria rapid test was associated with 0.64 [0.25, 1.02] cm shorter height, but 0.36 [0.18, 0.54] kg/m2 greater FMI. Anemia (according to hemoglobin) was associated with 0.20 [0.07, 0.33] kg less FFM in proportion to shorter height. Longer breastfeeding duration was associated with 0.03 [0.02, 0.04] kg greater FFM per month, in proportion to greater height. CONCLUSIONS: These children exhibited deficits in FM and FFM, proportionally to their stunted height, compared with United Kingdom references. Systemic inflammation correlated inversely with linear growth and FFM but positively with fatness, making it a possible target for intervention where fat-free tissue accretion is desirable. Longer breastfeeding may offer protection to lean linear growth, but findings for micronutrients were less clear. Longitudinal studies are warranted to support these findings. The study was registered at www.isrctn.com (Ref. ISRCTN13093195).

Evaluation of the cachexia index using a bioelectrical impedance analysis in elderly patients with non-Hodgkin's lymphoma: A single-center prospective study.

Cancer cachexia is a disorder that affects patient outcomes. The present study prospectively evaluated the prognostic value of the cachexia index (CXI) in elderly patients with non-Hodgkin's lymphoma (NHL). We prospectively analyzed 51 elderly patients who were diagnosed with NHL at our institution. CXI was calculated as follows: CXI = SMI × Alb/NLR (SMI: skeletal muscle index, Alb: serum albumin, NLR: neutrophil-to-lymphocyte ratio). SMI was measured by a bioelectrical impedance analysis (BIA) using the InBody 720. We determined the sex-specific cutoff values of the CXI by a receiver operating characteristic curve analysis and divided all patients into low- and high-CXI groups. The median age at the diagnosis was 78 years (60-93 years), and 28 (55%) were male. The histologic subtypes were B-cell lymphoma in 49 patients and T-cell lymphoma in 2. Twenty-eight (55%) patients were categorized into the high-CXI group, and 23 (45%) were categorized into the low-CXI group. The overall survival (OS) in the low-CXI group was significantly shorter than that in the high-CXI group (3-year OS, 70.4% vs. 95.7%, p = 0.007). Among 23 patients with DLBCL, patients with low-CXI had shorter OS than those with high-CXI (3-year OS, 55.6% vs. 92.9%, p = 0.008). On the other hand, sarcopenia had less impact on the clinical outcome of DLBCL patients. Low-CXI was associated with poor outcomes in elderly NHL and the CXI may be a clinical useful index for predicting prognosis. Further large prospective studies are needed to verify this conclusion.

Total and segmental phase angle in a cohort of hospitalised patients with COVID-19: mortality prediction and changes throughout hospitalisation.

Body composition and phase angle (PhA) have been used to predict mortality in multiple diseases. However, little has been studied regarding segmental measurements, which could potentially help assess subtle changes in specific tissue segments. This study aimed to identify the total PhA cut-off point associated with mortality risk and changes in body composition within a week of hospitalisation in non-critical hospitalised patients with COVID-19. A cohort study was conducted where patients underwent to a complete nutritional assessment upon admission and after seven days, and followed up until hospital discharge or death. A receiver operating characteristic curve was constructed to determine the PhA cut-off point, and the Kaplan­Meier estimator was used to determine survival analysis. Segmental and complete body compositions on admission and after 7 d were compared. We included 110 patients (60 men) with a mean age of 50·5 ± 15·0 years and a median BMI of 28·5 (IQR, 25·6­33·5) kg/m2. The median length of hospital stay was 6 (IQR, 4­9) d, and the mortality rate was 13·6 %. The PhA cut-off point obtained was 4°, with significant differences in the survival rate (P < 0·001) and mortality (HR = 5·81, 95 % CI: 1·80, 18·67, P = 0·003). Segmental and whole-body compositions were negatively affected within one week of hospitalisation, with changes in the approach by the graphical method in both sexes. Nutritional status deteriorates within a week of hospitalisation. PhA < 4° is strongly associated with increased mortality in non-critical hospitalised patients with COVID-19.

Exploring the association between phase angle of bioimpedance at 50 kHz and cardiovascular risk.

BACKGROUND: Cardiovascular diseases are characterized by chronic inflammation, leading to increased inflammatory markers that can cause cell damage and death. Phase angle has emerged as a marker of cellular health. It is considered a prognostic factor in various acute and chronic conditions. However, few studies have examined its association with cardiovascular disease risk measures. This study aims to investigate the relationship between phase angle, the general Framingham risk score, and the HEARTS cardiovascular risk score. METHODS: This cross-sectional study included a convenience sample of adult patients of 2 primary health care services. Phase angle was measured using multifrequency bioimpedance analysis at 50 kHz. The risk of cardiovascular events was calculated using the Framingham and HEARTS risk scores. Statistical analysis included generalized linear regression models, unadjusted and adjusted according to sex and age, to determine the association between scores, risk factors, and phase angle. RESULTS: The study included 164 individuals with a mean age 52.2 (SD 17.9). According to the HEARTS score, low-risk patients had higher phase angle values than those with high or very high risk [ß = -0.57 (95% CI -0.95; -0.19), P = 0.003]. Framingham scores showed a trend toward significance for higher mean phase angle values in low-risk than high-risk patients [ß = -0.43 (95% CI -0.88 to 0.02), P = 0.06]. CONCLUSION: Phase angle values were lower in high and very high-risk patients than in low-risk patients, which shows that phase angle is a promising risk predictor for patients with cardiovascular diseases.

Effect of peritoneal dialysate on bioelectrical impedance analysis variability in pediatric patients receiving peritoneal dialysis.

BACKGROUND: Previous adult studies have yielded conflicting results regarding whether the presence (D +) or absence (D-) of peritoneal dialysate affects the accuracy of bioelectrical impedance analysis (BIA) measurements. The aim of this study was to investigate whether the accuracy of BIA data varies between D + and D- measurements in children. METHODS: This cross-sectional study recruited chronic kidney disease stage 5 patients aged 3 to 18 years who received peritoneal dialysis. Body composition was assessed by multifrequency BIA, and values were compared between D + and D- measurements using the intraclass correlation coefficient (ICC). RESULTS: Fifty paired BIA measurements were collected from 18 patients with a mean age of 13.6 ± 4.1 years and a mean dialysate fill volume of 1,006 ± 239.7 ml/m2. Sixteen out of 17 BIA parameters (94.1%) exhibited excellent correlations between D + and D- measurements (ICC values = 0.954, 0.998). There was a trend of increased fluid status, including extracellular water, edema index, and overhydration, in D + measurements, with mean differences (95% CIs) of 0.5 (0.4, 0.6) L, 0.002 (0.001, 0.002), and 0.1 (0.1, 0.2) L, respectively. Soft lean mass and fat-free mass were higher in D + measurements, with mean differences (95% CIs) of 1.4 (1.2, 1.6), and 1.6 (1.4, 1.8) kg, respectively. In addition, patients older than 10 years had a stronger correlation between D + and D- measurements than younger patients. CONCLUSIONS: A total of 94.1% of BIA parameters exhibited excellent correlations between D + and D- measurements, especially patients older than 10 years. We recommend that BIA measurements be collected from children regardless of the presence of peritoneal dialysate.

Hemoglobin and hematocrit levels are positively correlated with phase angle in mixed cancer patients: an exploratory cross-sectional study.

The aim of this study is to verify the correlation between hemoglobin (Hb) and hematocrit (Ht) levels with phase angle (PhA) values in patients with cancer of the gastrointestinal tract and accessory digestive organs. A cross-sectional study was conducted with 82 patients (38 females/44 males) diagnosed with cancer of gastrointestinal tract and accessory organs of digestion. Hb (g/dL) and Ht (%) levels were assessed by the cyanomethemoglobin and microhematocrit methods, respectively. Body composition and PhA were evaluated by the bioelectrical impedance analysis (BIA). The cut-off point used to classify patients with low PhA was set < 4°. Fifty-five (67%) of patients had PhA ≥ 4° values. We observed that body weight, BMI, fat mass, % weight loss, Ht, and Hb were higher in the PhA ≥ 4° group than in the PhA < 4° group. In the regression analysis, we found a positive association between PhA, Ht, and Hb without and after adjustment for sex, age, BMI, and type of treatment. In mixed cancer patients, there was a positive correlation between blood-red cell markers and PhA. This may be evidence that we can use of hematological parameters to suggest changes in PhA values during oncological treatment.

Comparison of body mass index and fat mass index to classify body composition in adolescents-The EVA4YOU study.

The objectives of this study were to develop age- and sex-specific reference percentiles for fat mass index (FMI) and fat-free mass index (FFMI) in adolescents aged 14 to 19 years and to determine differences in overweight/obesity classification by FMI and body mass index (BMI). The EVA4YOU study is a single-center cross-sectional study conducted in western Austria. Cardiovascular risks including anthropometric measurements and bioelectrical impedance analysis were assessed in adolescents (mean age 17 years). FMI and FFMI were calculated as the ratio of fat mass (FM) and fat-free mass (FFM) to the square of height and compared to study population-specific BMI percentiles. One thousand four hundred twenty-two adolescents were included in the analysis. Girls had a significantly higher mean FM and FMI and a significantly lower mean FFM, FFMI (p < 0.001, each), and mean BMI (p = 0.020) than boys. Body composition classification by FMI and BMI percentiles shows a concordance for the < 75th and > 97th percentile, but a significant difference in percentile rank classifications between these two cut-off values (all p < 0.05). Based on FMI, 15.5% (221/1422) of the whole population and 29.4% (92/313) of those between the 75th and 97th percentiles are classified one category higher or lower than those assigned by BMI. CONCLUSION:  Classification of normal or pathologic body composition based on BMI and FMI shows good accordance in the clearly normal or pathologic range. In an intermediate range, FMI reclassifies categories based on BMI in more than a quarter of adolescents. Cut-off values to differentiate normal from pathologic FMI values on a biological basis are needed. TRIAL REGISTRATION: The study is registered at www. CLINICALTRIALS: gov  (Identifier: NCT04598685; Date of registration: October 22, 2020). WHAT IS KNOWN: • Chronic non-communicable diseases (NCDs) are the leading cause of morbidity and mortality globally, with major risk factors including unhealthy diets, harmful behaviors, and obesity. Obesity in children and adolescents is a key risk factor for later NCDs, which is commonly measured by Body Mass Index (BMI). • BMI can be misleading as it doesn't distinguish between fat mass (FM) and fat-free mass (FFM), leading to potential misclassification of obesity in children. Previous studies have already suggested the use of the Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI) as a more accurate measures of body composition. WHAT IS NEW: • This study adds the first age- and sex-specific reference values for FMI and FFMI in Austrian adolescents using bioelectrical impedance analysis (BIA) as a safe and secure measurement method of a large representative cohort. • We found percentile misclassification between BMI and FMI when categorizing for obesity, especially in intermediate categories of body composition. Furthermore, when comparing the new reference values for FMI and FFMI to existing ones from the US, UK, and Germany we could show a good alignment within the European cohorts and major differences with American values, indicating and confirming the difference of FMI and FFMI for different populations of different ethnical background, living on different continents.

Reference data for body composition parameters in normal-weight Polish adolescents: results from the population-based ADOPOLNOR study.

The aim of this study was to develop age- and sex-specific reference data for body composition parameters, including fat-free mass (FFM), body cell mass (BCM), fat mass (FM) and related indices, fat mass percentage (FM%), total body water (TBW) and muscle mass (MM) and to assess differences in these parameters between male and female adolescents. Bioelectrical impedance analysis (BIA) data were obtained from an ethnically homogeneous sub-sample of 4037 normal-weight participants selected on the basis of BMI from the total sample (2005 males and 2032 females aged 10-18 years) of the ADOPOLNOR study, a cross-sectional population-based survey conducted in western Poland. The LMS method and RefCurv version 0.4.2 software package were used to calculate centile values and plot smoothed centile curves. The results showed age-related changes in body composition parameters and a clear sexual dimorphism. From the age of 13 (for FFM) or 14 (for BCM, BCMI and MM) or throughout adolescence (for TBW and FFMI), boys had consistently higher values for these parameters than girls (p < 0.01 for each). However, they had significantly lower values for FM, FMI and FM% (1.3, 1.6 and 1.5 times lower at 18 years, respectively), indicating a lower proportion of body fat than girls (p < 0.01 for each). The centile values and curves were specific for boys and girls of all ages. Compared with other European adolescent cohorts, the data fit the normal-weight subsamples better than the population reference data. CONCLUSION: This study provides reference data for body composition in normal (healthy) weight Polish adolescents, providing a contextualised framework that takes into account the unique physiological and environmental factors of the region. These reference data may also be useful for other Central European adolescents. WHAT IS KNOWN: • Adolescence is a period of significant physical growth and increased susceptibility to nutritional problems due to factors such as suboptimal nutrition, unhealthy dietary choices, inadequate physical activity and psychosocial stressors related to body image concerns. • Body composition (BC) parameters, rather than BMI alone, are more effective in identifying nutritional abnormalities and health risks such as eating disorders, obesity and chronic diseases. Existing studies provide reference data for BC parameters, but often do not cover all relevant measures or specific regional populations. WHAT IS NEW: • This study provides new age- and sex-specific reference values for a comprehensive range of body composition parameters, including body cell mass (BCM), total body water (TBW) and muscle mass (MM), in addition to fat-free mass (FFM) and fat mass (FM), in a large, ethnically homogeneous, normal-weight population of Polish adolescents aged 10-18 years. • These reference values for the normalweight cohort reflect healthy adolescent growth and body composition patterns, minimising bias from abnormal weight status. In addition, they can be applied to other Central European adolescent populations.

Nutritional assessment and medical dietary therapy for management of obesity in patients with non-dialysis chronic kidney disease: a practical guide for endocrinologist, nutritionists and nephrologists. A consensus statement from the Italian society of endocrinology (SIE), working group of the club nutrition-hormones and metabolism; the Italian society of nutraceuticals (SINut), club ketodiets and nutraceuticals "KetoNut-SINut"; and the Italian society of nephrology (SIN).

PURPOSE: Chronic kidney disease (CKD) is a serious health concern with an estimated prevalence of about 13.4% worldwide. It is cause and consequence of various comorbidities, including cardiovascular diseases. In parallel, common pathological conditions closely related to ageing and unhealthy dietary habits increase the risk of CKD development and progression, including type 2 diabetes and obesity. Among these, obesity is either independent risk factor for new onset kidney disease or accelerates the rate of decline of kidney function by multiple mechanisms. Therefore, the role of diets aimed at attaining weight loss in patients with obesity is clearly essential to prevent CKD as to slow disease progression. Various dietary approaches have been licensed for the medical dietary therapy in CKD, including low-protein diet and Mediterranean diet. Interestingly, emerging evidence also support the use of low-carbohydrate/ketogenic diet (LCD/KD) in these patients. More specifically, LCD/KDs may efficiently promote weight loss, improve metabolic parameters, and reduce inflammation and oxidative stress, resulting in a dietary strategy that act globally in managing collateral conditions that are directly and indirectly related to the kidney function. CONCLUSION: This consensus statement from the Italian Society of Endocrinology (SIE), working group of the Club Nutrition - Hormones and Metabolism; the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut"; and the Italian Society of Nephrology (SIN) is intended to be a guide for Endocrinologist, Nutritionists and Nephrologist who deal with the management of patients with obesity with non-dialysis CKD providing a practical guidance on assessing nutritional status and prescribing the optimal diet in order to best manage obesity to prevent CKD and its progression to dialysis.

Effects of a single dose of rocuronium in patients with different body fat percentages: A randomised controlled trial.

The pharmacodynamics in patients with high body fat percentage might be similar to those in obese patients. This randomised controlled clinical trial observed the effects of rocuronium in patients with different percent body fats (PBFs). Fifty-four patients who underwent elective urological or pelvic surgery under general anaesthesia at Shanghai General Hospital were included in the present study; 51 patients were included for data analysis. Patients with normal PBF (<25%) were given a single dose of rocuronium calculated based on total body weight (N-TBW, control group). Patients with a higher PBF (≥25%) were given a single dose of rocuronium calculated based on total body weight (H-TBW). Patients with higher PBF and rocuronium were dosed based on fat-free mass (H-FFM). A train of four (TOF)-Watch acceleromyography monitor was used to measure the effects of the rocuronium. H-TBW (91.9 ± 28.8 s) had significantly shorter onset time than N-TBW and H-FFM (p = 0.003). H-TBW had significantly longer clinical duration time and pharmacological duration time than the other groups (p = 0.000 and 0.000, respectively); the TOF ratio0.25-0.9 time was significantly different among the three groups (p = 0.005). There were no significant differences in the recovery time (p = 0.103) or recovery index (p = 0.159) among the three groups. The effects of rocuronium dosed based on FFM in patients with high PBFs are similar to those in normal patients. A single dose of rocuronium calculated based on TBW might shorten the onset time, prolong the clinical and pharmacological duration times, and prolong the recovery time.

Phase angle variability on bleeding risks in hemodialysis patients.

BACKGROUND: This study investigated the association between Phase Angle (PhA), measured by bioelectrical impedance analysis, and bleeding risk in hemodialysis patients to evaluate PhA as a predictive marker for bleeding events. METHODS: This retrospective cohort study included 102 hemodialysis patients who underwent PhA measurements between July 2019 and April 2024. Demographic data, medical histories, dialysis parameters, and bleeding events were collected. Patients were stratified by PhA values and followed for a median of 832 days (IQR: 516-1304 days). Multivariate Cox proportional hazards regression and Kaplan-Meier analysis were performed. RESULTS: The cohort had an average age of 74.0 years and a median dialysis vintage of 6.7 years. During follow-up, 19 patients (18.6%) experienced major bleeding events. Lower PhA was an independent risk factor for bleeding (HR: 0.24, 95% CI 0.11-0.52, p < 0.001). Kaplan-Meier analysis showed that patients with PhA ≥ 4.00 had a higher probability of remaining free from major bleeding at 2 years (94.3%) compared to those with PhA < 4.00 (75.0%) (p < 0.001). In 82 patients with repeat PhA measurements, bleeding event-free rates at 2 years were 97.5%, 75%, 100%, and 78.3% for the High to High, High to Low, Low to High, and Low to Low groups, respectively (p < 0.001). CONCLUSION: PhA is a predictive marker for bleeding risk in hemodialysis patients. Routine PhA monitoring could help stratify bleeding risk and optimize clinical management.

Body Composition after Endoscopic Lung Volume Reduction with Endobronchial Valves: A Prospective Study.

INTRODUCTION: Patients with chronic obstructive pulmonary disease (COPD) and emphysema experience malnutrition and pulmonary cachexia. Endoscopic lung volume reduction (ELVR) with endobronchial valves has not only improved lung function, exercise capacity, and quality of life but also influenced body weight. Only a few data are available on body composition changes after ELVR. METHODS: This single-center prospective study of patients with advanced COPD investigates body composition before and after endoscopic valve treatment using multifrequency bioelectrical impedance analysis (BIA). The following parameters were evaluated in addition to clinical data and routine tests: body weight, body mass index (BMI), basal metabolic rate, total body water, body fat, cell percentage, phase angle, intracellular water (ICW), extracellular water (ECW), extracellular mass (ECM), body cell mass (BCM), lean body mass (ECM + BCM), and fat-free mass index. RESULTS: A total of 23 patients (mean emphysema index 37.2 ± 7.5%, BMI 23.4 ± 4.3 kg/m2) experienced improvements in lung function and exercise capacity with ELVR. Complete lobar atelectasis was achieved in 39.1% of participants. A non-statistically significant increase in body weight and BMI was observed after ELVR (p = 0.111 and p = 0.102). BIA measurement revealed a worsening of phase angle, cell percentage and ECM/BCM and thus of body composition, but without statistical significance. This is mainly due to a statistically significant increase in ECM, ECW, and ICW (all p < 0.001). CONCLUSION: ELVR demonstrated no beneficial changes in body composition, although patients tend to gain weight. A larger cohort is warranted to confirm these findings.

Associations between bioelectrical impedance analysis-derived phase angle, protein-energy wasting and all-cause mortality in older patients undergoing haemodialysis.

AIM: Protein-energy wasting (PEW) is a common syndrome in patients undergoing haemodialysis (HD) and is associated with poor prognosis. Bioelectrical impedance analysis (BIA)-derived phase angle (PA) is useful for predicting PEW, but sex and age need to be considered. We aimed to reveal sex-specific cut-off values of PA predicting PEW in HD patients aged ≥65. METHODS: This two-centre retrospective cohort study included patients on HD who underwent BIA. PEW was detected using the International Society of Renal Nutrition and Metabolism (ISRNM) criteria as a reference. The PA was measured using a multifrequency bioimpedance device. Sex-specific cut-off values of PA predicting PEW were detected by receiver-operator characteristic analysis. We investigated the association between PEW determined using sex-specific cut-off values for PA and all-cause mortality. RESULTS: This study included 274 patients undergoing HD, with a median age of 75 (70-80) years, mean PA of 3.8 ± 1.1° and PEW of 43%. Over a median follow-up duration of 1095 (400-1095) days, 111 patients died. Cut-off values of PA predicting PEW were as follows: female, 3.00° (sensitivity, 87.3%; specificity, 77.5%), and male, 3.84° (sensitivity, 77.6%; specificity, 71.4%). The kappa coefficient between sex-specific cut-off values of the PA and ISRNM criteria had a moderate coincidence level of 0.55. PEW detected by PA was independently associated with all-cause mortality (hazard ratio: 2.40; 95% confidence interval: 1.51-3.85; p < .001). CONCLUSIONS: Sex-specific cut-off values for PA in older HD patients may be useful as a screening tool for predicting PEW and mortality.

Effect of lateral position on rostral fluid shift and relationship to severity of Cheyne-Stokes respiration in heart failure patients.

PURPOSE: Lateral sleep position has a significant beneficial effect on the severity of Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) in patients with heart failure (HF). We hypothesized that a reduction in rostral fluid shift from the legs in this position compared with the supine position may contribute to this effect. METHODS: In patients with CSR-CSA and an apnea-hypopnea index (AHI) ≥ 15/h (by standard polysomnography), uncalibrated leg fluid volume was measured in the supine, left lateral decubitus, and right lateral decubitus positions (in-laboratory assessment). The correlation between postural changes in fluid volume and corresponding changes in AHI was evaluated. Since there was no difference in both leg fluid volume and AHI between the right and left positions, measurements in these two conditions were combined into a single lateral position. RESULTS: In 18 patients with CSR-CSA, leg fluid volume increased by 2.7 ± 3.1% (p = 0.002) in the lateral position compared to the supine position, while AHI decreased by 46 ± 20% (p < 0.0001) with the same postural change. The correlation between postural changes in AHI and leg fluid volume was 0.22 (p = 0.42). Changes in leg fluid volume were a slow phenomenon, whereas changes in CSR-CSA severity were almost synchronous with changes in posture. CONCLUSION: Lateral position causes a reduction in rostral fluid shift compared to the supine position, but this change does not correlate with the corresponding change in CSR-CSA severity. The two changes occur on different time scales. These findings question the role of postural changes in rostral fluid shift as a determinant of corresponding changes in CSR-CSA severity.

Bioelectrical impedance phase angle combined with physical function predicts pre-frailty in maintenance hemodialysis patients: a prospective study.

BACKGROUND: The prevalence of pre-frailty is notably high among maintenance hemodialysis (MHD) patients. Pre-frailty, an early and reversible condition between non-frailty and frailty, can lead to adverse outcomes such as increased unplanned hospital admissions and a higher risk of other chronic diseases. Early identification and intervention of pre-frailty in MHD patients are crucial. This study aimed to establish a simple and effective model for screening and identifying MHD patients at high risk of pre-frailty by using 50 kHz-Whole Body Phase Angle (PhA) measured by bioelectrical impedance analysis (BIA), hand grip strength (HGS), the Five-Times-Sit-to-Stand Test (FTSST), and laboratory parameters, with a specific focus on gender differences. METHODS: This prospective cross-sectional study was conducted from September to December 2023 at the Wenjiang Hemodialysis Center in the Department of Nephrology, West China Hospital, Sichuan University, Chengdu, China. A total of 244 MHD patients, including 130 males and 114 females, were enrolled, comprising 128 non-frail and 116 pre-frail individuals. Data were collected prospectively, including demographic information, physical measurements, and laboratory test results. All participants provided informed consent before enrollment. The FRAIL scale (FS) was used to assess pre-frailty in MHD patients. Grip strength was measured using an electronic grip strength tester, physical function was assessed using the Five-Times-Sit-to-Stand Test, and whole-body phase angle was measured using the InBody S10 device. RESULTS: A total of 244 MHD patients with a mean age of 53.75 ± 0.90 years were enrolled, including 130 males with a mean age of 54.12 ± 1.26 years and 114 females with a mean age of 53.32 ± 1.29 years. ROC curve analysis showed that in male patients, the AUC of PhA for predicting pre-frailty was 0.919, with a sensitivity of 94.5% and specificity of 91.3%, and a cutoff value of 6.05°; in female patients, the AUC of PhA was 0.870, with a sensitivity of 70.5% and specificity of 90.6%, and a cutoff value of 5.25°. The AUC of FTSST for screening pre-frailty in male patients was 0.827, with a sensitivity of 62.3% and specificity of 96.2%, and a cutoff value of 12.95 s; in female patients, the AUC of FTSST was 0.784, with a sensitivity of 67.3% and specificity of 84.0%, and a cutoff value of 12.95 s. Additionally, in male patients, the combination of PhA and FTSST resulted in an AUC of 0.930, with a sensitivity of 96.4% and specificity of 81.3%; in female patients, the AUC was 0.911, with a sensitivity of 78.7% and specificity of 92.5%. CONCLUSION: PhA measured by BIA, in combination with the Five-Times-Sit-to-Stand Test, serves as an effective screening tool and predictor of pre-frailty in MHD patients. The combination of PhA and FTSST shows enhanced diagnostic value in female patients, while PhA alone is sufficient for predicting pre-frailty in male patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100051111), registered on 2021-09-13.

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

PURPOSE: 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 20-91 years. METHODS: Data from 5164 adults (2869 women and 2295 men; mean age ± standard deviation, 60.9 ± 15.6 years) 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 50 kHz 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. RESULTS: 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. CONCLUSION: 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.

Big data-based reference centiles for body composition in Korean children and adolescents: a cross-sectional study.

BACKGROUND: The changes in body composition during puberty not only contribute to the differences in body composition between adult males and females but also have associations with growth problems and metabolic disorders, including obesity. Therefore, understanding the changes in body composition during the pubertal period and analyzing reference values based on race and gender are essential research resources. The objective of this study was to generate reference centiles for body composition on a monthly basis using an extensive dataset of body composition information from Korean children and adolescents. METHODS: A total of 88,069 measurements from 22,515 children (11,062 boys and 11,453 girls) aged 7-16 years using a bioelectrical impedance analysis were included in the study after performing a Z-score-based data management procedure. Height, weight, body fat mass (BFM), and fat-free mass (FFM) were measured and used to derive body fat percentage (BF%), body mass index (BMI), fat mass index (FMI), and fat-free mass index (FFMI). Sex- and age-specific centiles were estimated using generalized additive models for location, scale, and shape with the Box-Cox Cole and Green distribution (i.e., lambda-mu-sigma method). RESULTS: The sex- and age-related disparities in body composition were most pronounced when weight was partitioned into BFM and FFM. In boys, the FFM increased markedly during pubertal growth spurts, whereas BFM remained relatively stable. In girls, the BFM increased steadily, whereas the rate of FFM increased slowly. The BMI increased steadily with age in both sexes. However, when BMI was parsed into FMI and FFMI, it became clear that the FFMI increased substantially during pubertal growth in boys, whereas the FMI peaked around age 11 and then declined. Conversely, the FMI increased steadily in girls, albeit with a slowing rate in the increase of the FFMI beginning around age 12. CONCLUSIONS: This study produced age- and sex-specific reference percentiles for body composition indices in Korean children and adolescents using extensive biometric data.

Phase Angle as a Reliable Biomarker of Frailty to Predict Postoperative Outcomes in Patients Undergoing Off-Pump Coronary Artery Grafting: A Prospective Observational Study.

OBJECTIVE: To elucidate the association between phase angle (PA) and a composite adverse outcome in patients requiring off-pump coronary artery bypass grafting (OPCAB). DESIGN: A prospective observational study. SETTING: High-volume single center. PARTICIPANTS: A total of 229 adult patients who underwent OPCAB from May 2019 to October 2020. INTERVENTIONS: Each patient underwent bioelectrical impedance analysis, including PA assessment before surgery (PApre), immediately postoperatively (PApost), and 1 day postoperatively (PAPOD1), using an Inbody S10. Frailty index and nutritional assessments also were obtained before surgery. MEASUREMENTS AND MAIN RESULTS: Patient outcomes were assessed using a composite adverse outcome comprising death, myocardial infarction, revascularization, new-onset atrial fibrillation, acute kidney injury, stroke, postoperative pulmonary complications, wound complications, sepsis, reoperation, and/or delirium occurring during hospitalization and over the following year. Patients for whom composite adverse outcomes were reported had lower PApre than those without complications (5.4 ± 0.9 v 6.0 ± 0.9, p < 0.001). The PA was significantly associated with in-hospital and 1-year composite postoperative outcomes. The odds ratios (OR, [95% confidence interval]) for PApre by time were in-hospital complications (0.435 [0.314, 0.604], p < 0.001; 1-year complications: 0.459 [0.330, 0.638], p < 0.001) and PAPOD1 (OR, in-hospital complications: 0.400 [0.277, 0.576], 1-year complications: 0.429 [0.298, 0.619], p < 0.001). The PApre was significantly associated with days alive and out of hospital until 1 year. The cut-off value of PApre for optimal prediction of in-hospital complications was 6.0 (area under the curve: 0.691 [0.623-0.758], p < 0.001). CONCLUSION: Low PA as an indicator of frailty is associated with adverse postoperative outcomes after OPCAB. Low PA may be employed as a noninvasive and practical tool for the prediction of prognosis in patients with coronary artery disease.

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.

BACKGROUND: Muscle 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. METHODS: Muscle 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. RESULTS: This 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. CONCLUSIONS: Evaluation and interventions that consider muscle quality rather than muscle mass are important.