Development of a bioelectrical impedance analysis-based prediction equation for body composition of rural children aged 4-8 years in Myanmar.

Background: Reliable and accurate estimates of body composition are essential when studying the various health correlates of disease. Bioelectrical impedance analysis (BIA) is an affordable and feasible body composition assessment technique for clinical and field settings. Total body water (TBW) and hence fat-free mass is estimated by predictive regression algorithms using anthropometric measurements plus the resistance index. Aim: The study aimed to develop a BIA prediction equation for TBW in children in Myanmar using the deuterium dilution technique as the reference method. Methods: The study design was cross-sectional in a school setting with convenience sampling of participants. One hundred and two healthy children (57 boys and 45 girls) with aged 4 and 8 years participated; randomly divided into the prediction group (29 boys and 22 girls) and cross-validation group (28 boys and 23 girls). Whole-body impedance, anthropometric and TBW (by D2O dilution) measurements. The prediction equation was cross-validated using a split-group design and compared to published equations for contemporaneous populations. Results: TBW could be predicted by the following equation. TBW = 0.4597 * Weight (kg) + 0.1564 * Impedance index + 0.6075 (R2 = 0.891, P < 0.0001) with a correlation coefficient of 0.942 and limits of agreement of 0.98 kg TBW on cross-validation. Conclusions: This equation can be used to predict body composition in young (aged 4-8 years) children in Myanmar but because the age range of the participants in the present study was relatively narrow, more research in different age groups is required to establish its broader applicability.

Bioimpedance basics and phase angle fundamentals.

Measurement of phase angle using bioimpedance analysis (BIA) has become popular as an index of so-called "cellular health". What precisely is meant by this term is not always clear but strong relationships have been found between cellular water status (the relative amounts of extra- and intracellular water), cell membrane integrity and cellular mass. Much of the current research is empirical observation and frequently pays little regard to the underlying biophysical models that underpin the BIA technique or attempts to provide mechanistic explanations for the observations. This brief review seeks to provide a basic understanding of the electrical models frequently used to describe the passive electrical properties of tissues with particular focus on phase angle. In addition, it draws attention to some practical concerns in the measurement of phase angle and notes the additional understanding that can be gained when phase angle are obtained with bioimpedance spectroscopy (BIS) rather than single frequency BIA (SFBIA) along with the potential for simulation modelling.

Importance of health assessments for conservation in noncaptive wildlife.

Wildlife health assessments help identify populations at risk of starvation, disease, and decline from anthropogenic impacts on natural habitats. We conducted an overview of available health assessment studies in noncaptive vertebrates and devised a framework to strategically integrate health assessments in population monitoring. Using a systematic approach, we performed a thorough assessment of studies examining multiple health parameters of noncaptive vertebrate species from 1982 to 2020 (n = 261 studies). We quantified trends in study design and diagnostic methods across taxa with generalized linear models, bibliometric analyses, and visual representations of study location versus biodiversity hotspots. Only 35% of studies involved international or cross-border collaboration. Countries with both high and threatened biodiversity were greatly underrepresented. Species that were not listed as threatened on the International Union for Conservation of Nature Red List represented 49% of assessed species, a trend likely associated with the regional focus of most studies. We strongly suggest following wildlife health assessment protocols when planning a study and using statistically adequate sample sizes for studies establishing reference ranges. Across all taxa blood analysis (89%), body composition assessments (81%), physical examination (72%), and fecal analyses (24% of studies) were the most common methods. A conceptual framework to improve design and standardize wildlife health assessments includes guidelines on the experimental design, data acquisition and analysis, and species conservation planning and management implications. Integrating a physiological and ecological understanding of species resilience toward threatening processes will enable informed decision making regarding the conservation of threatened species.

Importancia de los exámenes diagnósticos para la conservación de fauna silvestre Resumen Los exámenes diagnósticos de fauna silvestre ayudan a identificar poblaciones en riesgo por desnutrición, enfermedades infecciosas y disminución poblacional, causadas por impactos antropogénicos. Revisamos los estudios disponibles que llevaron a cabo exámenes diagnósticos en fauna silvestre y diseñamos un marco de trabajo para integrar dichos exámenes en monitoreos poblacionales. Empleando un enfoque sistemático, evaluamos aquellos estudios que examinaban múltiples indicadores de salud en vertebrados no cautivos entre 1982 y 2020 (n = 261 estudios). Cuantificamos las tendencias estadísticas, clasificadas por taxones, del diseño del estudio y de los métodos diagnósticos usando modelos lineales generalizados, análisis bibliométricos y representaciones visuales del lugar de estudio versus los hotspots (puntos calientes) de biodiversidad. Sólo el 35% de los estudios incluían colaboraciones internacionales o transfronterizas, y los países ricos en biodiversidad y especies amenazadas estaban gravemente subrepresentados. Las especies no clasificadas como amenazadas en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza representaban el 49% de las especies examinadas; una tendencia posiblemente asociada al enfoque regional de la mayoría de los estudios. Recomendamos encarecidamente seguir protocolos diagnósticos y manuales de técnicas del estudio de la fauna silvestre, además de usar tamaños muestrales estadísticamente adecuados al establecer rangos de referencia. Los métodos diagnósticos más comunes para todos los taxones fueronanálisis sanguíneos (89%), evaluaciones de composición corporal (81%), exámenes físicos (72%) y análisis fecales (24% de los estudios). Presentamos un marco conceptual para mejorar y estandarizar los exámenes diagnósticos en estudios de fauna silvestre; dicho marco incluye guías para el diseño experimental, para la obtención y el análisis de datos, y para elaborar planes de acción para especies amenazadas. La combinación de conocimientos fisiológicos y ecológicos, relacionados con la resiliencia biológica de especies amenazadas, facilitará una toma de decisiones eficiente para el manejo y para la conservación de la biodiversidad.

Standardization of lower extremity quantitative lymphedema measurements and associated patient-reported outcomes in gynecologic cancers.

Practice changing standardization of lower extremity lymphedema quantitative measurements with integrated patient reported outcomes will likely refine and redefine the optimal risk-reduction strategies to diminish the devastating limb-related dysfunction and morbidity associated with treatment of gynecologic cancers. The National Cancer Institute (NCI), Division of Cancer Prevention brought together a diverse group of cancer treatment, therapy and patient reported outcomes experts to discuss the current state-of-the-science in lymphedema evaluation with the potential goal of incorporating new strategies for optimal evaluation of lymphedema in future developing gynecologic clinical trials.

Human milk immunomodulatory proteins are related to development of infant body composition during the first year of lactation.

BACKGROUND: To investigate relationships between infant body composition (BC) and human milk (HM) immunomodulatory proteins (IMPs) during the first 12 months of lactation. METHODS: BC of breastfeeding dyads (n = 20) was measured with ultrasound skinfolds (infants) and bioimpedance spectroscopy (infants/mothers) at 2, 5, 9, and/or 12 months post partum. Breastfeeding frequency, 24-h milk intake, and IMP concentrations (lactoferrin, lysozyme, secretory immunoglobulin A (sIgA)) were measured, and calculated daily intakes (CDIs) were determined. We used linear regression/mixed-effects models and adjusted results for multiple comparisons. RESULTS: No associations were seen between maternal characteristics and IMP concentrations/CDIs or between IMP concentrations and infant BC. Lactoferrin CDI was negatively associated with infant fat-free mass index (P = 0.002); lysozyme CDI was positively associated with infant fat mass (P = 0.004) and fat mass index (P = 0.004) measured with ultrasound skinfolds. CONCLUSION: In this small cohort of infants breastfed on demand during first year of life, we report differential associations of HM IMPs with infant BC, showing that in addition to their critical role in shaping infant immunity, lactoferrin, and lysozyme also influence development of infant BC, highlighting the importance of breastfeeding for 12 months and beyond. IMPACT: HM IMPs (concentrations and, most importantly, daily intakes) time-dependently and differentially associate with development of infant lean mass and adiposity during first 12 months of lactation. There is no information on how intakes and concentrations of these components affect development of infant BC. HM contains IMPs-lactoferrin, lysozyme, and sIgA, which not only play a critical role in shaping infant's immunity, but also influence infant growth and development of BC, highlighting the importance of breastfeeding for 12 months and beyond and warranting careful consideration of the dose effects of supplemented formula.

Comparison of segmental lean tissue mass in individuals with spinal cord injury measured by dual energy X-ray absorptiometry and predicted by bioimpedance spectroscopy.

STUDY DESIGN: Observational. OBJECTIVES: To compare two methods for predicting segmental (arms, legs, trunk) lean tissue mass (LTM: non-bone fat-free mass) from bioimpedance spectroscopy (BIS) against LTM measured from dual energy X-ray absorptiometry (DXA) in individuals with acute spinal cord injury (SCI). SETTING: Austin Health Victorian Spinal Cord Service, Victoria, Australia. METHODS: Fourteen participants (two female), within 8 weeks of traumatic SCI had BIS measured following an overnight fast and within 24 h of DXA scanning. Total body fat-free mass (FFM, body weight minus fat mass) and segmental LTM were predicted from BIS using manufacturer's proprietary software and a previously established SCI-specific prediction method. Appendicular LTM (ALM) was calculated from the sum of the LTM of the arms and legs. Agreement and strength of relationships with DXA for predicted LTM measures using both approaches were assessed using Lin's concordance coefficient and limits of agreement analysis (LOA). RESULTS: The BIS proprietary method performed better than the SCI-specific prediction method in predicting DXA LTM, demonstrating substantial concordance for total body FFM (rc = 0.80), ALM (rc = 0.78), arm (rc = 0.76) and leg LTM (rc = 0.65) and a smaller bias and LOA for ALM (+0.8 vs. -3.4 kg; LOA -4.9-6.4 vs. -11.9-5.1 kg), arm (+0.02 vs. -0.3 kg; LOA -1.1-1.1 kg vs. -2.2-1.6 kg) and leg (+0.4 vs. -1.4 kg; LOA -2.0-2.8 vs. -5.6-2.8) LTM. CONCLUSIONS: BIS can be used to accurately predict total body FFM, segmental LTM and ALM in individuals with acute SCI.

Incidence and risk factors for lower limb lymphedema associated with endometrial cancer: Results from a prospective, longitudinal cohort study.

BACKGROUND: Evidence on the incidence and risk factors for lower limb lymphedema (LLL) associated with endometrial cancer is limited. Our objective was to use data from a prospective, longitudinal gynecological cancer cohort study to determine LLL incidence up to 24 months post-diagnosis of endometrial cancer and to explore the relationship between personal and treatment-related factors and risk of developing LLL. METHODS: Women recently diagnosed with endometrial cancer (n = 235) were evaluated at regular intervals post-diagnosis (up to 3-monthly) using bioimpedance spectroscopy (BIS) and self-reported leg swelling (SRLS). RESULTS: Incidence of LLL at 24 months post-diagnosis was 33% and 45% according to BIS and SRLS, respectively. When analyses were restricted to obese women, incidence at 24 months post-diagnosis increased to 67% (BIS) and 54% (SRLS). Following adjusted analyses, higher body mass index was associated with higher odds of baseline lymphedema (BIS: OR 1.91, 95% CI 1.47-2.49, p < .01; SRLS: OR 1.06, 95% CI 1.00-1.12, p < .01) and LLL incidence by 24 months post-diagnosis (BIS: OR 1.29, 95% CI: 0.99-1.68, p = .055; SRLS: OR 1.06, 95% CI 1.02-1.11, p = .008). According to SRLS, presence of comorbidities was also associated with baseline lymphedema (OR: 1.43, 95% CI: 1.15-1.78, p = .001), and more extensive lymph node dissection (OR 1.06, 95% CI: 1.01-1.12, p = .026) and receipt of chemotherapy (OR: 2.65, 95% CI: 1.12-6.29, p = .027) were identified as risk factors for lymphedema incidence. CONCLUSIONS: These findings suggest that LLL following endometrial cancer is common, particularly in women with high body mass index, or comorbidities, and those requiring more extensive lymph node dissection or chemotherapy. Future studies should examine the potential of weight loss intervention as a strategy to reduce LLL incidence.

An evaluation of phase angle, bioelectrical impedance vector analysis and impedance ratio for the assessment of disease status in children with nephrotic syndrome.

BACKGROUND: Oedema, characterized by accumulation of extracellular water (ECW), is one of the major clinical manifestations in children suffering from nephrotic syndrome (NS). The lack of a simple, inexpensive and harmless method for assessing ECW may be solved by the use of the bioelectrical impedance analysis (BIA) technique. The aims of this study were to examine whether phase angle (PA), bioelectrical impedance vector analysis (BIVA) and the impedance ratio (IR) reflect change in disease status in children with NS. METHODS: Eight children (age range: 2-10 years) with active NS (ANS group) were enrolled. In five of these (ANS* subgroup), impedance was also measured at remission (NSR group). Thirty-eight healthy children (age range: 2-10 years) were included as healthy controls (HC group). Whole-body impedance was measured with a bioimpedance spectroscopy device (Xitron 4200) with surface electrodes placed on the wrist and ankle. RESULTS: Values of PA, BIVA and IR were found to be significantly lower (p-value range < 0.001 to < 0.01) in the ANS patients compared to the HC and NSR groups. No significant differences were observed between the NSR and HC groups. CONCLUSION: The studied parameters can be used to assess change in disease status in NS patients. Data were consistent with NS being associated with expansion of ECW.

Comparison of estimated energy requirements using predictive equations with total energy expenditure measured by the doubly labelled water method in acute spinal cord injury.

STUDY DESIGN: Prospective, observational OBJECTIVES: To evaluate agreement between a reference method (doubly labelled water, DLW) of total energy expenditure (TEE) and published equations for estimating energy requirements in acute spinal cord injury (SCI). SETTING: Victoria, Australia METHODS: Twenty participants (18 male) within 8 weeks of traumatic SCI completed DLW, anthropometric and dietary intake assessments. Energy requirements were predicted using Harris-Benedict, Schofield, Henry, Nelson, Buchholz and Chun equations, multiplied by a combined activity and stress factor of 1.3, and the ratio method (kJ/kg body weight). Fat-free mass (FFM) and fat mass (FM) were calculated from TBW-derived DLW and from bioelectrical impedance spectroscopy (BIS). RESULTS: Median time since injury was 41 days. Median TEE was 9.1 MJ. Fair agreement was found between TEE and predicted energy requirements for the Chun (rc = 0.39), the Harris-Benedict equation (rc = 0.30), the ratio method (rc = 0.23) and the Buchholz (rc = 0.31) and Nelson equations (rc = 0.35), which incorporate measures of FFM and/or FM. Other equations showed weak concordance with DLW. When two hypermetabolic patients were removed, agreement between TEE and predicted energy requirements using the Buchholz equation increased to substantial (rc = 0.72) and using the Nelson (rc = 0.53) and Chun equations (rc = 0.53) increased to moderate. The Buchholz equation had the smallest limits of agreement (-2.4-2.3 MJ/d). CONCLUSION: The population-specific Buchholz equation that incorporates FFM, predicted from either BIS or DLW, demonstrated the best agreement in patients with acute SCI. SPONSORSHIP: The study was funded by grants from the Institute for Safety, Compensation and Recovery Research (ISCRR Project # NGE-E-13-078) and Austin Medical Research Foundation. M Panisset was supported by an Australian Postgraduate Award.

Bioimpedance Resistance Indices and Cell Membrane Capacitance Used to Assess Disease Status and Cell Membrane Integrity in Children with Nephrotic Syndrome.

BACKGROUND: Accumulation of extracellular water (ECW) is a major clinical manifestation of nephrotic syndrome (NS) in children. Bioimpedance spectroscopy (BIS) is a simple, noninvasive technique that reflects body water volumes. BIS can further measure cell membrane capacitance (CM), which may be altered in NS. The aims of the study were to explore how BIS measurements could reflect disease status in NS, while avoiding prediction equations which are often only validated in adult populations. METHODS: The study involved 8 children (2-10 years) with active NS (ANS group), 5 of which were also studied at NS remission (NSR group), as well as 38 healthy children of similar age (HC group). BIS measurements determined resistances RINF, RE, and RI (reflecting total body water, extracellular water, and intracellular water) and CM. Also resistance indices based on height (H) were considered, RI = H2/R. RESULTS: It was found that RE and RINF were significantly lower in the ANS group than in both NSR and HC groups (p < 0.001). Corresponding resistance indices were significantly higher in the ANS group than in the NSR (p < 0.01) and the HC (p < 0.05) groups, in accordance with elevated water volumes in NS patients. Indices of intracellular water were not significantly different between groups. CM was significantly lower in the ANS group than in NSR and HC groups (p < 0.05). CONCLUSION: BIS could distinguish children with active NS from well-treated and healthy children. Studies with more children are warranted.

Effects of periconceptional maternal alcohol intake and a postnatal high-fat diet on obesity and liver disease in male and female rat offspring.

The effects of maternal alcohol consumption around the time of conception on offspring are largely unknown and difficult to determine in a human population. This study utilized a rodent model to examine if periconceptional alcohol (PC:EtOH) consumption, alone or in combination with a postnatal high-fat diet (HFD), resulted in obesity and liver dysfunction. Sprague-Dawley rats were fed a control or an ethanol-containing [12.5% (vol/vol) EtOH] liquid diet from 4 days before mating until 4 days of gestation ( n = 12/group). A subset of offspring was fed a HFD between 3 and 8 mo of age. In males, PC:EtOH and HFD increased total body fat mass ( PPC:EtOH < 0.05, PHFD < 0.0001); in females, only HFD increased fat mass ( PHFD < 0.0001). PC:EtOH increased microvesicular liver steatosis in male, but not female, offspring. Plasma triglycerides, HDL, and cholesterol were increased in PC:EtOH-exposed males ( PPC:EtOH < 0.05), and LDL, cholesterol, and leptin (Lep) were increased in PC:EtOH-exposed females ( PPC:EtOH < 0.05). mRNA levels of Tnf-α and Lep in visceral adipose tissue were increased by PC:EtOH in both sexes ( PPC:EtOH < 0.05), and Il-6 mRNA was increased in males ( PPC:EtOH < 0.05). These findings were associated with reduced expression of microRNA-26a, a known regulator of IL-6 and TNF-α. Alcohol exposure around conception increases obesity risk, alters plasma lipid and leptin profiles, and induces liver steatosis in a sex-specific manner. These programmed phenotypes were similar to those caused by a postnatal HFD, particularly in male offspring. These results have implications for the health of offspring whose mothers consumed alcohol around the time of conception.

Bedside quantification of fat-free mass in acute spinal cord injury using bioelectrical impedance analysis: a psychometric study.

STUDY DESIGN: Psychometric. OBJECTIVES: Assess the validity of bioimpedance-based measures of fat-free mass (FFM) in acute SCI and of current definitions of obesity based on body mass index (BMI). SETTING: Australia. METHODS: All admissions within eight weeks of a new traumatic SCI were screened. 29% were eligible. 71% of those consented. Twenty participants (18 male) completed deuterium dilution (DD) and bioimpedance-based measurements of FFM. Thirteen also underwent dual-energy x-ray absorptiometry. Strength of relationships and agreement were examined using Lin's concordance coefficient and limits of agreement analysis, respectively. Sensitivity and specificity were calculated for three BMI cutoffs for obesity, using percentage fat mass (%FM) obtained from DD as reference. RESULTS: Median time since injury was 41 days (IQR 28-48). FFM from DD and DXA were highly correlated but not identical. Concordance and agreement between DD and seven bioimpedance-based predictive equations are presented. The best-fitting equation demonstrated a low bias (+0.6 kg) and moderate dispersion (±5.2 kg). The cutoff for overweight in able-bodied people (BMI ≥25 kg/m2) provided sensitivity of 43.8%, compared to 25% for the cut-off for obesity (BMI ≥30 kg/m2). FM from bioimpedance gave the highest sensitivity (88.9%). CONCLUSIONS: BMI demonstrates poor specificity to classify obesity in acute SCI. Present findings support the utility of bioimpedance-based measurements for estimating FFM in acute SCI for group comparisons. These results are generalizable to traumatic SCI 4-8 weeks post injury; however, the present data reflect a high proportion of high cervical injuries. Further research is indicated to establish validity for assessment of individuals and for longitudinal monitoring. SPONSORSHIP: The present study was funded by a grant from the Institute for Safety, Compensation and Recovery Research (ISCRR Project #NGE-E-13-078). M Panisset was supported by an Australian Postgraduate Award. K Desneves was supported by the Austin Medical Research Foundation.

Lymphedema following gynecological cancer: Results from a prospective, longitudinal cohort study on prevalence, incidence and risk factors.

OBJECTIVE: Cancer-related lymphedema is a debilitating condition that adversely influences function, health and quality of life. The purpose of this study was to assess the prevalence, incidence, and risk factors of lower-limb lymphedema pre- through to 24months post-surgery for gynecological cancer. METHODS: A clinic-based sample of women (n=408) with gynecological cancer participated in a prospective, longitudinal study (2008-2011) using self-reported measures (swelling in one or both legs) and objectively measured lymphedema (bioimpedance spectroscopy) at baseline (pre-surgery), six weeks-three months, 6-12months, and 15-24months post-surgery. RESULTS: At pre-surgery, 15% of women self-reported lymphedema and 27% had measurable evidence of lymphedema. By 24months post-surgery, incidence of new self-reported or measured lymphedema was 45% and 37%, respectively. Three-quarters of these new cases presented by 12-months post-treatment. While lymphedema was transient for some women, 60% had persistent lymphedema. More extensive lymph node dissection, receipt of chemotherapy and radiation therapy, increasing body mass index, insufficient levels of physical activity, diagnosis of vulvar/vaginal cancer and presence of pre-treatment lymphedema were identified as potential risk factors (p<0.05). CONCLUSION: Findings support the need for integration of pre-surgical assessment, and prospective, post-treatment surveillance of lymphedema into gynecological cancer care. Future research exploring the role of maintaining healthy body weight, regular physical activity and education about early detection of lymphedema to improve gynecological cancer survivorship is warranted.

Determinants of body composition in breastfed infants using bioimpedance spectroscopy and ultrasound skinfolds-methods comparison.

BACKGROUND: Accurate, noninvasive, and inexpensive methods are required to measure infant body composition. Ultrasound (US) and bioimpedance spectroscopy (BIS) have been validated in adults and introduced in pediatric populations. The aim of this study was to evaluate the performance of both methods in determining percentage fat mass (%FM) in breastfed infants. METHODS: %FM of 2, 5, 9, and 12 mo-old healthy, breastfed term infants (n = 58) was calculated using BIS-derived total body water equations and skinfold equations then compared with reference models. Skinfolds were measured with US at two and four sites (biceps, suprailiac and/or triceps, and subscapular). RESULTS: %FM differed widely within and between methods, with the degree of variation affected by infant age/sex. Not a single method/equation was consistent with the distributions of appropriate reference values for all age/sex groups. Moderate number of matches with references values (13-24 out of 36) was seen for both types of equations. High number of matches (25-36) was seen for US skinfold-based equations. %FM values calculated from US and BIS were not significantly different (P = 0.35). CONCLUSION: Both BIS and US are practical for predicting %FM in infants. BIS calculations are highly dependent upon an appropriate set of validated age-matched equations.

Anti-inflammatory γ- and δ-tocotrienols improve cardiovascular, liver and metabolic function in diet-induced obese rats.

PURPOSE: This study tested the hypothesis that γ- and δ-tocotrienols are more effective than α-tocotrienol and α-tocopherol in attenuating the signs of diet-induced metabolic syndrome in rats. METHODS: Five groups of rats were fed a corn starch-rich (C) diet containing 68 % carbohydrates as polysaccharides, while the other five groups were fed a diet (H) high in simple carbohydrates (fructose and sucrose in food, 25 % fructose in drinking water, total 68 %) and fats (beef tallow, total 24 %) for 16 weeks. Separate groups from each diet were supplemented with either α-, γ-, δ-tocotrienol or α-tocopherol (85 mg/kg/day) for the final 8 of the 16 weeks. RESULTS: H rats developed visceral obesity, hypertension, insulin resistance, cardiovascular remodelling and fatty liver. α-Tocopherol, α-, γ- and δ-tocotrienols reduced collagen deposition and inflammatory cell infiltration in the heart. Only γ- and δ-tocotrienols improved cardiovascular function and normalised systolic blood pressure compared to H rats. Further, δ-tocotrienol improved glucose tolerance, insulin sensitivity, lipid profile and abdominal adiposity. In the liver, these interventions reduced lipid accumulation, inflammatory infiltrates and plasma liver enzyme activities. Tocotrienols were measured in heart, liver and adipose tissue showing that chronic oral dosage delivered tocotrienols to these organs despite low or no detection of tocotrienols in plasma. CONCLUSION: In rats, δ-tocotrienol improved inflammation, heart structure and function, and liver structure and function, while γ-tocotrienol produced more modest improvements, with minimal changes with α-tocotrienol and α-tocopherol. The most important mechanism of action is likely to be reduction in organ inflammation.

Inulin oligofructose attenuates metabolic syndrome in high-carbohydrate, high-fat diet-fed rats.

Prebiotics alter bacterial content in the colon, and therefore could be useful for obesity management. We investigated the changes following addition of inulin oligofructose (IO) in the food of rats fed either a corn starch (C) diet or a high-carbohydrate, high-fat (H) diet as a model of diet-induced metabolic syndrome. IO did not affect food intake, but reduced body weight gain by 5·3 and 12·3 % in corn starch+inulin oligofructose (CIO) and high-carbohydrate, high-fat with inulin oligofructose (HIO) rats, respectively. IO reduced plasma concentrations of free fatty acids by 26·2 % and TAG by 75·8 % in HIO rats. IO increased faecal output by 93·2 %, faecal lipid excretion by 37·9 % and weight of caecum by 23·4 % and colon by 41·5 % in HIO rats. IO improved ileal morphology by reducing inflammation and improving the density of crypt cells in HIO rats. IO attenuated H diet-induced increases in abdominal fat pads (C 275 (sem 19), CIO 264 (sem 40), H 688 (sem 55), HIO 419 (sem 32) mg/mm tibial length), fasting blood glucose concentrations (C 4·5 (sem 0·1), CIO 4·2 (sem 0·1), H 5·2 (sem 0·1), HIO 4·3 (sem 0·1) mmol/l), systolic blood pressure (C 124 (sem 2), CIO 118 (sem 2), H 152 (sem 2), HIO 123 (sem 3) mmHg), left ventricular diastolic stiffness (C 22·9 (sem 0·6), CIO 22·9 (sem 0·5), H 27·8 (sem 0·5), HIO 22·6 (sem 1·2)) and plasma alanine transaminase (C 29·6 (sem 2·8), CIO 32·1 (sem 3·0), H 43·9 (sem 2·6), HIO 33·6 (sem 2·0) U/l). IO attenuated H-induced increases in inflammatory cell infiltration in the heart and liver, lipid droplets in the liver and plasma lipids as well as impaired glucose and insulin tolerance. These results suggest that increasing soluble fibre intake with IO improves signs of the metabolic syndrome by decreasing gastrointestinal carbohydrate and lipid uptake.

Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis.

The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air-displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in an independent Western cohort. A total of 173 neonates at birth and 140 at two weeks of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable, and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations was assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week two but not at birth. Compared with the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0·01 kg with 2 sd limits of agreement (LOA) (0·18, -0·20). Prediction explained 88·9 % of variation but not beyond that of anthropometry. Applying these equations to the Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared with simple anthropometry in Asian populations. There is a need for population- and age-appropriate FFM prediction equations.

Seaweed supplements normalise metabolic, cardiovascular and liver responses in high-carbohydrate, high-fat fed rats.

Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330-340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium.

Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: comparison with dual-energy x-ray absorptiometry.

BACKGROUND: There is a need for a practical, inexpensive method to assess body composition in obese adolescents. This study aimed to 1) compare body composition parameters estimated by a stand-on, multi-frequency bioelectrical impendence (BIA) device, using a) the manufacturers' equations, and b) published and derived equations with body composition measured by dual-energy x-ray absorptiometry (DXA) and 2) assess percentage body fat (%BF) change after a weight loss intervention. METHODS: Participants were 66 obese adolescents, mean age (SD) 12.9 (2.0) years. Body composition was measured by Tanita BIA MC-180MA (Tanita BIA8) and DXA (GE-Lunar Prodigy). BIA resistance and reactance data at frequencies of 5, 50, 250 and 500 kHz, were used in published equations, and to generate a new prediction equation for fat-free mass (FFM) using a split-sample method. Approximately half (n = 34) of the adolescents had their body composition measured by DXA and BIA on two occasions, three to nine months apart. RESULTS: The correlations between FFM (kg), fat mass (kg) and %BF measured by BIA and DXA were 0.92, 0.93 and 0.78, respectively. The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA. The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM). After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement. CONCLUSION: The Tanita BIA8 could be a valuable clinical tool to measure body composition at the group level, but is inaccurate for the individual obese adolescent.

Effects of Body Positioning When Assessing Lymphedema of the Lower Limb Using Bioimpedance Spectroscopy.

Background: Bioimpedance spectroscopy (BIS) measurements are conventionally performed in supine position with a lead device attached to gel-backed electrodes, and more recently, with a stand-on device that uses fixed stainless-steel electrodes under the hands and feet. The aim of this study was to assess and compare BIS measurements made in supine, sitting, and standing positions using lead and stand-on impedance devices in participants with and without unilateral leg lymphedema. Materials and Methods: Participants with self-ascribed unilateral leg lymphedema (n = 24) and healthy controls (n = 71) were recruited using a cross-sectional study design. Triplicate BIS measurements were taken for each device in each position. Results: Impedance measurements with either device were reliable with coefficient of variation of 0.6% or lower. The magnitude of mean differences in absolute impedance values between devices were between 1% and 6% dependent on condition. L-Dex scores between the two devices were highly correlated (r = 0.82) and ∼70% of participants in the lymphedema group were classified as having lymphedema using the recommended cut-off with either device. There was no significant interleg difference of controls using the lead device; however, small, but significant differences (p = 0.0001) were found when using the stand-on device. Conclusion: The findings demonstrate that reliable impedance measurements of the legs can be made with either device in lying, sitting, or standing positions. However, data between the devices were not directly interchangeable. Although the risk of misidentification was small, reference ranges appropriate to the device and measurement position should be used when converting data to L-Dex scores.