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[en] Body composition is a useful means for athletes' body composition assessment, relying on reference population data. This study aims at comparing body composition multifrequency impedance data of athletes and healthy adult populations. Differences were found in tissular, hydration and metabolic indices. They were significant, in the expected direction, but quite weak and additional data from reference technologies would set if specific equations are needed. The current ones are nevertheless suitable for reliable follow-up studies.
[en] Radiographic methods of evaluating body composition have been applied for over five decades. A marked improvement in this approach occurred in the mid-nineteen-seventies with the introduction of computerized axial tomography. High image contrast, cross-sectional imaging and rapid computerized data processing make this technique a sophisticated clinically applicable tool. (author)
[en] OBJECTIVE: Assortative mating for adiposity increases the genetic burden on offspring, but its causes remain unclear. One hypothesis is that people who have high adiposity find other people with obesity more physically attractive than lean people. METHODS: The attractiveness of sets of images of males and females who varied in adiposity were rated by opposite sex subjects (559 males and 340 females) across 12 countries. RESULTS: There was tremendous individual variability in attractiveness ratings. For female attractiveness, most males favored the leanest subjects, but others favored intermediate fatness, some were indifferent to body composition, and others rated the subjects with obesity as most attractive. For male images rated by females, the patterns were more complex. Most females favored subjects with low levels of adiposity (but not the lowest level), whereas others were indifferent to body fatness or rated the images depicting individuals with obesity as the most attractive. These patterns were unrelated to rater BMI. Among Caucasian males who rated the images of the thinnest females as being more attractive, the magnitude of the effect depended on rater BMI, indicating limited ''mutual attraction''. CONCLUSIONS: Individual variations in ratings of physical attractiveness were broadly unrelated to rater BMI and suggest that mutual attraction is an unlikely explanation for assortative mating for obesity. (author)
[en] For the task of bone mineral measurement, single-energy quantitative CT has demonstrated its worth in terms of precision for most longitudinal clinical studies. However, for cross-sectional clinical studies, known inaccuracy exists due to less than robust beam-hardening corrections, and negatively biased bone mineral measurement, due to the effect of unknown variable concentration of bone marrow fat within the metabolically active trabecular bone space. A dual-energy measurement technique provides a solution to these deficiencies of single-energy measurements. The fundamental theory of dual-energy measurement techniques is based on a Compton-photoelectric approximation and the mixture rule for the total attenuation coefficient. Resolution of atomic composition and electron density components of attenuation should then be possible. To take full advantage of these principles, the raw dual-energy projection values are operated on before reconstruction. This method beam-hardening and composition-selective imaging. Rapid kilovoltage switching between projection measurements, rather than serial measurements, assures the best measurement quality
[en] We suggested an automatic fat range setting method in computed tomography to measure body fat. Quantitative measurement of body fat is important for the diagnosis and treatment of diseases related to obesity. A body fat measurement by computed tomography presents body fat volume quantitatively at a specific region. The method to set the body fat range in Hounsfield units proportional to the voxel's density in computed tomography images was not known. We suggested an automatic setting method of the histogram in the computed tomography image, and we show the body fat range for 20 persons and various region of person. (author)
[en] Loss of lean body mass is a common problem in many post-treatment cancer patients and may negatively affect physical capacity in terms of maximal muscle strength and functional performance. The purpose of this study was to systematically review the scientific evidence on the effect of progressive resistance training on lean body mass in post-treatment cancer patients. A comprehensive literature search was conducted and ultimately 12 studies were included. Methodological quality of the included studies was evaluated using the PEDro scale and the effect of progressive resistance training was reported as the range of mean changes among RCTs and non-RCTs. Six RCTs and six non-RCTs were included in the study. In the RCTs the change in lean body mass in the progressive resistance training groups relative to control groups ranged from −0.4% to 3.9%, and in four of six trials the training effect was significantly larger than the change in the control groups. In the six non-RCTs, the mean change in lean body mass over time ranged from −0.01 to 11.8% which was significant in two of the trials. The included studies reported no or very limited adverse events following progressive resistance training. Based on 12 heterogenic studies there is moderate evidence supporting a positive effect of progressive resistance training on lean body mass in post-treatment cancer patients
[en] The aim of this study was to evaluate the efficacy of helical CT using a combination of CT-attenuation values and visual assessment of stone density as well as discriminant linear analysis to predict the chemical composition of urinary calculi. One hundred human urinary calculi were obtained from a stone-analysis laboratory and placed in 20 excised pig kidneys. They were scanned at 80, 120 and 140 kV with 3-mm collimation. Average, highest and lowest CT-attenuation values and CT variability were recorded. The internal calculus structure was assessed using a wide window setting, and visual assessment of stone density was recorded. A stepwise discriminant linear analysis was performed. The following three variables were discriminant: highest CT-attenuation value, visual density, and highest CT-attenuation value/area ratio, all at 80 kV. The probability of correctly classifying stone composition with these three variables was 0.64, ranging from 0.54 for mixed calculi to 0.69 for pure calculi. The probabilities of correctly classifying calculus composition were: 0.91 for calcium oxalate monohydrate and brushite, 0.89 for cystine, 0.85 for uric acid, 0.11 for calcium oxalate dihydrate, 0.10 for hydroxyapatite, and 0.07 for struvite calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, 81% of the calculi were correctly classified. Assessment at 80 kV of the highest CT-attenuation value, visual density and the highest CT-attenuation value/area ratio accurately predicts the chemical composition of 64-81% of urinary calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, all cystine, calcium oxalate monohydrate and brushite calculi were correctly classified. (orig.)
[en] The objective of the study was to evaluate the maternal intention to breastfeed, duration of breastfeeding and reasons for weaning among mothers and babies from southern Brazil participating in a multicenter study. This is a cohort study conducted in Pelotas, RS, with participants from the Multi-Centre Body Composition Study. Mothers and babies were followed at 3, 6, 9, 12, 18 and 24 months of age. The reasons for weaning were investigated before 12 months. Median and interquartile intervals of breastfeeding duration were presented according to sociodemographic and nutritional characteristics. Of the 1377 mothers screened, 74% had intention to exclusive breastfeeding until 6 months and 91% to prolong breastfeeding until at least 12 months. Only 168 pairs of mothers and babies met all eligibility criteria and agreed to participate in the follow-up. The median breastfeeding was 11 months (IQR: 5.8-23.0 months), and 52% of the children were weaned before 12 months. The main reasons for weaning were insufficient milk (57%), return to work / school (45%) and unexplained refusal of the baby (40%). The results showed that despite the intention to breastfeed, there is a need to clarify the mothers and families about issues related to breastfeeding. (author)
[en] In this review article current developments and applications in quantitative osteoporosis imaging are presented. Developments in the field of DXA include geometrical parameters of the proximal femur such as the ''hip axis length'' and new ROIs to determine BMD. Advances in QCT are new volumetric techniques to quantify BMD at the lumbar spine and the proximal femur. In addition techniques to determine BMD in standard contrast-enhanced abdominal computed tomography studies are described. Currently with the new bone quality concept in full bloom techniques to quantify trabecular bone architecture as new surrogates of bone strength are of increasing significance. Spatial high-resolution techniques such as magnetic resonance imaging and new computed tomography techniques have shown their potential in assessing trabecular bone structure. In addition ultrasound is considered a low-cost technique to explore bone quality. (orig.)
[de]In der vorliegenden Arbeit werden die aktuellen Entwicklungen und Anwendungen auf dem Gebiet der radiologischen Osteoporosediagnostik vorgestellt. Weiterentwicklungen bzgl. der dualen Roentgenabsorptiometrie (dual energy x-ray absorptiometry, DXA) beinhalten geometrische Parameter des proximalen Femurs wie die ''hip axis length'' und neue Zielregionen (regions of interest, ROIs) zur Messung der Knochenmineraldichte (bone mineral density, BMD). Im Bereich der quantitativen Computertomographie (QCT) wurde gezeigt, dass nach Anwendung eines Konversionsfaktors die BMD auch aus klinischen abdominellen CTs aehnlich der QCT erfasst werden kann. Auch werden zunehmend volumetrische Methoden der BMD-Messung an der Wirbelsaeule und dem proximalen Femur eingesetzt. In den letzten Jahren war im Rahmen des neu entwickelten Knochenqualitaetskonzepts die Bestimmung der Knochenarchitektur ein zentraler Fokus. Die trabekulaere Strukturanalyse mittels hochaufloesender Verfahren wie der Magnetresonanztomographie und neuer computertomographischer Techniken wird daher in Zukunft fuer die Osteoporose an Bedeutung zunehmen. Mit dem quantitativen Ultraschall steht eine relativ preiswerte Methode zur Diagnostik der Knochenqualitaet zur Verfuegung. Mit diesen neuen Techniken ist in den naechsten Jahren von einem Paradigmenwechsel in der quantitativen Osteoporosediagnostik auszugehen. (orig.)
[en] The development of telemedicine requires finding solutions of reusable electrodes for use in patients' homes. The objective of this study is to evaluate the relevance of reusable elastomer electrodes for measuring body composition. We measured a population of healthy Caucasian (n = 17). A measurement was made with a reference device, the Xitron®, associated with AgCl Gel electrodes (Gel) and another measurement with a multifrequency impedancemeter Z-Metrix® associated with reusable elastomer electrodes (Elast). We obtained a low variability with an average error of repeatability of 0.39% for Re and 0.32% for Rinf. There is a non significantly difference (P T-test > 0.1) about 200 ml between extracellular water Ve measured with Gel and Elast in supine and in standing position. For total body water Vt, we note a non significantly difference (P T-test > 0.1) about 100 ml and 2.2 1 respectively in supine and standing position. The results give low dispersion, with R2 superior to 0.90, with a 1.5% maximal error between Gel and Elast on Ve in standing position. It looks possible, taking a few precautions, using elastomer electrodes for assessing body composition.