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1.
NPJ Microgravity ; 10(1): 72, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914554

RESUMO

Individuals in isolated and extreme environments can experience debilitating side-effects including significant decreases in fat-free mass (FFM) from disuse and inadequate nutrition. The objective of this study was to determine the strengths and weaknesses of three-dimensional optical (3DO) imaging for monitoring body composition in either simulated or actual remote environments. Thirty healthy adults (ASTRO, male = 15) and twenty-two Antarctic Expeditioners (ABCS, male = 18) were assessed for body composition. ASTRO participants completed duplicate 3DO scans while standing and inverted by gravity boots plus a single dual-energy X-ray absorptiometry (DXA) scan. The inverted scans were an analog for fluid redistribution from gravity changes. An existing body composition model was used to estimate fat mass (FM) and FFM from 3DO meshes. 3DO body composition estimates were compared to DXA with linear regression and reported with the coefficient of determination (R2) and root mean square error (RMSE). ABCS participants received only duplicate 3DO scans on a monthly basis. Standing ASTRO meshes achieved an R2 of 0.76 and 0.97 with an RMSE of 2.62 and 2.04 kg for FM and FFM, while inverted meshes achieved an R2 of 0.52 and 0.93 with an RMSE of 2.84 and 3.23 kg for FM and FFM, respectively, compared to DXA. For the ABCS arm, mean weight, FM, and FFM changes were -0.47, 0.06, and -0.54 kg, respectively. Simulated fluid redistribution decreased the accuracy of estimated body composition values from 3DO scans. However, FFM stayed robust. 3DO imaging showed good absolute accuracy for body composition assessment in isolated and remote environments.

2.
Commun Med (Lond) ; 4(1): 13, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38287144

RESUMO

BACKGROUND: Body shape, an intuitive health indicator, is deterministically driven by body composition. We developed and validated a deep learning model that generates accurate dual-energy X-ray absorptiometry (DXA) scans from three-dimensional optical body scans (3DO), enabling compositional analysis of the whole body and specified subregions. Previous works on generative medical imaging models lack quantitative validation and only report quality metrics. METHODS: Our model was self-supervised pretrained on two large clinical DXA datasets and fine-tuned using the Shape Up! Adults study dataset. Model-predicted scans from a holdout test set were evaluated using clinical commercial DXA software for compositional accuracy. RESULTS: Predicted DXA scans achieve R2 of 0.73, 0.89, and 0.99 and RMSEs of 5.32, 6.56, and 4.15 kg for total fat mass (FM), fat-free mass (FFM), and total mass, respectively. Custom subregion analysis results in R2s of 0.70-0.89 for left and right thigh composition. We demonstrate the ability of models to produce quantitatively accurate visualizations of soft tissue and bone, confirming a strong relationship between body shape and composition. CONCLUSIONS: This work highlights the potential of generative models in medical imaging and reinforces the importance of quantitative validation for assessing their clinical utility.


Body composition, measured quantities of muscle, fat, and bone, is typically assessed through dual energy X-ray absorptiometry (DXA) scans, which requires specialized equipment, trained technicians and involves exposure to radiation. Exterior body shape is dependent on body composition and recent technological advances have made three-dimensional (3D) scanning for body shape accessible and virtually ubiquitous. We developed a model which uses 3D body surface scan inputs to generate DXA scans. When analyzed with commercial software that is used clinically, our model generated images yielded accurate quantities of fat, lean, and bone. Our work highlights the strong relationship between exterior body shape and interior composition. Moreover, it suggests that with enhanced accuracy, such medical imaging models could be more widely adopted in clinical care, making the analysis of body composition more accessible and easier to obtain.

3.
Am J Clin Nutr ; 118(4): 812-821, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37598747

RESUMO

BACKGROUND: New recommendations for the assessment of malnutrition and sarcopenia include body composition, specifically reduced muscle mass. Three-dimensional optical imaging (3DO) is a validated, accessible, and affordable alternative to dual X-ray absorptiometry (DXA). OBJECTIVE: Identify strengths and weaknesses of 3DO for identification of malnutrition in participants with low body mass index (BMI) and eating disorders. DESIGN: Participants were enrolled in the cross-sectional Shape Up! Adults and Kids studies of body shape, metabolic risk, and functional assessment and had BMI of <20 kg/m2 in adults or <85% of median BMI (mBMI) in children and adolescents. A subset was referred for eating disorders evaluation. Anthropometrics, scans, strength testing, and questionnaires were completed in clinical research centers. Lin's Concordance Correlation Coefficient (CCC) assessed agreement between 3DO and DXA; multivariate linear regression analysis examined associations between weight history and body composition. RESULTS: Among 95 participants, mean ± SD BMI was 18.3 ± 1.4 kg/m2 in adult women (N = 56), 19.0 ± 0.6 in men (N = 14), and 84.2% ± 4.1% mBMI in children (N = 25). Concordance was excellent for fat-free mass (FFM, CCC = 0.97) and strong for appendicular lean mass (ALM, CCC = 0.86) and fat mass (FM, CCC = 0.87). By DXA, 80% of adults met the low FFM index criterion for malnutrition, and 44% met low ALM for sarcopenia; 52% of children and adolescents were <-2 z-score for FM. 3DO identified 95% of these cases. In the subset, greater weight loss predicted lower FFM, FM, and ALM by both methods; a greater percentage of weight regained predicted a higher percentage of body fat. CONCLUSIONS: 3DO can accurately estimate body composition in participants with low BMI and identify criteria for malnutrition and sarcopenia. In a subset, 3DO detected changes in body composition expected with weight loss and regain secondary to eating disorders. These findings support the utility of 3DO for body composition assessment in patients with low BMI, including those with eating disorders. This trial was registered at clinicaltrials.gov as NCT03637855.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Desnutrição , Sarcopenia , Adulto , Masculino , Criança , Adolescente , Humanos , Feminino , Índice de Massa Corporal , Composição Corporal/fisiologia , Desnutrição/diagnóstico , Absorciometria de Fóton/métodos , Redução de Peso
4.
Clin Nutr ; 42(9): 1619-1630, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37481870

RESUMO

BACKGROUND: Excess adiposity in children is strongly correlated with obesity-related metabolic disease in adulthood, including diabetes, cardiovascular disease, and 13 types of cancer. Despite the many long-term health risks of childhood obesity, body mass index (BMI) Z-score is typically the only adiposity marker used in pediatric studies and clinical applications. The effects of regional adiposity are not captured in a single scalar measurement, and their effects on short- and long-term metabolic health are largely unknown. However, clinicians and researchers rarely deploy gold-standard methods for measuring compartmental fat such as magnetic resonance imaging (MRI) and dual X-ray absorptiometry (DXA) on children and adolescents due to cost or radiation concerns. Three-dimensional optical (3DO) scans are relatively inexpensive to obtain and use non-invasive and radiation-free imaging techniques to capture the external surface geometry of a patient's body. This 3D shape contains cues about the body composition that can be learned from a structured correlation between 3D body shape parameters and reference DXA scans obtained on a sample population. STUDY AIM: This study seeks to introduce a radiation-free, automated 3D optical imaging solution for monitoring body shape and composition in children aged 5-17. METHODS: We introduce an automated, linear learning method to predict total and regional body composition of children aged 5-17 from 3DO scans. We collected 145 male and 206 female 3DO scans on children between the ages of 5 and 17 with three scanners from independent manufacturers. We used an automated shape templating method first introduced on an adult population to fit a topologically consistent 60,000 vertex (60 k) mesh to 3DO scans of arbitrary scanning source and mesh topology. We constructed a parameterized body shape space using principal component analysis (PCA) and estimated a regression matrix between the shape parameters and their associated DXA measurements. We automatically fit scans of 30 male and 38 female participants from a held-out test set and predicted 12 body composition measurements. RESULTS: The coefficient of determination (R2) between 3DO predicted body composition and DXA measurements was at least 0.85 for all measurements with the exception of visceral fat on 3D scan predictions. Precision error was 1-4 times larger than that of DXA. No predicted variable was significantly different from DXA measurement except for male trunk lean mass. CONCLUSION: Optical imaging can quickly, safely, and inexpensively estimate regional body composition in children aged 5-17. Frequent repeat measurements can be taken to chart changes in body adiposity over time without risk of radiation overexposure.


Assuntos
Obesidade Infantil , Adulto , Adolescente , Humanos , Criança , Masculino , Feminino , Pré-Escolar , Obesidade Infantil/diagnóstico por imagem , Composição Corporal , Índice de Massa Corporal , Absorciometria de Fóton/métodos , Adiposidade
5.
Am J Clin Nutr ; 118(3): 657-671, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37474106

RESUMO

BACKGROUND: The obesity epidemic brought a need for accessible methods to monitor body composition, as excess adiposity has been associated with cardiovascular disease, metabolic disorders, and some cancers. Recent 3-dimensional optical (3DO) imaging advancements have provided opportunities for assessing body composition. However, the accuracy and precision of an overall 3DO body composition model in specific subgroups are unknown. OBJECTIVES: This study aimed to evaluate 3DO's accuracy and precision by subgroups of age, body mass index, and ethnicity. METHODS: A cross-sectional analysis was performed using data from the Shape Up! Adults study. Each participant received duplicate 3DO and dual-energy X-ray absorptiometry (DXA) scans. 3DO meshes were digitally registered and reposed using Meshcapade. Principal component analysis was performed on 3DO meshes. The resulting principal components estimated DXA whole-body and regional body composition using stepwise forward linear regression with 5-fold cross-validation. Duplicate 3DO and DXA scans were used for test-retest precision. Student's t tests were performed between 3DO and DXA by subgroup to determine significant differences. RESULTS: Six hundred thirty-four participants (females = 346) had completed the study at the time of the analysis. 3DO total fat mass in the entire sample achieved R2 of 0.94 with root mean squared error (RMSE) of 2.91 kg compared to DXA in females and similarly in males. 3DO total fat mass achieved a % coefficient of variation (RMSE) of 1.76% (0.44 kg), whereas DXA was 0.98% (0.24 kg) in females and similarly in males. There were no mean differences for total fat, fat-free, percent fat, or visceral adipose tissue by age group (P > 0.068). However, there were mean differences for underweight, Asian, and Black females as well as Native Hawaiian or other Pacific Islanders (P < 0.038). CONCLUSIONS: A single 3DO body composition model produced accurate and precise body composition estimates that can be used on diverse populations. However, adjustments to specific subgroups may be warranted to improve the accuracy in those that had significant differences. This trial was registered at clinicaltrials.gov as NCT03637855 (Shape Up! Adults).


Assuntos
Composição Corporal , Etnicidade , Adulto , Feminino , Humanos , Masculino , Absorciometria de Fóton/métodos , Índice de Massa Corporal , Estudos Transversais , Obesidade/diagnóstico por imagem , Imagem Óptica
6.
Am J Clin Nutr ; 117(4): 802-813, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36796647

RESUMO

BACKGROUND: Recent 3-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise in clinical measures made by DXA. However, the sensitivity for monitoring body composition change over time with 3DO body shape imaging is unknown. OBJECTIVES: This study aimed to evaluate the ability of 3DO in monitoring body composition changes across multiple intervention studies. METHODS: A retrospective analysis was performed using intervention studies on healthy adults that were complimentary to the cross-sectional study, Shape Up! Adults. Each participant received a DXA (Hologic Discovery/A system) and 3DO (Fit3D ProScanner) scan at the baseline and follow-up. 3DO meshes were digitally registered and reposed using Meshcapade to standardize the vertices and pose. Using an established statistical shape model, each 3DO mesh was transformed into principal components, which were used to predict whole-body and regional body composition values using published equations. Body composition changes (follow-up minus the baseline) were compared with those of DXA using a linear regression analysis. RESULTS: The analysis included 133 participants (45 females) in 6 studies. The mean (SD) length of follow-up was 13 (5) wk (range: 3-23 wk). Agreement between 3DO and DXA (R2) for changes in total FM, total FFM, and appendicular lean mass were 0.86, 0.73, and 0.70, with root mean squared errors (RMSEs) of 1.98 kg, 1.58 kg, and 0.37 kg, in females and 0.75, 0.75, and 0.52 with RMSEs of 2.31 kg, 1.77 kg, and 0.52 kg, in males, respectively. Further adjustment with demographic descriptors improved the 3DO change agreement to changes observed with DXA. CONCLUSIONS: Compared with DXA, 3DO was highly sensitive in detecting body shape changes over time. The 3DO method was sensitive enough to detect even small changes in body composition during intervention studies. The safety and accessibility of 3DO allows users to self-monitor on a frequent basis throughout interventions. This trial was registered at clinicaltrials.gov as NCT03637855 (Shape Up! Adults; https://clinicaltrials.gov/ct2/show/NCT03637855); NCT03394664 (Macronutrients and Body Fat Accumulation: A Mechanistic Feeding Study; https://clinicaltrials.gov/ct2/show/NCT03394664); NCT03771417 (Resistance Exercise and Low-Intensity Physical Activity Breaks in Sedentary Time to Improve Muscle and Cardiometabolic Health; https://clinicaltrials.gov/ct2/show/NCT03771417); NCT03393195 (Time Restricted Eating on Weight Loss; https://clinicaltrials.gov/ct2/show/NCT03393195), and NCT04120363 (Trial of Testosterone Undecanoate for Optimizing Performance During Military Operations; https://clinicaltrials.gov/ct2/show/NCT04120363).


Assuntos
Composição Corporal , Imagem Óptica , Masculino , Adulto , Feminino , Humanos , Absorciometria de Fóton/métodos , Estudos Transversais , Estudos Retrospectivos , Composição Corporal/fisiologia , Impedância Elétrica , Índice de Massa Corporal
7.
Med Phys ; 49(10): 6395-6409, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35837761

RESUMO

BACKGROUND: Many predictors of morbidity caused by metabolic disease are associated with body shape. 3D optical (3DO) scanning captures body shape and has been shown to accurately and precisely predict body composition variables associated with mortality risk. 3DO is safer, less expensive, and more accessible than criterion body composition assessment methods such as dual-energy X-ray absorptiometry (DXA). However, 3DO scanning has not been standardized across manufacturers for pose, mesh resolution, and post processing methods. PURPOSE: We introduce a scanner-agnostic algorithm that automatically fits a topologically consistent human mesh to 3DO scanned point clouds and predicts clinically important body metrics using a standardized body shape model. Our models transform raw scans captured by any 3DO scanner into fixed topology meshes with anatomical consistency, standardizing the outputs of 3DO scans across manufacturers and allowing for the use of common prediction models across scanning devices. METHODS: A fixed-topology body mesh template was automatically registered to 848 training scans from three different 3DO systems. Participants were between 18 and 89 years old with body mass index ranging from 14 to 52 kg/m2 . Scans were registered by first performing a coarse nearest neighbor alignment between the template and the input scan with an anatomically constrained principal component analysis (PCA) domain deformation using a device and gender specific bootstrap basis trained on 70 seed scans each. The template mesh was then optimized to fit the target with a smooth per-vertex surface-to-surface deformation. A combined unified PCA model was created from the superset of all automatically fit training scans including all three devices. Body composition predictions to DXA measurements were learned from the training mesh PCA coefficients using linear regression. Using this final unified model, we tested the accuracy of our body composition models on a withheld sample of 562 scans by fitting a PCA parameterized template mesh to each raw scan and predicting the expected body composition metrics from the principal components using the learned regression model. RESULTS: We achieved coefficients of determination (R2 ) above 0.8 on all nine fat and lean predictions except female visceral fat (0.77). R2 was as high as 0.94 (total fat and lean, trunk fat), and all root-mean-squared errors were below 3.0 kg. All predicted body composition variables were not significantly different from reference DXA measurements except for visceral fat and female trunk fat. Repeatability precision as measured by the coefficient of variation (%CV) was around 2-3x worse than DXA precision, with visceral fat %CV below 2x DXA %CV and female total fat mass at 5x. CONCLUSIONS: Our method provides an accurate, automated, and scanner agnostic framework for standardizing 3DO scans and a low cost, radiation-free alternative to criterion radiology imaging for body composition analysis. We published a web-app version of this work at https://shapeup.shepherdresearchlab.org/3do-bodycomp-analyzer/ that accepts mesh file uploads and returns templated meshes with body composition predictions for demo purposes.


Assuntos
Tecido Adiposo , Composição Corporal , Absorciometria de Fóton , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Análise de Componente Principal , Cintilografia , Adulto Jovem
8.
Obesity (Silver Spring) ; 29(11): 1835-1847, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34549543

RESUMO

OBJECTIVE: The aim of this study was to investigate whether digitally re-posing three-dimensional optical (3DO) whole-body scans to a standardized pose would improve body composition accuracy and precision regardless of the initial pose. METHODS: Healthy adults (n = 540), stratified by sex, BMI, and age, completed whole-body 3DO and dual-energy X-ray absorptiometry (DXA) scans in the Shape Up! Adults study. The 3DO mesh vertices were represented with standardized templates and a low-dimensional space by principal component analysis (stratified by sex). The total sample was split into a training (80%) and test (20%) set for both males and females. Stepwise linear regression was used to build prediction models for body composition and anthropometry outputs using 3DO principal components (PCs). RESULTS: The analysis included 472 participants after exclusions. After re-posing, three PCs described 95% of the shape variance in the male and female training sets. 3DO body composition accuracy compared with DXA was as follows: fat mass R2 = 0.91 male, 0.94 female; fat-free mass R2 = 0.95 male, 0.92 female; visceral fat mass R2 = 0.77 male, 0.79 female. CONCLUSIONS: Re-posed 3DO body shape PCs produced more accurate and precise body composition models that may be used in clinical or nonclinical settings when DXA is unavailable or when frequent ionizing radiation exposure is unwanted.


Assuntos
Composição Corporal , Imagem Corporal Total , Absorciometria de Fóton , Tecido Adiposo , Adulto , Antropometria , Feminino , Humanos , Modelos Lineares , Masculino
9.
Clin Appl Thromb Hemost ; 27: 10760296211000129, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33724895

RESUMO

A growing researchers have suggested that fibrin monomer (FM) plays an important role in early diagnosis of thrombotic diseases. We explored the application of FM in the diagnosis and classification of acute ischemic stroke (AIS). The differences in FM, D-dimer, and NIHSS scores between different TOAST (Trial of ORG 10172 in Acute Stroke Treatment) types were analyzed with one-way ANOVA; the correlation between FM, D-dimer and NIHSS score in patients with different TOAST classification was analyzed by Pearson linear correlation. The ROC curve was utilized to analyze the diagnostic performance. 1. FM was more effective in diagnosing patients with AIS than D-dimer. 2. The FM level in cardiogenic AIS was significantly different from that in non-cardiogenic patients (P < 0.05); the NIHSS score in cardiogenic stroke was significantly higher than in atherosclerotic and unexplained stroke group. Whereas, no statistical difference was observed in the D-dimer level between these groups (P > 0.05). 3. The correlation between FM and NIHSS scores in the cardiogenic (r = 0.3832) and atherosclerotic (r = 0.3144) groups was statistically significant. 4. FM exhibited the highest diagnostic efficacy for cardiogenic AIS; furthermore, FM combined with the NIHSS score was more conducive to the differential diagnosis of cardiogenic and non-cardiogenic AIS. FM detection contributes to the early diagnosis of AIS, and is important for the differential diagnosis of different TOAST types of AIS. Moreover, FM combined with the NIHSS score is valuable in the differential diagnosis of cardiogenic and non-cardiogenic AIS.


Assuntos
AVC Isquêmico/diagnóstico , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Estudos Retrospectivos
10.
Eur J Clin Nutr ; 74(6): 920-929, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31551533

RESUMO

BACKGROUND/OBJECTIVES: Three-dimensional optical (3DO) imaging systems that rapidly and accurately provide body shape and composition information are increasingly available in research and clinical settings. Recently, relatively low-cost and space efficient 3DO systems with the ability to report and track individual assessments were introduced to the consumer market for home use. This study critically evaluated the first 3DO imaging device intended for personal operation, the Naked Body Scanner (NBS), against reference methods. PARTICIPANTS/METHODS: Circumferences at six standardized anatomic sites were measured with a flexible tape in 90 participants ranging in age (5-74 years), ethnicity, and adiposity. Regression analysis and Bland-Altman plots compared these direct measurements and dual-energy X-ray absorptiometry (DXA) %fat estimates to corresponding NBS values. Method precision was analyzed from duplicate anthropometric and NBS measurements in a subgroup of 51 participants. RESULTS: The NBS exhibited greater variation in test-retest reliability (CV, 0.4-2.7%) between the six measured anatomic locations when compared with manually measured counterparts (0.2-0.4%). All six device-derived circumferences correlated with flexible tape references (R2s, 0.84-0.97; p < 0.0001). Measurement bias was apparent for three anatomic sites while mean differences were present for five. The NBS's %fat estimates also correlated with DXA results (R2 = 0.73, p < 0.0001) with no significant bias. CONCLUSIONS: This system opens a new era of digital home-based assessments that can be incorporated into weight loss or exercise interventions accessible to clinical investigators as well as individual users.


Assuntos
Tecnologia Biomédica/métodos , Composição Corporal , Tamanho Corporal , Imagem Óptica/métodos , Absorciometria de Fóton , Adiposidade , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Criança , Pré-Escolar , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
11.
Am J Clin Nutr ; 110(6): 1316-1326, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31553429

RESUMO

BACKGROUND: Three-dimensional optical (3DO) body scanning has been proposed for automatic anthropometry. However, conventional measurements fail to capture detailed body shape. More sophisticated shape features could better indicate health status. OBJECTIVES: The objectives were to predict DXA total and regional body composition, serum lipid and diabetes markers, and functional strength from 3DO body scans using statistical shape modeling. METHODS: Healthy adults underwent whole-body 3DO and DXA scans, blood tests, and strength assessments in the Shape Up! Adults cross-sectional observational study. Principal component analysis was performed on registered 3DO scans. Stepwise linear regressions were performed to estimate body composition, serum biomarkers, and strength using 3DO principal components (PCs). 3DO model accuracy was compared with simple anthropometric models and precision was compared with DXA. RESULTS: This analysis included 407 subjects. Eleven PCs for each sex captured 95% of body shape variance. 3DO body composition accuracy to DXA was: fat mass R2 = 0.88 male, 0.93 female; visceral fat mass R2 = 0.67 male, 0.75 female. 3DO body fat test-retest precision was: root mean squared error = 0.81 kg male, 0.66 kg female. 3DO visceral fat was as precise (%CV = 7.4 for males, 6.8 for females) as DXA (%CV = 6.8 for males, 7.4 for females). Multiple 3DO PCs were significantly correlated with serum HDL cholesterol, triglycerides, glucose, insulin, and HOMA-IR, independent of simple anthropometrics. 3DO PCs improved prediction of isometric knee strength (combined model R2 = 0.67 male, 0.59 female; anthropometrics-only model R2 = 0.34 male, 0.24 female). CONCLUSIONS: 3DO body shape PCs predict body composition with good accuracy and precision comparable to existing methods. 3DO PCs improve prediction of serum lipid and diabetes markers, and functional strength measurements. The safety and accessibility of 3DO scanning make it appropriate for monitoring individual body composition, and metabolic health and functional strength in epidemiological settings.This trial was registered at clinicaltrials.gov as NCT03637855.


Assuntos
Tecido Adiposo/diagnóstico por imagem , Composição Corporal , Joelho/fisiologia , Absorciometria de Fóton , Adolescente , Adulto , Antropometria , Estudos Transversais , Feminino , Humanos , Imageamento Tridimensional , Insulina/sangue , Lipoproteínas HDL/sangue , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue , Adulto Jovem
12.
Am J Clin Nutr ; 108(4): 708-715, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30099474

RESUMO

Background: The 4-component (4C) model is a criterion method for human body composition that separates the body into fat, water, mineral, and protein, but requires 4 measurements with significant cost and time requirements that preclude wide clinical use. A simplified model integrating only 2 measurements-dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA)-and 10 min of patient time has been proposed. Objective: We aimed to validate a rapid, simplified 4C DXA + BIA body composition model in a clinical population. Design: This was a cross-sectional observational study of 31 healthy adults. Participants underwent whole-body DXA, segmental BIA, air displacement plethysmography (ADP), and total body water (TBW) measurement by deuterium (D2O) dilution. 4C composition was calculated through the use of the Lohman model [DXA mineral mass, D2O TBW, ADP body volume (BV), scale weight] and the simplified model (DXA mineral mass and BV, BIA TBW, scale weight). Accuracy of percentage of fat (%Fat) and protein measurements was assessed via linear regression. Test-retest precision was calculated with the use of duplicate DXA and BIA measurements. Results: Of 31 participants, 23 were included in the analysis. TBWBIA showed good test-retest precision (%CV = 5.2 raw; 1.1 after outlier removal) and high accuracy to TBWD2O [TBWD2O = 0.956*TBWBIA, R2= 0.92, root mean squared error (RMSE) = 2.2 kg]. %Fat estimates from DXA, ADP, D2O, and BIA all showed high correlation with the Lohman model. However, only the 4C simplified model provides high accuracy for both %Fat (R2 = 0.96, RMSE = 2.33) and protein mass (R2= 0.76, RMSE = 1.8 kg). %Fat precision from 4C DXA + BIA was comparable with DXA (root mean square-SD = 0.8 and 0.6 percentage units, respectively). Conclusions: This work validates a simplified 4C method that measures fat, water, mineral, and protein in a 10-min clinic visit. This model has broad clinical application to monitor many conditions including over/dehydration, malnutrition, obesity, sarcopenia, and cachexia.


Assuntos
Absorciometria de Fóton , Tecido Adiposo/metabolismo , Composição Corporal , Água Corporal/metabolismo , Impedância Elétrica , Minerais/metabolismo , Proteínas/metabolismo , Adulto , Estudos Transversais , Feminino , Humanos , Técnicas de Diluição do Indicador , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Pletismografia , Reprodutibilidade dos Testes , Adulto Jovem
13.
Zhonghua Yi Xue Za Zhi ; 89(27): 1889-91, 2009 Jul 21.
Artigo em Chinês | MEDLINE | ID: mdl-19953910

RESUMO

OBJECTIVE: To obtain the mimotope recognized by anti-keratin antibody (AKA) by screening a phage random peptide library and evaluate its diagnostic value. METHODS: IgG was purified from AKA positive pooled serum of rheumatoid arthritis (RA) patients by 33.3% (NH4)2SO4 (AKA measured with indirect immunofluorescence). Then the antibody was used as the ligand for biopanning of a 12-mer phage random peptide library. The serum of patients with RA, SLE and normal people were detected with the positive clone by indirect ELISA. RESULTS: After 4 rounds of screening, the peptide of mimotope associated with RA was acquired. The diagnostic specificity, positive predictive value and Youden's index were 95.6%, 90% and 155.6% respectively. Its amino acid sequence was QSESAGPTTSRR. This sequence was similar to 137-148 amino acid sequence of human filaggrin. CONCLUSION: The RA-associated peptide is acquired by screening a phage random peptide library using polyclonal AKA of RA patients. It may be a specific diagnostic tool of RA.


Assuntos
Artrite Reumatoide/diagnóstico , Biblioteca de Peptídeos , Peptídeos , Adolescente , Adulto , Idoso , Feminino , Proteínas Filagrinas , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Adulto Jovem
14.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 25(3): 193-6, 2009 May.
Artigo em Chinês | MEDLINE | ID: mdl-19803201

RESUMO

OBJECTIVE: To determine the effect, safety, and feasibility of embolization of high flow arteriovenous malformations (AVMs) with HepaSphere microspheres. METHODS: HepaSphere particles swell by absorbing fluids and become soft and deformable with a precisely calibrated diameter. 13 patients with AVMs were treated by transarterial embolization with HepaSphere particles. 3 cases underwent a following AVMs resection surgery. The follow-up period was 3 months to 3 years. Symptoms improvement and image examination were studied. RESULTS: 28 transarterial embolizations were performed in 13 cases. The resection operation was performed in 3 cases after transarterial embolizations. The symptoms in diffused AVMs improved after several transarterial embolizations. Histologically, HepaSphere particles penetrated into the intralesional vessels and conformed to the vessel lumen, resulting in vessel occlusion. Minimal perivascular reaction was observed. CONCLUSIONS: Embolization of high flow AVMs with HepaSphere microspheres is safe and effective. Combined treatment is necessary for diffuse AVMs.


Assuntos
Malformações Arteriovenosas/terapia , Embolização Terapêutica/métodos , Adolescente , Adulto , Feminino , Humanos , Masculino , Microesferas , Pessoa de Meia-Idade , Adulto Jovem
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