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1.
Med Sci Monit ; 25: 8438-8446, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31705647

RESUMO

BACKGROUND Hypernatremia is associated with poor outcomes in critically ill patients, and an accurate assessment of water volume is important to determine appropriate fluid hydration. Bioelectrical impedance analysis (BIA) is a new, noninvasive, and relatively easy method for measuring hydration status. This study aimed to investigate whether bioelectrical impedance measurements of body water could reduce the frequency of blood sampling for fluid replacement in patients with hypernatremia. MATERIAL AND METHODS Fifty-one hospitalized patients were studied with hypernatremia, defined as a serum sodium ≥150 mmol/L determined by laboratory testing. Laboratory and BIA measurements were compared, and water deficiency was calculated with a conventional formula (sodium-corrected Watson formula) and measured by BIA. RESULTS The value of the absolute fluid overload (AFO) equivalent to the overhydration (OH) value, determined using BIA, did not accurately represent water deficit in patients with hypernatremia (r=0.137, P=0.347). Although the total body water (TBW) measured by BIA showed a significant correlation with that determined by the conventional formula (r=0.861, P<0.001), there was a proportional bias (r=0.617, P<0.001). The intracellular water (ICW) measured by BIA underestimated the TBW level calculated by the conventional formula by about 14.06±4.0 L in the Bland-Altman analysis. CONCLUSIONS It is not currently possible to replace blood testing with BIA for assessing volume status in hypernatremic patients. However, ICW value measured by BIA might represent plasma sodium level more accurately than extracellular water (ECW) or TBW value in patients with hypernatremia.


Assuntos
Hipernatremia/diagnóstico , Hipernatremia/metabolismo , Estado de Hidratação do Organismo/fisiologia , Adulto , Composição Corporal , Água Corporal/fisiologia , Desidratação/diagnóstico , Impedância Elétrica , Espaço Extracelular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Água
2.
Nutrients ; 11(11)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703309

RESUMO

At present, obesity and overweight are major public health concerns. Their classical determinants do not sufficiently explain the current situation and it is urgent to investigate other possible causes. In recent years, it has been suggested that water intake could have important implications for weight management. Thus, the aim of this study was to examine the effect of hydration status on body weight and composition in healthy adolescents from Spain. The study involved 372 subjects, aged 12-18 years. Water intake was assessed through the validated "hydration status questionnaire adolescent young". Anthropometric measurements were performed according to the recommendations of the International Standards for Anthropometric Assessment (ISAK) and body composition was estimated by bioelectrical impedance analysis. Water intake normalized by body weight was positively correlated with body water content (boys (B): r = 0.316, p = 0.000; girls (G): r = 0.245, p = 0.000) and inversely with body mass index (BMI) (B: r = -0.515, p = 0.000; G: r = -0.385, p =0.000) and fat body mass (B: r = -0.306, p = 0.000; G: r = -0.250, p = 0.001). Moreover, according to BMI, overweight/obese individuals consumed less water than normal weight ones. In conclusion, higher water balance and intake seems to be related with a healthier body composition. In conclusion, higher water balance and intake is associated with a healthier body composition.


Assuntos
Composição Corporal/fisiologia , Água Corporal/fisiologia , Ingestão de Líquidos/fisiologia , Adolescente , Peso Corporal/fisiologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Espanha/epidemiologia
3.
Nutrients ; 11(8)2019 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-31405195

RESUMO

Hypohydration, defined as a state of low body water, increases thirst sensations, arginine vasopressin release, and elicits renin-angiotensin-aldosterone system activation to replenish intra- and extra-cellular fluid stores. Hypohydration impairs mental and physical performance, but new evidence suggests hypohydration may also have deleterious effects on cardiovascular health. This is alarming because cardiovascular disease is the leading cause of death in the United States. Observational studies have linked habitual low water intake with increased future risk for adverse cardiovascular events. While it is currently unclear how chronic reductions in water intake may predispose individuals to greater future risk for adverse cardiovascular events, there is evidence that acute hypohydration impairs vascular function and blood pressure (BP) regulation. Specifically, acute hypohydration may reduce endothelial function, increase sympathetic nervous system activity, and worsen orthostatic tolerance. Therefore, the purpose of this review is to present the currently available evidence linking acute hypohydration with altered vascular function and BP regulation.


Assuntos
Água Corporal/fisiologia , Doenças Cardiovasculares/etiologia , Fenômenos Fisiológicos Cardiovasculares , Desidratação/complicações , Equilíbrio Hidroeletrolítico/fisiologia , Humanos
4.
Nutrients ; 11(8)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394869

RESUMO

With the collection of water-intake data, the National Health and Nutrition Examination Survey (NHANES) is becoming an increasingly popular resource for large-scale inquiry into human hydration. However, are we leveraging this resource properly? We sought to identify the opportunities and limitations inherent in hydration-related inquiry within a commonly studied database of hydration and nutrition. We also sought to critically review models published from this dataset. We reproduced two models published from the NHANES dataset, assessing the goodness of fit through conventional means (proportion of variance, R2). We also assessed model sensitivity to parameter configuration. Models published from the NHANES dataset typically yielded a very low goodness of fit R2 < 0.15. A reconfiguration of variables did not substantially improve model fit, and the goodness of fit of models published from the NHANES dataset may be low. Database-driven inquiry into human hydration requires the complete reporting of model diagnostics in order to fully contextualize findings. There are several emergent opportunities to potentially increase the proportion of explained variance in the NHANES dataset, including novel biomarkers, capturing situational variables (meteorology, for example), and consensus practices for adjustment of co-variates.


Assuntos
Água Corporal/fisiologia , Ingestão de Líquidos , Inquéritos Nutricionais , Índice de Massa Corporal , Bases de Dados Factuais , Humanos , Modelos Teóricos , Estado Nutricional , Estado de Hidratação do Organismo , Concentração Osmolar , Reprodutibilidade dos Testes , Urina
5.
Skin Res Technol ; 25(5): 595-605, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31111588

RESUMO

BACKGROUND: The skin provides a permeable barrier which may be impaired in occupational settings. Transepidermal water loss (TEWL), stratum corneum hydration (SCH) and skin surface pH (SSpH) have been used in occupational settings to predict early onset of occupational skin diseases, to measure the effectiveness of prevention strategies for occupational skin diseases, and to assess skin condition during exposure. The aim was to compare the findings, identify shortcomings in the methodology and data reporting and furthermore, to make recommendations for future studies. MATERIALS AND METHODS: A literature study was conducted on studies published before December 2018 to provide a review on the measurement of TEWL, SCH and SSpH in occupational settings. RESULTS: TEWL, SCH and SSpH were previously measured in a wide variety of industries. Results between studies were highly variable, due to different study designs and different anatomical positions measured. Not all of the measurement conditions were reported and variations in study objectives led to data being reported and interpreted differently for most studies. CONCLUSION: Incomplete reporting of methodology hinders comparison of bioengineering measurements. No bioengineering method has been proven useful as a predictive tool for occupational skin diseases, however, it is useful in the acute assessment of skin condition. It is recommended that future studies on TEWL, SCH and SSpH adhere to guidelines for occupational settings as far as possible to enable comparison between studies.


Assuntos
Epiderme/fisiologia , Doenças Profissionais/fisiopatologia , Estado de Hidratação do Organismo/fisiologia , Dermatopatias/fisiopatologia , Perda Insensível de Água/fisiologia , Agricultura , Água Corporal/fisiologia , Humanos , Concentração de Íons de Hidrogênio , Indústrias , Enfermagem , Impressão , Fenômenos Fisiológicos da Pele
6.
Eur J Radiol ; 113: 158-164, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30927942

RESUMO

BACKGROUND: Marrow fat accumulates in diabetic conditions but remains elusive. The published works on the relationships between marrow fat phenotypes and glucose homeostasis are controversial. PURPOSE: To detect the association of insulin resistance with marrow adiposity in postmenopausal women with newly diagnosed type 2 diabetes (T2D) using chemical shift-encoded water-fat MRI. METHODS: We measured vertebral proton density fat fraction (PDFF) by 3T-MRI in 75 newly diagnosed T2D and 20 nondiabetic postmenopausal women. Bone mineral density (BMD), whole body fat mass and lean mass were determined by dual-energy X-ray absorptiometry. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS: Lumbar spine PDFF was higher in women with T2D (65.9 ± 6.8%) than those without diabetes (59.5 ± 6.1%, P = 0.009). There was a consistent inverse association between the vertebral PDFF and BMD. PDFF had a positive association with glycated hemoglobin and HOMA-IR but not with fasting plasma glucose and insulin. PDFF was significantly increased, and BMD was decreased in a linear trend from the lowest (<1.90) to highest (≥2.77) HOMA-IR quartile. Multivariate linear regression analyses revealed a positive association between log-transformed HOMA-IR and PDFF after adjustment for multiple covariates (ß = 0.382, P < 0.001). The positive association of HOMA-IR with PDFF remained robust when total body lean mass and fat mass, BMD was entered into the multivariate regression model, respectively (ß = 0.293 and ß = 0.251, respectively; all P <0.05). CONCLUSIONS: Elevated HOMA-IR was linked to higher marrow fat fraction in postmenopausal women with newly diagnosed T2D independently of body compositions.


Assuntos
Adiposidade/fisiologia , Doenças da Medula Óssea/patologia , Diabetes Mellitus Tipo 2/patologia , Resistência à Insulina/fisiologia , Absorciometria de Fóton/métodos , Tecido Adiposo/patologia , Composição Corporal/fisiologia , Água Corporal/fisiologia , Medula Óssea/patologia , Estudos Transversais , Feminino , Homeostase/fisiologia , Humanos , Vértebras Lombares , Imagem por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Pós-Menopausa/fisiologia
7.
Skin Res Technol ; 25(5): 653-661, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30932226

RESUMO

BACKGROUND: Skin hydration is essential for maintaining stratum corneum (SC) flexibility and facilitating maturation events. Moisturizers contain multiple ingredients to maintain and improve skin hydration although a complete understanding of hydration mechanisms is lacking. The ability to differentiate the source of the hydration (water from the environment or deeper skin regions) upon application of product will aid in designing more efficacious formulations. MATERIALS AND METHODS: Novel confocal Raman microscopy (CRM) experiments allow us to investigate mechanisms and levels of hydration in the SC. Using deuterium oxide (D2 O) as a probe permits the differentiation of endogenous water (H2 O) from exogenous D2 O. Following topical application of D2 O, we first compare in vivo skin depth profiles with those obtained using ex vivo skin. Additional ex vivo experiments are conducted to quantify the kinetics of D2 O diffusion in the epidermis by introducing D2 O under the dermis. RESULTS: Relative D2 O depth profiles from in vivo and ex vivo measurements compare well considering procedural and instrumental differences. Additional in vivo experiments where D2 O was applied following topical glycerin application increased the longevity of D2 O in the SC. Reproducible rates of D2 O diffusion as a function of depth have been established for experiments where D2 O is introduced under ex vivo skin. CONCLUSION: Unique information regarding hydration mechanisms are obtained from CRM experiments using D2 O as a probe. The source and relative rates of hydration can be delineated using ex vivo skin with D2 O underneath. One can envision comparing these depth-dependent rates in the presence and absence of topically applied hydrating agents to obtain mechanistic information.


Assuntos
Estado de Hidratação do Organismo/fisiologia , Fenômenos Fisiológicos da Pele , Água Corporal/fisiologia , Óxido de Deutério/farmacologia , Epiderme/fisiologia , Humanos , Microscopia Confocal/métodos , Análise Espectral Raman/métodos , Perda Insensível de Água/fisiologia
8.
Skin Res Technol ; 25(3): 251-257, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30937980

RESUMO

BACKGROUND: Two clinical methods of assessing a moisturizer's effect on stratum corneum (SC) barrier repair were evaluated in female subjects with dry skin, to identify an assessment method for future studies. METHODS: In this single-centre, split-body study, women with dry skin applied moisturizer before (method A) or after (method B) SC barrier perturbation using D-Squame® stripping discs. Transepidermal water loss (TEWL) and residual protein on D-Squame discs were assessed over 14 days. RESULTS: Twenty-four subjects were included. For method A, the mean slope values of plots of 1/TEWL vs cumulative protein removed decreased over time for both treated and untreated areas, indicating improved SC barrier quality. There were no significant differences between treated and untreated areas, although a trend to a more negative slope was observed by Day 14 in the treated areas (P = 0.082), suggesting treatment improved barrier quality. For method B, using pre- and post-stripping as covariates, no statistical differences/trends were observed between treated and untreated areas for change in TEWL from post-stripping to any evaluation from Days 3-14. TEWL values returned towards pre-stripping values for treated and untreated areas by the initial Day 3 evaluation. CONCLUSION: For method A, there were trends suggesting the moisturizing treatment improved SC barrier quality. For method B, there were no significant differences/trends between treated and untreated areas. Further assessment with different methodologies is warranted to design appropriate clinical protocols for evaluating accelerated skin barrier repair. These data are insufficient to conclude whether the product or methodology was responsible for the results.


Assuntos
Emolientes/farmacologia , Epiderme/fisiologia , Creme para a Pele/farmacologia , Perda Insensível de Água/efeitos dos fármacos , Adulto , Água Corporal/fisiologia , Epiderme/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Estado de Hidratação do Organismo/efeitos dos fármacos , Adulto Jovem
9.
Ann Biomed Eng ; 47(6): 1463-1469, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30891658

RESUMO

Bio-electrical impedance analysis (BIA) is frequently used to assess body composition in man. Its accuracy in patients is limited, possibly because the employed algorithms are based on the assumption that total body electrical resistance (TBER) is exclusively related to body water volume, and that variation in fluid composition and its effect on fluid resistivity can be ignored. This may introduce substantial calculation errors. The aim of this study was to develop an objective method to assess plasma resistivity (ρplasma) based on measurements by a conductivity probe, as a surrogate for extracellular fluid resistivity (ρe). Sample measurements were standardized at body temperature. Analytical variation was 0.6% within runs and 0.9% between runs. The critical difference, i.e. the smallest difference needed to consider changes within individuals significant, was 1.8% for measurements within runs and 4.3% for measurements between runs. The normal range was defined by a mean ± SD of 66.9 ± 1.8 Ω cm. Multiple regression demonstrated that ρplasma was inversely related to plasma sodium and chloride concentrations, and positively related to total protein (overall R2 = 0.92, p < 0.001). In conclusion, ρplasma measurements were sufficiently robust to be useful as a tool to examine and improve the validity of BIA in clinical settings.


Assuntos
Impedância Elétrica , Plasma/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Água Corporal/fisiologia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Temperatura , Adulto Jovem
10.
Skin Res Technol ; 25(3): 258-269, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30345567

RESUMO

BACKGROUND: Natures and amounts of water retained at the surface of stratum corneum (SC) of human skins, affecting skin health and penetration of chemical components, remain unclear. METHODS: A keratin film, a main component of human SC surface, was measured by IR micro-spectroscopy combined with a quartz crystal microbalance (QCM) and a relative humidity (RH) control system. RESULTS: Water contents increased with RH up to about 19 wt% and were correlated linearly with the OH + NH band areas in IR spectra of the keratin film. The OH + NH band areas for the triple helix collagen film are about twice as large as those for the keratin film (double helix). The free water component increases with RH by keeping the bound water component minor for the keratin film. About twice of water retention capacity of the collagen film can be due to increasing adsorption of free water, interacting possibly with hydrophobic aliphatic CH surfaces. CONCLUSION: The present results suggest relatively low water contents less than about 19 wt% of outermost SC layers of human skin composed mostly of keratin exposed to ambient RH conditions. The triple helix collagen can be used as an effective moisturizing agent.


Assuntos
Colágeno/fisiologia , Epiderme/fisiologia , Queratinas/fisiologia , Fenômenos Fisiológicos da Pele , Água/química , Adsorção , Água Corporal/fisiologia , Colágeno/química , Epiderme/química , Humanos , Umidade , Queratinas/química , Espectrofotometria Infravermelho
11.
Clin Transl Oncol ; 21(5): 615-620, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30327938

RESUMO

BACKGROUND: Apart from surgery, the methods of treatment of HNC are radiotherapy (RTH) and/or chemotherapy (CRTH/CHT). One of the most frequent and serious complications of RTH is oral mucositis (OM). There is a strict correlation between the inflammation and the status of hydration. The aim of the study was to evaluate the changes in hydration, occurring in the course of RTH, measured by means of bioelectrical impedance analysis (BIA) and to analyze them in correlation with the intensification of OM in HNC patients. PATIENTS AND METHODS: Data from 49 HNC patients (stages I-IV) were analyzed. All of them were irradiated using IMRT technique with the doses of 50-70 Gy. Oral mucositis (OM) was evaluated according to RTOG/EORTC guidelines. BIA was performed using ImpediMed bioimpedance analysis SFB7 BioImp v1.55. RESULTS: In the fourth week of RTH, 4-5 days before the occurrence of severe OM, it was found that patients with OM grade 3 or higher compared to OM grade 2 or lower had significantly: lower ICW% values (respectively, 53.02% vs 50.72%; p = 0.0047), higher: ECW%: (47.95% vs 46.92%; p = 0.0020), TBW% (respectively, 56.34% vs 51.06%; p = 0.0455), ECW/ICW (respectively, 0.96 vs 0.86; p = 0.0007) and ECW/TBW (respectively, 0.49 vs 0.46, p = 0.0033). CONCLUSION: Our study indicates that HNC patients undergo changes in hydration in the course of RTH. We have also confirmed that the intensification of OM leads to ICW decrease and the increase of ECW, TBW as well as ECW/ICW and ECW/TBW values.


Assuntos
Água Corporal/fisiologia , Impedância Elétrica , Neoplasias de Cabeça e Pescoço/radioterapia , Estado de Hidratação do Organismo , Lesões por Radiação/diagnóstico , Radioterapia/efeitos adversos , Estomatite/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Lesões por Radiação/etiologia , Estomatite/etiologia
12.
Mod Rheumatol ; 29(3): 491-495, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29652197

RESUMO

OBJECTIVES: Locomotive syndrome (LS) is a condition requiring nursing care for musculoskeletal disorders. Our aim was to evaluate the correlation between body composition, measured by bioelectrical impedance analysis (BIA), and LS, measured using the 25-question Geriatric Locomotive Functional Scale (GLFS-25). METHODS: We enrolled 286 individuals who were undergoing regular health follow-up. All individuals completed the GLFS-25, body composition analysis by BIA, and five physical performance tests related to LS: timed up-and-go test, 10-m gait time, maximum stride length, back strength, and grip strength. Measured variables and demographic data were compared between individuals with and without LS. RESULTS: The extracellular water ratio, the extracellular water/total body water (ECW/TBW) ratio differentiated the LS and non-LS groups (p=.005), with all physical function measures being lower among individuals with a high, compared to low, ECW/TBW ratio. The risk ratio for LS among individuals with a high ECW/TBW ratio was 2.31, with an odds ratio of 2.67. CONCLUSION: The ECW/TBW ratio is predictive of LS. Based on our results, we propose that BIA should routinely be performed, with follow-up and intervention, as needed, for individuals with a high ECW/TBW ratio, as they are at risk for developing LS.


Assuntos
Composição Corporal , Doenças Musculoesqueléticas/fisiopatologia , Idoso , Água Corporal/fisiologia , Feminino , Força da Mão , Humanos , Vida Independente , Japão , Masculino , Pessoa de Meia-Idade , Doenças Musculoesqueléticas/epidemiologia , Aptidão Física , Pletismografia de Impedância
13.
Skin Res Technol ; 25(2): 158-164, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30368923

RESUMO

BACKGROUND/PURPOSE: Skin care via moisturization compensates for the lack of skin barrier function. However, moisturizer application methods are not clearly decided. Here, we focused on and examined the retention of externally applied ceramide in the stratum corneum (SC) using fluorescent imaging method. This study aimed to compare ceramide retention in the SC between normal skin and dry skin using an animal model. METHODS: Nine-week-old Sprague-Dawley rats were divided into two groups: normal skin and dry skin model. The dry skin model group was treated with acetone-diethyl ether solution. A fluorescently labeled ceramide solution was prepared and applied to rats' back skin. Skin samples were taken at 0 minute and 12 hours after ceramide application. Fluorescently labeled ceramide was evaluated and observed under a microscope. RESULTS: The intensity of externally applied ceramide in the normal skin group showed no significant change from 0 minute to 12 hours after application. In contrast, in the dry skin model group, the intensity of externally applied ceramide increased significantly from 0 minute to 12 hours after application. CONCLUSION: Our findings demonstrate that the externally applied ceramide penetrated the SC of dry skin more than that of normal skin.


Assuntos
Ceramidas/administração & dosagem , Epiderme/metabolismo , Pele/diagnóstico por imagem , Pele/metabolismo , Animais , Água Corporal/efeitos dos fármacos , Água Corporal/fisiologia , Ceramidas/farmacologia , Epiderme/anatomia & histologia , Epiderme/efeitos dos fármacos , Epiderme/ultraestrutura , Masculino , Microscopia de Fluorescência/instrumentação , Modelos Animais , Ratos , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/ultraestrutura , Anormalidades da Pele/tratamento farmacológico , Absorção Cutânea/efeitos dos fármacos , Absorção Cutânea/fisiologia , Fenômenos Fisiológicos da Pele/efeitos dos fármacos
14.
Acad Radiol ; 26(5): e47-e55, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30041922

RESUMO

RATIONALE AND OBJECTIVES: To investigate the value of using rapid kVp switching dual energy computed tomography (rsDECT) for the multi-parameter analysis of the heterogeneity of fatty liver in rat. MATERIALS AND METHODS: Twenty-four male rats were randomly divided into experimental (n = 16) and control (n = 8) groups. Four rats in the experimental group and two in the control group were examined by rsDECT every 3 weeks starting from week 8. The liver fat contents (LFC) of the left and right liver lobes were measured on the fat(water)-based material decomposition images to calculate fat content and CT value of liver and spleen were measured on the 70keV monochromatic images to calculate the liver-to-spleen CT value ratio [(L/S)70 keV] and difference at 70keV[(L-S)70 keV], and the spectral curve slopes of the left and right liver lobes (Slope-L, Slope-R). Measurements were evaluated statistically. RESULTS: The statistical analysis showed that the (L/S)70 keV, (L-S)70 keV, Slope and LFC in the different fatty liver groups were all significantly different (p < 0.05). Pearson correlation analysis results showed that the rsDECT results of the left and right liver lobes correlated with the fat percentage from pathological analysis (p < 0.05), with the left liver lobe having better correlation. Paired t-tests showed that the fat percentage of the left liver lobe was significantly higher than that of the right one, while (L/S)70 keV, and (L-S)70 keV were significantly lower. Diagnostic analysis using ROC curve showed that the areas under the curves with parameters of the left liver lobe were also greater than those of the right liver lobe. CONCLUSION: rsDECT multi-parameter imaging could quantitatively evaluate the heterogeneity of fat deposition in the liver, providing valuable information for the accurate and effective assessment of the heterogeneity of fatty liver.


Assuntos
Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Água Corporal/fisiologia , Fígado/diagnóstico por imagem , Masculino , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Curva ROC , Distribuição Aleatória , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Baço/diagnóstico por imagem , Baço/patologia , Tomografia Computadorizada por Raios X/métodos
15.
Clin Nutr ; 38(1): 227-233, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29429643

RESUMO

BACKGROUND/OBJECTIVES: Accuracy of impedance analysis depends on population-specific prediction equations. The aim of this study was to propose new prediction equations to estimate body composition using impedance analysis for healthy Tunisian children and validate them using the deuterium oxide dilution (D2O) technique. SUBJECTS/METHODS: Body composition was estimated by the Tanita impedance analyzer. The validity of this system was investigated in 134 school children aged between 8 and 11 years. The validity of other published equations was also tested in our sample. Total body water (TBW) and Fat-Free Mass (FFM) were determined using the D2O technique. Participants were divided equally into development (n = 67) and validation groups (n = 67) to develop prediction equation using linear regression models. RESULTS: The comparison between body composition obtained by Tanita system and by D2O technique illustrated a significant difference (p < 0.01). Compared to D2O technique, Tanita impedance analysis underestimates fat mass and overestimates FFM and TBW. The prediction equations for TBW and FFM were developed with sex, age, weight and resistance index as possible predictor variables. The selected equations presented the highest adjusted coefficient of determination (R2), the lowest standard error of the estimate (SEE) value and the lowest p-values. The pure error was 1.263 for the TBW equation and 1.646 for the FFM. The Bland Altman plot illustrated the good level of concordance between the TBW and FFM predicted by the new equations and measured by isotope dilution. CONCLUSIONS: Our study provides valid prediction equations for estimation of TBW, FFM from impedance analysis measures for Tunisian children. These equations are applicable to children aged between 8 and 11 years.


Assuntos
Composição Corporal/fisiologia , Água Corporal/fisiologia , Impedância Elétrica , Criança , Óxido de Deutério , Feminino , Humanos , Técnicas de Diluição do Indicador , Masculino , Reprodutibilidade dos Testes , Tunísia
16.
Nutrients ; 10(12)2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30563134

RESUMO

Water is essential for metabolism, substrate transport across membranes, cellular homeostasis, temperature regulation, and circulatory function. Although nutritional and physiological research teams and professional organizations have described the daily total water intakes (TWI, L/24h) and Adequate Intakes (AI) of children, women, and men, there is no widespread consensus regarding the human water requirements of different demographic groups. These requirements remain undefined because of the dynamic complexity inherent in the human water regulatory network, which involves the central nervous system and several organ systems, as well as large inter-individual differences. The present review analyzes published evidence that is relevant to these issues and presents a novel approach to assessing the daily water requirements of individuals in all sex and life-stage groups, as an alternative to AI values based on survey data. This empirical method focuses on the intensity of a specific neuroendocrine response (e.g., plasma arginine vasopressin (AVP) concentration) employed by the brain to regulate total body water volume and concentration. We consider this autonomically-controlled neuroendocrine response to be an inherent hydration biomarker and one means by which the brain maintains good health and optimal function. We also propose that this individualized method defines the elusive state of euhydration (i.e., water balance) and distinguishes it from hypohydration. Using plasma AVP concentration to analyze multiple published data sets that included both men and women, we determined that a mild neuroendocrine defense of body water commences when TWI is ˂1.8 L/24h, that 19⁻71% of adults in various countries consume less than this TWI each day, and consuming less than the 24-h water AI may influence the risk of dysfunctional metabolism and chronic diseases.


Assuntos
Água Corporal/fisiologia , Ingestão de Líquidos , Equilíbrio Hidroeletrolítico , Desidratação , Humanos
18.
Pediatr Dermatol ; 35(6): e425-e426, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30298555

RESUMO

A cross-sectional observational study of 43 infants and 60 adult women was performed in South Africa to assess skin barrier (SB) function through noninvasive quantification of transepidermal water loss (TEWL) and skin surface hydration (SSH). TEWL and SSH improved with age and in anatomic locations with chronic environmental exposure in keeping with reported trends in other ethnicities.


Assuntos
Água Corporal/fisiologia , Epiderme/fisiologia , Fenômenos Fisiológicos da Pele , Perda Insensível de Água/fisiologia , Adolescente , Adulto , Grupo com Ancestrais do Continente Africano , Estudos Transversais , Grupos Étnicos , Feminino , Humanos , Lactente , África do Sul , Adulto Jovem
19.
Exp Gerontol ; 113: 120-127, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30267871

RESUMO

Bioelectrical impedance spectroscopy (BIS) can assess intracellular water (ICW) and total water (TW) in limbs. This study aimed to examine whether BIS can explain a part of the inter-individual variation of the muscle size-strength relationship in older adults. We analyzed the data of 79 participants aged 64-86 years. The maximal voluntary isometric torques of dorsiflexion and plantar flexion on the right side were measured. The anterior and posterior muscle thickness (MT) in the right lower leg was assessed using ultrasonography. The length of the right lower leg (L) was measured, and the ICW-to-TW ratio (ICW/TW) in the right lower leg was obtained using BIS. The MT was multiplied by L to represent an index of muscle volume (MV). Correlation and stepwise regression analyses were performed. The anterior and posterior MT × L significantly and positively correlated with the muscle torque of dorsiflexion and plantar flexion (r = 0.710 and 0.649, respectively, P < 0.001). In the stepwise regression analyses, ICW/TW was selected as a significant predictor of muscle torque independent of MT × L (P < 0.05) for both dorsiflexion and plantar flexion. Electrical parameters of BIS (membrane capacitance, characteristics frequency, and phase angle) in the lower leg also significantly correlated with muscle torques. In addition, the skeletal muscle mass index (appendicular lean mass/height2) was also associated with ICW/TW (P < 0.001). The present results suggest that ICW/TW explains the interindividual variations of the muscle size-strength relationship.


Assuntos
Envelhecimento/fisiologia , Água Corporal/fisiologia , Espaço Extracelular/fisiologia , Atrofia Muscular/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Impedância Elétrica , Feminino , Humanos , Perna (Membro)/fisiologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Força Muscular , Músculo Esquelético/fisiologia , Ultrassonografia
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