New prediction equations for knee isokinetic strength in young and middle-aged non-athletes.

BACKGROUND: This study aimed to develop alternative prediction equations to predict isokinetic muscle strength at 60°/s based on anthropometric characteristics, including body mass, height, age, and sex for young and middle-aged non-athlete populations. METHODS: Three hundred and thirty-two healthy non-athletic participants (174 females, 158 males) between 20 and 59 years underwent a 60°/s isokinetic knee joint concentric contraction test. Forty people were randomly selected for retesting to assess the reliability of the isokinetic instrument. Multivariate linear regression was used to establish extension peak torque (EPT) and flexion peak torque (FPT) prediction equations. Sixty extra participants were used individually to validate the prediction equations, and Bland Altman plots were constructed to assess the agreement of predicted values with actual measurements. RESULTS: The result demonstrated that the instrument we used has excellent reliability. The multivariable linear regression model showed that body mass, age, and sex were significant predictors of PT (EPT: Adjusted R2 = 0.804, p < 0.001; FPT: Adjusted R2 = 0.705, p < 0.001). Furthermore, the equations we established had higher prediction accuracy than those of Gross et al. and Harbo et al. CONCLUSION: The equations developed in this study provided relatively low bias, thus providing a more suitable reference value for the knee isokinetic strength of young and middle-aged non-athletes.

Reference Values for Spirometry in Moroccan Adults.

INTRODUCTION: This novel study aimed to establish spirometric reference values and prediction equations based on a sample of the adult Moroccan population, an endeavor that has not been attempted previously. METHODS: In this cross-sectional study involving healthy Moroccan adults, data was collected through a mobile spirometry setup. RESULTS: Our sample comprised 841 healthy adults (384 men and 457 women) aged 18-86 years who underwent spirometry. For both sexes, the Global Lung Function Initiative 2012 equations for Caucasians corresponded the best to the studied sample but were not perfectly compatible. CONCLUSION: The spirometric prediction equations established in this study for Moroccan adults aged 18-86 years best represent the Moroccan population. More extensive future studies are needed to enrich the database of reference values and prediction equations derived from our research.

Race Adjustment of Pulmonary Function Tests in the Diagnosis and Management of COPD: A Scoping Review.

Aim: Increasing evidence suggests that the inclusion of self-identified race in clinical decision algorithms may perpetuate longstanding inequities. Until recently, most pulmonary function tests utilized separate reference equations that are race/ethnicity based. Purpose: We assess the magnitude and scope of the available literature on the negative impact of race-based pulmonary function prediction equations on relevant outcomes in African Americans with COPD. Methods: We performed a scoping review utilizing an English language search on PubMed/Medline, Embase, Scopus, and Web of Science in September 2022 and updated it in December 2023. We searched for publications regarding the effect of race-specific vs race-neutral, race-free, or race-reversed lung function testing algorithms on the diagnosis of COPD and COPD-related physiologic and functional measures. Joanna Briggs Institute (JBI) guidelines were utilized for this scoping review. Eligibility criteria: The search was restricted to adults with COPD. We excluded publications on other lung disorders, non-English language publications, or studies that did not include African Americans. The search identified publications. Ultimately, six peer-reviewed publications and four conference abstracts were selected for this review. Results: Removal of race from lung function prediction equations often had opposite effects in African Americans and Whites, specifically regarding the severity of lung function impairment. Symptoms and objective findings were better aligned when race-specific reference values were not used. Race-neutral prediction algorithms uniformly resulted in reclassifying severity in the African Americans studied. Conclusion: The limited literature does not support the use of race-based lung function prediction equations. However, this assertion does not provide guidance for every specific clinical situation. For African Americans with COPD, the use of race-based prediction equations appears to fall short in enhancing diagnostic accuracy, classifying severity of impairment, or predicting subsequent clinical events. We do not have information comparing race-neutral vs race-based algorithms on prediction of progression of COPD. We conclude that the elimination of race-based reference values potentially reduces underestimation of disease severity in African Americans with COPD.

Predicting feed intake in confined beef cows.

Six existing equations (three for nonlactating and three for lactating; NRC, 1987, Predicting feed intake of food-producing animals. Washington, DC: The National Academies Press, National Academy of Science; doi: 10.17226/950; NRC, 1996, Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791; Hibberd and Thrift, 1992. Supplementation of forage-based diets. J. Anim. Sci. 70:181. [Abstr]) were evaluated for predicting feed intake in beef cows. Each of the previously published equations are sensitive to cow-shrunk BW and feed energy concentration. Adjustments in feed intake prediction are provided for level of milk yield in NRC (1987. Predicting feed intake of food-producing animals. Washington, DC: The National Academies Press, National Academy of Science; doi: 10.17226/950) and NRC (1996 Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) equations. The equation published in 1996 used data generated between 1979 and 1993. Our objectives were to validate the accuracy of the published equations using more recent data and to propose alternative prediction models. Criteria for inclusion in the evaluation dataset included projects conducted or published since 2002, direct measurement of feed intake, adequate protein supply, and pen feeding (no metabolism crate data). After removing outliers, the dataset included 53 treatment means for nonlactating cows and 32 treatment means for lactating cows. Means for the nonlactating dataset were dry matter intake (DMI) = 13.2 ±â€…2.9 kg/d, shrunk body weight (SBW) = 578 ±â€…83.9 kg, body condition score = 5.7 ±â€…0.73, and Mcal net energy for maintenance (NEm)/kg of feed = 1.27 ±â€…0.15 Mcal/kg. Means for the lactating dataset were DMI = 14.6 ±â€…2.24 kg/d, SBW = 503 ±â€…73.4 kg, body condition score = 4.7 ±â€…0.58, and Mcal NEm/kg feed = 1.22 ±â€…0.16. Simple linear regression was used to determine slope, intercept, and bias when observed DMI (y) was regressed against predicted DMI (x). The NRC (1996. Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) nonlactating equation underestimated feed intake in diets moderate to high in energy density with intercept differing from 0 and slope differing from one (P ≤ 0.01). Average deviation from observed values was 2.4 kg/d. Similarly, when the NRC (1996. Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) equation was used to predict DMI in lactating cows, the slope differed from one (P < 0.01) with average deviation from observed values of 3.0 kg/d. New models were developed by pooling the two datasets and including a categorical variable for stage of production (0 = nonlactating and 1 = lactating). Continuous variables included study-average SBW0.75 and diet NEm, Mcal/kg. The best-fit empirical model accounted for 68% of the variation in daily feed intake with standard error of the estimate Sy root mean squared error = 1.31. The proposed equation needs to be validated with independent data.

Equations to estimate human milk intake in infants aged 7 to 10 months: prediction models from a cross-sectional study.

BACKGROUND: Obtaining valid estimates of nutrient intake in infants is currently limited by the difficulties of accurately measuring human milk intake. Current methods are either unsuitable for large-scale studies (i.e., the gold standard dose-to-mother stable isotope technique) or use set amounts, regardless of known variability in individual intake. OBJECTIVES: This cross-sectional study aimed to develop equations to predict human milk intake using simple measures and to carry out external validation of existing methods against the gold standard technique. METHODS: Data on human milk intake were obtained using the dose-to-mother stable isotope technique in 157 infants aged 7-10 mo and their mothers. Predictive equations were developed using questionnaire and anthropometric data (Model 1) and additional dietary data (Model 2) using lasso regression. Bland-Altman plots and intraclass correlation coefficients (ICC) also assessed the validity of existing methods (FITS and ALSPAC studies). RESULTS: The strongest univariate predictors of human milk intake in infants of 8.3 mo on average (46% female) were infant age, infant body mass index (BMI), number of breastfeeds a day, infant formula consumption, and energy from complementary food intake. Mean [95% confidence interval (CI)] differences in predicted versus measured human milk intake [mean (SD): 762 (257) mL/day] were 0.0 mL/day (-26, 26) for Model 1 (ICC 0.74) and 0.5 mL/day (-21, 22) for Model 2 (ICC 0.83). Corresponding differences were -197 mL/day (-233, -161; ICC 0.32) and -175 mL/day (-216, -134; ICC 0.41) for the methods used by FITS and ALSPAC, respectively. CONCLUSIONS: The Human Milk Intake Level Calculation provides substantial improvements on existing methods to estimate human milk intake in infants aged 7-10 mo, while utilizing data commonly collected in nutrition surveys. Although further validation in an external sample is recommended, these equations can be used to estimate human milk intake at this age with some confidence. This clinical trial was registered at http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=379436) as ACTRN12620000459921.

GLI-12 Reference Values versus Fixed 0.7 Ratio for the Detection of Airflow Obstruction in the Presence of Lung Hyperinflation.

Introduction: Airflow obstruction (AO) is evidenced by reduced forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) with the threshold for diagnosis often being set at <0.7. However, currently the ATS/ERS standards for interpretation of lung function tests recommend the lower limit of normal (LLN), calculated by reference equations of the Global Lung Initiative from 2012 (GLI-12), as a threshold for AO diagnosis. The present study aims to investigate phenotypes, with focus on hyperinflation, which influence AO prevalence defined by FEV1/FVC < LLN when compared to the fixed 0.7 threshold. Methods: Data from 3,875 lung function tests (56.4% men, aged 18-95) including 3,824 body plethysmography recordings performed from July 2021 to June 2022 were analysed. The difference between both classifiers was quantified, before and after stratification by sex, age, and hyperinflation. Results: AO diagnosis was significantly less frequent with the LLN threshold (18.2%) compared to the fixed threshold (28.0%) (p < 0.001) with discordance rate of 10.5%. In the presence of mild or moderate hyperinflation, there was substantial agreement (Cohen's kappa: 0.616, 0.718) between the classifiers compared to near perfect agreement in the presence of severe hyperinflation (Cohen's kappa: 0.896). In addition, subgroup analysis after stratification for sex, age, and hyperinflation showed significant differences between both classifiers. Conclusion: The importance of using the LLN threshold instead of the fixed 0.7 threshold for the diagnosis of AO is highlighted. When using the fixed threshold AO, misdiagnosis was more common in the presence of mild to moderate hyperinflation.

Validation of basal metabolic rate equations in persons with innervated and denervated chronic spinal cord injury.

Basal metabolic rate (BMR) measurement is time consuming and requires specialized equipment. Prediction equations allow clinicians and researchers to estimate BMR; however, their accuracy may vary across individuals with chronic spinal cord injury (SCI). The objective of this study was to investigate the validity of SCI-specific equations as well as able-bodied (AB) prediction equations in individuals with upper motor neuron (UMN), lower motor neuron (LMN), and females with SCI. Twenty-six men and women with chronic SCI (n = 12 innervated males, n = 6 innervated females, n = 8 denervated males) participated in this cross-sectional study. BMR values were measured by indirect calorimetry. Body composition (dual-energy X-ray absorptiometry and anthropometrics) assessment was conducted. AB-prediction equations [Cunningham, Nelson, Owen, Harris and Benedict, Mifflin, Schofield, Henry] and SCI-specific equations [Chun and Nightingale & Gorgey] were used to estimate and validate BMR. The accuracy of AB-specific FFM equations in predicting BMR was evaluated using Bland-Altman plots, paired t-tests, and error metrics. Measured BMR for innervated males, females, and denervated males was 1436 ± 213 kcal/day, 1290 ± 114, and 1597 ± 333 kcal/day, respectively. SCI-specific equations by Chun et al., Nightingale & Gorgey, and AB-specific FFM equations accurately predicted BMR for innervated males. For the denervated males, Model 4 equation by Nightingale & Gorgey was not different (p = 0.18), and Bland-Altman analyses showed negative mean bias but similar limits of agreement between measured and predicted BMR for the SCI-specific equations and AB-specific FFM equations. We demonstrated that SCI-specific equations accurately predicted BMR for innervated males but underpredicted it for denervated males. The Model 4 equation by Nightingale & Gorgey accurately estimated BMR in females with SCI. Findings from the current study will help to determine caloric needs in different sub-groups of SCI.

Predicción del porcentaje de grasa por medio antropometríaen niños y adolescentes de chile: propuesta de percentilespara su evaluación / Prediction of fat percentage by anthropometry in children and adolescents in Chile: proposal of percentiles for its evaluation

Introducción: El porcentaje de grasa es determinante enla evaluación de la atención primaria.Objetivo: Comparar ecuaciones antropométricas regio-nales que predicen el porcentaje de grasa corporal (%GC)con ecuaciones extranjeras y, proponer percentiles para va-lorar el % GC de niños y adolescentes de la región delMaule, Chile. Metodología: Se efectuó un estudio transversal (correla-cional) en escolares de la región del Maule (Chile). Se estudióa 1,126 escolares (588 hombres y 538 mujeres) con un rangode edad desde los 6,0 hasta los 17,9 años. Se evaluó la edad,el peso, estatura, circunferencia del abdomen, dos plieguescutáneos (tricipital y subescapular). Se calculó el índice demasa corporal (IMC), Índice Ponderal (IP, Índice Cintura-Talla(ICT), %GC por dos ecuaciones regionales y tres ecuacionesextranjeras (Boileau, Slaughter y Deuremberg). Resultados: Las ecuaciones regionales de chile presentaronvalores de 26,2±7,1%GC (ecuación 1) y 26,2±7,05%GC (ecua-ción 2) en varones, mientras que en mujeres reflejaron 33,6±4,72%GC (ecuación 1) y 33,6±4,70%GC (ecuación 2).Las ecuaciones extranjeras reflejaron valores similares en varo-nes, por ejemplo, de 19,3%±6,9%GC (Boileau), 20,1±8,7%GC(Slaughter) y 20,6±5,3%GC (Deuremberg), mientras que, enlas mujeres fue de 25,9±6,1%GC (Boileau), 25,2±8,8%GC(Slaughter) y 25,0±5,3%GC (Deuremberg). Hubo diferenciassignificativas entre las ecuaciones regionales con las ecuacio-nes extranjeras en ambos sexos (p<0,05). Los percentiles cal-culados fueron: (P3, P5, P10, P15, P25, P50, P75, P85, P90,P95 y P97). Los valores de %GC en las mujeres a edades avan-zadas (próximas a la adultez) oscilan entre 32 a 34%, y en loshombres entre 19 a 20%. Conclusión: Se evidenció que las tres ecuaciones extran-jeras de Boileau, Slaughter y Deuremberg no son aplicables amuestra de escolares chilenos, además, se desarrolló percen-tiles utilizando ecuaciones antropométricas para estimar el%GC desde los 6 hasta los 17,9 años.(AU)

Introduction: Fat percentage is determinant in primarycare evaluation. Objective: To compare regional anthropometric equationsthat predict body fat percentage (%BF) with foreign equa-tions and to propose percentiles to assess %BF in childrenand adolescents in the Maule region, Chile. Methodology: A cross-sectional (correlational) study wascarried out in schoolchildren from the Maule region (Chile). We studied 1,126 schoolchildren (588 males and 538 fe-males) with an age range from 6.0 to 17.9 years. Age, weight,height, abdomen circumference, and two skinfolds (tricipitaland subscapular) were evaluated. Body mass index (BMI),Ponderal Index (PI), Height-Waist Index (WHI), %GC werecalculated by two regional equations and three foreign equa-tions (Boileau, Slaughter and Deuremberg). Results: The Chilean regional equations presented valuesof 26.2±7.1% WC in males, while in females they reflected33.6±4.7% WC (p<0.05). The foreign equations reflectedsimilar values in males, i.e., 19.3%±6.9%GC (Boileau),20.1±8.7%GC (Slaughter) and 20.6±5.3%GC (Deuremberg),whereas, in females it was 25.9±6.1%GC (Boileau), 25.2±8.8%GC (Slaughter) and 25.0±5.3%GC (Deuremberg).There were significant differences between regional equa-tions with foreign equations in both sexes (p<0.05). The cal-culated percentiles were: (P3, P5, P10, P15, P25, P50, P75,P85, P90, P95 and P97). The %GC values in women at ad-vanced ages (close to adulthood) ranged from 32 to 34%,and in men from 19 to 20%. Conclusion: It was shown that the three foreign equationsof Boileau, Slaughter and Deuremberg are not applicable to asample of Chilean schoolchildren. In addition, percentileswere developed using anthropometric equations to estimate%BF from 6 to 17.9 years of age.(AU)

Estudio morfométrico y ecuaciones de predicción del peso corporal en llamas (Lama glama) Ch'aku y Q'ara / Morphometric study and body weight prediction equations in llamas (Lama glama) Ch'aku and Q'ara

RESUMEN: En el estudio se utilizó una población de 180 llamas de ambos sexos (machos y hembras) clasificados por edades (dientes de leche; dos dientes y cuatro dientes). Se registraron datos del peso corporal y las siguientes medidas morfométricas: En la cabeza: Longitud de la cabeza (LC); ancho de cabeza (ACa) y longitud de oreja (LO). En el cuello: Longitud del cuello (LCU); Perímetro de cuello anterior (PCuA) y perímetro de cuello posterior (PCuP). En el tronco y extremidades: Altura a la cruz (AC); altura de la grupa (AGRU), diámetro dorso esternal (DDE), perímetro torácico (PT), longitud del cuerpo (LOCU), longitud de la cruz a la grupa (LCG), longitud de grupa (LGRU), perímetro de caña anterior (PCA); perímetro de caña posterior (PCP). Los datos fueron procesados utilizando el software estadístico R. Concluyendo que los rasgos de conformación en llamas (Lama glama) Ch'aku y Q'ara están influenciados por la edad, sexo y raza. Los modelos de regresión simple y múltiple para la predicción del peso corporal fueron significativos.

SUMMARY: The study used a population of 180 llamas of both sexes (males and females) classified by age (milk teeth; two teeth and four teeth). Body weight data and the following morphometric measurements were recorded: Head: Head length (CL); head width (ACa) and ear length (LO). On the neck: Neck length (LCU); anterior neck circumference (PCuA) and posterior neck circumference (PCuP). On the trunk and limbs: Height at withers (AC); height at rump (AGRU), sternal dorsal diameter (DDE), thoracic perimeter (PT), body length (LOCU), length from withers to rump (LCG), rump length (LGRU), anterior canine perimeter (PCA); posterior canine perimeter (PCP). The data were processed using R statistical software. It was concluded that conformation traits in Ch'aku and Q'ara llamas (Lama glama) are influenced by age, sex and breed. Simple and multiple regression models for body weight prediction were significant.

Equations to predict height and weight in Asian- Chinese adults

@#Introduction: Height and weight measurements are required for the assessment of nutritional status. However, it is difficult to measure these parameters in nonambulatory persons. Hence, simple predictive equations that estimate these measurements using various anthropometric measurements are necessary. Methods: A total of 441 Asian-Chinese adults (174 males, median age = 32.5, IQR: 27.8 years; 267 females, median age = 34.6, IQR: 28.5 years) were used to build height and weight sex-specific prediction equations. An additional 111 Asian- Chinese adults (44 males, median age = 31.1, IQR: 25.0 years; 67 females, median age = 30.6, IQR: 25.6 years) were used to validate the newly developed prediction equations. Results: The best predictive model for height included arm length, knee height measurements and age (R2 = 0.70, standard error of estimate [SEE] = 3.38 for males; R2 = 0.71, SEE = 3.14 for females). The best weight predictive model included age, arm circumference and waist circumference (R2 = 0.79, SEE = 4.66 for males; R2 = 0.78, SEE = 4.38 for females). The new predictive models for height and weight have non-significant prediction biases as compared to the Cereda et al. (2010) and Ross equations, respectively. Conclusion: Height and weight predictive equations with a higher degree of accuracy have been developed for Asian Chinese adults.

Development of clinically based prediction models using machine learning and Bayesian statistics / Desarrollo de modelos de predicción basados clínicamente utilizando aprendizaje automático y estadísticas bayesianas

Abstract In this work, the framework for developing generic clinically based models is emphasized and illustrated with Bayesian statistics neurologic grade prediction models in order to exemplify the type of models that can be developed from a mathematical point of view. The models are based on clinical records of patients who underwent radiotherapy treatment due to glioblastoma which is an aggressive brain cancer. A first model requires as a parameter the neurologic grade of the patient before the treatment then predicts the grade after the treatment. A second, enhanced, model was developed with the aim of making the prediction more realistic and it uses the neurologic grade before the treatment as well, but it additionally depends on the Clinical Target Volume (CTV). Furthermore, with the aid of Bayesian statistic we were able to estimate the uncertainty of the predictions.

Resumen En este trabajo el marco teórico, para desarrollar modelos genéricos basados en datos clínicos, se enfatiza e ilustra con estadísticas bayesianas las cuales predicen grados neurológicos para ilustrar los tipos de modelos que se pueden desarrollar desde un punto de vista matemático. Los modelos se basan en datos clínicos de pacientes que se han sometido a radioterapia por causa de un glioblastoma, el cual es un cáncer de cerebro agresivo. Un primer modelo requiere como parámetro el grado neurológico del paciente antes del tratamiento y predice el grado después del tratamiento. Un segundo modelo, mejorado, fue desarrollado con el propósito de hacerlo más real, éste emplea también el grado neurológico antes del tratamiento; además depende del Volumen Blanco Clínico (CTV por sus siglas en inglés). Por último, con el uso de estadísticas bayesianas fue posible estimar la incertidumbre de las predicciones.

Digestibility and net energy prediction of rice by products determined with piglets / Digestibilidade e predição da energia líquida de subprodutos de arroz determinado com leitões

ABSTRACT: The aim of this study was to determine the chemical composition, digestibility, and net energy (NE) of broken rice (BRR), stabilized rice bran (SRB), and parboiled rice bran (PRB) for piglets. Two digestibility trials were performed with 12 and 18 male pigs with initial weights of 8 and 16kg, respectively. We performed total fecal collection using ferric oxide as fecal marker. The digestibility coefficients of organic matter, crude protein, and gross energy were higher (P<0.001) for the BRR compared to the SRB and PRB. The PRB presented a digestible energy 2% lower than that of BR and 5% higher than that of SRB. For BRR, average NE value was 3,228kcal/kg dry matter (DM), and the difference between the lower and higher value was 311kcal/kg DM. Average NE values of SRB and PRB were 2,896 and 3,293kcal/kgDM, respectively. The difference between the energy predicted by each equation reached 190kcal/kgDM for SRB and 285kcal/kgDM for PRB. In conclusion, BRR showed higher nutrient digestibility coefficients, except for EE and GE, which can be attributed to differences in the production processes. Regardless of the type of feedstuff tested, equations to predict NE values should be used carefully due to considerable differences in energy content.

RESUMO: O objetivo deste estudo foi determinar a composição química, a digestibilidade e a energia líquida (EL) da quirera (QR), farelo de arroz estabilizado (FAE) e farelo de arroz parboilizado (FAP) para leitões. Foram realizados dois ensaios de digestibilidade com 12 e 18 suínos machos com pesos iniciais de 8 e 16kg, respectivamente. A coleta fecal total foi realizada usando óxido férrico como marcador fecal. Os coeficientes de digestibilidade da matéria orgânica, proteína e energia bruta (EB) foram maiores (P<0,001) para o QR em comparação com o FAE e FAP. O FAP apresentou energia digestível 2% inferior à da QR e 5% maior que a da FAE. Para QR, o valor médio de EL foi de 3,228kcal/kg de matéria seca (DM), e a diferença entre o valor inferior e o valor superior foi de 311kcal/kg de MS. Os valores médios de EL de FAE e FAP foram de 2.896 e 3.293kcal/kgMS, respectivamente. A diferença entre a energia predita por cada equação atingiu 190kcal/kgMS para FAE e 285kcal/kgMS para FAP. Em conclusão, QR mostrou maiores coeficientes de digestibilidade dos nutrientes, exceto EE e EB, o que pode ser atribuído a diferenças nos processos de produção. Independentemente do tipo de alimento testado, as equações para prever os valores de EL devem ser usadas com cuidado devido a diferenças consideráveis no conteúdo energético.

Predicting the metabolizable energy of first and second corn harvests for piglets / Predição da energia metabolizável do milho de primeira e segunda safra para leitões

ABSTRACT Corn is one of the primary ingredients in swine diets, but there is a variation in its chemical composition and metabolizable energy (ME) content. Therefore, faster methods are required that can determine more accurate ME values to improve piglet diets. This study determined and predicted the ME of corn from first and second harvests for piglets. Two experiments were conducted to determine the ME values for 18 corn batches, evaluating corn from first and second harvests. The corn batches were analysed to determine the concentration of dry matter (DM), starch (ST), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), ether extract (EE), ash, calcium (Ca), phosphorus (P) and gross energy (GE). To determine the ME values, 40 piglets were used in each experiment, grouped into a randomized block design with four replicates. The ME of the corn from the first and second crops ranged from 3281 to 3509 and from 3143 to 3652 kcal/kg on an as-fed basis, respectively, and the fitted equations to predict the ME presented a low R2. The best fit equation for predicting the ME of corn for piglets was determined to be ME= - 6306.15 + 400.652ADF + 117.286ST + 24924.7Ca + 2489.66P - 148.41CP (R2=0.44) for the first harvest; ME= -7560.08 + 2.66895GE - 120.69ADF (R2=0.48) for the second harvest; and ME= 2848.95 + 68.5714NDF + 161.938EE - 5563.5Ca - 1454.2P (R2=0.41) for the joint harvest.

RESUMO O milho é um dos principais alimentos utilizados em rações para suínos, porém existem variações em sua composição química e conteúdo de energia metabolizável (EM). Portanto, são necessários métodos rápidos para se determinar os valores de EM de forma precisa, melhorando as dietas dos leitões. O trabalho determinou e ajustou equações de predição de EM do milho de 1a e 2a safra para leitões. Foram realizados dois experimentos para determinar os valores de EM de 18 cultivares de milho, avaliando-se os milhos de 1ª e 2ª safras. Foram realizadas as análises de matéria seca (MS), amido (AMI), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), proteína bruta (PB), extrato etéreo (EE), matéria mineral (MM), cálcio (Ca), fósforo (P) e energia bruta (EB) dos milhos. Para a determinação dos valores energéticos foram utilizados 40 animais em cada experimento, distribuídos em um delineamento experimental de blocos ao acaso com quatro repetições. Os valores de EM dos milhos de 1ª e 2ª safra variaram de 3281 a 3509 e de 3143 a 3652 kcal/kg MN, respectivamente, as equações ajustadas para predizer a EM apresentaram baixo R2. Os melhores ajustes para predizer a EM do milho para leitões são representados pelas equações EM= - 6306,15 + 400,652FDA + 117,286AMI + 24924,7Ca + 2489,66P - 148,41PB (R2=0,44), para os milhos de 1ª safra; EM = -7560,08 + 2,66895EB - 120,69FDA (R2=0,48), para os milhos de 2ª safra; e para o período completo de safras foi ajustada a equação EM= 2848,95 + 68,5714FDN + 161,938EE - 5563,5Ca - 1454,2P (R2=0,41).

Desarrollo y validación de ecuaciones para estimar composición corporal en niños de 4 a 6 años de Uruguay / Development and validation of equations for estimating body composition in 4-6 year old children from Uruguay

A correct diagnosis of obesity requires estimating body composition since it is linked to excess fat. Therefore it is necessary to have practical and sensitive methods of measurement. The aim of this study was to develop and validate bioelectrical impedance (BIA) and anthropometric equations to estimate fat mass (FM) and fat-free mass (FFM). Anthropometric measurements, BIA and deuterium dilution technique as the reference standard were performed in 191 children (4-6 years). Two equations were developed using multiple regression models and were validated in a subsample. Bland and Altman was applied to evaluate the bias differences between the means of both methods. The BIA equation was FFM (kg)= 2,089 + (0,346 * Fieight²/Resistance) + (0,312 * Weight) + (0,660 * Sex); with R2= 0.92, SRMSE 0,67 kg, bias 0,140 kg and precision 0,73 kg. The anthropometric equation was FM (kg)= 0.841 + (0,408 * Weight) + (0,137 * Subscapular-Skinfolds-Thickness) + (0,104 * Tricipital-Skinfolds-Thickness) - (0,764 * Sex) - (0,054 * Feight); with R2= 0.89, SRMSE 0,68 kg, bias -0,01 kg and precision 0,76 kg. The equations validated had a good predictive capacity and can be especially useful in epidemiological studies.

Un correcto diagnóstico de obesidad requiere estimar la composición corporal pues ésta se vincula al exceso de grasa, siendo necesario disponer de métodos prácticos y sensibles para su medición. El objetivo fue desarrollar y validar ecuaciones antropométricas y de bio-impedancia para estimar masa grasa (MG) y masa libre de grasa (MLG). Se realizaron mediciones antropométricas, de bio-impedancia y se aplicó la técnica de dilución con óxido de deuterio como patrón oro a 191 preescolares. Se desarrollaron dos ecuaciones utilizando modelos de regresión múltiple y se validaron en una submuestra. Se aplicó Bland-Altman para evaluar el sesgo entre las diferencias de las medias de ambos métodos. Las ecuaciones diseñadas fueron: MLG (kg)= 2,089 + (0,346* Talla²/Resistencia) + (0,312* Peso) + (0,660* Sexo); con R2= 0,92; SRMSE 0,67kg; sesgo 0,140 kg y precisión 0,73 kg; y MG (kg)= 0,841 + (0,408* Peso) + (0,137* Pliegue Subescapular) + (0,104* Pliegue Tricipital) - (0,764* Sexo) - (0,054* Talla) con R2= 0,89; SRMSE 0. 68.kg, sesgo -0,01 kg y precisión 0,76 kg. Las ecuaciones validadas tienen adecuada capacidad predictiva. Pueden ser especialmente útiles en estudios epidemiológicos.

Desarrollo de ecuaciones y propuesta de valores referenciales para estimar la masa grasa de niños y adolescentes chilenos / Development of equations and proposed reference values to estimate body fat mass among Chilean children and adolescents

Introducción. La evaluación de la composición corporal es relevante para determinar el estado nutricional e identificar posibles riesgos para la salud. Objetivo. a) Desarrollar ecuaciones de regresión para predecir la masa grasa (MG) utilizando como método de referencia la absorciometría de rayos X de doble energía; b) proponer valores referenciales de MG en función de la edad cronológica y biológica para niños y adolescentes chilenos. Metodología. Estudio transversal en niños y adolescentes de 5,0 a 18,9 años de la región del Maule (Chile). La muestra fue conformada de forma probabilística (estratificada) por 3593 sujetos. Se evaluó el peso, estatura de pie, estatura sentada y circunferencia de la cintura. Se calculó el índice de masa corporal y los años de pico de velocidad del crecimiento (APVC). La composición corporal (MG, masa libre de grasa, masa ósea y porcentaje de grasa) fueron determinados por medio del escaneo de absorciometría de rayos X de doble energía. Resultados. Los APVC (edad biológica) se presentaron en los hombres a los 14,9 ± 0,9 APVC y, en las mujeres, a los 11,5 ± 0,7 APVC. Se generaron ecuaciones para estimar la MG para hombres y mujeres, utilizando como predictores la edad cronológica, APVC y circunferencia de cintura. Se desarrollaron percentiles para evaluar la MG por absorciometría de rayos X de doble energía y por ecuaciones de regresión. Conclusión. Las ecuaciones mostraron aceptabilidad para determinar la MG; además, se han propuesto valores referenciales para evaluar la MG en función de la edad cronológica y biológica.

Introduction. The assessment of body composition is relevant to establish nutritional status and identify potential health risks. Objective. a) To develop regression equations to predict fat mass (FM) using a dual-energy X-ray absorptiometry as reference method; b) to propose reference FM values based on chronological and biological age for Chilean children and adolescents. Methodology. Cross-sectional study in children and adolescents aged 5.0 to 18.9 years from the Maule Region (Chile). The sample was made up of 3593 subjects in a probabilistic fashion (stratified). Subjects' weight, standing height, sitting height, and waist circumference were assessed. Body mass index and age at peak development velocity (APGV) were estimated. Body composition (FM, fat-free mass, bone mass, and fat percentage) were established based on a dual-energy X-ray absorptiometry scan. Results. APGV (biological age) was 14.9 ± 0.9 years among boys and 11.5 ± 0.7 among girls. Equations were developed to estimate FM among boys and girls using chronological age, APGV, and waist circumference as predictors. Percentiles were estimated to assess FM by dual-energy X-ray absorptiometry and regression equations. Conclusion. Equations were acceptable to establish FM; in addition, reference values were proposed to assess FM based on chronological and biological age.

Prediction equations for spirometry in four- to six-year-old children / Equações de predição da espirometria em crianças de quatro a seis anos

Abstract Objective To generate prediction equations for spirometry in 4- to 6-year-old children. Methods Forced vital capacity, forced expiratory volume in 0.5 s, forced expiratory volume in one second, peak expiratory flow, and forced expiratory flow at 25–75% of the forced vital capacity were assessed in 195 healthy children residing in the town of Sete Lagoas, state of Minas Gerais, Southeastern Brazil. The least mean squares method was used to derive the prediction equations. The level of significance was established as p < 0.05. Results Overall, 85% of the children succeeded in performing the spirometric maneuvers. In the prediction equation, height was the single predictor of the spirometric variables as follows: forced vital capacity = exponential [(−2.255) + (0.022 × height)], forced expiratory volume in 0.5 s = exponential [(−2.288) + (0.019 × height)], forced expiratory volume in one second = exponential [(−2.767) + (0.026 × height)], peak expiratory flow = exponential [(−2.908) + (0.019 × height)], and forced expiratory flow at 25–75% of the forced vital capacity = exponential [(−1.404) + (0.016 × height)]. Neither age nor weight influenced the regression equations. No significant differences in the predicted values for boys and girls were observed. Conclusion The predicted values obtained in the present study are comparable to those reported for preschoolers from both Brazil and other countries.

Resumo Objetivo Gerar equações de predição da espirometria em crianças de quatro a seis anos. Métodos Capacidade vital forçada, volume expiratório forçado em 0,5 segundo, volume expiratório forçado em um segundo, pico de fluxo expiratório e fluxo expiratório forçado com 25-75% da capacidade vital forçada foram avaliados em 195 crianças saudáveis que residem em Sete Lagoas, Estado de Minas Gerais, Sudeste do Brasil. O método dos mínimos quadrados foi usado para derivar as equações de predição. O nível de significância foi estabelecido como p < 0,05. Resultados No geral, 85% das crianças foram bem-sucedidas ao fazer as manobras espirométricas. Na equação de predição, a estatura foi a única variável preditora das variáveis espirométricas, da seguinte forma: capacidade vital forçada = exponencial [(-2,255) + (0,022 x estatura)], volume expiratório forçado em 0,5 segundo = exponencial [(-2,288) + (0,019 x estatura)], volume expiratório forçado em um segundo = exponencial [(-2,767) + (0,026 x estatura)], pico do fluxo expiratório = exponencial [(-2,908) + (0,019 x estatura)] e fluxo expiratório forçado com 25-75% da capacidade vital forçada = exponencial [(-1,404) + (0,016 x estatura)]. Nem a idade nem o peso influenciaram as equações de regressão. Não foi observada diferença significativa nos valores previstos em meninos e meninas. Conclusão Os valores previstos obtidos neste estudo são comparáveis àqueles relatados em crianças em idade pré-escolar tanto do Brasil quanto de outros países.

Energy consumption assessment by indirect calorimetry in critically ill children / 临床儿科杂志

Nutritional and metabolic disorders are the common problems in PICU. They often lead to deterioration in child nutrition and vice versa. Reasonable assessment of the energy consumption can provide theoretical basis for proper nutrition support in critically ill children. In this review, the methods of evaluating the energy consumption which included energy metabolism measurement and prediction equations were introduced, and the importance of indirect calorimetry was emphasized. Meanwhile, the research situation of energy consumption assessment at home and abroad and the current status of its clinical application were also reviewed.

Validação das equações metabólicas para caminhada e corrida propostas pelo American College of Sports Medicine em homens entre 20 e 30 anos de idade / Validation of the ACSM walking and running metabolic equations among men aged 20 to 30 years

O American College of Sports Medicine (ACSM) sugere equações para estimativa do gasto metabólico da caminhada e da corrida, concebidas a partir de pressupostos: 1) que o indivíduo esteja executando uma atividade em estado de equilíbrio e 2) que o consumo de oxigênio (VO2) tem relação linear com a intensidade do trabalho. O objetivo deste estudo foi verificar a validade concorrente dessas equações metabólicas em homens regularmente ativos entre 20 e 30 anos de idade, tendo como medida critério a espirometria (TEEM-100, AeroSport). Participaram deste estudo 36 homens jovens e ativos. No primeiro dia, os voluntários executaram um teste máximo de exercício na esteira (ATL 10200, Inbrasport). Os indivíduos completaram um trabalho padronizado de 30 minutos com seis diferentes estágios de caminhada e corrida (80,4; 120,6 e 160,8m.min-1) com (5 por cento) e sem inclinação, 48 a 96h após o teste máximo. Além da estatística descritiva, utilizaram-se a correlação linear de Pearson, o coeficiente de determinação, a ANOVA com um fator e o teste t pareado, com o nível de significância estabelecido em 0,05. Todos os procedimentos foram realizados no pacote estatístico SPSS. Os resultados apontaram para a superestimação do VO2 em ambas as atividades (p < 0,05), sobretudo na corrida, com exceção para 80,4 e 120,6m.min-1, sem inclinação (diferença média de -30 a 20 por cento para caminhada e de 3,2 a 12 por cento para corrida). Os valores de erro padrão de estimativa (EPE) variaram entre 1,56 e 3,15ml O2.kg-1.min-1 e em torno de 3,5ml O2.kg-1.min-1, para caminhada e corrida, respectivamente. A correlação foi maior que 0,7 para todos os estágios. Contudo, seguindo os critérios estabelecidos por Lohman (1992), as equações não foram validadas. Dessa forma, em homens ativos, o EPE deverá ser considerado, pois as equações metabólicas propostas pelo ACSM superestimam os valores de VO2.

The American College of Sports Medicine (ACSM) has proposed equations for estimating metabolic cost of walking and running, which were based on two conditions: 1. that the subject is performing a steady state exercise, and 2. that the oxygen consumption (VO2) has a linear relationship with the workload. The purpose of this study was to verify the concurrent validity of these equations among men, aged 20 to 30 years and who were regularly active, using the spirometry as a criterion measure (AeroSport TEEM-100 gas analyzer). The sample was composed of 36 men. On day 1, they performed a maximal exercise test on a treadmill (ATL 10200, INBRASPORT). The subjects completed a standard 6-stage protocol with different speeds (80.4, 120.6 and 160.8 m.min-1) and grades (0 and 5 percent), 48 to 96 hours after maximal test. Besides descriptive statistics, other procedures included Pearson's linear correlation, the coefficient of determination, one-way ANOVA and paired t-Student test with level of significance established at 0.05. The analyses were performed with the SPSS package. The results showed that there was VO2 overestimation for both activities (p < 0.05), especially for running, except at 80.4 and 120.6 m.min-1, with no inclination (mean difference from -30 to 20 percent for walking and 3.2 to 12 percent for running). The standard error of the estimate (SEE) varied between 1.56 and 3.15 ml O2.kg-1.min-1 and around 3.5 ml O2.kg-1.min-1, for walking and running, respectively. Correlation coefficients were greater than 0.7 for all stages. However, according to Lohman's criteria (1992), the equations were not validated. Therefore, among young men, SEE should be taken into account, due to the fact that the ACSM equations for walking and running overestimate VO2 values.

Prediction Equations of Pulmonary Function Parameters Derived from the Forced Expiratory Spirogram for Healthy Adults over 50 years old in rural area / 결핵

BACKGROUND: The studies on prediction equations of pulmonary function parameters for adults in Korea have been performed in a reference population mainly consisted of young and middle ages. So they included a relatively few elderly who conducted pulmonary function test frequently in clinic. We established prediction equations of pulmonary function parameters for healthy adults over 50 years old in rural area and compared this results with those of other studies. Therefore we attempted to consider normative values of pulmonary function tests for elderly in Korea. METHOD: Five hundred thirty-three women and men over 50 years old in rural area were participated. A "healthy" subgroup of 110 women and 32 men were identified by excluding those who had conditions that negatively influenced pulmonary function. We derived prediction equations for FVC, FEV1, and FEV1% by multiple linear regression method from their age, heights and weights in each sex. RESULTS: Prediction equations for FVC and FEV1 in each sex were derived as follows Male; FVC (L) = 0.02488Height(cm) - 0.0269Age(years) + 0.493 FEV1(L) = 0.01874Weight(kg) - 0.0282Age(years) + 2.906 Female; FVC(L) = 0.02160Height(cm) - 0.0192Age(years) - 0.0125 FEV1 (L) = 0.01720Height(cm) - 0.0194Age(years) + 0.3890 Prediction equations for FEV1 % were not derived because FEV1 % didn't have statistically significant terms. Comparing Predicted values that were calculated by substitution into the equations of various studies of mean values of age, heights and weights from this study, FVC and FEV1 values in men of this study were lower than those of other studies. In women, FVC and VEV1 values of this study were as similar as or lower than those of the study conducted for healthy elderly blacks in U.S.A respectively. CONCLUSION: We have got prediction equations of pulmonary function parameters which were driven from forced expiratory spirogram in adults over 50 years old in rural area. Predicted values of this study were lower than those of other studies which were conducted in Korea. So we consider that the study for spirometry reference values for elderly Korean using the method compatible with ATS recommendation need to be conducted more frequently forward.