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.

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.

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.

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.

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.

Linkage of in situ ruminal degradation of crude protein with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows.

The objectives of this study were to determine the range in ruminal degradability of crude protein (CP) and intestinal digestibility of rumen undegradable protein in commercial soybean meal (SBM) and to investigate the range in in situ ruminal AA and phytate (InsP6) degradation and their relationship to CP degradation. An in situ study was conducted using 3 lactating Jersey cows with permanent rumen cannulas. Seventeen SBM variants from Europe, Brazil, Argentina, North America, and India were tested for ruminal CP and AA degradation, and in vitro intestinal digestibility of rumen undegradable protein. Nine variants were used to investigate the ruminal degradation of InsP6. The estimated rapidly degradable fraction (a) of CP showed an average value of 4.5% (range: 0.0%-9.0%), the slowly degradable fraction (b) averaged 95% (91%-100%), and the potential degradation was complete for all 17 SBM variants. The degradation of fraction b started after a mean lag phase of 1.7 h (1.1-2.0 h) at an average rate (c) of 10% per hour, but with a high range from 4.5% to 14% per hour. Differences in the degradation parameters induced a considerable range in CP effective degradation at a rumen passage rate of 6% per hour (CPED6) from 38% to 67%; hence, the concentration of rumen undegradable protein varied widely from 33% to 62%. The range in AA degradation between the SBM variants was high, with Ser showing the widest range, from 28% to 96%, and similar for the other AA. The regression equations showed close relationships between CP and AA degradation after 16 h of in situ incubation. However, the slopes of the linear regressions were significantly different between AA, suggesting that degradation among individual AA differs upon a change in CP degradation. The concentrations of InsP6 and myo-inositol pentakisphosphate in bag residues in the in situ study decreased constantly with longer ruminal incubation times. The ruminal degradation parameters of InsP6 ranged from 11% to 37% for fraction a, 63% to 89% for fraction b, and from 7.7% to 21% per hour for degradation rate c, with average values of 21%, 79%, and 16% per hour, respectively. The calculated InsP6 effective degradation at a rumen passage rate of 6% per hour (InsP6ED6) varied from 61% to 84% among the SBM variants. Significant correlations were detected between InsP6ED6 and CPED6 and between InsP6ED6 and chemical protein fractions A, B1, B2, B3, and C. Linear regression equations were developed to predict ruminal InsP6 degradation using CPED6 and chemical protein fractions B3 and C chosen by a stepwise selection procedure. We concluded that a high range in CP, AA, and InsP6 degradation exists among commercial SBM, suggesting that general degradability values may not be precise enough for diet formulation for dairy cows. Degradation of CP in SBM may be used to predict rumen degradation of AA and InsP6 using linear regression equations. Degradation of CP and InsP6 could also be predicted from the chemical protein fractions.

Early Evidence of Chronic Obstructive Pulmonary Disease Obscured by Race-Specific Prediction Equations.

Rationale: The identification of early chronic obstructive pulmonary disease (COPD) is essential to appropriately counsel patients regarding smoking cessation, provide symptomatic treatment, and eventually develop disease-modifying treatments. Disease severity in COPD is defined using race-specific spirometry equations. These may disadvantage non-White individuals in diagnosis and care. Objectives: Determine the impact of race-specific equations on African American (AA) versus non-Hispanic White individuals. Methods: Cross-sectional analyses of the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) cohort were conducted, comparing non-Hispanic White (n = 6,766) and AA (n = 3,366) participants for COPD manifestations. Measurements and Main Results: Spirometric classifications using race-specific, multiethnic, and "race-reversed" prediction equations (NHANES [National Health and Nutrition Examination Survey] and Global Lung Function Initiative "Other" and "Global") were compared, as were respiratory symptoms, 6-minute-walk distance, computed tomography imaging, respiratory exacerbations, and St. George's Respiratory Questionnaire. Application of different prediction equations to the cohort resulted in different classifications by stage, with NHANES and Global Lung Function Initiative race-specific equations being minimally different, but race-reversed equations moving AA participants to more severe stages and especially between the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 0 and preserved ratio impaired spirometry groups. Classification using the established NHANES race-specific equations demonstrated that for each of GOLD stages 1-4, AA participants were younger, had fewer pack-years and more current smoking, but had more exacerbations, shorter 6-minute-walk distance, greater dyspnea, and worse BODE (body mass index, airway obstruction, dyspnea, and exercise capacity) scores and St. George's Respiratory Questionnaire scores. Differences were greatest in GOLD stages 1 and 2. Race-reversed equations reclassified 774 AA participants (43%) from GOLD stage 0 to preserved ratio impaired spirometry. Conclusions: Race-specific equations underestimated disease severity among AA participants. These effects were particularly evident in early disease and may result in late detection of COPD.

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.

Predicting microbial crude protein synthesis in cattle from intakes of dietary energy and crude protein.

Accurate predictions of microbial crude protein (MCP) synthesis are needed to predict metabolizable protein supply in ruminants. Since 1996, the National Academies of Sciences, Engineering, and Medicine series on beef cattle nutrient requirements has used the intake of total digestible nutrients (TDN) to predict ruminal MCP synthesis. Because various tabular energy values for feeds are highly correlated, our objective was to determine whether intakes of digestible energy (DE), metabolizable energy (ME), and net energy for maintenance (NEm) could be used as predictors of MCP synthesis in beef cattle. A published database of 285 treatment means from experiments that evaluated MCP synthesis was updated with 50 additional treatment mean observations. When intakes of TDN, fat-free TDN, DE, ME, NEm, dry matter, organic matter, crude protein (CP), ether extract, neutral detergent fiber, and starch were used in a stepwise regression analysis to predict MCP, only intakes of DE and CP met the P < 0.10 criterion for entry into the model. Mixed-model regression analyses were used to adjust for random intercept and slope effects of citations to evaluate intake of DE alone or in combination with CP intake as predictors of MCP synthesis, and the intakes of TDN, ME, and NEm as alternatives to DE intake. Similar precisions in predicting MCP synthesis were obtained with all measures of energy intake (CV = root mean square error [RMSE] as a percentage of the overall mean MCP varied from 9% to 9.67%), and adding CP intake to statistical models increased precision (CV ranged from 8.43% to 9.39%). Resampling analyses were used to evaluate observed vs. predicted values for the various energy intake models with or without CP intake, as well as the TDN-based equation used in the current beef cattle nutrient requirements calculations. The coefficient of determination, concordance correlation coefficient, and RMSE of prediction as a percentage of the mean averaged 0.595%, 0.730%, and 28.6% for the four measures of energy intake, with average values of 0.630%, 0.757%, and 27.4%, respectively, for equations that included CP intake. The TDN equation adopted by the 2016 beef cattle nutrient requirements system yielded similar results to newly developed equations but had a slightly greater mean bias. We concluded that any of the measures of energy intake we evaluated can be used to predict MCP synthesis by beef cattle and that adding CP intake improves model precision.

The ability to accurately and precisely predict microbial protein synthesis is crucial in predicting the supply of metabolizable protein in beef cattle. We updated a database previously used to predict microbial crude protein (CP) supply in beef cattle. Then we evaluated the utility of using total digestible nutrients (TDN) and different measures of energy intake to predict ruminal microbial protein synthesis. Using regression analyses, we found that intakes of digestible and metabolizable energy and intake of net energy for maintenance were as effective as the intake of TDN as independent variables to predict microbial protein synthesis. Adding the intake of CP to the models improved the precision of predictions, and all models performed as well or better than the regression model adopted by the 2016 nutrient requirement system for beef cattle.

Differences in calculated body fat percentage estimated from published equations based on bioelectric impedance analysis in healthy young South African adults.

Background: Adult overweight and obesity, in addition to the intake of saturated fat and total serum cholesterol must be monitored as biological risk factors for non-communicable diseases (NCDs). Bioelectric impedance analysis (BIA) provides data on body fat for use in epidemiological settings. However, optimized equations should be used to calculate percentage body fat (%BF). The purpose of this study was to assess the differences between %BF calculated using different published BIA equations and %BF measured by BIA in young South African adults. Design and methods: In this observational study, differences in calculated %BF were assessed, with different BIA equations retrieved from the literature used in 1128 healthy young adults aged 20-30 years. The %BF (measured by BIA) was compared between equations, between Black and White men and women, respectively. Results: The results showed statistically significant differences in the %BF calculated from published BIA equations when used in young South African adults (χ² = 946, χ² = 2528, χ² = 2088, respectively, p < 0.0001). In Black and White men and women, respectively, %BF levels were significantly higher when calculated by equations, than when measured by BIA (p < 0.0001). Conclusion: There seem to be large discrepancies in estimating %BF by BIA equations and these values cannot be used interchangeably for young South African adults. A South African age, ethnicity and sex-specific BIA equation needs to be developed to accurately estimate %BF in young South African adults.

Accuracy of equations for estimating resting energy expenditure in children and adolescents living with phenylketonuria.

BACKGROUND: Measuring resting energy expenditure (REE) in individuals living with phenylketonuria (PKU) using indirect calorimetry (IC) is unusual in healthcare facilities because it requires specific protocols and expensive equipment. Considering that determining REE is crucial for devising nutritional strategies for the management of PKU, the aim of this study was to identify the predictive equations that provide the best estimates of REE in children and adolescents living with PKU and to propose a predictive equation for determining REE in this population. METHODS: An REE concordance study was conducted with children and adolescents living with PKU. Anthropometric and body composition assessments using bioimpedance and REE assessment using IC were performed. The results were compared to 29 predictive equations. RESULTS: Fifty-four children and adolescents were evaluated. The REE obtained using IC differed from all estimated REE, except Henry's equation for male children (p = 0.058). Only this equation showed good agreement (0.900) with IC. Eight variables were associated with the REE obtained using IC with emphasis on fat-free mass (kg) (r = 0.786), weight (r = 0.775), height (r = 0.759) and blood phenylalanine (r = 0.503). With these variables, three REE equations were suggested, with R2 = 0.660, 0.635 and 0.618, respectively, and the third equation, which involves weight and height, showed adequate sample size for a statistical power of 0.942. CONCLUSION: Most equations, not specific for individuals living with PKU, overestimate the REE of this population. We propose a predictive equation for assessing REE for children and adolescents living with PKU to be used in settings where IC is not available.

Practical Utilization of Prediction Equations in Chronic Kidney Disease.

Chronic kidney disease (CKD) is common and can lead to kidney failure, cardiovascular complications, and early mortality. While nephrologists can provide valuable insights for patients at all stages of CKD, these scarce resources should be targeted at patients with the highest risk of progression and adverse outcomes. Prediction models are tools that can help providers risk stratify patients if they are effectively implemented into the clinical workflow. We believe these equations should demonstrate (1) clinical utility: where they can provide useful information to the physician and patients; and (2) clinical usability: where they are able to be easily integrated into clinical workflow and do not result in unnecessary costs or visits. CKD often remains unrecognized until later stages when a large window of opportunity to delay progression has already passed. Models to determine progression of CKD using thresholds such as a 40% decline in eGFR can provide clinical utility in risk stratifying patients at all stages of CKD, an endpoint that has been recommended by the FDA for the evaluation of drug approvals for disease-modifying therapies. For patients at more advanced stages of CKD with a greater risk of kidney failure, tools such as the kidney failure risk equation can be implemented to help guide most costly decisions, such as referral to multidisciplinary care, commencing dialysis modality education, or planning for vascular access placement surgery. In addition, models focused on determining outcomes following dialysis initiation can help inform shared decision-making between patient and provider to better inform decisions around conservative care. To ensure widespread adoption of these tools, it is important to ensure that they are broadly generalizable to many health settings and easily implemented into existing clinic workflows with minimum disruption.

Adults with early diagnosis of phenylketonuria have higher resting energy expenditure than adults with late diagnosis.

INTRODUCTION: To date, there is a gap regarding resting energy expenditure (REE) in adults with phenylketonuria (PKU), whether PKU type and time of diagnosis interfere with REE, and whether the available predictive equations are valid in this population. OBJECTIVE: To compare the REE of adult subjects with PKU with healthy subjects and secondarily, examine the REE of adults with PKU according to type and time of diagnosis, and check the agreement of commonly used predictive equations of REE. METHODS: Concordance study with adults with PKU and a comparison group (CG) with healthy adults. Anthropometric and body composition assessments and REE assessment by indirect calorimetry (IC) were performed. The results obtained by IC were compared with predictive equations. RESULTS: Sixty-nine adults were evaluated (PKU: 36; CG: 33). The REE of adults with mild and classic PKU is similar (p>.05) and similar to CG (p>.05). The REE of individuals with early diagnosis is higher (p < .05) than the REE of individuals with late diagnosis. The REE obtained by IC differed (p < .05) from all estimated REE. CONCLUSION: Late diagnosis of PKU showed lower REE compared to individuals with early diagnosis. The REE of adults with PKU does not differ in relation to the type of PKU, nor does it differ from the CG. Predictive equations overestimate REE.

Prediction Equations for In Vitro Ileal Disappearance of Dry Matter and Crude Protein Based on Chemical Composition in Dog Diets.

The aims of this study were to determine in vitro ileal disappearance (IVID) of dry matter (DM) and crude protein (CP) in commercial dog diets and to develop equations for predicting the IVID of DM and CP in dog diets based on chemical composition. Eighteen commercial dog diets were analyzed for IVID of DM and CP using a two-step in vitro procedure for dogs. The diet samples in flasks with digestive enzymes were incubated for 2 h and 4 h to simulate digestion in the stomach and the small intestine, respectively. The contents of CP, ether extract, neutral detergent fiber (NDF), and ash in the diets ranged from 14.4 to 42.5%, 3.5 to 23.5%, 6.4 to 34.6%, and 4.9 to 10.0%, respectively, on an as-is basis. The NDF contents were negatively correlated with the IVID of DM and CP (r = -0.73 and r = -0.62, respectively; p < 0.05). The most suitable prediction equations for the IVID of DM and CP in the dog diets were: IVID of DM (%) = 81.33 + 0.46 × CP - 0.77 × NDF, R2 = 0.78; IVID of CP (%) = 81.25 + 0.33 × CP - 0.49 × NDF, R2 = 0.64, where all nutrients were in % on an as-is basis. In conclusion, dry matter and protein utilization of dog diets based on in vitro digestibility assays can be estimated fairly well using protein and fiber concentrations as independent variables.

Morphological Description and Live Weight Prediction from Body Measurements of Socorro Island Merino Lambs.

The aim of this study was to describe the morphology and estimate live weight from body measurements of Socorro Island Merino lambs. A group of Socorro Island Merino lambs was recorded from birth to year for live weight, rump width, rump length, withers height, body length, cannon bone perimeter, and chest girth, width, and depth. The effect of the lamb type on body measurements and live weight was analyzed using ANOVA, Pearson's correlation analysis was performed to estimate the relationship between body measurements and live weight, multiple linear regressions were fitted to obtain prediction equations of live weight from the body measurements and finally, chest girth was used to generate prediction equations using linear and exponential models. At birth and at year, differences were observed in body measurements, especially those related to the thoracic region, with crossbred males showing the highest values. Live weight was correlated with almost all the body measurements, with the highest coefficients observed with chest girth, chest width, and chest depth. Live weight can be accurately predicted from multiple regression equations using several body measurements, but using only chest girth (CG) as a predictor, the exponential equation W0-365 = 0.9142 exp(0.0462 CG) showed the best accuracy.

How to account for Inuit ancestry in lung function prediction.

Rigorous lung function prediction equations for the Inuit are lacking. We used spirometry from 351 Inuit and 29 people of other ancestry obtained during an occupational survey in Greenland to determine how to obtain valid lung function predictions for the Inuit using Global Lung Function Initiative (GLI) equations for Europeans. Standing height for the Inuit was used in the predictions as well as their height modified in line with the known differences in standing to sitting height ratio (SHR) for the Inuit. With recorded height in predicting lung function, mean±SD Inuit z-scores for FVC and FEV1 were significantly higher than predicted (0.81±1.20 and 0.53±1.36, respectively, p<0.0001) which was not true for the non-Inuit participants (-0.01±1.04 and 0.15±1.17, respectively). When using height modified for SHR the mean±SD Inuit z-scores for FVC and FEV1 were no longer significantly different from predicted (0.10±1.10 and -0.12±1.24, respectively). The mean±SD Inuit FEV1/FVC z-scores were not significantly different from the non-Inuit, being respectively -0.45±0.98 and -0.01±1.04. Modified height changed the mean±SD Inuit FEV1/FVC z-scores to -0.39±0.99. Representative lung function predictions from GLI equations can be made for Inuit by using standing height modified for the known differences in SHR between Inuit and those of European ancestry.

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)

Comparison between predicted and measured resting energy expenditures in Korean male collegiate soccer players.

PURPOSE: This study aimed to evaluate the differences between predicted resting energy expenditure (REE), using fat-free mass (FFM)-based prediction equations, and measured REE in Korean male collegiate soccer players. METHODS: Fifteen male collegiate soccer players (18-21 years) participated in this study. The REE measurements were conducted using the Douglas bag method. Body composition was measured by dual-energy X-ray absorptiometry (DXA). The differences between the measured REE and predicted REE, using the five FFM-based REE equations, were analyzed using the t-test, calculation of errors, regression analysis, and the Bland-Altman method. RESULTS: The Cunningham (1980) and ten Haaf and Weijs (2014) equations showed significantly overestimated REE (1,808 ± 99 kcal/d, p <0.01; 1,838 ± 103 kcal/d, p <0.01; respectively), but the Owen (1988), Taguchi (2011), and Kim (2015) equations' estimations were not significantly different from the measured REE (1,589 ± 106 kcal/d, 1,640 ± 124 kcal/d, and 1,622 ± 68 kcal/d, respectively). The Taguchi equation gave the best prediction of REE with the lowest constant error (-6 ± 125) and effect size (-0.05), and a non-significant proportional bias (p = 0.95). CONCLUSION: The Taguchi equation is recommended for predicting REE in Korean collegiate soccer players. The selection process of a REE-prediction equation must take into consideration the target population's characteristics. Future studies are recommended to evaluate the validity of the different FFM-based REE-prediction equations in various Korean athletes.

Prediction of degradability and digestibility parameters of protein supplements used in sheep nutrition from nutrient composition.

The objective of this study was the formation of prediction equations of the degradability and digestibility parameters of protein supplements used in sheep nutrition by the use of their chemical composition. Four trials were conducted (one in situ degradability trial, using 3 × 9 incomplete Latin square experimental design and three in vivo digestibility trials using 3 × 3, 4 × 4, 4 × 4 Latin square experimental design, respectively). The nine tested feeds were soybean meal (SBM), rapeseed meal (RSM), sunflower meal (SFM), lupin seeds (LS), faba bean seeds (FBS), Vetch seeds (VS), pea seeds (PS), chickpea seeds (CS) and flax seeds (FS). Incubation in the rumen of the three ruminally cannulated indigenous Chios breed rams lasted 0, 3, 6, 12, 24 and 48 h in order to measure dry matter and crude protein degradability parameters ("a", "b", "degradability-D", "effective degradability-ED" and "c" for 0-48 h). Additionally, three in vivo digestibility trials were conducted in order to measure digestibility coefficients of nutrients of these nine protein supplements. The best fit equation for CP effective degradability was ED (g/100 gDM) = 100.757 + 0.182 × ADF + 0.042 × ADF2 - 4.351 × ADL + 0.036 × ADL2 (adjusted R2 = 0.90). In conclusion, it can be said that prediction equations can be constructed to estimate nutritional parameters for different feeds.