Body Composition in Youths Aged 10‒17 Years by Deuterium Oxide Dilution, Air Displacement Plethysmography, and DXA: Validation of the Medical Body Composition Analyzer Bioimpedance Device by a 4-Compartment Model.

BACKGROUND: The medical body composition analyzer (mBCA) incorporates advances in multifrequency technology and has been validated using a 4-compartment (4C) model in adults but not in youths aged <18 y. OBJECTIVES: This study aimed to formulate a 4C model based on 3 reference methods and develop and validate a body composition prediction equation for the mBCA in youths aged 10‒17 y. METHODS: The body density of 60 female and male youths was measured by air displacement plethysmography, total body water by deuterium oxide dilution, and BMC by DXA. Data from the equation group (n = 30) were used to formulate a 4C model. The all-possible-regressions method was used to select variables. The model was validated in a second cohort (n = 30) in a random split design. The accuracy, precision, and potential bias were evaluated by the Bland and Altman procedure. RESULTS: Mean age, weight (W), height (H), waist circumference, and z-score of BMI were 13.6 ± 2.3 y, 54.5 ± 15.5 kg, 156 ± 11.9 cm, 75.5 ± 10.9 cm, and 0.70 ± 1.32 z, respectively. The prediction equation was as follows: FFM in kg (FFMkg) = ([0.2081] ∗ [W] + [0.8814] ∗ [H2cm/RΩ] + [0.2055 ∗ XcΩ])-15.343; R2 = 0.96; standardized root-mean-square error (SRMSE) = 2.18 kg. FFM did not differ between the 4C method (38.9 ± 12.0 kg) and the mBCA (38.4 ± 11.4 kg) (P > 0.05). The relationship between these 2 variables did not deviate from the identity line, was not significantly different from 0, and the slope was not significantly different from 1.0. In the precision prediction model of mBCA, the R2 value was 0.98 and SRMSE was 2.1. No significant bias was found when regressing differences between methods and their means (P = 0.08). CONCLUSIONS: The equation for the mBCA was accurate, precise, had no significant bias, had substantial strength of agreement and could be used in this age group when subjects were preferentially within the constraints of a specified body size.

Predictive equations for fat mass in older Hispanic adults with excess adiposity using the 4-compartment model as a reference method.

BACKGROUND: Predictive equations are the best option for assessing fat mass in clinical practice due to their low cost and practicality. However, several factors, such as age, excess adiposity, and ethnicity can compromise the accuracy of the equations reported to date in the literature. OBJECTIVE: To develop and validate two predictive equations for estimating fat mass: one based exclusively on anthropometric variables, the other combining anthropometric and bioelectrical impedance variables using the 4C model as the reference method. SUBJECTS/METHODS: This is a cross-sectional study that included 386 Hispanic subjects aged ≥60 with excess adiposity. Fat mass and fat-free mass were measured by the 4C model as predictive variables. Age, sex, and certain anthropometric and bioelectrical impedance data were considered as potential predictor variables. To develop and to validate the equations, the multiple linear regression analysis, and cross-validation protocol were applied. RESULTS: Equation 1 included weight, sex, and BMI as predictor variables, while equation 2 considered sex, weight, height squared/resistance, and resistance as predictor variables. R2 and RMSE values were ≥0.79 and ≤3.45, respectively, in both equations. The differences in estimates of fat mass by equations 1 and 2 were 0.34 kg and -0.25 kg, respectively, compared to the 4C model. This bias was not significant (p < 0.05). CONCLUSIONS: The new predictive equations are reliable for estimating body composition and are interchangeable with the 4C model. Thus, they can be used in epidemiological and clinical studies, as well as in clinical practice, to estimate body composition in older Hispanic adults with excess adiposity.

External validation of a prediction model for estimating fat mass in children and adolescents in 19 countries: individual participant data meta-analysis.

OBJECTIVE: To evaluate the performance of a UK based prediction model for estimating fat-free mass (and indirectly fat mass) in children and adolescents in non-UK settings. DESIGN: Individual participant data meta-analysis. SETTING: 19 countries. PARTICIPANTS: 5693 children and adolescents (49.7% boys) aged 4 to 15 years with complete data on the predictors included in the UK based model (weight, height, age, sex, and ethnicity) and on the independently assessed outcome measure (fat-free mass determined by deuterium dilution assessment). MAIN OUTCOME MEASURES: The outcome of the UK based prediction model was natural log transformed fat-free mass (lnFFM). Predictive performance statistics of R2, calibration slope, calibration-in-the-large, and root mean square error were assessed in each of the 19 countries and then pooled through random effects meta-analysis. Calibration plots were also derived for each country, including flexible calibration curves. RESULTS: The model showed good predictive ability in non-UK populations of children and adolescents, providing R2 values of >75% in all countries and >90% in 11 of the 19 countries, and with good calibration (ie, agreement) of observed and predicted values. Root mean square error values (on fat-free mass scale) were <4 kg in 17 of the 19 settings. Pooled values (95% confidence intervals) of R2, calibration slope, and calibration-in-the-large were 88.7% (85.9% to 91.4%), 0.98 (0.97 to 1.00), and 0.01 (-0.02 to 0.04), respectively. Heterogeneity was evident in the R2 and calibration-in-the-large values across settings, but not in the calibration slope. Model performance did not vary markedly between boys and girls, age, ethnicity, and national income groups. To further improve the accuracy of the predictions, the model equation was recalibrated for the intercept in each setting so that country specific equations are available for future use. CONCLUSION: The UK based prediction model, which is based on readily available measures, provides predictions of childhood fat-free mass, and hence fat mass, in a range of non-UK settings that explain a large proportion of the variability in observed fat-free mass, and exhibit good calibration performance, especially after recalibration of the intercept for each population. The model demonstrates good generalisability in both low-middle income and high income populations of healthy children and adolescents aged 4-15 years.

Determination of Fat-Free Mass Density and its Components in Older Hispanic Adults by In Vivo Methods.

The densitometry method estimates body composition based on cadaver reference values, mainly the fat-free mass density value of 1.100 g/cm3. However, several changes in fat-free mass components by aging, ethnicity, and excess adiposity could influence their density and affect body composition estimations. The present study aimed to compare the mean fat-free mass component values in older Hispanic adults to cadaver reference values. This cross-sectional study included a sample of 420 subjects aged ≥60 yr from northern Mexico. Fat-free mass was determined by the four-compartment model using air displacement plethysmography, the deuterium dilution technique, and dual-energy X-ray absorptiometry for body density, aqueous and mineral fractions of body weight, respectively. A 1-sample t test was used to compare the fat-free mass density and aqueous, mineral, and residue fractions of fat-free mass from subjects in the study to the assumed cadaver reference values. The mean fat-free mass density value for the total sample of older Hispanic adults (1.096 ± 0.011 g/cm3) was significantly (p < 0.001) lower than the assumed value of 1.100 g/cm3, except in obese older men. The mean aqueous fraction of fat-free mass (74.8 ± 3.3%) was higher than the assumed value of 73.8%, and the mean residue fraction of fat-free mass value was lower (18.3 ± 3.4%) than the reference value of 19.4%. Indeed, only the mean mineral fraction of fat-free mass value (6.8 ± 0.8%) was similar to the reference value. In the total sample, all characteristic mean fat-free mass values in these older Hispanic adults differed from cadaver reference values, except the mineral fraction of fat-free mass value.

Agreement between laboratory methods and the 4-compartment model in assessing fat mass in obese older Hispanic-American adults.

BACKGROUND/OBJECTIVES: Densitometry (Siri's and Brozek's equations), hydrometry (by the deuterium dilution technique), and dual-energy X-ray absorptiometry (DXA) are three methods for estimating body composition. However, because they are all based on certain assumptions, they may not be applicable to aged and obese subjects due to changes in their body composition. Hence, the validity of these "laboratory methods" could be affected in obese older people. The main aim was to assess the agreement between densitometry, hydrometry, and DXA with the 4-compartment (4C) model to estimate fat mass (FM) in obese older Hispanic-American adults. As secondary goals, we explored whether the bias in densitometry and hydrometry results could be improved by modifying the assumptions regarding fat-free mass (FFM) density and hydration factor (HF) values, respectively. In the case of DXA, we explored the factors that contribute to bias. SUBJECTS/METHODS: This is a cross-sectional study based on a sample of 171 obese subjects aged ≥60 years from 3 regions of northern Mexico. Body composition was assessed by the 4C model as the reference method and by all three laboratory methods. Agreement of the latter with the 4C model was probed by Bland and Altman analysis, a paired sample t-test, and simple linear regression analyses. In addition, the mean FFM density estimated in this sample, and HF values (published previously) of 0.737 and 0.753 for obese older Hispanic-American men and women, respectively, were considered as ethnic- and gender-specific values. These values were used to modify the densitometric and hydrometric equations in order to improve their bias. Finally, we tested whether the hydration status and indirect markers of adiposity are contributing factors to the bias of DXA using multiple linear regression analysis. RESULTS: Siri's equation overestimated FM by 0.57 kg (p < 0.01), while Brozek's equation, hydrometry, and DXA underestimated it by 1.24 kg, 0.89 kg, and 0.79 kg (p < 0.01), respectively, compared to the 4C model. The bias in the densitometry and hydrometry results was eliminated by substituting the ethnic- and gender-specific values into the equations. Finally, we found that hip circumference contributes to the bias in DXA. CONCLUSION: The densitometry, hydrometry, and DXA methods are not interchangeable with the 4C model for assessing fat mass in obese, older Hispanic-American adults. The lack of agreement could indicate that the assumptions of each method do not apply to this population.

High Hydration Factor in Older Hispanic-American Adults: Possible Implications for Accurate Body Composition Estimates.

Age- and obesity-related body composition changes could influence the hydration factor (HF) and, as a result, body composition estimates derived from hydrometry. The aim of the present study was to compare the HF in older Hispanic-American adults to some published values. This cross-sectional study included a sample of 412 subjects, men and women, aged ≥60 years from northern Mexico. HF values were calculated based on the ratio of total body water-using the deuterium dilution technique-to fat-free mass, derived from the four-compartment model. The mean HF value for the total sample (0.748 ± 0.034) was statistically (p ≤ 0.01) higher than the traditionally assumed value of 0.732 derived from chemical analysis, the "grand mean'' value of 0.725 derived from in vivo methods, and the 0.734 value calculated for older French adults via the three-compartment model. The HF of the older women did not differ across the fat mass index categories, but in men the obese group was lower than the normal and excess fat groups. The hydration factor calculated for the total sample of older Hispanic-American people is higher than the HF values reported in the literature. Therefore, the indiscriminate use of these assumed values could produce inaccurate body composition estimates in older Hispanic-American people.

[EFFECT OF OVERWEIGHT AND OBESITY ON THE EQUILIBRIUM TIME, BUT NO IN THE TOTAL BODY WATER AND BODY COMPOSITION COMPARTMENTS IN WOMEN SUBJECTS OVER 60 YEARS OF AGE]. / INFLUENCIA DEL SOBREPESO Y LA OBESIDAD SOBRE EL TIEMPO DE EQUILIBRIO DEL DEUTERIO, PERO NO EN EL AGUA CORPORAL TOTAL Y LA COMPOSICIÓN CORPORAL EN MUJERES MAYORES DE 60 AÑOS.

INTRODUCTION: aging and obesity cause changes in water exchange rate, which could affect the equilibrium time of deuterium oxide (2H2O). OBJECTIVE: to assess the effect of overweight and obesity on the equilibrium time of the stable isotope deuterium in saliva samples of older adults. METHODS: a sample of 18 women over 63 years with a body mass index (BMI) of 20.8 to 40.5 kg/m2 were included. A basal saliva sample was took and immediately a dose of 30 g of 2H2O was administered orally. Saliva samples at 2, 2.5, 3, 3.5 and 4 hours post-dose were taken. Deuterium in saliva samples were analyzed by Fourier Transform Infrared spectroscopy technique. RESULTS: the average in equilibrium time (plateau) in women of normal BMI (18.5-24.9 kg/m2) was 3.6 ± 0.2 hours, which was statistically different to those obtained in the group with overweight (25-29.9 kg/m2) and obese (>30 kg/m2) of 2.9 ± 0.4 hours and 2.8 ± 0.4 hours, respectively (p0.05). CONCLUSION: obesity had an effect on the equilibrium times; however, did not affect the calculation of total body water and body composition in this older women adult group.

Introducción: el envejecimiento y la obesidad producen cambios en la tasa de recambio de agua, lo que podría afectar al tiempo de equilibrio del óxido de deuterio (2H2O). Objetivo: se evaluó el efecto del sobrepeso y la obesidad sobre el tiempo de equilibrio del isótopo estable de deuterio en muestras de saliva de adultos mayores. Métodos: se incluyeron 18 mujeres entre 63 y 80 años con un índice de masa corporal (IMC) de 20,8 a 40,5 kg/m2. Después de la toma de una muestra de saliva basal se administró una dosis vía oral de 30 g de 2H2O. Se tomaron muestras de saliva a las 2, 2,5, 3, 3,5 y 4 horas post-dosis, las cuales fueron analizadas mediante espectrometría infrarroja con transformada de Fourier. Resultados: el tiempo de equilibrio (plateau) promedio en las mujeres con un IMC normal (18,5-24,9 kg/m2) fue de 3,6 ± 0,2 horas, el cual fue diferente estadísticamente al obtenido en el grupo con sobrepeso (25-29,9 kg/m2) y obesidad (>30 kg/m2) de 2,9 ± 0,4 horas y 2,8 ± 0,4 horas, respectivamente (p0,05). Conclusión: se encontró un efecto de la obesidad sobre el tiempo de equilibrio; sin embargo, no afectó al cálculo del agua corporal total y a la composición corporal en este grupo etario.

Influencia del sobrepeso y la obesidad sobre el tiempo de equilibrio del deuterio, pero no en el agua corporal total y la composición corporal en mujeres mayores de 60 años / Effect of overweight and obesity on the equilibrium time, but no in the total body water and body composition compartments in women subjects over 60 years of age

Introducción: el envejecimiento y la obesidad producen cambios en la tasa de recambio de agua, lo que podría afectar al tiempo de equilibrio del óxido de deuterio (2 H2 O). Objetivo: se evaluó el efecto del sobrepeso y la obesidad sobre el tiempo de equilibrio del isótopo estable de deuterio en muestras de saliva de adultos mayores. Métodos: se incluyeron 18 mujeres entre 63 y 80 años con un índice de masa corporal (IMC) de 20,8 a 40,5 kg/m2. Después de la toma de una muestra de saliva basal se administró una dosis vía oral de 30 g de 2 H2 O. Se tomaron muestras de saliva a las 2, 2,5, 3, 3,5 y 4 horas post-dosis, las cuales fueron analizadas mediante espectrometría infrarroja con transformada de Fourier. Resultados: el tiempo de equilibrio (plateau) promedio en las mujeres con un IMC normal (18,5-24,9 kg/m2) fue de 3,6 ± 0,2 horas, el cual fue diferente estadísticamente al obtenido en el grupo con sobrepeso (25-29,9 kg/m2) y obesidad (>30 kg/m2) de 2,9 ± 0,4 horas y 2,8 ± 0,4 horas, respectivamente (p0,05). Conclusión: se encontró un efecto de la obesidad sobre el tiempo de equilibrio; sin embargo, no afectó al cálculo del agua corporal total y a la composición corporal en este grupo etario (AU)

Introduction: aging and obesity cause changes in water exchange rate, which could affect the equilibrium time of deuterium oxide (2 H2 O). Objective: to assess the effect of overweight and obesity on the equilibrium time of the stable isotope deuterium in saliva samples of older adults. Methods: a sample of 18 women over 63 years with a body mass index (BMI) of 20.8 to 40.5 kg/m2 were included. A basal saliva sample was took and immediately a dose of 30 g of 2 H2 O was administered orally. Saliva samples at 2, 2.5, 3, 3.5 and 4 hours post-dose were taken. Deuterium in saliva samples were analyzed by Fourier Transform Infrared spectroscopy technique. Results: the average in equilibrium time (plateau) in women of normal BMI (18.5-24.9 kg/m2 ) was 3.6 ± 0.2 hours, which was statistically different to those obtained in the group with overweight (25-29.9 kg/m2 ) and obese (>30 kg/m2 ) of 2.9 ± 0.4 hours and 2.8 ± 0.4 hours, respectively (p0.05). Conclusion: obesity had an effect on the equilibrium times; however, did not affect the calculation of total body water and body composition in this older women adult group (AU)

Efecto de considerar la ingestión y eliminación de líquidos en la determinación de la composición corporal con el método de dilución con deuterio en escolares / Effect of ingestion and excretion of fluids in determining body composition with deuterium dilution method in school children

Introducción: el método de dilución con deuterio es una técnica de referencia en composición corporal en los trabajos de campo. A pesar de su amplia utilidad, aún no se ha reportado cómo es que algunos procedimientos empleados afectan a la medición del agua corporal total (ACT) y a otras estimaciones. Objetivo: analizar si considerar o no que la ingestión de líquidos y la eliminación de orina durante la prueba afectan a la medición del ACT, la masa grasa (MG) y la masa libre de grasa (MLG). Resultados y discusión: en 139 escolares (65 niñas y 74 niños) se midió la ingestión y eliminación de líquidos durante las tres horas de la prueba. La composición corporal resultó ser significativamente diferente (p < 0.001) cuando se corrige por los volúmenes ingeridos y eliminados; sin embargo, las diferencias obtenidas en ACT (100-200 mL), MLG y MG (100-300g) no se consideran importantes en cuanto a composición corporal en comparación con las diferencias resultantes con otros métodos (AU)

Introduction: the deuterium dilution technique is a reference method for measuring body composition in children. However, to our knowledge, there is no report on how some of the procedures used affect the measurement of total body water (TBW) and other estimates. Objective: to analyze whether considering fluid intake and urine excretion during the test affects the final TBW, fat mass and fat free mass results. Results and discussion: ingestion of fluids (100 mL rinse water + orange juice 150 mL) and excretion (urine) were measured in 139 schoolchildren (65 girls) during the determination of TBW. We found significant differences in body composition (p < 0.001), TBW (100-200 mL), FFM and FM (100-300 g) when corrected by volume of fluids ingested and excreted. However, these differences were not considered clinically relevant (AU)

[EFFECT OF INGESTION AND EXCRETION OF FLUIDS IN DETERMINING BODY COMPOSITION WITH DEUTERIUM DILUTION METHOD IN SCHOOL CHILDREN]. / EFECTO DE CONSIDERAR LA INGESTIÓN Y ELIMINACIÓN DE LÍQUIDOS EN LA DETERMINACIÓN DE LA COMPOSICIÓN CORPORAL CON EL MÉTODO DE DILUCIÓN CON DEUTERIO EN ESCOLARES.

INTRODUCTION: the deuterium dilution technique is a reference method for measuring body composition in children. However, to our knowledge, there is no report on how some of the procedures used affect the measurement of total body water (TBW) and other estimates. OBJECTIVE: to analyze whether considering fluid intake and urine excretion during the test affects the final TBW, fat mass and fat free mass results. RESULTS AND DISCUSSION: ingestion of fluids (100 mL rinse water + orange juice 150 mL) and excretion (urine) were measured in 139 schoolchildren (65 girls) during the determination of TBW. We found significant differences in body composition (p < 0.001), TBW (100-200 mL), FFM and FM (100-300 g) when corrected by volume of fluids ingested and excreted. However, these differences were not considered clinically relevant.

Introducción: el método de dilución con deuterio es una técnica de referencia en composición corporal en los trabajos de campo. A pesar de su amplia utilidad, aún no se ha reportado cómo es que algunos procedimientos empleados afectan a la medición del agua corporal total (ACT) y a otras estimaciones. Objetivo: analizar si considerar o no que la ingestión de líquidos y la eliminación de orina durante la prueba afectan a la medición del ACT, la masa grasa (MG) y la masa libre de grasa (MLG). Resultados y discusión: en 139 escolares (65 niñas y 74 niños) se midió la ingestión y eliminación de líquidos durante las tres horas de la prueba. La composición corporal resultó ser significativamente diferente (p < 0.001) cuando se corrige por los volúmenes ingeridos y eliminados; sin embargo, las diferencias obtenidas en ACT (100-200 mL), MLG y MG (100-300g) no se consideran importantes en cuanto a composición corporal en comparación con las diferencias resultantes con otros métodos.

[Impact of fortified milk on the iron and zinc levels in Mexican preschool children]. / Efecto de la leche fortificada liconsa en el estado de hierro y zinc en prescolares Mexicanos.

The aim of this study was to assess the efficacy of a national program of consumption of fortified milk "Liconsa" on the nutritional status of iron and zinc in pre-school children (3-5 y). The study was conducted in 77 healthy children of both genders. 54 of them consumed Liconsa fortified milk (GCLFL) and 23 consumed no fortified milk (GR). Iron status was determined by measuring hemoglobin and ferritin and zinc status by serum zinc. The consumption of milk was on free demand and it was estimated at baseline and 6 mo after. Through 24-h recall of measured consumption of iron and zinc in the total diet. Descriptive statistics, Student's t test for independent samples and chi-square test for differences in proportions. Children who consumed fortified milk showed an increase of hemoglobin and ferritin levels [1.13 g/dL (p < 0.05) and 5.83 µg/L (p < 0.05) respectively]. Additionally, a decrease was found of the prevalence of low iron stores from 20.4 to 4.1% (p < 0.05). The serum zinc level showed an increase of 45.2 µg/dL (p < 0.05). At the end of the study no child showed a micronutrient deficiency. Children who did not consume fortified milk Liconsa showed no significant change in their serum iron and zinc values. The average consumption of milk powder Liconsa was 22.7 ± 14.5 g, providing 2.5 mg of daily iron and zinc. Supplied diet 9.2 ± 3.4 mg of iron and 6.9 ± 3 mg of zinc. The consumption of fortified milk had a beneficial effect on the serum levels of iron and zinc in children's social welfare program Liconsa.

Introducción: Existen programas que buscan mejorar el estado nutricio de la población vulnerable mediante la fortificación de alimentos. En México, el programa de leche fortificada Liconsa está dirigido a familias de bajo nivel socioeconómico. Objetivo: Evaluar el efecto del consumo de leche fortificada Liconsa en el estado de nutrición de hierro y zinc, en preescolares. Sujetos y métodos: Estudio cuasiexperimental, conducido en colonias marginadas de Hermosillo, México. Participaron 77 niños sanos, de los cuales 54 consumieron leche fortificada Liconsa (GCLFL) y 23 conformaron el grupo de referencia (GR, consumo de leche fluida de vaca, no fortificada). El estado de hierro se midió a través de hemoglobina, ferritina, hierro sérico, capacidad total de fijación de hierro, saturación de transferrina; y zinc sérico. También se estimó el consumo de leche fortificada a libre demanda, en la etapa basal y después de 6 meses. Mediante dos recordatorios de 24 horas, no consecutivos, se midió el consumo de hierro y zinc en la dieta total. Se realizó estadística descriptiva, prueba t-student para muestras independientes y prueba de ji cuadrada para diferencias de proporciones. Resultados: Los niños que consumieron leche fortificada incrementaron sus niveles de hemoglobina (1,13 g/dL, p < 0,05) y ferritina (5,83 µg/L, p < 0,05). La prevalencia de bajas reservas de hierro disminuyó de 20,4% a 4,1% (p < 0,05) y el zinc sérico aumentó en 45,2 µg/dL (p < 0,05). En el grupo de referencia, no hubo cambios significativos. El promedio diario del consumo de leche fortificada Liconsa fue de 22,7 ± 14,5 g, que suministró 2,5 mg/d de hierro y zinc. La dieta aportó 9,2 ± 3,4 mg/d de hierro y 6,9 ± 3 mg/d de zinc. Conclusiones: El consumo de leche fortificada beneficia el estado bioquímico de hierro y zinc en los niños del programa de abasto social de Liconsa.

Efecto de la leche fortificada Liconsa en el estado de hierro y zinc en preescolares Mexicanos / Impact of fortified milk on the iron and zinc levels in mexican preschool children

Introducción: Existen programas que buscan mejorar el estado nutricio de la población vulnerable mediante la fortificación de alimentos. En México, el programa de leche fortificada Liconsa está dirigido a familias de bajo nivel socioeconómico. Objetivo: Evaluar el efecto del consumo de leche fortificada Liconsa en el estado de nutrición de hierro y zinc, en preescolares. Sujetos y métodos: Estudio cuasiexperimental, conducido en colonias marginadas de Hermosillo, México. Participaron 77 niños sanos, de los cuales 54 consumieron leche fortificada Liconsa (GCLFL) y 23 conformaron el grupo de referencia (GR, consumo de leche fluida de vaca, no fortificada). El estado de hierro se midió a través de hemoglobina, ferritina, hierro sérico, capacidad total de fijación de hierro, saturación de transferrina; y zinc sérico. También se estimó el consumo de leche fortificada a libre demanda, en la etapa basal y después de 6 meses. Mediante dos recordatorios de 24 horas, no consecutivos, se midió el consumo de hierro y zinc en la dieta total. Se realizó estadística descriptiva, prueba t-student para muestras independientes y prueba de ji cuadrada para diferencias de proporciones. Resultados: Los niños que consumieron leche fortificada incrementaron sus niveles de hemoglobina (1,13 g/dL, p < 0,05) y ferritina (5,83 μg/L, p < 0,05). La prevalencia de bajas reservas de hierro disminuyó de 20,4% a 4,1% (p < 0,05) y el zinc sérico aumentó en 45,2 μ/dL (p < 0,05). En el grupo de referencia, no hubo cambios significativos. El promedio diario del consumo de leche fortificada Liconsa fue de 22,7 ± 14,5 g, que suministró 2,5 mg/d de hierro y zinc. La dieta aportó 9,2 ± 3,4 mg/d de hierro y 6,9 ± 3 mg/d de zinc. Conclusiones: El consumo de leche fortificada beneficia el estado bioquímico de hierro y zinc en los niños del programa de abasto social de Liconsa (AU)

The aim of this study was to assess the efficacy of a national program of consumption of fortified milk "Liconsa" on the nutritional status of iron and zinc in pre-school children (3-5 y). The study was conducted in 77 healthy children of both genders. 54 of them consumed Liconsa fortified milk (GCLFL) and 23 consumed no fortified milk (GR). Iron status was determined by measuring hemoglobin and ferritin and zinc status by serum zinc. The consumption of milk was on free demand and it was estimated at baseline and 6 mo after. Through 24-h recall of measured consumption of iron and zinc in the total diet. Descriptive statistics, Student's t test for independent samples and chi-square test for differences in proportions. Children who consumed fortified milk showed an increase of hemoglobin and ferritin levels [1.13 g/dL (p < 0.05) and 5.83 μg/L (p < 0.05) respectively]. Additionally, a decrease was found of the prevalence of low iron stores from 20.4 to 4.1% (p < 0.05). The serum zinc level showed an increase of 45.2 μg/dL (p < 0.05). At the end of the study no child showed a micronutrient deficiency. Children who did not consume fortified milk Liconsa showed no significant change in their serum iron and zinc values. The average consumption of milk powder Liconsa was 22.7±14.5 g, providing 2.5 mg of daily iron and zinc. Supplied diet 9.2 ± 3.4 mg of iron and 6.9 ± 3 mg of zinc. The consumption of fortified milk had a beneficial effect on the serum levels of iron and zinc in children's social welfare program Liconsa (AU)

Lifestyle intervention in primary care settings improves obesity parameters among Mexican youth.

Intervention studies in youth with obesity that can be translated into primary care are limited. We compared a lifestyle intervention to a brief intervention applied by primary care physicians (control group) for treating pediatric obesity in the primary care setting. Seventy-six youth with obesity (body mass index [BMI] >95th percentile or >90th percentile plus waist circumference >90th percentile, aged 9 to 17 years) participated in a 12-month, randomized, controlled trial, conducted at a primary care unit in Northern México from June 2006 through October 2007. Participants randomized to lifestyle intervention attended a family-centered program consisting of 12 sessions of behavioral curriculum, dietary advice from a registered dietitian (weekly for the first 3 months and monthly thereafter), and monthly consultations with a primary care physician. Control group participants attended monthly consultations with a primary care physician who received a brief training on obesity. Forty-three (57%) participants completed the 12 months of study. After 12 months, mean changes (95% confidence interval) in body weight for the lifestyle group and the control group were -0.8 kg (-3.2, 1.5) vs +5.6 kg (3, 8.2; P<0.001) and mean changes in BMI were -1.8 (-2.6, -0.9) vs +0.4 (-0.5, 1.3; P<0.001), respectively. Intention-to-treat analysis at 12 months confirmed significant differences in primary outcomes (weight -3.5 kg, P=0.02; BMI -1.2, P=0.03) in favor of the lifestyle group. This study provides preliminary evidence that primary care physicians supported by a registered dietitian and a behavioral curriculum can be a successful strategy for treating pediatric obesity in the primary care setting.

Efecto de la suplementación con una dosis masiva de vitamina A en niños de 6 a 36 meses de edad / Effect of massive vitamin A supplement in children from 6 to 36 months of age

Objetivo. Evaluar el impacto de la suplementación con una dosis masiva de vitamina A en el estado nutricio de dicha vitamina y del hierro, en niños de zonas urbanas marginadas de Hermosillo, Sonora, México. Material y métodos. Se seleccionaron 60 niños (6-36 meses), a los que se les administró una dosis de 100 00 UI (6-12 meses) y 200 000 UI (12-36 meses) de vitamina A en el Día Nacional de Salud de la Secretaría de Salud (junio de 1994). Se midieron niveles séricos de retinol, carotenioide, hierro, transferrina y ferritina, en tres fases: basal, a las dos semanas y después de tres meses. Resultados. En la primera fase, la mediana de retinol fue 0.7 µmol/l; en la segunda aumentó a 0.97 µmol/l (p< 0.001), y en la tercera disminuyó a 0.83 µmol/l (p> 0.05). Un 6.3 por ciento de los niños presentó deficiencia severa de vitamina A al inicio, y no se encontró ningún caso en las fases posteriores a la suplementación. En la fase basal, 42 por ciento de los casos presentaron deficiencia moderada y la mayoría fue normal en las siguientes fases. No hubo diferencias en los niveles de hierro y transferrina (p> 0.05), pero sí en ferritina (p< 0.001), lo que indica un mejoramiento en las reservas de hierro a los tres meses. Conclusiones. Las campañas de distribución de dosis masivas pueden tener un impacto importante en el estado nutricio de vitamina A y hierro