Biophysical Parameters of Plasma-Derived Extracellular Vesicles as Potential Biomarkers of Bone Disturbances in Breast Cancer Patients Receiving an Individualized Nutrition Intervention.

Extracellular vesicles (EVs) are implicated in several biological conditions, including bone metabolism disturbances in breast cancer patients (BCPs). These disorders hinder the adjustment of nutrition interventions due to changes in bone mineral density (BMD). The biophysical properties of EVs (e.g., size or electrostatic repulsion) affect their cellular uptake, however, their clinical relevance is unclear. In this study, we aimed to investigate the association between the biophysical properties of the plasma-derived EVs and BMDs in BCPs who received an individualized nutrition intervention during the first six months of antineoplastic treatment. As part of the nutritional assessment before and after the intervention, body composition including bone densitometry and plasma samples were obtained. In 16 BCPs, EVs were isolated using ExoQuick® and their biophysical properties were analyzed using light-scattering techniques. We found that the average hydrodynamic diameter of large EVs was associated with femoral neck bone mineral content, lumbar spine BMD, and neoplasms' molecular subtypes. These results provide evidence that EVs play a role in BCPs' bone disorders and suggest that the biophysical properties of EVs may serve as potential nutritional biomarkers. Further studies are needed to evaluate EVs' biophysical properties as potential nutritional biomarkers in a clinical context.

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.

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.

[Antineoplastic treatment impact on nutritional status in patients with breast cancer]. / Impacto del tratamiento antineoplásico en el estado nutricional en pacientes con cáncer de mama.

BACKGROUND: Breast cancer is the most commonly diagnosed malignancy in women in Mexico and also has the highest mortality. Although treatment has improved significantly, it can affect the nutritional status of the recipients. OBJECTIVE: The aim of this study was to assess the impact of the initial phase of antineoplastic therapy on the nutritional status in patients with breast cancer. METHODS: Forty subjects with primary diagnosed of invasive breast cancer were studied in a before and after intervention (six month apart) using a quasi-experimental design. Basal and six month after intervention measurements included were anthropometry, body composition by dual X-ray absorptiometry (DEXA), diet by 24-hour recall and food frequency questionnaire, as well as serum -carotene and retinol. The therapy effect was analyzed using repeated measurements mixed linear regression. RESULTS: Lean tissue decreased after the studied period (p=0.032). Addicionally, there was an interaction between weight, BMI and body fat parameters with menopausal status, increasing in these variables due to therapy only premenopausal patients (p=0.005, 0.006 and 0.001, respectively). Decreased serum retinol (p=0.049) despite the improvement in -carotene status (p=0.03). In general there was an increase the consumption of vegetables food products whilst a decrease in animal foods. CONCLUSION: The breast cancer antineoplastic treatment had a negative effect on weight and body fat, especially in young women. Although there were some positive dietary changes, vegetables consumption remained insufficient, which was also reflected in serum biomarkers.

Presentación: El cáncer de mama es el tipo de tumor más frecuentemente diagnosticado entre las mujeres de México y también el de más alta mortalidad. Aunque el tratamiento ha mejorado significativamente, puede afectar al estado nutricional del paciente. Objetivo: El objetivo de este estudio era evaluar el impacto de la fase inicial de la terapia antineoplásica sobre el estado nutricional en pacientes con cáncer de mama. Métodos: Cuarenta sujetos con diagnóstico primario de cáncer de mama invasivo fueron estudiados antes y después de la intervención (con seis meses de desfase) usando un diseño quasi-experimental. Las mediciones al inicio y seis meses después de la intervención incluyeron antropometría, composición corporal mediante absorciometría dual de rayos X (DEXA), cuestionario de recopilación de dieta en 24 horas y frecuencia de comidas, y suero beta-caroteno y retinol. El efecto de la terapia fue analizado empleando mediciones repetidas y regresión lineal mixta. Resultados: El tejido magro disminuyó tras el periodo de estudio (p=0.032). Además, se dio una interacción entre los parámetros de peso, IMC y grasa corporal con el estado de menopausia, aumentando en estas variables debido a la terapia solo en pacientes premenopáusicas (p=0.005, 0.006 y 0.001, respectivamente). Descenso de retinol sérico (p=0.049) a pesar de la mejoría en el estado de beta-caroteno (p=0.03). En general hubo un aumento en el consumo de verdura y un descenso de productos animales. Conclusión: El tratamiento antineoplásico del cáncer de mama tuvo un efecto negativo sobre el peso y la grasa corporal, especialmente en mujeres jóvenes. Aunque se observaron algunos cambios positivos en la dieta, el consumo de verdura siguió siendo insuficiente, lo que también se reflejó en los biomarcadores séricos.

Changes in serum zinc levels associated with giardiasis and dietary zinc intake in mice.

The association of giardiasis with the malabsorption of zinc remains controversial. This study investigated changes in serum zinc levels in Giardia-infected mice subjected to different dietary zinc regimens. Thirty-five mice (strain C(3)H/H(e)J) were randomly categorized into two groups. The first group was inoculated with 5 × 10(6) Giardia trophozoites (n = 18), and the second group remained Giardia free (n = 17). Each group (Giardia infected and Giardia free) was randomly classified into three subgroups and given low (9 mg Zn/kg), normal (33 mg Zn/kg), and high levels (288 mg Zn/kg) of dietary zinc over a 2-week period for acclimation. Fourteen days post-Giardia infection, all of the mice were euthanized and blood samples were collected. The number of trophozoites was quantified (hematocytometer), and serum zinc levels were determined via atomic absorption spectrophotometry. Significant increases in the median weights were only found in the Giardia-free mice (p < 0.05). A higher final median weight was found in the Giardia-free group when compared with that of the Giardia-infected group given low dietary zinc (p = 0.013). In the Giardia-infected group with low dietary zinc, the geometric mean of trophozoites was 3,498 ± 101 (SE) per milliliter. The Giardia-infected group had lower serum zinc levels than did the Giardia-free group with the high dietary zinc regimens (p < 0.05). Our results are consistent with studies among human populations, but further studies are required to elucidate the actual mechanism governing the zinc-giardiasis interaction.

[Prevalence of iron deficiency and iron deficiency anemia in pregnant adolescents from northwest Mexico, 2007-2008]. / Prevalencia de deficiencia de hierro y de anemia por deficiencia de hierro en adolescentes embarazadas del noroeste de México, 2007-2008.

Iron deficiency anemia (IDA) remains a word public health problem, particularly in children and child-bearing-age women. Iron demands need to be covered by adolescent women due to the increased physical growing, menstruation, pregnancy and fetal growing tissues at this life stage. This study was proposed to investigate the prevalence of iron deficiency and IDA in pregnant adolescent women from Northwestern Mexico. Participated 186 women under 19 years old during the first or second trimester of pregnancy who attended the local health institutions in Hermosillo Sonora. Questionnaires and 24 hr recalls were administered to collect socioeconomic and dietary information respectively. Hemoglobin (Hb), hematocrit, ferritin and eritrocytic protoporphyrin were measured. Hb and ferritin values were used to categorize the recruited women into normal (37.4%), iron deficient (55.5%) and IDA (7.1%) groups. Six and seven women showed moderated and light anemia status in the IDA group. Fe and fiber intake and weeks of pregnancy were associated with the biochemical indicators of iron at least in two women groups. The high percentage of iron deficient women in this study is demanding the identification and attention of maternal factors and food habits that are risk of iron deficiency in pregnant women.

Prevalencia de deficiencia de hierro y de anemia por deficiencia de hierro en adolescentes embarazadas del noroeste de México 2007-2008 / Prevalence of iron deficiency and iron deficiency anemia in pregnant adolescents from northwest Mexico 2007-2008

La anemia por deficiencia de hierro (Fe) es un problema de salud pública mundial, principalmente en niños y en mujeres en edad fértil. Las adolescentes requieren cubrir las demandas de Fe propias del crecimiento acelerado y del inicio de la menstruación y en adolescentes embarazadas se agrega el crecimiento de los tejidos fetales. El objetivo de este estudio fue determinar la prevalencia de deficiencia de Fe y de anemia por deficiencia de Fe en adolescentes embarazadas del noroeste de México. Participaron 186 mujeres menores de 19 años de edad, comprendidas en el primer o segundo trimestre del embarazo y atendidas en Centros de Salud Públicos de la ciudad de Hermosillo, Sonora. Se aplicaron cuestionarios sobre el nivel socioeconómico e información dietaria mediante la aplicación de recordatorio de 24 horas. Se cuantificó hemoglobina (Hb), hematocrito, ferritina y protoporfirina eritrocitaria. De acuerdo a los valores de Hb y ferritina, se agruparon como normales (37.4 por ciento de las voluntarias), como deficientes de Fe sin anemia (55.5 por ciento) y con anemia por deficiencia de Fe (7.1 por ciento). En este último grupo, seis participantes clasificaron con anemia moderada y siete con anemia ligera. Las variables que se asociaron con indicadores de Fe, en al menos dos grupos de mujeres fueron la ingesta de Fe y de fibra y las semanas de embarazo. El elevado porcentaje de mujeres con reserva deficiente de Fe demanda la identificación y atención de factores maternos y de hábitos de consumo de alimentos que afectan el estado de Fe en las adolescentes embarazadas.

Iron deficiency anemia (IDA) remains a word public health problem, particularly in children and child-bearing-age women. Iron demands need to be covered by adolescent women due to the increased physical growing, menstruation, pregnancy and fetal growing tissues at this life stage. This study was proposed to investigate the prevalence of iron deficiency and IDA in pregnant adolescent women from Northwestern Mexico. Participated 186 women under 19 years old during the first or second trimester of pregnancy who attended the local health institutions in Hermosillo Sonora. Questionnaires and 24 hr recalls were administered to collect socioeconomic and dietary information respectively. Hemoglobin (Hb), hematocrit, ferritin and eritrocytic protoporphyrin were measured. Hb and ferritin values were used to categorize the recruited women into normal (37.4 percent), iron deficient (55.5 percent) and IDA (7.1 percent) groups. Six and seven women showed moderated and light anemia status in the IDA group. Fe and fiber intake and weeks of pregnancy were associated with the biochemical indicators of iron at least in two women groups. The high percentage of iron deficient women in this study is demanding the identification and attention of maternal factors and food habits that are risk of iron deficiency in pregnant women.

[The menarche age in teenagers of the Northwest of Mexico]. / Edad de la menarquia en adolescentes del noroeste de México.

The beginning of sexual maturity in individuals is a measure commonly used as an indicator of a population's quality of life. Among women, one of the most frequently used indicators is the age of menarche. The objectives of this research were to obtain the age of menarche in school age girls from the Northwest of Mexico, and to establish the relationship between the latter with their socioeconomic level, body weight, and height. The sample was taken from 857 girls between 7 and 17 years old from different socioeconomic level sectors. The age of menarche of these girls was determined by the statu quo method. The value found for menarche was 12.06 +/- 0.44 years old. We also found an association of menarche to height (p < 0.01) and to socioeconomic level (p < 0.01). The value for age of menarche in this study was similar to the one reported for other Latin-American populations. Taking into consideration that approximately 70% of the Mexican population has been considered of low income level and that the environmental conditions are not entirely favorable, it is possible that this could be the result of genetic and environmental interactions.

Edad de la menarquia en adolescentes del noroeste de México / The Menarche Age in Teenagers of the Northwest of Mexico

El inicio de la maduración sexual en los individuos es un parámetro utilizado para conocer la calidad de vida de una población. En mujeres, el indicador más utilizado es la edad de la menarquia. Considerando que en esta región no existen estudios que muestren esta información, los objetivos del presente trabajo fueron obtener la edad de la menarquia en mujeres escolares del Noroeste de México y establecer la relación de ésta con el nivel socioeconómico, el peso y la talla. Se seleccionó al azar una muestra de 857 mujeres escolares de 7 a 17 años de edad, a las cuales se les determinó la edad de la menarquia por medio del método statu quo. Para la menarquia el valor encontrado fue de 12.06 ± 0.44 años, encontrándose una relación significativa con la talla (p < 0.01) y con el nivel socioeconómico (p < 0.01). En conclusión, el valor encontrado en este estudio es semejante al reportado en otras poblaciones latinoamericanas. Por otra parte, considerando que alrededor del 70 por ciento de la población mexicana tiene un nivel socioeconómico bajo, es posible que la edad de la menarquia sea el resultado de interacciones genéticas y ambientales

Comparación entre los valores analizados y calculados del contenido de energía, grasa, proteína, fibra dietética, hierro y zinc en dietas del noroeste de México de diferentes niveles socioeconómicos / Comparison of analized and calculated energy, fat, protein, dietary fiber, iron and zinc values in diets from different socieconomic levels in Northern México

Las bases de datos de composición química de alimentos facilitan en gran medida el cálculo de nutrientes en diferentes dietas. Sin embargo existen problemas con el uso de bases de datos. En México la dificultad más importante que en ellas no se incluyen platillos ni alimentos regionales. La base de datos ALIM 10.000 incluye una gran cantidad de alimentos y platillos de Sonora, México, además de tablas de composición de alimentos nacionales y extranjeras. Los objetivos del presente trabajo fueron: analizar los valores de hierro, zinc, grasa, proteína, fibra dietética y energía de dietas regionales de Sonora, México y comparar los valores analizados con los estimados por dos bases de datos. Los resultados indican que las dietas son adecuadas en cuanto al aporte energético proveniente de grasa, proteínas y carbohidratos. La comparación entre los resultados analizados y calculados mostró que las diferencias fueron menores para macronutrientes entre los valores analizados y el ALIM 10.000, mientras que la estimación de minerales traza no fue confiable con ninguna de las dos bases de datos. Los resultados de este estudio ponen de manifiesto la necesidad de incluir alimentos y platillos regionales en las bases de datos, así como actualizar algunos resultados obtenidos con técnicas de análisis de mayor presión.