Iron incorporation in red blood cells of pediatric sickle cell anemia: a stable isotope pilot investigation.

BACKGROUND/OBJECTIVES: Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO. SUBJECTS/METHODS: SCA children (n = 12; SCAtotal) ingested an oral stable iron isotope (57Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method. RESULTS: The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCAtotal group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCAtotal: r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020). CONCLUSION: SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt.

Iron absorption in adults with sickle cell anemia: a stable-isotope approach.

PURPOSE: Iron absorption in sickle cell anemia (SCA) remains unclear and studies in adults with SCA are scarce. The aim of this study was to evaluate the iron absorption SCA adults and its association with iron status and hepcidin concentration. METHODS: SCA patients (n = 13; SCAtotal) and control participants (n = 10) ingested an oral stable iron isotope (57Fe). Iron absorption was measured by inductively coupled plasma mass spectrometry (ICP-MS) 14 days after isotope administration. Patients with ≥ 1000 ng/mL serum ferritin were considered to present iron overload (IO) (SCAio+; n = 3) and others classified without IO (SCAio-; n = 10). RESULTS: Iron absorption in the control group ranged from 0.3 to 26.5% (median = 0.9%), while it varied from 0.3 to 5.4% in SCAio+ (median = 0.5%) and from 0.3 to 64.2% in the SCAio- (median = 6.9%). Hepcidin median values were 14.1 ng/mL (3.0-31.9 ng/mL) in SCAio-, 6.2 ng/mL (3.3-7.8 ng/mL) in SCAio + and 6.2 ng/mL (0.6-9.3 ng/mL) in control. Iron absorption was associated with ferritin level (r = - 0.641; p = 0.018) and liver iron concentration (LIC; r = - 0.786; p = 0.036) in the SCAtotal group. CONCLUSION: Our data suggest that SCAio- individuals may be at risk of developing primary IO. Simultaneously, secondary IO may induce physiological adaptation, resulting in reduced iron absorption. Further studies evaluating intestinal iron absorption using larger sample sizes should be conducted to help establish a safe nutrition approach to be adopted and to ensure the security of food-fortifying public policies for these patients. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br (Identifier RBR-4b7v8pt).

Combined Oral Contraceptives: Association with Serum 25-Hydroxyvitamin D and Calcium and Bone Homeostasis.

Background: Use of combined oral contraceptives (COCs) has been found to increase serum 25-hydroxyvitamin D [25(OH)D] but effects on calcium and bone homeostasis are unclear. Materials and Methods: Serum 25(OH)D, parathyroid hormone (PTH), alkaline phosphatase (ALK) and estradiol, dietary intake of bone-related nutrients and foods, bone mineral density (BMD), and body fat were compared in adult women (20-35 years; body mass index 21.5 ± 2.3 kg/m2) users (+COC, n = 32) and nonusers (-COC, n = 20) of COC. Biochemical markers were measured by automated assays. BMD at total body (TB), lumbar spine (LS), femoral neck (FN) and trochanter (TR), and body fat, were measured by dual-energy X-ray absorptiometry. Dietary intake was assessed by a food frequency questionnaire. Results: Intake of calcium, dairy foods, and fruits and vegetables, were adequate and did not differ by COC. Mean 25(OH)D was 35% higher in +COC (110.4 ± 27.3 nmol/L, 44.2 ± 1.8 ng/mL) compared with -COC (81.7 ± 22.8 nmol/L, 32.7 ± 2.3 ng/mL; p < 0.001). Mean PTH, ALK, and estradiol were 28%, 12%, and 62% lower, respectively, in +COC compared with -COC (p ≤ 0.05). Mean BMD z-scores (all sites) were adequate and did not differ by COC. There were no correlations between 25(OH)D and dietary, biochemical, and body composition variables. PTH was inversely correlated with TR-BMD z-score in -COC (r = -0.47; p = 0.04), and ALK was inversely correlated with TB-, TR-, and LS-BMD z-scores in -COC (r ≤ -0.43; p ≤ 0.04), but not in +COC. Conclusions: Increased serum 25(OH)D with COC use was paralleled by expected physiologic adjustments in calcium and bone homeostasis, and adequate bone mass status, in nonobese young adult women consuming bone-healthy diets.

Calcium plus vitamin D supplementation during pregnancy reduces postpartum fat mass in adolescents: A randomized trial.

BACKGROUND: Pregnancy during adolescence may increase the risk of overweight/obesity. There is evidence that increasing calcium intake, alone or vitamin D-combined, may favor loss of weight and/or fat mass. OBJECTIVES: We hypothesized that calcium supplementation during pregnancy reduces excessive fat accumulation during postpartum period. We aimed to investigate the effect of calcium plus vitamin D supplementation during pregnancy on body composition measurements throughout 1 year postpartum in Brazilian adolescents with habitually low calcium intake (~600 mg/day). METHODS: Adolescents (14-19 years) were randomly assigned to receive a daily supplement (600 mg of calcium plus 200 UI of cholecalciferol, n = 30) or a placebo (n = 26) from 26 weeks of gestation until parturition. Body composition was determined at 5, 20, and 56 weeks postpartum by dual-energy x-ray absorptiometry. The effects of intervention group, time point, as well as their interaction were assessed using repeated measures mixed-effects models. RESULTS: In the adjusted analysis, those supplemented showed lower total body mass [mean difference = -3.32 kg; confidence interval (CI) 95% -6.12 to -0.52 kg], trunk (-1.25 kg; CI 95% -2.34 to -0.15 kg), android (-0.29 kg; CI 95% -0.53 to -0.04 kg) and subcutaneous (-0.23 kg; CI 95% -0.43 to -0.03 kg) fat masses. In the supplemented group, BMI and postpartum weight retention significantly decreased from 5 to 20 weeks (-0.90 kg/m2 and -1.76 kg, respectively; p < .05). At 56 weeks, BMI was still lower (-1.22 kg/m2 ; p < .05) than 5 weeks. CONCLUSIONS: Our findings suggest that increasing calcium intake through supplementation in combination with vitamin D contributes to a more pronounced reduction in total body mass overtime, mostly as a consequence of fat mass reductions in central body regions. This trial was registered at clinicaltrials.gov as NCT01732328.

Birth weight, skeletal maturity and dietary patterns are associated with body composition compartments differently in male and female physically active adolescents.

Background: Adequate body composition is important for health and performance of physically active adolescents; however, some factors can influence body composition. Aim: The purpose of this study was to evaluate the association between body composition and birth weight, skeletal maturity and dietary patterns, in male (n = 124) and female (n = 107) physically active adolescents. Methods: Birth weight was obtained from health booklets. Dual-energy X-ray absorptiometry (DXA) was used to estimate fat mass (FM), fat-free mass (FFM), visceral adipose tissue (VAT) and abdominal adipose tissue (ASAT). Skeletal maturity was assessed by a hand and fist scanner using DXA. Food intake was assessed using a food frequency questionnaire and dietary patterns by factorial analysis. Results: Seventy one percent (male = 16%, female = 55%) of the participants were mature. Two dietary patterns (in natura/minimally processed and processed/ultra-processed) were identified. In males, FM (>15%, P = 0.043) and ASAT (>30%, P = 0.042) were higher in those with low-median compared to high-median birth weight. FFM (>24%) was higher in skeletally mature compared to those immatures (P = 0.001), and VAT (>28%) was higher in processed/ultra-processed compared to in natura/minimally processed dietary patterns (P = 0.015). In females, FFM (>9%) was higher in those with low-median compared to high-median birth weight (P = 0.019); and FFM (>16%), FM (>28%) and ASAT (>45%) were higher in skeletally mature compared to those immatures (P = 0.001). Conclusion: Our results may contribute to a better understanding of the complex association among body composition, birth weight, skeletal maturity and dietary patterns and in physically active adolescents, differently according to sex.

Salt-related practices and its association with 24-hour urinary sodium excretion in an Uruguayan population cohort.

Objectives: To evaluate the association between knowledge, attitudes, and behavior (KAB) towards sodium use and sodium intake measured by 24-hour urinary collection in an adult cohort from Uruguay (Genotype Phenotype and Environment of Hypertension Study, GEFA-HT-UY). Methods: In a cross-sectional study (n = 159), a single 24-hour urinary sample, participants' physical, biochemical and blood pressure measurements and questionnaire data were collected. The association between KAB and 24-hour urinary sodium excretion was assessed using general linear models. Results: Mean age of participants was 49.8±15.5 years, 67.9% were women, and mean 24-hour urinary sodium excretion was 3.6±1.7 g/day. Although 90.6% of participants exceeded the maximum recommended intake as indicated by urinary sodium excretion, more than half misperceived their actual intake, reporting consuming "the right amount." Almost three-quarters of the participants reported being concerned about the amount of sodium in their diet, but only 52.8% reported taking action to control it. Lack of procedural knowledge was observed. There was no association between KAB and sodium use and intake assessed by 24-hour urinary sodium excretion. Conclusions: The lack of association between KAB towards the use of sodium and intake measured by 24-hour urinary excretion reflects the need to support people with opportunities and motivations to reduce sodium consumption. Structural actions to promote an adequate food environment, such as the effective implementation of the front-of-package nutrition labeling in Uruguay, are positive steps.

Salt-related practices and its association with 24-hour urinary sodium excretion in an Uruguayan population cohort

[ABSTRACT]. Objectives. To evaluate the association between knowledge, attitudes, and behavior (KAB) towards sodium use and sodium intake measured by 24-hour urinary collection in an adult cohort from Uruguay (Genotype Phenotype and Environment of Hypertension Study, GEFA-HT-UY). Methods. In a cross-sectional study (n = 159), a single 24-hour urinary sample, participants' physical, bio- chemical and blood pressure measurements and questionnaire data were collected. The association between KAB and 24-hour urinary sodium excretion was assessed using general linear models. Results. Mean age of participants was 49.8±15.5 years, 67.9% were women, and mean 24-hour urinary sodium excretion was 3.6±1.7 g/day. Although 90.6% of participants exceeded the maximum recommended intake as indicated by urinary sodium excretion, more than half misperceived their actual intake, reporting consuming “the right amount.” Almost three-quarters of the participants reported being concerned about the amount of sodium in their diet, but only 52.8% reported taking action to control it. Lack of procedural knowl- edge was observed. There was no association between KAB and sodium use and intake assessed by 24-hour urinary sodium excretion. Conclusions. The lack of association between KAB towards the use of sodium and intake measured by 24-hour urinary excretion reflects the need to support people with opportunities and motivations to reduce sodium consumption. Structural actions to promote an adequate food environment, such as the effective implementation of the front-of-package nutrition labeling in Uruguay, are positive steps.

[RESUMEN]. Objetivos. Evaluar la relación entre conocimientos, actitudes y comportamientos en lo relativo a la ingesta de sodio medida por la recolección de orina de 24 horas en una cohorte de adultos en Uruguay (GEnotipo, Fenotipo y Ambiente de la HiperTensión Arterial en UruguaY, GEFA-HT-UY). Métodos. En un estudio transversal (n = 159), se obtuvo una muestra urinaria de 24 horas y los datos de un cuestionario y de las mediciones físicas, bioquímicas y de presión arterial de los participantes. Se evaluó la asociación entre conocimientos, actitudes y comportamientos y la excreción urinaria de sodio en 24 horas con modelos lineales generales. Resultados. La edad media de los participantes fue 49,8±15,5 años, 67,9% eran mujeres y la excreción urinaria media de sodio en 24 horas fue de 3,6±1,7 g/día. Aunque 90,6% de los participantes excedieron la ingesta máxima recomendada de acuerdo con la excreción urinaria de sodio, más de la mitad percibió su ingesta real incorrectamente al señalar que consumía “la cantidad correcta”. Casi tres cuartas partes de los participantes manifestaron estar preocupados por la cantidad de sodio en su dieta, si bien solo 52,8% declaró haber tomado medidas para controlarla. Se observó una falta de conocimiento sobre los procedimientos. No se encontró una asociación entre conocimientos, actitudes y comportamientos y la ingesta de sodio evaluada mediante la excreción urinaria de sodio en 24 horas. Conclusiones. La falta de relación entre conocimientos, actitudes y comportamientos respecto del consumo de sodio y su ingesta medida por excreción urinaria en 24 horas refleja la necesidad de apoyar a las perso- nas con oportunidades y motivaciones para reducir el consumo de sodio. Adoptar medidas estructurales que promuevan unas condiciones alimentarias adecuadas, como la aplicación efectiva del etiquetado nutricional frontal en Uruguay, constituye un paso en la dirección correcta.

[RESUMO]. Objetivos. Avaliar a associação entre conhecimento, atitudes e comportamento (KAB, sigla do inglês Knowl- edge, Attitudes, Behavior) e o uso e ingestão de sódio, medida pela coleta de urina de 24 horas em uma coorte de adultos do Uruguai (Estudo do Genótipo, Fenótipo e Ambiente da Hipertensão, GEFA-HT-UY). Métodos. Em um estudo transversal (n = 159), foi coletada uma única amostra de urina de 24 horas dos par- ticipantes, medidas físicas, bioquímicas e de pressão arterial, e dados de questionários. A associação entre KAB e excreção urinária de sódio nas 24 horas foi avaliada por meio de modelos lineares gerais. Resultados. A idade média dos participantes foi de 49,8±15,5 anos; 67,9% eram mulheres e a excreção média de sódio na urina de 24 horas foi de 3,6±1,7 g/dia. Embora 90,6% dos participantes excedessem a ingestão máxima recomendada, conforme indicado pela excreção urinária de sódio, mais da metade dos participantes não tinha percepção da real ingestão de sódio, relatando consumir "a quantidade correta". Quase três quartos dos participantes relataram estar preocupados com a quantidade de sódio na dieta, mas apenas 52,8% relataram ter implementado medidas para controlá-la. Observou-se falta de conhecimento de procedimentos. Não houve associação entre KAB e o uso e a ingestão de sódio avaliada pela excreção de sódio na urina de 24 horas. Conclusões. A falta de associação entre KAB e o uso e a ingestão do sódio avaliada pela excreção urinária de 24 horas reflete a necessidade de oferecer apoio aos indivíduos por meio de oportunidades e motivações para reduzir o consumo de sódio. Ações estruturais para promover um ambiente alimentar adequado, como a implementação efetiva de advertências na rotulagem frontal dos alimentos no Uruguai, são passos positivos.

Daily Intake of a Functional Synbiotic Yogurt Increases Calcium Absorption in Young Adult Women.

BACKGROUND: Foods containing both prebiotics and probiotics (synbiotics) might enhance calcium bioavailability. OBJECTIVES: We investigated the acute effect in young adult women on calcium absorption of consuming (185 mL) a synbiotic yogurt (SYN) containing inulin (4 g) and Lactobacillus rhamnosus GG (>1 × 107 CFU/mL) compared with a control yogurt (CON). METHODS: Adult normal-weight women (25.0 ± 3.5 y, n = 30) participated in a 3-wk crossover study testing daily consumption of SYN compared with CON. Habitual dietary intake, bone mineral density (BMD), calcium biomarkers, and serum 25-hydroxyvitamin D were measured at baseline. Calcium absorption was tested after each phase of the study using a 42Ca oral tracer. Cumulative tracer recovery was measured in 0-4-h,  0-24-h, and 0-36-h urine pools collected postdosing. The SYN/CON tracer ratio from the timed urine pools was the primary outcome. A beneficial response to SYN was defined as 0-36-h SYN/CON tracer ratio >1. RESULTS: Net 42Ca recovered increased over time in each of the SYN and CON urine pools postdosing (Friedman, P < 0.001), with a trend for higher 42Ca recovery in the 0-36-h urine pool postdosing in the SYN (1.14%) compared with the CON (0.90%) study (Wilcoxon, P = 0.07). For CON, the majority of total tracer was recovered in the 0-24-h pool (86%), whereas for SYN only 50% of total tracer was recovered in the 0-24-h pool (Friedman, P = 0.001). The SYN/CON tracer ratio in the 0-36-h pool (1.24) was >1 (Wilcoxon, P = 0.015). About two-thirds (n = 19) of women studied responded to the SYN treatment. Responders had higher vegetable intake (P = 0.03), tended to have higher potassium and calcium intakes (P ≤ 0.08), and had higher total body BMD (P = 0.09), than nonresponders. CONCLUSIONS: Short-term daily consumption of a synbiotic yogurt enhanced calcium absorption relative to a control yogurt in adult women. Given the observed time delays in tracer recovery, enhancement of calcium absorption likely occurred in the large intestine.The study was registered at clinicaltrials.gov (study registration ID: NCT03420716).

Salt-related practices and its association with 24-hour urinary sodium excretion in an Uruguayan population cohort / Prácticas relacionadas con la sal y su asociación con la excreción urinaria de sodio en 24 horas en una cohorte de población en Uruguay / Práticas relacionadas ao uso do sal e sua associação com a excreção de sódio na urina de 24 horas em uma coorte populacional uruguaia

Abstract Objectives. To evaluate the association between knowledge, attitudes, and behavior (KAB) towards sodium use and sodium intake measured by 24-hour urinary collection in an adult cohort from Uruguay (Genotype Phenotype and Environment of Hypertension Study, GEFA-HT-UY). Methods. In a cross-sectional study (n = 159), a single 24-hour urinary sample, participants' physical, biochemical and blood pressure measurements and questionnaire data were collected. The association between KAB and 24-hour urinary sodium excretion was assessed using general linear models. Results. Mean age of participants was 49.8±15.5 years, 67.9% were women, and mean 24-hour urinary sodium excretion was 3.6±1.7 g/day. Although 90.6% of participants exceeded the maximum recommended intake as indicated by urinary sodium excretion, more than half misperceived their actual intake, reporting consuming "the right amount." Almost three-quarters of the participants reported being concerned about the amount of sodium in their diet, but only 52.8% reported taking action to control it. Lack of procedural knowledge was observed. There was no association between KAB and sodium use and intake assessed by 24-hour urinary sodium excretion. Conclusions. The lack of association between KAB towards the use of sodium and intake measured by 24-hour urinary excretion reflects the need to support people with opportunities and motivations to reduce sodium consumption. Structural actions to promote an adequate food environment, such as the effective implementation of the front-of-package nutrition labeling in Uruguay, are positive steps.

RESUMEN Objetivos. Evaluar la relación entre conocimientos, actitudes y comportamientos en lo relativo a la ingesta de sodio medida por la recolección de orina de 24 horas en una cohorte de adultos en Uruguay (GEnotipo, Fenotipo y Ambiente de la HiperTensión Arterial en UruguaY, GEFA-HT-UY). Métodos. En un estudio transversal (n = 159), se obtuvo una muestra urinaria de 24 horas y los datos de un cuestionario y de las mediciones físicas, bioquímicas y de presión arterial de los participantes. Se evaluó la asociación entre conocimientos, actitudes y comportamientos y la excreción urinaria de sodio en 24 horas con modelos lineales generales. Resultados. La edad media de los participantes fue 49,8±15,5 años, 67,9% eran mujeres y la excreción urinaria media de sodio en 24 horas fue de 3,6±1,7 g/día. Aunque 90,6% de los participantes excedieron la ingesta máxima recomendada de acuerdo con la excreción urinaria de sodio, más de la mitad percibió su ingesta real incorrectamente al señalar que consumía "la cantidad correcta". Casi tres cuartas partes de los participantes manifestaron estar preocupados por la cantidad de sodio en su dieta, si bien solo 52,8% declaró haber tomado medidas para controlarla. Se observó una falta de conocimiento sobre los procedimientos. No se encontró una asociación entre conocimientos, actitudes y comportamientos y la ingesta de sodio evaluada mediante la excreción urinaria de sodio en 24 horas. Conclusiones. La falta de relación entre conocimientos, actitudes y comportamientos respecto del consumo de sodio y su ingesta medida por excreción urinaria en 24 horas refleja la necesidad de apoyar a las personas con oportunidades y motivaciones para reducir el consumo de sodio. Adoptar medidas estructurales que promuevan unas condiciones alimentarias adecuadas, como la aplicación efectiva del etiquetado nutricional frontal en Uruguay, constituye un paso en la dirección correcta.

RESUMO Objetivos. Avaliar a associação entre conhecimento, atitudes e comportamento (KAB, sigla do inglês Knowledge, Attitudes, Behavior) e o uso e ingestão de sódio, medida pela coleta de urina de 24 horas em uma coorte de adultos do Uruguai (Estudo do Genótipo, Fenótipo e Ambiente da Hipertensão, GEFA-HT-UY). Métodos. Em um estudo transversal (n = 159), foi coletada uma única amostra de urina de 24 horas dos participantes, medidas físicas, bioquímicas e de pressão arterial, e dados de questionários. A associação entre KAB e excreção urinária de sódio nas 24 horas foi avaliada por meio de modelos lineares gerais. Resultados. A idade média dos participantes foi de 49,8±15,5 anos; 67,9% eram mulheres e a excreção média de sódio na urina de 24 horas foi de 3,6±1,7 g/dia. Embora 90,6% dos participantes excedessem a ingestão máxima recomendada, conforme indicado pela excreção urinária de sódio, mais da metade dos participantes não tinha percepção da real ingestão de sódio, relatando consumir "a quantidade correta". Quase três quartos dos participantes relataram estar preocupados com a quantidade de sódio na dieta, mas apenas 52,8% relataram ter implementado medidas para controlá-la. Observou-se falta de conhecimento de procedimentos. Não houve associação entre KAB e o uso e a ingestão de sódio avaliada pela excreção de sódio na urina de 24 horas. Conclusões. A falta de associação entre KAB e o uso e a ingestão do sódio avaliada pela excreção urinária de 24 horas reflete a necessidade de oferecer apoio aos indivíduos por meio de oportunidades e motivações para reduzir o consumo de sódio. Ações estruturais para promover um ambiente alimentar adequado, como a implementação efetiva de advertências na rotulagem frontal dos alimentos no Uruguai, são passos positivos.

Association of Dietary Patterns with Cardiovascular and Kidney Phenotypes in an Uruguayan Population Cohort.

The impact of habitual diet on chronic diseases has not been extensively characterized in South America. We aimed to identify major dietary patterns (DP) in an adult cohort in Uruguay (Genotype Phenotype and Environment of Hypertension Study-GEFA-HT-UY) and to assess associations with metabolic, anthropometric characteristics, and cardiovascular and kidney phenotypes. In a cross-sectional study (n = 294), DP were derived by the principal component analysis. Blood and urine parameters, anthropometrics, blood pressure, pulse wave velocity, and glomerular filtration rate were measured. Multivariable adjusted linear models and adjusted binary logistic regression were used. Three DP were identified (Meat, Prudent, Cereal and Mate) explaining 22.6% of total variance in food intake. The traditional Meat DP, characterized by red and barbecued meat, processed meat, bread, and soft drinks, was associated with worse blood lipid profile. Prudent DP, characterized by vegetables, fish, and nuts, and lower loads for bread and crackers, was associated with reduced risk of vitamin D deficiency. Cereal and Mate DP, was characterized by higher loads of cereals, bread, and crackers, and mate infusion, with higher odds of excessive body weight. No direct associations of dietary patterns with hypertension, arterial stiffness, chronic kidney disease, and nephrolithiasis were found in the studied population, nor by age categories or sex.

Polycyclic aromatic hydrocarbons in yerba mate (Ilex paraguariensis) infusions and probabilistic risk assessment of exposure.

The aim of this study was to assess the risk of exposure to polycyclic aromatic hydrocarbons (PAH) from yerba mate infusions in Uruguay using the margin of exposure approach (MOE) and a probabilistic method (Monte Carlo simulation). Servings/day, portion size, weekly frequency of mate consumption and body weight were the factors considered. The amount in infusions of benz[a]pyrene (B[a]P), PAH2 (sum of chrysene and B[a]P), and PAH4 (sum of benz[a]anthracene, chrysene, benz[b]fluoranthene and B[a]P) were used as markers of PAH exposure. Total content of PAH in infusions had large inter-brand variability (48-54 %) with significant differences among brands. PAH content in infusions prepared as habitually consumed was about 40 % of total content. The probability of occurrence of MOE < 10,000 varied according to the infusion preparation and the marker of exposure used, being higher for infusions prepared for total content and when B[a]P was used as marker of exposure. When the average B[a]P amount in infusion as habitually consumed was used in the simulation model, the probability of MOE < 10,000 was 9 %. The main factors contributing to B[a]P MOE variance were B[a]P amount (28.4 %), servings/day (17.3 %), and portion size (9.6 %). Heavy drinkers of yerba mate with high B[a]P content are those at risk to PAH exposure from mate infusions.

Bioimpedance parameters in adolescent athletes in relation to bone maturity and biochemical zinc indices.

Phase angle (PA) is derived from resistance and reactance determined by bioimpedance analysis (BIA) and it appears to relate to cellular stability and integrity. Interpretation of PA values could be complemented by bioelectrical impedance vector analysis (BIVA), which relates to body hydration and structure. Body composition, age, sex, and nutrients are known to stabilize cell membranes, such as zinc, have been related to PA although information is scarce in adolescent athletes. The aim of the present study was to assess the association of body composition, skeletal maturity and zinc biochemical indices with phase angle and bioelectrical impedance parameters, in forty male adolescent soccer athletes (13.4±0.6years). BIA was performed with a single-frequency tetrapolar analyzer. PA and BIVA were determined using resistance and reactance BIA data. Plasma and erythrocyte zinc concentrations were measured using inductively coupled plasma-optical emission spectrometry. Body composition was determined by dual-energy X-ray absorptiometry, and bone age by hand X-ray measurements. PA was higher in adolescents classified by bone age as "Early" (6.8±0.9°) compared to "Late" (5.7±0.5°) (p<0.05). PA correlated with bone age (r=0.562), BMI (r=0.382), fat-free mass (r=0.468), and erythrocyte zinc (r=0.379) (p<0.05). BIVA confidence ellipses were sensitive to skeletal maturity status. Phase angle was higher in adolescents with erythrocyte zinc concentration above the median (>0.66µmol.g hemoglobin-1) compared to those below the median. Multiple linear regression analysis showed that bone age (B=0.254, p=0.001) and erythrocyte zinc concentration (B=1.168, p=0.047) were significantly related to PA in this group, and accounted for 34% of its variability. Our results indicate that bone age and zinc erythrocyte contribute to PA values in the young male soccer athletes and that BIVA is influenced by skeletal maturity status in this group.

Influência de contraceptivos hormonais sobre indicadores de homeostase de zinco e de turnover ósseo em mulheres adultas jovens / Influence of hormonal contraceptives on indices of zinc homeostasis and bone remodeling in young adult women

OBJETIVO: Investigar a influência de anticoncepcionais hormonais (ACH) orais em indicadores bioquímicos relacionados à utilização metabólica e distribuição de zinco e ao turnover ósseo em mulheres adultas jovens.MÉTODOS: Estudo transversal. Amostras de sangue e urina de não usuárias (-ACH; controle; n=69) e usuárias há pelo menos três meses de contraceptivos hormonais orais (+ACH; n=62) foram coletadas em condições padronizadas. Foram analisados os indicadores de homeostase de zinco e de turnoverósseo em soro ou plasma (zinco total e nas frações de albumina e α2-macroglobulina, albumina e atividade de fosfatase alcalina total e de origem óssea), em eritrócitos (zinco e metalotioneína) e em urina (zinco, cálcio e hidroxiprolina). Ingestões habituais de zinco e cálcio foram avaliadas por questionário de frequência de consumo.RESULTADOS: A ingestão alimentar de zinco foi semelhante nos grupos e, em média, acima do recomendado, enquanto que a ingestão de cálcio foi similarmente subadequada em +ACH e -ACH. Comparadas às controles, as +ACH apresentaram menores concentrações de zinco em soro, total e ligado à α2-macroglobulina (11 e 28,5%, respectivamente, p<0,001); albumina em soro (13%, p<0,001); atividade de fosfatase alcalina em plasma, total e de origem óssea (13 e 18%, respectivamente, p<0,05); metalotioneína em eritrócitos (13%, p<0,01) e zinco urinário (34%, p<0,05).CONCLUSÕES: O uso de ACH reduz o zinco sérico, altera a distribuição de zinco nas principais proteínas ligantes do soro com possíveis efeitos na captação tecidual, aumenta a retenção de zinco no organismo e reduz o turnover ósseo. O uso prolongado de ACH poderia levar a menor pico de massa óssea e/ou prejudicar a manutenção de massa óssea em mulheres jovens, principalmente com ingestão marginal de cálcio. Os efeitos de ACH verificados foram mais evidentes nas mulheres <25 anos de idade e nas nulíparas, as quais merecem especial atenção em estudos posteriores.

PURPOSE: To investigate the influence of the use of oral hormonal contraceptive agents (OCA) on the biochemical indices related to metabolic zinc utilization and distribution, and to bone turnover in young adult women.METHODS: Cross-sectional study. Blood and urine samples from non-users (-OCA; control; n=69) and users of hormonal contraceptives for at least 3 months (+OCA; n=62) were collected under controlled conditions. Indices of zinc homeostasis and of bone turnover were analyzed in serum or plasma (total, albumin-bound and α2-macroglobulin-bound zinc, albumin and total and bone alkaline phosphatase activity), in erythrocytes (zinc and metallothionein) and in urine (zinc, calcium and hydroxyproline). The habitual zinc and calcium intakes were evaluated by a food frequency questionnaire.RESULTS: Dietary zinc intake was similar in both groups and on average above recommended values, whereas calcium intake was similarly sub-adequate in +OCA and -OCA. Compared to controls, +OCA had lower concentrations of total and α2-macroglobulin-bound zinc (11 and 28.5%, respectively, p<0.001), serum albumin (13%, p<0.01), total and bone-specific alkaline phosphatase activity (13 and 18%, respectively, p<0.05), erythrocyte metallothionein (13%, p<0.01), and, urinary zinc (34%, p<0.05).CONCLUSIONS: OCA use decreases serum zinc, alters zinc distribution in major serum fractions with possible effects on tissue uptake, enhances zinc retention in the body and decreases bone turnover. Prolonged OCA use may lead to lower peak bone mass and/or to impaired bone mass maintenance in young women, particularly in those with marginal calcium intake. The observed OCA effects were more evident in women younger than 25 years and in nulliparous women, deserving special attention in future studies.

[Influence of hormonal contraceptives on indices of zinc homeostasis and bone remodeling in young adult women]. / Influência de contraceptivos hormonais sobre indicadores de homeostase de zinco e de turnover ósseo em mulheres adultas jovens.

PURPOSE: To investigate the influence of the use of oral hormonal contraceptive agents (OCA) on the biochemical indices related to metabolic zinc utilization and distribution, and to bone turnover in young adult women. METHODS: Cross-sectional study. Blood and urine samples from non-users (-OCA; control; n=69) and users of hormonal contraceptives for at least 3 months (+OCA; n=62) were collected under controlled conditions. Indices of zinc homeostasis and of bone turnover were analyzed in serum or plasma (total, albumin-bound and α2-macroglobulin-bound zinc, albumin and total and bone alkaline phosphatase activity), in erythrocytes (zinc and metallothionein) and in urine (zinc, calcium and hydroxyproline). The habitual zinc and calcium intakes were evaluated by a food frequency questionnaire. RESULTS: Dietary zinc intake was similar in both groups and on average above recommended values, whereas calcium intake was similarly sub-adequate in +OCA and -OCA. Compared to controls, +OCA had lower concentrations of total and α2-macroglobulin-bound zinc (11 and 28.5%, respectively, p<0.001), serum albumin (13%, p<0.01), total and bone-specific alkaline phosphatase activity (13 and 18%, respectively, p<0.05), erythrocyte metallothionein (13%, p<0.01), and, urinary zinc (34%, p<0.05). CONCLUSIONS: OCA use decreases serum zinc, alters zinc distribution in major serum fractions with possible effects on tissue uptake, enhances zinc retention in the body and decreases bone turnover. Prolonged OCA use may lead to lower peak bone mass and/or to impaired bone mass maintenance in young women, particularly in those with marginal calcium intake. The observed OCA effects were more evident in women younger than 25 years and in nulliparous women, deserving special attention in future studies.

Isoflavones and soyasaponins in soy infant formulas in Brazil: profile and estimated consumption.

In the present study we determine the contents of isoflavones and soyasaponins in seven soy-based infant formulas available in the Brazilian market to estimate the intake of these bioactive compounds by infants. The mean contents of isoflavones and soyasaponins were 65.9mg/kg and 55.0mg/100g, respectively. ß-Glycosylated isoflavones and soyasaponin B-I were the most abundant components in the analysed samples. The mean estimated intake of isoflavones by infants fed soy-based formulas was 0.8mg/day/kg of body weight, which is twice that of Japanese adults. For soyasaponins, the mean estimated intake was 9.2mg/day/kg of body weight, which is up to 6 times higher than the daily intake of saponins from beans by vegetarians. Considering the estimated intake of these bioactive compounds from soy-based formulas and the paucity of data regarding their bioavailability, the potential biological effects of isoflavones and soyasaponins in infants should not be overlooked and merits further investigation.

Maternal zinc intakes and homeostatic adjustments during pregnancy and lactation.

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide.

Chemical characterization and evaluation of antioxidant properties of açaí fruits (Euterpe oleraceae Mart.) during ripening.

Consumption of açaí fruits has been linked to positive health effects due to its phenolic content and nutritive value. The objective of this study was to characterize açaí fruits chemically and to determine the antioxidant capacity at three different maturity stages. With the exception of fat, amounts of macronutrients, minerals and titratable acids decreased during the ripening process. The same trend was observed for most of the phenolic constituents identified by HPLC-ESI-MS/MS. A consistent decline was shown for flavones and hydroxycinnamic acids. The concentration of the anthocyanins increased in the course of ripening. In accordance with the total amount of the identified phenolic compounds, the antioxidant capacity, measured by TEAC and TOSC, also decreased. However, the contribution of the main phenolic compounds to the overall antioxidant capacity evaluated by TOSC was estimated to be low.

Plasma zinc, copper, and serum thyroid hormones and insulin levels after zinc supplementation followed by placebo in competitive athletes.

Intense physical activity is associated with biological adaptations involving hormones and trace elements. Zinc supplementation may affect plasma copper concentration, thyroid-stimulating hormone (TSH), thyroid hormones, insulin, and glucose homeostasis, but data in athletes are scarce. The aim of this study was to evaluate in competitive athletes (cyclists, n = 7, 32 ± 8 years) the effect of zinc supplementation (22 mg/day as zinc gluconate) during 30 days, and discontinuation using placebo (maltodextrin) during the following 30 days, on plasma zinc and copper concentrations, serum thyroid hormones, insulin and glucose levels, and HOMA2-IR. Compared to baseline, plasma zinc and Zn:Cu plasma ratio increased, but plasma copper decreased after zinc supplementation (day 30) and discontinuation (day 60) (p < 0.05). Zn supplementation and discontinuation had no effect on TSH, T3, and T4. Fasting serum insulin and HOMA2-IR increased (27% and 47%, respectively) on day 60 compared to baseline (p = 0.03), suggesting a delayed effect of zinc supplementation. Moreover, plasma zinc was positively associated with serum insulin (r = 0.87, p = 0.009) and HOMA2-IR (r = 0.81, p = 0.03) after zinc supplementation (day 30), indicating that supplemental zinc may impair glucose utilization in cyclists.

Effect of zinc supplementation on the antioxidant, copper, and iron status of physically active adolescents.

Puberty associated with intense physical activity results in oxidation stress. Zinc supplementation may benefit antioxidant capacity although it may also affect iron and copper status. This study evaluated the effect of zinc supplementation on antioxidant, zinc and copper status of physically active male football players (13 years +/- 0.4 years), divided in two groups and studied during 12 weeks: Zn-supplemented (Zn-SUP, 22 mg Zn d(-1) as zinc gluconate, n = 21) and placebo (PLA, n = 26). At baseline, there was no significant difference in biochemical indices between the two groups. After treatment, plasma zinc and erythrocyte iron increased in both groups (p < 0.001); urinary zinc increased (p < 0.001) only in Zn-SUP, and erythrocyte zinc decreased (p = 0.002) only in PLA. Plasma iron and copper decreased (p = 0.01 and p = 0.015, respectively) only in Zn-SUP. Plasma ferric-reducing ability and plasma conjugated dienes increased, and erythrocyte osmotic fragility decrease in both groups, although the latter two were significantly lower in Zn-SUP compared to PLA (p < 0.01). In conclusion, our study indicates that the use of 22 mg d(-1) of supplemental zinc during 12 week in adolescent athletes did not affect growth, improved markers of antioxidant status but reduced plasma iron and copper. Therefore, it appears that the use of zinc supplementation by healthy adolescent athletes benefits their antioxidant capacity but impairs copper and iron nutritional status.

Plasma leptin, plasma zinc, and plasma copper are associated in elite female and male judo athletes.

The purpose of this study was to compare plasma leptin, plasma zinc, and plasma copper levels and their relationship in trained female and male judo athletes (n = 10 women; n = 8 men). Blood samples were obtained 24 h after training to measure plasma zinc, copper, and leptin levels. Subjects presented similar values to age (22 +/- 2 years old), body mass index (24 +/- 1 kg/m(2)), plasma zinc (17.2 +/- 2 micromol/L), copper (12.5 +/- 2 micromol/L), and leptin (5.6 +/- 1.3 microg/L). However, height, total body mass, lean mass, fat mass, and sum of ten-skinfold thickness were higher in male than female. Plasma leptin was associated with sum of ten skinfolds in male (r = 0.91; p < 0.001) and female athletes (r = 0.84; p < 0.003). Plasma zinc was associated with leptin in males (r = 0.82; p < 0.05) while copper was associated with plasma leptin in females (r = 0.66; p < 0.05). Our results suggest that young judo athletes lost sex-related differences in leptin levels. Plasma zinc, plasma copper, and energy homeostasis may be involved in regulation of plasma leptin.