Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Lancet Glob Health ; 11(1): e105-e116, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36521942

RESUMO

BACKGROUND: Iron deficiency is the most prevalent nutritional disorder worldwide. Iron supplementation has modest efficacy, causes gastrointestinal side-effects that limit compliance, and has been associated with serious adverse outcomes in children across low-income settings. We aimed to compare two hepcidin-guided screen-and-treat regimens designed to reduce overall iron dosage by targeting its administration to periods when children were safe and ready to receive iron supplementation, with WHO's recommendation of universal iron supplementation. METHODS: We conducted an individually randomised, three-arm, double-blind, controlled, proof-of-concept, non-inferiority trial in 12 rural communities across The Gambia. Eligible participants were children aged 6-23 months with anaemia. Participants were randomly assigned (1:1:1) to either the WHO recommended regimen of one sachet of multiple micronutrient powder (MMP) daily containing 12·0 mg iron as encapsulated ferrous fumarate (control group); to MMP with 12·0 mg per day iron for the next 7 days if plasma hepcidin concentration was less than 5·5 µg/L, or to MMP without iron for the next 7 days if plasma hepcidin concentration was at least 5·5 µg/L (12 mg screen-and-treat group); or to MMP with 6·0 mg per day iron for the next 7 days if plasma hepcidin concentration was less than 5·5 µg/L, or to MMP without iron for the next 7 days if plasma hepcidin concentration was at least 5·5 µg/L (6 mg screen-and-treat group). Randomisation was done by use of a permuted block design (block size of 9), with stratification by haemoglobin and age, using computer-generated numbers. Participants and the research team (except for the data manager) were masked to group allocation. The primary outcome was haemoglobin concentration, with a non-inferiority margin of -5 g/L. A per-protocol analysis, including only children who had consumed at least 90% of the supplements (ie, supplement intake on ≥75 days during the study), was done to assess non-inferiority of the primary outcome at day 84 using a one-sided t test adjusted for multiple comparisons. Safety was assessed by use of ex-vivo growth tests of Plasmodium falciparum in erythrocytes and three species of sentinel bacteria in plasma samples from participants. This trial is registered with the ISRCTN registry, ISRCTN07210906. FINDINGS: Between April 23, 2014, and Aug 7, 2015, we prescreened 783 children, of whom 407 were enrolled into the study: 135 were randomly assigned to the control group, 136 to the 12 mg screen-and-treat group, and 136 to the 6 mg screen-and-treat group. 345 (85%) children were included in the per-protocol population: 115 in the control group, 116 in the 12 mg screen-and-treat group, and 114 in the 6 mg screen-and-treat group. Directly observed adherence was high across all groups (control group 94·8%, 12 mg screen-and-treat group 95·3%, and 6 mg screen-and-treat group 95·0%). 82 days of iron supplementation increased mean haemoglobin concentration by 7·7 g/L (95% CI 3·2 to 12·2) in the control group. Both screen-and-treat regimens were significantly less efficacious at improving haemoglobin (-5·6 g/L [98·3% CI -9·9 to -1·3] in the 12 mg screen-and-treat group and -7·8 g/L [98·3% CI -12·2 to -3·5] in the 6 mg screen-and-treat group) and neither regimen met the preset non-inferiority margin of -5 g/L. The 12 mg screen-and-treat regimen reduced iron dosage to 6·1 mg per day and the 6 mg screen-and-treat regimen reduced dosage to 3·0 mg per day. 580 adverse events were observed in 316 participants, of which eight were serious adverse events requiring hospitalisation mainly due to diarrhoeal disease (one [1%] participant in the control group, three [2%] in the 12 mg screen-and-treat group, and four [3%] in the 6 mg screen-and-treat group). The most common causes of non-serious adverse events (n=572) were diarrhoea (145 events [25%]), upper respiratory tract infections (194 [34%]), lower respiratory tract infections (62 [11%]), and skin infections (122 [21%]). No adverse events were deemed to be related to the study interventions. INTERPRETATION: The hepcidin-guided screen-and-treat strategy to target iron administration succeeded in reducing overall iron dosage, but was considerably less efficacious at increasing haemoglobin and combating iron deficiency and anaemia than was WHO's standard of care, and showed no differences in morbidity or safety outcomes. FUNDING: Bill & Melinda Gates Foundation and UK Medical Research Council.


Assuntos
Anemia Ferropriva , Deficiências de Ferro , Humanos , Criança , Pré-Escolar , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/tratamento farmacológico , Hepcidinas , Gâmbia , Ferro/uso terapêutico , Hemoglobinas
2.
J Sci Food Agric ; 102(2): 514-522, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34143490

RESUMO

BACKGROUND: Zinc-biofortified rice could contribute to zinc intake in deficient populations, but processing it into parboiled rice could affect this potential benefit. Zinc and iron true retention (TR) in milled rice produced under conditions resembling household and commercial parboiled methods was evaluated. Zinc and iron TR in milled rice obtained from biofortified and non-biofortified rice subjected to different soaking temperatures during parboiling was also evaluated. RESULTS: Conditions resembling commercial parboiling methods resulted in 52.2-59.7% zinc TR and 55.4-79.1% iron TR, whereas those used for household parboiling resulted in 70.7-79.6% zinc TR and 78.2-119.8% iron TR. Zinc TR in milled (8-16% bran removal) biofortified and non-biofortified parboiled rice was 50.6-66.8% when soaking rough rice at 20 °C and 29.9-56.0% when soaking rough rice at 65 °C; both had lower zinc TR than non-parboiled rice (58.0-80.6%). Iron TR was generally similar between milled non-parboiled and parboiled rice (26.2-67.6%) and between parboiled biofortified and non-biofortified milled rice. CONCLUSION: Parboiling conditions used to obtain milled rice targeted for own household consumption resulted in higher zinc and iron TR compared to parboiling conditions used for milled rice targeted for markets. More zinc from the inner endosperm moved towards the outer layers at high soaking temperature, resulting in lower zinc TR for milled parboiled rice soaked in hotter water. Parboiled rice soaked at temperatures used in households could provide more zinc to diets compared to rice soaked in hotter water commonly used in large rice mills, especially when rice is extensively milled. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Culinária/métodos , Ferro/análise , Oryza/química , Zinco/análise , Biofortificação , Manipulação de Alimentos , Alimentos Fortificados/análise , Temperatura Alta , Ferro/metabolismo , Oryza/metabolismo , Amido/química , Amido/metabolismo , Zinco/metabolismo
3.
Nat Med ; 27(4): 653-658, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33619371

RESUMO

Malaria and iron deficiency (ID) are common and interrelated public health problems in African children. Observational data suggest that interrupting malaria transmission reduces the prevalence of ID1. To test the hypothesis that malaria might cause ID, we used sickle cell trait (HbAS, rs334 ), a genetic variant that confers specific protection against malaria2, as an instrumental variable in Mendelian randomization analyses. HbAS was associated with a 30% reduction in ID among children living in malaria-endemic countries in Africa (n = 7,453), but not among individuals living in malaria-free areas (n = 3,818). Genetically predicted malaria risk was associated with an odds ratio of 2.65 for ID per unit increase in the log incidence rate of malaria. This suggests that an intervention that halves the risk of malaria episodes would reduce the prevalence of ID in African children by 49%.


Assuntos
Deficiências de Ferro , Malária/complicações , Absorção Fisiológica , Adolescente , África , Criança , Pré-Escolar , Feminino , Geografia , Hepcidinas/metabolismo , Humanos , Lactente , Masculino , Análise da Randomização Mendeliana , Traço Falciforme/complicações
4.
Br J Haematol ; 192(1): 179-189, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32862453

RESUMO

We report the first measurements of long-term iron absorption and loss during iron supplementation in African children using a stable isotope of iron (57 Fe). After uniform labelling of body iron with 57 Fe, iron absorption is proportional to the rate of decrease in the 57 Fe tracer concentration, while iron loss is proportional to the rate of decrease in the 57 Fe tracer amount. Anaemic Gambian toddlers were given 2 mg 57 Fe orally to equilibrate with total body iron over 8-11 months. After assignment to the positive control arm of the HIGH study, 22 toddlers consumed a micronutrient powder containing 12 mg iron for 12 weeks followed by 12 weeks without iron supplementation. Their daily iron absorption increased 3·8-fold during the iron supplementation period compared to the control period [median (interquartile range, IQR): 1·00 (0·82; 1·28) mg/day vs. 0·26 (0·22; 0·35) mg/day; P = 0·001]. Unexpectedly, during the supplementation period, daily iron loss also increased by 3·4-fold [0·75 (0·55; 0·87) mg/day vs. 0·22 (0·19; 0·29) mg/day; P = 0·005]. Consequently, most (~72%) of the absorbed iron was lost during supplementation. Long-term studies of iron absorption and loss are a promising and accurate method for assessing and quantifying long-term iron balance and may provide a reference method for evaluating iron intervention programs in vulnerable population groups. This study was registered as ISRCTN 0720906.


Assuntos
Anemia/terapia , Ferro/farmacocinética , Administração Oral , Pré-Escolar , Suplementos Nutricionais/análise , Humanos , Lactente , Absorção Intestinal , Ferro/administração & dosagem , Isótopos de Ferro/administração & dosagem , Isótopos de Ferro/farmacocinética
5.
J Nutr ; 150(12): 3094-3102, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33188398

RESUMO

BACKGROUND: Sweetpotato and potato are fast-maturing staple crops and widely consumed in low- and middle-income countries. Conventional breeding to biofortify these crops with iron could improve iron intakes. To our knowledge, iron absorption from sweetpotato and potato has not been assessed. OBJECTIVE: The aim was to assess iron absorption from regular and iron-biofortified orange-fleshed sweetpotato in Malawi and yellow-fleshed potato and iron-biofortified purple-fleshed potato in Peru. METHODS: We conducted 2 randomized, multiple-meal studies in generally healthy, iron-depleted women of reproductive age. Malawian women (n = 24) received 400 g regular or biofortified sweetpotato test meals and Peruvian women (n = 35) received 500 g regular or biofortified potato test meals. Women consumed the meals at breakfast for 2 wk and were then crossed over to the other variety. We labeled the test meals with 57Fe or 58Fe and measured cumulative erythrocyte incorporation of the labels 14 d after completion of each test-meal sequence to calculate iron absorption. Iron absorption was compared by paired-sample t tests. RESULTS: The regular and biofortified orange-fleshed sweetpotato test meals contained 0.55 and 0.97 mg Fe/100 g. Geometric mean (95% CI) fractional iron absorption (FIA) was 5.82% (3.79%, 8.95%) and 6.02% (4.51%, 8.05%), respectively (P = 0.81), resulting in 1.9-fold higher total iron absorption (TIA) from biofortified sweetpotato (P < 0.001). The regular and biofortified potato test meals contained 0.33 and 0.69 mg Fe/100 g. FIA was 28.4% (23.5%, 34.2%) from the regular yellow-fleshed and 13.3% (10.6%, 16.6%) from the biofortified purple-fleshed potato meals, respectively (P < 0.001), resulting in no significant difference in TIA (P = 0.88). CONCLUSIONS: FIA from regular yellow-fleshed potato was remarkably high, at 28%. Iron absorbed from both potato test meals covered 33% of the daily absorbed iron requirement for women of reproductive age, while the biofortified orange-fleshed sweetpotato test meal covered 18% of this requirement. High polyphenol concentrations were likely the major inhibitors of iron absorption. These trials were registered at www.clinicaltrials.gov as NCT03840031 (Malawi) and NCT04216030 (Peru).


Assuntos
Biofortificação , Ipomoea batatas/metabolismo , Ferro/administração & dosagem , Solanum tuberosum/metabolismo , Adulto , Transporte Biológico , Dieta , Feminino , Análise de Alimentos , Alimentos Fortificados , Humanos , Ipomoea batatas/química , Ferro/química , Ferro/metabolismo , Malaui , Peru , Solanum tuberosum/química , Adulto Jovem
6.
Lancet Glob Health ; 7(11): e1564-e1574, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31607468

RESUMO

BACKGROUND: WHO recommends daily iron supplementation for pregnant women, but adherence is poor because of side-effects, effectiveness is low, and there are concerns about possible harm. The iron-regulatory hormone hepcidin can signal when an individual is ready-and-safe to receive iron. We tested whether a hepcidin-guided screen-and-treat approach to combat iron-deficiency anaemia could achieve equivalent efficacy to universal administration, but with lower exposure to iron. METHODS: We did a three-arm, randomised, double-blind, non-inferiority trial in 19 rural communities in the Jarra West and Kiang East districts of The Gambia. Eligible participants were pregnant women aged 18-45 years at between 14 weeks and 22 weeks of gestation. We randomly allocated women to either WHO's recommended regimen (ie, a daily UN University, UNICEF, and WHO international multiple-micronutrient preparation [UNIMMAP] containing 60 mg iron), a 60 mg screen-and-treat approach (ie, daily UNIMMAP containing 60 mg iron for 7 days if weekly hepcidin was <2·5 µg/L or UNIMMAP without iron if hepcidin was ≥2·5 µg/L), or a 30 mg screen-and-treat approach (ie, daily UNIMMAP containing 30 mg iron for 7 days if weekly hepcidin was <2·5 µg/L or UNIMMAP without iron if hepcidin was ≥2·5 µg/L). We used a block design stratified by amount of haemoglobin at enrolment (above and below the median amount of haemoglobin on every enrolment day) and stage of gestation (14-18 weeks vs 19-22 weeks). Participants and investigators were unaware of the random allocation. The primary outcome was the amount of haemoglobin at day 84 and was measured as the difference in haemoglobin in each screen-and-treat group compared with WHO's recommended regimen; the non-inferiority margin was set at -5·0 g/L. The primary outcome was assessed in the per-protocol population, which comprised all women who completed the study. This trial is registered with the ISRCTN registry, number ISRCTN21955180. FINDINGS: Between June 16, 2014, and March 3, 2016, 498 participants were randomised, of whom 167 were allocated to WHO's recommended regimen, 166 were allocated to the 60 mg per day screen-and-treat approach, and 165 were allocated to the 30 mg per day screen-and-treat approach. 78 participants were withdrawn or lost to follow-up during the study; thus, the per-protocol population comprised 140 women assigned to WHO's recommended regimen, 133 allocated to the 60 mg screen-and-treat approach, and 147 allocated to the 30 mg screen-and-treat approach. The screen-and-treat approaches did not exceed the non-inferiority margin. Compared with WHO's recommended regimen, the difference in the amount of haemoglobin at day 84 was -2·2 g/L (95% CI -4·6 to 0·1) with the 60 mg screen-and-treat approach and -2·7 g/L (-5·0 to -0·5) with the 30 mg screen-and-treat approach. Adherence, reported side-effects, and adverse events were similar between the three groups. The most frequent side-effect was stomachache, which was similar in the 60 mg screen-and-treat group (82 cases per 1906 person-weeks) and with WHO's recommended regimen (81 cases per 1974 person-weeks; effect 1·0, 95% CI 0·7 to 1·6); in the 30 mg screen-and-treat group the frequency of stomachache was slightly lower than with WHO's recommended regimen (58 cases per 2009 person-weeks; effect 0·7, 95% CI 0·5 to 1·1). No participants died during the study. INTERPRETATION: The hepcidin-guided screen-and-treat approaches had no advantages over WHO's recommended regimen in terms of adherence, side-effects, or safety outcomes. Our results suggest that the current WHO policy for iron administration to pregnant women should remain unchanged while more effective approaches continue to be sought. FUNDING: Bill & Melinda Gates Foundation and the UK Medical Research Council.


Assuntos
Anemia Ferropriva/sangue , Anemia Ferropriva/tratamento farmacológico , Hepcidinas/sangue , Ferro/administração & dosagem , Complicações Hematológicas na Gravidez/sangue , Complicações Hematológicas na Gravidez/tratamento farmacológico , Oligoelementos/administração & dosagem , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Gâmbia , Hepcidinas/efeitos dos fármacos , Humanos , Ferro/farmacologia , Programas de Rastreamento , Gravidez , Oligoelementos/farmacologia , Resultado do Tratamento , Adulto Jovem
7.
Sci Adv ; 5(3): eaav9020, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30944864

RESUMO

Iron deficiency anemia (IDA) is the most prevalent nutritional condition worldwide. We studied the contribution of hepcidin-mediated iron blockade to IDA in African children. We measured hepcidin and hemoglobin weekly, and hematological, inflammatory, and iron biomarkers at baseline, 7 weeks, and 12 weeks in 407 anemic (hemoglobin < 11 g/dl), otherwise healthy Gambian children (6 to 27 months). Each child maintained remarkably constant hepcidin levels (P < 0.0001 for between-child variance), with half consistently maintaining levels that indicate physiological blockade of iron absorption. Hepcidin was strongly predicted by nurse-ascribed adverse events with dominant signals from respiratory infections and fevers (all P < 0.0001). Diarrhea and fecal calprotectin were not associated with hepcidin. In multivariate analysis, C-reactive protein was the dominant predictor of hepcidin and contributed to iron blockade even at very low levels. We conclude that even low-grade inflammation, especially associated with respiratory infections, contributes to IDA in African children.


Assuntos
Anemia Ferropriva/sangue , Hepcidinas/sangue , Ferro/metabolismo , Infecções Respiratórias/fisiopatologia , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/fisiopatologia , Biomarcadores/sangue , Proteína C-Reativa/análise , Pré-Escolar , Feminino , Gâmbia , Humanos , Lactente , Inflamação/sangue , Inflamação/fisiopatologia , Ferro/farmacocinética , Masculino , Análise Multivariada , Infecções Respiratórias/sangue
8.
Sci Rep ; 7(1): 17674, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29247172

RESUMO

Anaemia and malaria are both common in pregnant women in Sub-Saharan Africa. Previous evidence has shown that iron supplementation may increase malaria risk. In this observational cohort study, we evaluated P. falciparum pathogenesis in vitro in RBCs from pregnant women during their 2nd and 3rd trimesters. RBCs were collected and assayed before (n = 327), 14 days (n = 82), 49 days (n = 112) and 84 days (n = 115) after iron supplementation (60 mg iron as ferrous fumarate daily). P. falciparum erythrocytic stage growth in vitro is reduced in anaemic pregnant women at baseline, but increased during supplementation. The elevated growth rates parallel increases in circulating CD71-positive reticulocytes and other markers of young RBCs. We conclude that Plasmodium growth in vitro is associated with elevated erythropoiesis, an obligate step towards erythroid recovery in response to supplementation. Our findings support current World Health Organization recommendations that iron supplementation be given in combination with malaria prevention and treatment services in malaria endemic areas.


Assuntos
Eritrócitos/metabolismo , Eritropoese/fisiologia , Ferro/metabolismo , Malária Falciparum/metabolismo , Adulto , Anemia Ferropriva/metabolismo , Estudos de Coortes , Suplementos Nutricionais , Feminino , Humanos , Gravidez
9.
Nutrients ; 9(7)2017 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-28708072

RESUMO

Iron deficiency anemia (IDA) is a major public health problem in sub-Saharan Africa. The efficacy of iron fortification against IDA is uncertain in malaria-endemic settings. The objective of this study was to evaluate the efficacy of a complementary food (CF) fortified with sodium iron EDTA (NaFeEDTA) plus either ferrous fumarate (FeFum) or ferric pyrophosphate (FePP) to combat IDA in preschool-age children in a highly malaria endemic region. This is a secondary analysis of a nine-month cluster-randomized controlled trial conducted in south-central Côte d'Ivoire. 378 children aged 12-36 months were randomly assigned to no food intervention (n = 125; control group), CF fortified with 2 mg NaFeEDTA plus 3.8 mg FeFum for six days/week (n = 126; FeFum group), and CF fortified with 2 mg NaFeEDTA and 3.8 mg FePP for six days/week (n = 127; FePP group). The outcome measures were hemoglobin (Hb), plasma ferritin (PF), iron deficiency (PF < 30 µg/L), and anemia (Hb < 11.0 g/dL). Data were analyzed with random-effect models and PF was adjusted for inflammation. The prevalence of Plasmodium falciparum infection and inflammation during the study were 44-66%, and 57-76%, respectively. There was a significant time by treatment interaction on IDA (p = 0.028) and a borderline significant time by treatment interaction on iron deficiency with or without anemia (p = 0.068). IDA prevalence sharply decreased in the FeFum (32.8% to 1.2%, p < 0.001) and FePP group (23.6% to 3.4%, p < 0.001). However, there was no significant time by treatment interaction on Hb or total anemia. These data indicate that, despite the high endemicity of malaria and elevated inflammation biomarkers (C-reactive protein or α-1-acid-glycoprotein), IDA was markedly reduced by provision of iron fortified CF to preschool-age children for 9 months, with no significant differences between a combination of NaFeEDTA with FeFum or NaFeEDTA with FePP. However, there was no overall effect on anemia, suggesting most of the anemia in this setting is not due to ID. This trial is registered at clinicaltrials.gov (NCT01634945).


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Férricos/análise , Alimentos Fortificados/análise , Fenômenos Fisiológicos da Nutrição do Lactente , Ferro da Dieta/administração & dosagem , Malária Falciparum/complicações , Anemia Ferropriva/sangue , Pré-Escolar , Análise por Conglomerados , Côte d'Ivoire/epidemiologia , Difosfatos/administração & dosagem , Difosfatos/análise , Ácido Edético/administração & dosagem , Ácido Edético/análise , Doenças Endêmicas , Compostos Férricos/administração & dosagem , Ferritinas/sangue , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/análise , Hemoglobinas/análise , Humanos , Lactente , Absorção Intestinal , Ferro/administração & dosagem , Ferro/análise , Ferro da Dieta/farmacologia , Malária Falciparum/epidemiologia , Glycine max , Zea mays
10.
J Nutr ; 147(6): 1131-1137, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28424258

RESUMO

Background: Antenatal anemia is a risk factor for adverse maternal and fetal outcomes and is prevalent in sub-Saharan Africa. Less than half of antenatal anemia is considered responsive to iron; identifying women in need of iron may help target interventions. Iron absorption is governed by the iron-regulatory hormone hepcidin.Objective: We sought to characterize changes in hepcidin and its associations with indexes of iron stores, erythropoiesis, and inflammation at weeks 14, 20, and 30 of gestation and to assess hepcidin's diagnostic potential as an index of iron deficiency.Methods: We measured hemoglobin and serum hepcidin, ferritin, soluble transferrin receptor (sTfR), and C-reactive protein (CRP) at 14, 20, and 30 wk of gestation in a cohort of 395 Gambian women recruited to a randomized controlled trial. Associations with hepcidin were measured by using linear regression, and hepcidin's diagnostic test accuracy [area under the receiver operating characteristic curve (AUCROC), sensitivity, specificity, cutoffs] for iron deficiency at each time point was analyzed.Results: The prevalence of anemia increased from 34.6% at 14 wk of gestation to 50.0% at 20 wk. Hepcidin concentrations declined between study enrollment and 20 wk, whereas ferritin declined between 20 and 30 wk of gestation. The variations in hepcidin explained by ferritin, sTfR, and CRP declined over pregnancy. The AUCROC values for hepcidin to detect iron deficiency (defined as ferritin <15 µg/L) were 0.86, 0.83, and 0.84 at 14, 20, and 30 wk, respectively. Hepcidin was superior to hemoglobin and sTfR as an indicator of iron deficiency.Conclusions: In Gambian pregnant women, hepcidin appears to be a useful diagnostic test for iron deficiency and may enable the identification of cases for whom iron would be beneficial. Hepcidin suppression in the second trimester suggests a window for optimal timing for antenatal iron interventions. Hemoglobin does not effectively identify iron deficiency in pregnancy. This trial was registered at www.isrctn.com as ISRCTN49285450.


Assuntos
Anemia Ferropriva/diagnóstico , Hepcidinas/sangue , Deficiências de Ferro , Complicações na Gravidez/diagnóstico , Adulto , Anemia Ferropriva/sangue , Anemia Ferropriva/complicações , Anemia Ferropriva/epidemiologia , Área Sob a Curva , Proteína C-Reativa/metabolismo , Estudos de Coortes , Eritropoese , Feminino , Ferritinas/sangue , Gâmbia/epidemiologia , Idade Gestacional , Hemoglobinas/metabolismo , Humanos , Inflamação/sangue , Ferro/sangue , Estudos Longitudinais , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/epidemiologia , Prevalência , Curva ROC , Receptores da Transferrina/sangue , Sensibilidade e Especificidade , Adulto Jovem
11.
Nutr Rev ; 75(1): 49-60, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27974599

RESUMO

In light of evidence that high-dose iron supplements lead to a range of adverse events in low-income settings, the safety and efficacy of lower doses of iron provided through biological or industrial fortification of foodstuffs is reviewed. First, strategies for point-of-manufacture chemical fortification are compared with biofortification achieved through plant breeding. Recent insights into the mechanisms of human iron absorption and regulation, the mechanisms by which iron can promote malaria and bacterial infections, and the role of iron in modifying the gut microbiota are summarized. There is strong evidence that supplemental iron given in nonphysiological amounts can increase the risk of bacterial and protozoal infections (especially malaria), but the use of lower quantities of iron provided within a food matrix, ie, fortified food, should be safer in most cases and represents a more logical strategy for a sustained reduction of the risk of deficiency by providing the best balance of risk and benefits. Further research into iron compounds that would minimize the availability of unabsorbed iron to the gut microbiota is warranted.


Assuntos
Anemia Ferropriva/prevenção & controle , Dieta , Alimentos Fortificados , Ferro da Dieta/administração & dosagem , Ferro da Dieta/sangue , Anemia Ferropriva/dietoterapia , Anemia Ferropriva/tratamento farmacológico , Biofortificação , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Microbioma Gastrointestinal , Hepcidinas/sangue , Humanos , Ferro da Dieta/farmacocinética , Malária/sangue , Malária/prevenção & controle , Estado Nutricional , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
BMC Pediatr ; 16(1): 149, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27585745

RESUMO

BACKGROUND: Iron deficiency prevalence rates frequently exceed 50 % in young children in low-income countries. The World Health Organization (WHO) recommended universal supplementation of young children where anaemia rates are >40 %. However, large randomized trials have revealed that provision of iron to young children caused serious adverse effects because iron powerfully promotes microbial growth. Hepcidin - the master regulator of iron metabolism that integrates signals of infection and iron deficiency - offers the possibility of new solutions to diagnose and combat global iron deficiency. We aim to evaluate a hepcidin-screening-based iron supplementation intervention using hepcidin cut-offs designed to indicate that an individual requires iron, is safe to receive it and will absorb it. METHODS: The study is a proof-of-concept, three-arm, double blind, randomised controlled, prospective, parallel-group non-inferiority trial. Children will be randomised to receive, for a duration of 12 weeks, one of three multiple micronutrient powders (MNP) containing: A) 12 mg iron daily; B) 12 mg or 0 mg iron daily based on a weekly hepcidin screening indicating if iron can be given for the next seven days or not; C) 6 mg or 0 mg iron daily based on a weekly hepcidin screening indicating if iron can be given for the next seven days or not. The inclusion criteria are age 6-23 months, haemoglobin (Hb) concentration between 7 and 11 g/dL, z-scores for Height-for-Age, Weight-for-Age and Weight-for-Height > -3 SD and free of malaria. Hb concentration at 12 weeks will be used to test whether the screen-and-treat approaches are non-inferior to universal supplementation. Safety will be assessed using caregiver reports of infections, in vitro bacterial and P. falciparum growth assays and by determining the changes in the gut microbiota during the study period. DISCUSSION: A screen-and-treat approach using hepcidin has the potential to make iron administration safer in areas with widespread infections. If this proof-of-concept study shows promising results the development of a point-of-care diagnostic test will be the next step. TRIAL REGISTRATION: ISRCTN07210906 , 07/16/2014.


Assuntos
Anemia Ferropriva/diagnóstico , Anemia Ferropriva/tratamento farmacológico , Suplementos Nutricionais , Compostos Ferrosos/administração & dosagem , Hepcidinas/sangue , Micronutrientes/administração & dosagem , Serviços de Saúde Rural , Anemia Ferropriva/sangue , Biomarcadores/sangue , Protocolos Clínicos , Países em Desenvolvimento , Método Duplo-Cego , Feminino , Compostos Ferrosos/uso terapêutico , Seguimentos , Gâmbia , Hemoglobinas/metabolismo , Humanos , Lactente , Masculino , Programas de Rastreamento/métodos , Micronutrientes/uso terapêutico , Estudos Prospectivos , Saúde da População Rural
13.
BMC Pregnancy Childbirth ; 16(1): 157, 2016 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-27411564

RESUMO

BACKGROUND: Until recently, WHO recommended daily iron supplementation for all pregnant women (60 mg/d iron combined with 400ug/d folic acid) where anaemia rates exceeded 40 %. Recent studies indicate that this may pose a risk to pregnant women. Therefore, there is a need to explore screen-and-treat options to minimise iron exposure during pregnancy using an overall lower dosage of iron that would achieve equivalent results as being currently recommended by the WHO. However, there is a lack of agreement on how to best assess iron deficiency when infections are prevalent. Here, we test the use of hepcidin a peptide hormone and key regulator of iron metabolism, as a potential index for 'safe and ready to receive' iron. DESIGN/METHODS: This is a 3-arm randomised-controlled proof-of-concept trial. We will test the hypothesis that a screen-and-treat approach to iron supplementation using a pre-determined hepcidin cut-off value of <2.5 ng/ml will achieve similar efficacy in preventing iron deficiency and anaemia at a lower iron dose and hence will improve safety. A sample of 462 pregnant women in rural Gambia will be randomly assigned to receive: a) UNU/UNICEF/WHO international multiple micronutrient preparation (UNIMMAP) containing 60 mg/d iron (reference arm); b) UNIMMAP containing 60 mg/d iron but based on a weekly hepcidin screening indicating if iron can be given for the next 7 days or not; c) or UNIMMAP containing 30 mg/d iron as in (b) for 12 weeks in rural Gambia. The study will test if the screen-and-treat approach is non-inferior to the reference arm using the primary endpoint of haemoglobin levels at a non-inferiority margin of 0.5 g/dl. Secondary outcomes of adverse effects, compliance and the impact of iron supplementation on susceptibility to infections will also be assessed. DISCUSSION: This trial is expected to contribute towards minimising the exposure of pregnant women to iron that may not be needed and therefore potentially harmful. If the evidence in this study shows that the overall lower dosage of iron is non-inferior to 60 mg/day iron, this may help decrease side-effects, improve compliance and increase safety. The potential for the use of hepcidin for a simple point-of-care (PoC) diagnostic for when it is most safe and effective to give iron may improve maternal health outcomes. TRIAL REGISTRATION: ISRCTN21955180.


Assuntos
Anemia Ferropriva/terapia , Suplementos Nutricionais , Hepcidinas/sangue , Ferro/administração & dosagem , Complicações na Gravidez/terapia , Oligoelementos/administração & dosagem , Adulto , Anemia Ferropriva/sangue , Anemia Ferropriva/diagnóstico , Biomarcadores/sangue , Método Duplo-Cego , Feminino , Gâmbia , Humanos , Testes para Triagem do Soro Materno , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/diagnóstico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Resultado do Tratamento , Adulto Jovem
14.
Gut ; 65(12): 2007-2016, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26185161

RESUMO

BACKGROUND: The natural history of chronic HBV infection in sub-Saharan Africa is unknown. Data are required to inform WHO guidelines that are currently based on studies in Europe and Asia. METHODS: Between 1974 and 2008, serosurveys were repeated in two Gambian villages, and an open cohort of treatment-naive chronic HBV carriers was recruited. Participants were followed to estimate the rates of hepatitis B e (HBeAg) and surface antigen (HBsAg) clearance and incidence of hepatocellular carcinoma (HCC). In 2012-2013, a comprehensive liver assessment was conducted to estimate the prevalence of severe liver disease. RESULTS: 405 chronic carriers (95% genotype E), recruited at a median age of 10.8 years, were followed for a median length of 28.4 years. Annually, 7.4% (95% CI 6.3% to 8.8%) cleared HBeAg and 1.0% (0.8% to 1.2%) cleared HBsAg. The incidence of HCC was 55.5/100 000 carrier-years (95% CI 24.9 to 123.5). In the 2012-2013 survey (n=301), 5.5% (95% CI 3.4% to 9.0%) had significant liver fibrosis. HBV genotype A (versus E), chronic aflatoxin B1 exposure and an HBsAg-positive mother, a proxy for mother-to-infant transmission, were risk factors for liver fibrosis. A small proportion (16.0%) of chronic carriers were infected via mother-to-infant transmission; however, this population represented a large proportion (63.0%) of the cases requiring antiviral therapy. CONCLUSIONS: The incidence of HCC among chronic HBV carriers in West Africa was higher than that in Europe but lower than rates in East Asia. High risk of severe liver disease among the few who are infected by their mothers underlines the importance of interrupting perinatal transmission in sub-Saharan Africa.


Assuntos
Portador Sadio/epidemiologia , Antígenos de Superfície da Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/sangue , Hepatite B Crônica/epidemiologia , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Carcinoma Hepatocelular/epidemiologia , Criança , Feminino , Seguimentos , Gâmbia/epidemiologia , Hepatite B Crônica/transmissão , Humanos , Incidência , Lactente , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Gravidez , Prevalência , Fatores de Risco , Inquéritos e Questionários
15.
Sci Rep ; 5: 16670, 2015 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-26593732

RESUMO

Iron deficiency is the most common nutrient deficiency worldwide and routine supplementation is standard policy for pregnant mothers and children in most low-income countries. However, iron lies at the center of host-pathogen competition for nutritional resources and recent trials of iron administration in African and Asian children have resulted in significant excesses of serious adverse events including hospitalizations and deaths. Increased rates of malaria, respiratory infections, severe diarrhea and febrile illnesses of unknown origin have all been reported, but the mechanisms are unclear. We here investigated the ex vivo growth characteristics of exemplar sentinel bacteria in adult sera collected before and 4 h after oral supplementation with 2 mg/kg iron as ferrous sulfate. Escherichia coli, Yersinia enterocolitica and Salmonella enterica serovar Typhimurium (all gram-negative bacteria) and Staphylococcus epidermidis (gram-positive) showed markedly elevated growth in serum collected after iron supplementation. Growth rates were very strongly correlated with transferrin saturation (p < 0.0001 in all cases). Growth of Staphylococcus aureus, which preferentially scavenges heme iron, was unaffected. These data suggest that even modest oral supplements with highly soluble (non-physiological) iron, as typically used in low-income settings, could promote bacteremia by accelerating early phase bacterial growth prior to the induction of immune defenses.


Assuntos
Escherichia coli/efeitos dos fármacos , Compostos Ferrosos/administração & dosagem , Ferro/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos , Yersinia enterocolitica/efeitos dos fármacos , Administração Oral , Adulto , Meios de Cultura/farmacologia , Escherichia coli/crescimento & desenvolvimento , Voluntários Saudáveis , Humanos , Ferro/sangue , Masculino , Pessoa de Meia-Idade , Salmonella typhimurium/crescimento & desenvolvimento , Soro/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento , Transferrina/metabolismo , Transferrina/farmacologia , Yersinia enterocolitica/crescimento & desenvolvimento
16.
Malar J ; 14: 347, 2015 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-26377199

RESUMO

BACKGROUND: Iron deficiency (ID) and malaria co-exist in tropical regions and both contribute to high rates of anaemia in young children. It is unclear whether iron fortification combined with intermittent preventive treatment (IPT) of malaria would be an efficacious strategy for reducing anaemia in young children. METHODS: A 9-month cluster-randomised, single-blinded, placebo-controlled intervention trial was carried out in children aged 12-36 months in south-central Côte d'Ivoire, an area of intense and perennial malaria transmission. The study groups were: group 1: normal diet and IPT-placebo (n = 125); group 2: consumption of porridge, an iron-fortified complementary food (CF) with optimised composition providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferrous fumarate 6 days per week (CF-FeFum) and IPT-placebo (n = 126); group 3: IPT of malaria at 3-month intervals, using sulfadoxine-pyrimethamine and amodiaquine and no dietary intervention (n = 127); group 4: both CF-FeFum and IPT (n = 124); and group 5: consumption of porridge, an iron-fortified CF with the composition currently on the Ivorian market providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferric pyrophosphate 6 days per week (CF-FePP) and IPT-placebo (n = 127). The primary outcome was haemoglobin (Hb) concentration. Linear and logistic regression mixed-effect models were used for the comparison of the five study groups, and a 2 × 2 factorial analysis was used to assess treatment interactions of CF-FeFum and IPT (study groups 1-4). RESULTS: After 9 months, the Hb concentration increased in all groups to a similar extent with no statistically significant difference between groups. In the 2 × 2 factorial analysis after 9 months, no treatment interaction was found on Hb (P = 0.89). The adjusted differences in Hb were 0.24 g/dl (95 % CI -0.10 to 0.59; P = 0.16) in children receiving IPT and -0.08 g/dl (95 % CI -0.42 to 0.26; P = 0.65) in children receiving CF-FeFum. At baseline, anaemia (Hb <11.0 g/dl) was 82.1 %. After 9 months, IPT decreased the odds of anaemia (odds ratio [OR], 0.46 [95 % CI 0.23-0.91]; P = 0.023), whereas iron-fortified CF did not (OR, 0.85 [95 % CI 0.43-1.68]; P = 0.68), although ID (plasma ferritin <30 µg/l) was decreased markedly in children receiving iron fortified CF (OR, 0.19 [95 % CI 0.09-0.40]; P < 0.001). CONCLUSIONS: IPT alone only modestly decreased anaemia, but neither IPT nor iron fortified CF significantly improved Hb concentration after 9 months. Additionally, IPT did not augment the effect of the iron fortified CF. CF fortified with highly bioavailable iron improved iron status but not Hb concentration, despite three-monthly IPT of malaria. Thus, further research is necessary to develop effective combination strategies to prevent and treat anaemia in malaria endemic regions. TRIAL REGISTRATION: http://www.clinicaltrials.gov ; identifier NCT01634945; registered on July 3, 2012.


Assuntos
Anemia , Antimaláricos/uso terapêutico , Alimentos Fortificados , Ferro/uso terapêutico , Malária , Amodiaquina/administração & dosagem , Amodiaquina/uso terapêutico , Anemia/tratamento farmacológico , Anemia/epidemiologia , Anemia/prevenção & controle , Antimaláricos/administração & dosagem , Pré-Escolar , Côte d'Ivoire/epidemiologia , Difosfatos/administração & dosagem , Difosfatos/uso terapêutico , Combinação de Medicamentos , Ácido Edético/administração & dosagem , Ácido Edético/uso terapêutico , Compostos Férricos/administração & dosagem , Compostos Férricos/uso terapêutico , Hemoglobinas , Humanos , Lactente , Inflamação/epidemiologia , Ferro/administração & dosagem , Ferro/sangue , Deficiências de Ferro , Malária/tratamento farmacológico , Malária/epidemiologia , Malária/prevenção & controle , Masculino , Prevalência , Pirimetamina/administração & dosagem , Pirimetamina/uso terapêutico , Sulfadoxina/administração & dosagem , Sulfadoxina/uso terapêutico
17.
Am J Clin Nutr ; 101(3): 462-70, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25733630

RESUMO

BACKGROUND: In sub-Saharan Africa, parasitic diseases and low bioavailable iron intake are major causes of anemia. Anemia results from inflammation, preventing iron recycling and decreasing dietary iron absorption. Hookworm, Plasmodium, and Schistosoma infections contribute to anemia, but their influence on dietary iron absorption and recycling is unknown. OBJECTIVE: The objective was to measure inflammation biomarkers, hepcidin, iron absorption, and utilization pre- and posttreatment in children with afebrile malaria, hookworm, and Schistosoma haematobium infection. DESIGN: Ivorian children aged 11-17 y with afebrile Plasmodium falciparum (n = 17), hookworm (n = 16), or S. haematobium infection (n = 8) consumed a syrup containing 3 mg 57Fe as ferrous sulfate and received an intravenous infusion of 50 µg 58Fe as ferrous citrate. Children were treated for their respective infection, and the iron studies were repeated 4 wk later. Iron and inflammation biomarkers and hepcidin were measured. RESULTS: Geometric mean iron absorptions in the afebrile malaria and hookworm groups were 12.9% and 32.2% (P < 0.001) before treatment and 23.6% and 30.0% (P = 0.113) after treatment, respectively. Treatment of afebrile malaria reduced inflammation (P < 0.001) and serum hepcidin (P = 0.004) and improved iron absorption (P = 0.003). Treatment of hookworm infection neither affected inflammation biomarkers nor altered iron absorption. Similarly, there was a lack of treatment effects in the S. haematobium-infected group; however, the small sample size limits conclusions. Geometric mean iron utilization ranged between 79.1% and 88.0% in the afebrile malaria and hookworm groups with no significant differences pre- and posttreatment. CONCLUSIONS: In school-age children, hookworm infection does not produce inflammation or increase serum hepcidin, and it does not influence iron absorption or utilization. In contrast, afebrile malaria causes inflammation, increases hepcidin, and reduces iron absorption but not utilization. These findings provide insights into the iron metabolism and the etiology of anemia in parasitic infections.


Assuntos
Anemia Ferropriva/etiologia , Regulação para Baixo , Infecções por Uncinaria/metabolismo , Absorção Intestinal , Mucosa Intestinal/metabolismo , Ferro da Dieta/metabolismo , Malária Falciparum/metabolismo , Adolescente , Anemia Ferropriva/prevenção & controle , Animais , Anti-Helmínticos/uso terapêutico , Antimaláricos/uso terapêutico , Biomarcadores/sangue , Criança , Estudos de Coortes , Côte d'Ivoire , Regulação para Baixo/efeitos dos fármacos , Feminino , Hepcidinas/sangue , Infecções por Uncinaria/tratamento farmacológico , Infecções por Uncinaria/imunologia , Infecções por Uncinaria/fisiopatologia , Humanos , Mediadores da Inflamação/sangue , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/parasitologia , Isótopos de Ferro , Malária Falciparum/tratamento farmacológico , Malária Falciparum/imunologia , Malária Falciparum/fisiopatologia , Masculino , Esquistossomose Urinária/tratamento farmacológico , Esquistossomose Urinária/imunologia , Esquistossomose Urinária/metabolismo , Esquistossomose Urinária/fisiopatologia
18.
Malar J ; 13: 397, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25301296

RESUMO

BACKGROUND: In sub-Saharan Africa, children with Plasmodium falciparum malaria and anaemia are often given iron supplementation at the time of malaria treatment. Inflammation during and after malaria may decrease iron absorption, thus, absorption might be improved if the start of supplementation is delayed. The study objective was to measure iron absorption from iron supplements started immediately or delayed by two weeks after completion of therapy against uncomplicated P. falciparum malaria. METHODS: Malawian toddlers (n=48; age 12-24 months) were alternatively assigned to two groups according to their appearance at the health centre: group A was provided iron supplements (30 mg Fe daily) as a FeSO4-containing syrup for eight weeks starting immediately after malarial treatment; group B was given the iron after a two-week delay. Iron absorption from the syrup was measured on the first day of iron supplementation, and after two and eight weeks in both groups. Haemoglobin (Hb), iron status and inflammation were assessed every two weeks. Fractional iron absorption at each time point and cumulative absorption was quantified by measuring erythrocyte incorporation of 57Fe and compared using mixed models. RESULTS: Comparing group A and B, geometric mean iron absorption did not differ on the first day of supplementation (9.0% vs. 11.4%, P=0.213) and cumulative iron absorption from the three time points did not differ (6.0% vs. 7.2%, P=0.124). Hb concentration increased in both groups two weeks after malaria treatment (P<0.001) and did not differ after eight weeks of supplementation (P=0.542). CONCLUSIONS: In anaemic toddlers after uncomplicated malaria, a two-week delay in starting iron supplementation did not significantly increase iron absorption or Hb concentration. Iron absorption is sufficiently high in the immediate post-malaria period to warrant supplementation. These findings suggest there is no need to change the current practice of immediate iron supplementation in this setting. TRIAL REGISTRATION: This trial was registered at Pan African Clinical Trials Registry (pactr.org) as PACTR2010050002141682.


Assuntos
Anemia/tratamento farmacológico , Anemia/etiologia , Hemoglobinas/análise , Ferro/metabolismo , Ferro/uso terapêutico , Malária Falciparum/complicações , Anemia/epidemiologia , Antimaláricos/uso terapêutico , Feminino , Humanos , Lactente , Inflamação , Ferro/administração & dosagem , Estudos Longitudinais , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malaui/epidemiologia , Masculino
19.
J Nutr ; 144(11): 1703-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25332469

RESUMO

BACKGROUND: Calcium inhibits and ascorbic acid (AA) enhances iron absorption from iron-fortified foods. Absorption efficiency depends on iron status, although the interaction is unclear. OBJECTIVE: We investigated the ability of AA to overcome calcium-induced inhibition of iron absorption in children differing in iron status. METHODS: The effect of calcium (0, 100, and 200 mg/test meal) on iron absorption in the absence and presence of AA (0, 42.5, and 85 mg/test meal) from a casein/whey-based drink fortified with ferrous sulfate was assessed in a series of randomized crossover studies both in iron-replete (IR) Indian schoolchildren and in children with iron deficiency anemia (IDA) (6-11 y; n = 14-16/group) by using stable isotopes. RESULTS: In the absence of calcium and AA, iron absorption from the casein/whey-based drink was 20% lower in IR children than in children with IDA. The addition of calcium reduced mean iron absorption by 18-27%, with the effect being stronger for high added calcium (P < 0.01). AA at a 2:1 or 4:1 molar ratio enhanced iron absorption by a factor of 2-4 and greatly overcompensated for the inhibitory effect of calcium on iron absorption in a dose-dependent manner (P < 0.001). The dose-response effect tended to be stronger (P < 0.1) in the IDA group, and iron status was of far less influence on iron absorption than the enhancing effect of AA. CONCLUSION: When adding AA to iron-fortified milk products, care should be taken not to provide absorbable iron in excess of needs.


Assuntos
Ácido Ascórbico/farmacocinética , Bebidas/análise , Cálcio/farmacocinética , Caseínas/química , Ferro/metabolismo , Proteínas do Leite/química , Ácido Ascórbico/química , Criança , Fenômenos Fisiológicos da Nutrição Infantil , Estudos Cross-Over , Suplementos Nutricionais , Interações Medicamentosas , Feminino , Humanos , Índia , Ferro/farmacocinética , Masculino , Proteínas do Soro do Leite
20.
J Nutr ; 144(9): 1467-73, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24966411

RESUMO

Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P < 0.001). Adding Na2EDTA at an EDTA:zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P < 0.02). The combined inhibitory effect of polyphenols and PA was overcome by EDTA. In conclusion, ZnSO4 was better absorbed than ZnO, phytase used to degrade PA during digestion or during food preparation substantially increased zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.


Assuntos
6-Fitase/farmacologia , Ácido Edético/farmacologia , Grão Comestível/química , Alimentos Fortificados , Ácido Fítico/farmacologia , Polifenóis/farmacologia , Zinco/metabolismo , Adulto , Disponibilidade Biológica , Feminino , Humanos , Absorção Intestinal , Ferro/metabolismo , Compostos de Ferro/metabolismo , Ferro da Dieta/metabolismo , Masculino , Sorghum/química , Adulto Jovem , Zea mays/química , Óxido de Zinco/metabolismo , Sulfato de Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA