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BACKGROUND/OBJECTIVE: To assess the effects of micronutrient supplementation on head circumference of rural Nepali infants and children. SUBJECTS/METHODS: We used a randomized controlled trial to assess the effects of micronutrient supplementation on head circumference in 569 rural Nepali infants and children aged 4-17 months. Children were randomized to: (1) zinc, (2) iron-folic acid, (3) zinc plus iron-folic acid or (4) a placebo group. Data on head circumference were collected during five visits at â¼3 month intervals over the course of a year. We calculated change in head circumference in treatment groups receiving zinc and iron comparing the first and fifth visits as well as used generalized estimating equations (GEE) to take advantage of data from all points in time. Models were adjusted for covariates unbalanced in the randomization and for baseline head circumference. RESULTS: Estimating differences in head circumference between baseline and visit 5, children in the zinc treatment group showed smaller decreases in head circumference z-score compared with placebo (adjusted ß=0.13, 95% confidence interval (CI): 0.03 to 0.23). Using GEE, zinc treatment was associated with 0.11 (95% CI: 0.05 to 0.17) decrease in the rate of decline in head circumference z-score across visits as compared with placebo. Iron-folic acid supplementation was not associated with head circumference z-scores when comparing visits 1 with 5 or including data across all visits in adjusted models. CONCLUSION: Our results suggest that zinc supplementation confers a beneficial effect on the rate of head growth in Nepali infants.
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Suplementos Dietéticos , Ácido Fólico/farmacología , Cabeza/crecimiento & desarrollo , Hierro de la Dieta/farmacología , Hierro/farmacología , Micronutrientes/farmacología , Zinc/farmacología , Desarrollo Infantil/efectos de los fármacos , Intervalos de Confianza , Femenino , Humanos , Lactante , Masculino , Desnutrición/complicaciones , Nepal , Población RuralRESUMEN
Hepcidin is a peptide produced by hepatocytes and detectable in blood and urine. Urinary hepcidin excretion appeared to be significantly increasing in humans with acute and chronic infections or inflammatory diseases. However, the effects of common tropical parasitic infections on hepcidin have not been sufficiently examined. We carried out a study in school children from Mali living in a neighborhood where Plasmodium falciparum malaria and Schistosoma haematobium infections are prevalent. Anemia (hemoglobin < 120 g/l) prevalence was very high among these children (68%); 24% had iron deficiency anemia. The prevalence of infections was also high (65% had at least one infection and 41% had C-reactive protein (CRP) levels > 10 mg/L). S. haematobium was diagnosed in 64%. We assessed first morning urine hepcidin excretion in a sub-sample of 15 children with either S. haematobium, P. falciparum malaria or none; 14 of these 15 children were included in the analyses. Children with P. falciparum malaria excreted significantly higher levels of hepcidin than those with S. haematobium (chi2 = 3.86; p = 0.05) or without any infection (chi2 = 5.95; p = 0.01). Urinary hepcidin correlated significantly with CRP (Spearman's r = 0.59; p = 0.001) and serum ferritin (Spearman's r = 0.73; p = 0.003). Our study confirms the still limited evidence of an association between human malaria and increased urinary hepcidin and points out the need for further studies to define the contribution of hepcidin to anemia associated with this disease.
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Anemia/etiología , Péptidos Catiónicos Antimicrobianos/orina , Malaria Falciparum/complicaciones , Anemia/epidemiología , Anemia/orina , Anemia Ferropénica/epidemiología , Anemia Ferropénica/etiología , Anemia Ferropénica/orina , Péptidos Catiónicos Antimicrobianos/fisiología , Proteína C-Reactiva/análisis , Niño , Estudios Transversales , Enfermedades Endémicas , Femenino , Hepcidinas , Humanos , Absorción Intestinal/fisiología , Hierro de la Dieta/farmacocinética , Hígado/metabolismo , Hígado/parasitología , Malaria Falciparum/sangre , Malaria Falciparum/epidemiología , Malaria Falciparum/orina , Masculino , Malí/epidemiología , Modelos Biológicos , Prevalencia , Esquistosomiasis Urinaria/sangre , Esquistosomiasis Urinaria/complicaciones , Esquistosomiasis Urinaria/epidemiología , Esquistosomiasis Urinaria/orinaRESUMEN
OBJECTIVES: The relationship between Fe status and HIV infection is complex and poorly understood. While anaemia is a major complication of HIV infection, higher Fe stores may be associated with disease progression. There is limited and conflicting data available from Africa. DESIGN: Cross-sectional and prospective cohort study. SETTING, SUBJECTS AND METHODS: We examined the association between postpartum Fe status (Hb, serum ferritin (SF) and transferrin receptor (TfR)) and viral load (VL) and HIV-related mortality in 643 HIV-positive Zimbabwean women over a period of 12 months. RESULTS: In non-anaemic women a log10 increase in SF was associated with a 2.3-fold increase in VL (P = 0.019); this association was absent in anaemic women. In prospective analyses, a log10 increase in SF was associated with a 4-fold increase in mortality by 12 months (P = 0.002). Hb was negatively associated with VL (P = 0.001) and mortality (P = 0.047). The adverse associations between SF and both VL and mortality were found at SF concentrations > 45 microg/l (P < 0.05). Controlling for alpha1 acid glycoprotein, a marker of inflammation, attenuated the association between both SF and VL and mortality, but these remained significant. CONCLUSIONS: These results are consistent with the hypothesis that high Fe stores have adverse consequences in HIV infection. If adverse consequences are real, our data suggest that they occur at SF concentrations exceeding those consistent with adequate Fe nutriture.
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Ferritinas/sangre , Infecciones por VIH/sangre , Infecciones por VIH/mortalidad , Hierro/metabolismo , Carga Viral , Adulto , Estudios de Cohortes , Estudios Transversales , Femenino , Hemoglobinas/metabolismo , Humanos , Deficiencias de Hierro , Estimación de Kaplan-Meier , Estado Nutricional , Periodo Posparto , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Oligoelementos/deficiencia , Oligoelementos/metabolismo , ZimbabweRESUMEN
OBJECTIVES: The acute phase response (APR) influences indicators of iron status. A recent WHO/CDC consultation recommended concurrent measurement of alpha-1-acid-glycoprotein (AGP) in surveys to control for the APR, and aid in interpreting iron status. They proposed further exploratory analyses using AGP. We examined whether the APR (measured by AGP) influences the expected relationships between iron status indicators in an HIV-infected population. SUBJECTS: We measured hemoglobin (Hb), serum ferritin (SF), transferrin receptor (TfR), erythropoietin (EPO) and AGP in a cross-sectional survey of 643 HIV-positive Zimbabwean women. RESULTS: SF was significantly higher in APR-positive (AGP>1 g/l) women (P<0.001), in whom there was no association between SF and Hb. TfR was inversely associated with Hb, in both APR-positive and APR-negative women (P<0.001). However, among anemic women (Hb<110 g/l), APR-positive women had marginally lower TfR concentrations (P=0.053). There was no difference in EPO response to decreasing Hb among APR-positive and APR-negative women. CONCLUSIONS: AGP captured the influence of the APR on iron indicators and their relationships with each other. The APR influenced SF and its relationship with Hb as expected. TfR behaved unexpectedly. Although TfR has been promoted as an iron indicator that is uninfluenced by the APR, TfR concentrations were depressed among anemic APR-positive women. Because TfR reflects iron deficiency and erythropoietic activity, pro-inflammatory cytokines associated with the APR may be inhibiting erythropoiesis, which is reflected by lower TfR concentrations. We support the WHO/CDC recommendation that AGP is a useful indicator to assess the influence of the APR on iron status indicators.
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Anemia Ferropénica/complicaciones , Ferritinas/sangre , Seropositividad para VIH/complicaciones , Inflamación/complicaciones , Orosomucoide/metabolismo , Receptores de Transferrina/sangre , Estudios Transversales , Femenino , Seropositividad para VIH/sangre , Hemoglobinas/metabolismo , Humanos , Periodo Posparto , ZimbabweRESUMEN
OBJECTIVE: To accurately measure blood loss during childbirth in a developing country. METHOD: The alkaline hematin technique was used to quantify blood lost during delivery and 24 h postpartum in 158 women in Pemba Island, Zanzibar. RESULT: Women were found to lose less blood during childbirth and 24 h postpartum than previously reported. Compared with laboratory values, nurse-midwives approximated blood loss accurately (mean difference, i.e., mean underestimation by nurse-midwives, 4.90 mL); however, their imprecision was greater for higher laboratory values. CONCLUSION: This study may prompt further investigation, as no comparable data exist for developing countries where maternal mortality is high and severe anemia prevalent.
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Hemina/análisis , Tercer Periodo del Trabajo de Parto/sangre , Parto/sangre , Hemorragia Posparto/sangre , Adolescente , Adulto , Parto Obstétrico , Países en Desarrollo , Femenino , Humanos , Embarazo , TanzaníaRESUMEN
The implications of delta-aminolevulinic acid dehydratase (ALAD) polymorphism for lead kinetics and toxicity have been mainly studied in occupationally exposed adults. Therefore, our purpose was to evaluate the distribution of ALAD genotype and its association with biomarkers of exposure (PbB levels) and effect (Blood ZPP) among children living in a smelter community in Mexico. We recruited 569 children from nine elementary schools close to a smelter site. PbB was determined by electrothermal atomic absorption spectrometry. A polymerase chain reaction (PCR)-based protocol was used for ALAD genotyping. Zinc protoporphyrin (ZPP) in blood was measured by direct fluorometry. Most children (93.15%) were homozygous for ALAD (1-1), 6.67% were heterozygous for ALAD for (1-2), and one child was homozygous for ALAD (2-2). There was an increased proportion of ALAD (1-2/2-2) genotype with respect to PbB levels. The ZPP geometric mean was slightly higher in ALAD (1-1) genotype children (63.48 mu mol ZPP/mol Hb) than in those having the ALAD-2 genotype (58.22 mu mol ZPP/mol Hb; p = 0.051). Linear and quadratic models showed significant relationships between ZPP and PbB. A significant increase in the odds ratio (OR) for the effect of lead exposure on ZPP levels was observed for ALAD (1-1) children having PbB values above 20 mu g/dL, as compared to those having PbB levels below 10 mu g/dL (OR = 2.95, 95% CI = 1.45-5.97; p = 0.003), whereas no significant increases were observed for the ALAD (1-2/2-2) children. In summary, our results suggest that heme biosynthesis was less affected in ALAD (1-2/2-2) lead-exposed children than in those carrying the ALAD (1-1) genotype.
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OBJECTIVE: To describe the distribution of hemoglobin and prevalence of anemia in Nepali children living in the Terai region by potential risk factors for deficiency. DESIGN: This was a cross-sectional, community-based study of baseline characteristics of children enrolled in a randomized, placebo-controlled clinical trial between January and March 2002. Participants were weighed and measured and had their blood drawn. Their mothers contributed demographic, morbidity, and feeding data. SUBJECTS: There were 569 4- to 17-month-old children. Statistical models were based on 490 children. RESULTS: Anemia was prevalent: 58% of the children had a hemoglobin <105 g/l. Iron-deficiency anemia (anemia with erythrocyte protoporphyrin (EP) > or =90 micromol/mol heme) was present in 43% of the children. Severe anemia was rare: less than 2% of the children had a hemoglobin <70 g/l. The mean (s.d.) hemoglobin concentration was 101 (12.5) g/l. Stunting and wasting were prevalent: 30.8% were stunted (length-for-age Z-score <-2) and 18.1% were wasted (weight-for-length Z-score <-2). Bivariate analyses revealed that age, caste, socioeconomic status, dietary diversity, stunting, and underweight were associated with hemoglobin concentration and/or anemia. In multivariate models with and without EP, age and caste were found to be strong predictors of both hemoglobin concentration and anemia. CONCLUSIONS: Anemia and iron deficiency increased strongly with age and low-caste status among the study children. The data reveal the importance of targeting interventions to children in the first year of life before they become anemic and iron deficient.
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Anemia Ferropénica/epidemiología , Anemia/epidemiología , Hemoglobinas/análisis , Fenómenos Fisiológicos Nutricionales del Lactante , Clase Social , Factores de Edad , Anemia/sangre , Anemia Ferropénica/sangre , Estudios Transversales , Femenino , Humanos , Recién Nacido , Masculino , Análisis Multivariante , Nepal/epidemiología , Prevalencia , Factores de RiesgoRESUMEN
OBJECTIVE: To measure the effects of iron supplementation and anthelmintic treatment on iron status, anaemia, growth, morbidity, and development of children aged 6-59 months. DESIGN: Double blind, placebo controlled randomised factorial trial of iron supplementation and anthelmintic treatment. SETTING: Community in Pemba Island, Zanzibar. PARTICIPANTS: 614 preschool children aged 6-59 months. MAIN OUTCOME MEASURES: Development of language and motor skills assessed by parental interview before and after treatment in age appropriate subgroups. RESULTS: Before intervention, anaemia was prevalent and severe, and geohelminth infections were prevalent and light-Plasmodium falciparum infection was nearly universal. Iron supplementation significantly improved iron status, but not haemoglobin status. Iron supplementation improved language development by 0.8 (95% confidence interval 0.2 to 1.4) points on the 20 point scale. Iron supplementation also improved motor development, but this effect was modified by baseline haemoglobin concentrations (P=0.015 for interaction term) and was apparent only in children with baseline haemoglobin concentrations <90 g/l. In children with a baseline haemoglobin concentration of 68 g/l (one standard deviation below the mean value), iron treatment increased scores by 1.1 (0.1 to 2.1) points on the 18 point motor scale. Mebendazole significantly reduced the number and severity of infections caused by Ascaris lumbricoides and Trichuris trichiura, but not by hookworms. Mebendazole increased development scores by 0.4 (-0.3 to 1.1) points on the motor scale and 0.3 (-0.3 to 0.9) points on the language scale. CONCLUSIONS: Iron supplementation improved motor and language development of preschool children in rural Africa. The effects of iron on motor development were limited to children with more severe anaemia (baseline haemoglobin concentration <90 g/l). Mebendazole had a positive effect on motor and language development, but this was not statistically significant.
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Antihelmínticos/uso terapéutico , Discapacidades del Desarrollo/prevención & control , Hierro/uso terapéutico , Desarrollo del Lenguaje , Destreza Motora/efectos de los fármacos , Anemia Ferropénica/tratamiento farmacológico , Anemia Ferropénica/psicología , Antropometría , Preescolar , Discapacidades del Desarrollo/etiología , Método Doble Ciego , Femenino , Estudios de Seguimiento , Trastornos del Crecimiento/etiología , Helmintiasis/tratamiento farmacológico , Helmintiasis/psicología , Humanos , Lactante , Masculino , Mebendazol/uso terapéuticoRESUMEN
This paper provides summary judgments about the strength of the evidence that iron deficiency or anemia causes the six functional outcomes that were reviewed in the preceding papers, highlights priority research needs and discusses the implications of these conclusions for advocacy and programs. A significant body of evidence supports a causal relationship between iron deficiency and deficits in work productivity and child development, and between severe anemia and maternal and child mortality. Causal evidence is lacking or contradictory for iron deficiency and low birth weight and infectious disease, and for mild-to-moderate anemia and child or maternal mortality. Future research is required to expand or refine these conclusions. In the meantime, advocacy should focus on the outcomes supported by substantial causal evidence. These causal relationships can be separated into a problem of severe anemia (which causes mortality) and tissue iron deficiency (which causes deficits in work performance and child development). The simple model depicting severe anemia and tissue iron deficiency as distinct but overlapping entities with distinct functional outcomes is presented and may be useful in designing and evaluating programs.
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Anemia Ferropénica/complicaciones , Deficiencias de Hierro , Anemia Ferropénica/epidemiología , Anemia Ferropénica/fisiopatología , Discapacidades del Desarrollo/etiología , Eficiencia , Femenino , Humanos , Mortalidad Infantil , Recién Nacido de Bajo Peso , Recién Nacido , Mortalidad Materna , InvestigaciónRESUMEN
Anemia and iron deficiency during pregnancy are prevalent in developing countries, but their causes are not always known. We assessed the prevalence and severity of anemia and iron deficiency and their association with helminths, malaria and vitamin A deficiency in a community-based sample of 336 pregnant women in the plains of Nepal. Hemoglobin, erythrocyte protoporphyrin (EP) and serum ferritin were assessed in venous blood samples. Overall, 72.6% of women were anemic (hemoglobin < 110 g/L), 19.9% had moderate to severe anemia (hemoglobin < 90 g/L) and 80.6% had iron deficiency (EP > 70 micromol/mol heme or serum ferritin < 10 microg/L). Eighty-eight percent of cases of anemia were associated with iron deficiency. More than half of the women (54.2%) had a low serum retinol concentration (<1.05 micromol/L), 74.2% were infected with hookworms and 19.8% had Plasmodium vivax malaria parasitemia. Hemoglobin, EP and serum ferritin concentrations were significantly worse and the prevalence of anemia, elevated EP and low serum ferritin was increased with increasing intensity of hookworm infection. Hookworm infection intensity was the strongest predictor of iron status, especially of depleted iron stores. Low serum retinol was most strongly associated with mild anemia, whereas P. vivax malaria and hookworm infection intensity were stronger predictors of moderate to severe anemia. These findings reinforce the need for programs to consider reducing the prevalence of hookworm, malaria infection and vitamin A deficiency where indicated, in addition to providing iron supplements to effectively control anemia.
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Anemia/etiología , Infecciones por Uncinaria/complicaciones , Deficiencias de Hierro , Malaria Vivax/complicaciones , Complicaciones del Embarazo , Deficiencia de Vitamina A/complicaciones , Adolescente , Adulto , Anemia/epidemiología , Eritrocitos/química , Femenino , Ferritinas/sangre , Hemoglobinas/análisis , Humanos , Modelos Logísticos , Nepal/epidemiología , Paridad , Embarazo , Protoporfirinas/sangre , Factores de Riesgo , Grosor de los Pliegues Cutáneos , Vitamina A/sangreRESUMEN
In Zanzibar and other tropical regions, iron deficiency, malaria and multiple helminth infections coexist. We addressed the following questions: 1) What are the predictors of low hemoglobin in Zanzibari preschool children? 2) Are indicators of iron status informative in this population? 3) Does malaria modify the relation of iron indicators to hemoglobin? We used multivariate regression to analyze cross-sectional data from a community-based sample of rural Zanzibari children who were not ill (n = 490; 4-71 mo of age) in whom we assessed hemoglobin, serum ferritin (SF), erythrocyte protoporphyrin (EP), serum transferrin receptor (TfR), recent fever, malaria parasitemia and helminth fecal egg counts. Of hemoglobin values, 80% were <100 g/L and 15.5% were <70 g/L. In children <18 mo of age, 40.2% of hemoglobin values were <70 g/L. Our primary findings were as follows: 1) In children <30 mo old, hemoglobin was associated with malaria but not hookworms, whereas in children >/=30 mo, hemoglobin was related to hookworms but not malaria. In the younger age group, male sex and recent fever also predicted lower hemoglobin. 2) The three iron indicators were informative in this population but did not reflect only iron status. Malaria elevated SF in younger children and TfR and EP in both age groups. Fever elevated SF in older children and EP in both age groups, but not TfR. 3) Malaria modified the relation of all three indicators to hemoglobin. The relation of SF to hemoglobin was weak overall, and absent in malaria-infected children. EP and TfR were strongly related to hemoglobin, but this relation was attenuated by malaria.
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Anemia/complicaciones , Fiebre/complicaciones , Infecciones por Uncinaria/complicaciones , Hierro/fisiología , Malaria/complicaciones , Factores de Edad , Anemia/inmunología , Animales , Biomarcadores , Preescolar , Eritrocitos/química , Femenino , Fiebre/inmunología , Hemoglobinas/análisis , Infecciones por Uncinaria/inmunología , Humanos , Lactante , Recién Nacido , Malaria/inmunología , Masculino , Estado Nutricional , Protoporfirinas/sangre , Receptores de Transferrina/sangre , TanzaníaRESUMEN
The objective of this study was to evaluate the performance of the Haemoglobin Colour Scale, developed by Stott and Lewis, to diagnose anaemia in a primary health care setting where anaemia was prevalent and severe. Three measures of anaemia were compared in 535 preschool children: haemoglobin based on the Haemoglobin Colour Scale, clinical assessment in three sites (conjunctiva, palm and nail bed) and haemoglobin based on a digital haemoglobinometer (HemoCue method) taken as gold standard. A statistically significant correlation (r = 0.80, coefficient = 0.77 and Y intercept = 2.33) was obtained between the results of the Haemoglobin Colour Scale and the HemoCue. In more than 80% of cases, the difference between the colour scale readings and the results of the HemoCue was within 1 g/dl. Of 415 anaemic children (Hb < 11 g/dl by HemoCue), 85.2% were so identified by the Haemoglobin Colour Scale and 19.7% were classified anaemic by clinical pallor. Of 19 severely anaemic children (Hb < 7 g/dl by HemoCue), 73.6% were identified as severely anaemic and 100% were classified as anaemic by the colour scale, 61.1% were classified as anaemic using clinical pallor. We found the Haemoglobin Colour Scale to be a useful tool in identifying anaemic and severely anaemic children. Efficiencies in term of cost, accuracy and time make it an important resource in primary health care settings in developing countries. Further testing with other staff in other settings is recommended to determine the usefulness of large-scale distribution.
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Anemia/diagnóstico , Hemoglobinas/análisis , Niño , Preescolar , Color , Estudios de Evaluación como Asunto , Femenino , Humanos , Modelos Lineales , Masculino , Palidez/diagnóstico , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Distribución por SexoRESUMEN
BACKGROUND: Conflicting results have been reported regarding the relative performance of serum retinol, the modified-relative-dose-response (MRDR) ratio, and breast-milk vitamin A concentrations in detecting changes in maternal vitamin A status. OBJECTIVE: We used receiver operating characteristic analyses and standardized differences to compare the ability of these indicators to detect a response to postpartum vitamin A supplementation in lactating Bangladeshi women. DESIGN: At 2 wk postpartum, women were randomly assigned to receive either a single dose of vitamin A [200000 IU (60000 retinol equivalents); n = 74] or placebo (n = 73). Data from maternal serum and breast milk collected 3 mo postpartum and from infant serum collected 6 mo postpartum were used to examine the ability of serum retinol, the MRDR ratio, and breast-milk vitamin A to discriminate between individuals in the supplemented and unsupplemented groups. Breast milk was collected by expressing the entire contents of one breast that had not been used to feed an infant for > or =2 h (full samples) or without controlling the time since the last breast-feeding episode (casual samples). RESULTS: Casual breast-milk samples performed better than full breast-milk samples in detecting a response to maternal supplementation. The MRDR ratio performed better than serum retinol in both the women and their infants. Overall, the most responsive indicator was the measurement of breast-milk vitamin A per gram of fat in casual breast-milk samples. CONCLUSIONS: Breast-milk vitamin A and the MRDR ratio are responsive indicators of vitamin A status, especially in women with mild vitamin A deficiency.
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Suplementos Dietéticos , Leche Humana/química , Periodo Posparto , Vitamina A/sangre , Adulto , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Lactancia , Estado Nutricional , Placebos , Vitamina A/administración & dosificación , Vitamina A/análisis , Deficiencia de Vitamina A/tratamiento farmacológicoRESUMEN
BACKGROUND: Vitamin A deficiency is associated with stunting and wasting in preschool children, but vitamin A supplementation trials have not shown a consistent effect on growth. OBJECTIVE: We examined the effect of vitamin A supplementation on height and weight increments among Indonesian preschool children. DESIGN: Data were obtained from a randomized, double-masked, placebo-controlled trial of rural Javanese children aged 6-48 mo. Children received 206000 IU vitamin A (103000 IU if aged <12 mo) or placebo every 4 mo. RESULTS: High-dose vitamin A supplementation modestly improved the linear growth of the children by 0.16 cm/4 mo. The effect was modified by age, initial vitamin A status, and breast-feeding status. Vitamin A supplementation improved height by 0.10 cm/4 mo in children aged <24 mo and by 0.22 cm/4 mo in children aged >/=24 mo. The vitamin A-supplemented children with an initial serum retinol concentration <0.35 micromol/L gained 0.39 cm/4 mo more in height and 152 g/4 mo more in weight than did the placebo group. No growth response to vitamin A was found among children with an initial serum retinol concentration >/=0.35 micromol/L. In non-breast-fed children, vitamin A supplementation improved height by 0.21 cm/4 mo regardless of age. In breast-fed children, vitamin A supplementation improved linear growth by approximately 0.21 cm/4 mo among children aged >/=24 mo, but had no significant effect on the growth of children aged <24 mo. CONCLUSION: High-dose vitamin A supplementation improves the linear growth of children with very low serum retinol and the effect is modified by age and breast-feeding.
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Suplementos Dietéticos , Crecimiento/efectos de los fármacos , Vitamina A/farmacología , Factores de Edad , Estatura/efectos de los fármacos , Estatura/etnología , Peso Corporal/efectos de los fármacos , Lactancia Materna , Preescolar , Femenino , Humanos , Indonesia , Lactante , Masculino , Vitamina A/administración & dosificación , Vitamina A/sangreRESUMEN
BACKGROUND: Studies on the effect of vitamin A supplementation on growth have yielded various results. It is possible that such growth is dependent on the burden of infectious diseases in the population. METHODS: We analysed data from a randomized, double-masked, placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation. A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months, and 4430 child treatment cycles were used in this analysis. RESULTS: Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement (<400 RE/day). Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height than the placebo group, but those with > or =21.5% of days of respiratory infection did not show a significant growth response to vitamin A supplementation. Children who experienced no respiratory infection and had vitamin A intake <400 RE/day benefited most, gaining 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height compared to the placebo group. Diarrhoea was associated with poorer growth, but did not significantly modify the effect of vitamin A supplementation on growth. CONCLUSIONS: Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections.
PIP: This randomized, double-masked, placebo-controlled trial study examined the role of respiratory infections and diarrhea in modifying the growth response to vitamin A supplementation. A total of 1405 children aged 6-48 months were given a single high dose of vitamin A or placebo every 4 months, and 4430 child treatment cycles were used in this analysis. The study was conducted in two rural subdistricts located on the southern coast of central Java, Indonesia. Analytic findings indicate that vitamin A supplementation resulted in a modest improvement in the linear and not in the ponderal growth of children. Those who had an adequate intake of 400 RE/day and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height. Conversely, there were no significant growth responses to vitamin A supplementation among children with 21.5% of days or higher of respiratory infection. In addition, children who experienced no respiratory infection and had vitamin A intake below the normative requirement (400 RE/day) gained 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height than the placebo group. Moreover, diarrhea was associated with poorer growth but did not modify the effect of vitamin A supplementation on growth. In conclusion, vitamin A supplementation improves linear growth in children but not among those with a high prevalence of respiratory infections.
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Estatura/efectos de los fármacos , Diarrea/complicaciones , Trastornos del Crecimiento/prevención & control , Infecciones del Sistema Respiratorio/complicaciones , Vitamina A/administración & dosificación , Peso Corporal/efectos de los fármacos , Preescolar , Intervalos de Confianza , Diarrea/diagnóstico , Suplementos Dietéticos , Método Doble Ciego , Femenino , Trastornos del Crecimiento/complicaciones , Humanos , Lactante , Masculino , Valores de Referencia , Infecciones del Sistema Respiratorio/diagnóstico , Resultado del TratamientoRESUMEN
Clinical pallor is recommended as a simple way to detect severe anemia, but more data are needed on its accuracy and usefulness when assessed by nonphysicians in diverse settings. We measured hemoglobin and trained non-physician health workers to assess clinical pallor of the conjunctiva, palm and nail beds in five population samples in Nepal and Zanzibar, where severe anemia is common. In total, 5,760 individuals were examined, 3,072 of whom were anemic and 192 of whom had severe anemia (hemoglobin <70 g/L). The prevalence of pallor did not correspond to the prevalence of anemia or severe anemia in the groups studied. However, in all studies, pallor at each anatomical site was associated with a significantly lower hemoglobin concentration. The relative performance of different anatomical sites was not consistent among studies, and we recommend that multiple sites be assessed. Pallor at any of the three sites detected severe anemia with >84% specificity. However, the sensitivity varied from 81% in Nepalese postpartum women to 29% in Zanzibari preschoolers in 1996. Overall estimates for sensitivity and specificity were 50 and 92%, respectively. Although imperfect, use of pallor to screen and treat severe anemia by primary care providers is feasible and worthwhile where severe anemia is common. Usually, the majority of persons with severe anemia will be detected at practically no cost. Many people who are not severely anemic will also receive treatment, but the costs of this error are low compared to the benefits.
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Anemia/diagnóstico , Palidez/diagnóstico , Adolescente , Adulto , Anemia/sangre , Anemia/patología , Niño , Conjuntiva/patología , Femenino , Personal de Salud , Hemoglobinas/análisis , Hemoglobinas/normas , Humanos , Uñas/patología , Nepal , Palidez/sangre , Embarazo , TanzaníaRESUMEN
BACKGROUND: School-based deworming programmes have been promoted as a cost-effective strategy for control of nematode infection in developing countries. While numerous efficacy studies have been conducted, there is little information on actual programme effectiveness in areas of intense transmission. METHODS: A randomized trial of a school-based deworming programme was conducted in 12 primary schools on Pemba Island, Zanzibar. Four schools each were randomized to control, twice a year deworming with single dose mebendazole or three times a year deworming. Baseline and 12-month follow-up data on helminth infection using the Kato-Katz technique, demographic information and nutritional status were collected on 3028 children from March 1994 to May 1995. RESULTS: Intensity of infection measured as eggs per gram of faeces (epg) declined significantly for Ascaris lumbricoides, Trichuris trichiura and hookworm infections in both treatment groups. A. lumbricoides infection intensity declined 63.1% and 96.7% in the twice and three times per year treatment groups compared to the controls. T. trichiura infection intensity declined 40.4% and 75.9% respectively and hookworm intensity declined 35.3% and 57.2% respectively compared to control schools. CONCLUSIONS: These results suggest that school-based programmes can be a cost-effective approach for controlling the intensity of intestinal helminth infection even in environments where transmission is high.
Asunto(s)
Antinematodos/administración & dosificación , Ascariasis/tratamiento farmacológico , Ascaris lumbricoides , Infecciones por Uncinaria/tratamiento farmacológico , Mebendazol/administración & dosificación , Tricuriasis/tratamiento farmacológico , Animales , Ascariasis/epidemiología , Niño , Estudios de Evaluación como Asunto , Infecciones por Uncinaria/epidemiología , Humanos , Prevalencia , Estudios Prospectivos , Instituciones Académicas , Tanzanía/epidemiología , Tricuriasis/epidemiologíaRESUMEN
The effects of maternal postpartum vitamin A or beta-carotene supplementation on maternal and infant serum retinol concentrations, modified relative dose-response (MRDR) ratios and breast milk vitamin A concentrations were assessed during a community-based trial in Matlab, Bangladesh. At 1-3 wk postpartum, women were randomly assigned to receive either (1) a single dose of 200,000 international units [60,000 retinol equivalents (RE)] vitamin A followed by daily placebos (n = 74), (2) daily doses of beta-carotene [7.8 mg (1300 RE)] (n = 73) or (3) daily placebos (n = 73) until 9 mo postpartum. Compared to placebos, vitamin A supplementation resulted in lower maternal MRDR ratios (i.e., increased liver stores) and higher milk vitamin A concentrations at 3 mo, but these improvements were not sustained. The beta-carotene supplementation acted more slowly, resulting in milk vitamin A concentrations higher than the placebo group only at 9 mo. Irrespective of treatment group, over 50% of women produced milk with low vitamin A concentrations (=1.05 micromol/L or =0.28 micromol/g fat) throughout the study. Overall, mean maternal serum retinol concentrations were not affected by supplementation. Compared to the placebo group, the mean MRDR ratio of 6-mo-old infants was higher in the vitamin A group. Infants (33%) had serum retinol concentrations <0.70 micromol/L and 88% had MRDR ratios >/=0. 06. We conclude that while both interventions were beneficial, neither was sufficient to correct the underlying subclinical vitamin A deficiency in these women nor to bring their infants into adequate vitamin A status.
Asunto(s)
Suplementos Dietéticos , Lactancia , Vitamina A/administración & dosificación , beta Caroteno/administración & dosificación , Adulto , Bangladesh , Método Doble Ciego , Femenino , Humanos , Lactante , Masculino , Leche Humana/química , Estado Nutricional , Cooperación del Paciente , Placebos , Periodo Posparto , Vitamina A/análisis , Vitamina A/sangre , beta Caroteno/análisisRESUMEN
This paper addresses two questions: 1) What is the relation of hemoglobin in the second gestational month to preterm birth and low birth weight? 2) How does the relation differ when hemoglobin in the fifth or eighth month or the lowest pregnancy hemoglobin are examined in place of first trimester values? These relations were examined prospectively in 829 women from Shanghai, China in 1991-1992. The population was nearly homogeneous by race, parity, antenatal care, and smoking. Rates of birth outcomes were compared between hemoglobin categories based on 10 g/liter groupings, with 110-119 g/liter as the reference group. Rates of low birth weight and preterm birth (but not small-for-gestational age) were related to early pregnancy hemoglobin concentration in a U-shaped manner. The relative risks (95% confidence intervals) for preterm birth in women by g/liter of hemoglobin were 2.52 (0.95-6.64) for > or = 130 g/liter, 1.11 (0.41-2.99) for 120-129 g/liter, 1.64 (0.77-3.47) for 100-109 g/liter, 2.63 (1.17-5.90) for 90-99 g/liter, and 3.73 (1.36-10.23) for 60-89 g/liter. Use of hemoglobin values in the fifth or eighth month attenuated the association with preterm birth. When lowest pregnancy hemoglobin values were used, the association of anemia with both outcomes was obscured, and risk of preterm birth at high hemoglobin values increased dramatically.
PIP: The association of hemoglobin in the second gestational month with preterm birth and low birth weight (LBW), as well as the impact on this relationship of using hemoglobin values collected at times other than the second month, were investigated in a prospective observational study of 829 pregnant women from Shanghai, China, in 1991-92. Rates of LBW and preterm birth were related to early pregnancy hemoglobin concentrations in a U-shaped manner. The relative risks for preterm birth by g/l of hemoglobin were 2.52 (95% confidence interval (CI), 0.95-6.64) for 130 g/l and above, 1.11 (95% CI, 0.41-2.99) for 120-129 g/l, 1.64 (95% CI, 0.77-3.47) for 100-109 g/l, 2.63 (95% CI, 1.17-5.90) for 90-99 g/l, and 3.73 (95% CI, 1.36-10.23) for 60-89 g/l. Use of hemoglobin values in the 5th or 8th month of pregnancy attenuated the association with preterm birth. When the lowest pregnancy hemoglobin values were used, the association of anemia with both outcomes was obscured and the risk of preterm birth at high hemoglobin values increased markedly.