RESUMO

The objective of this study was to evaluate the benefit of screening for anemia in infants in relation to their previous diet. The iron status of 854 nine-month-old infants on three different feeding regimens and on a regimen including iron dextran injection was determined by analysis of hemoglobin, serum ferritin, and erythrocyte protoporphyrin levels and of serum transferrin saturation. Infants were categorized as having iron deficiency if two or three of the three biochemical test results were abnormal and as having iron deficiency anemia if, in addition, the hemoglobin level was less than 110 gm/L. The prevalence of iron deficiency was highest in infants fed cow milk formula without added iron (37.5%), intermediate in the group fed human milk (26.5%), much lower in those fed cow milk formula with added iron (8.0%), and virtually absent in those injected with iron dextran (1.3%). The corresponding values for iron deficiency anemia were 20.2%, 14.7%, 0.6%, and 0%, respectively. The use of iron supplements is therefore justified in infants fed cow milk formula without added iron, even when there is no biochemical evidence of iron deficiency. The low prevalence of iron deficiency in the group fed iron-fortified formula appears to make it unnecessary to screen routinely for anemia in such infants. These results also support the recommendation that infants who are exclusively fed human milk for 9 months need an additional source of iron after about 6 months of age.

PIP: The objective of this study was to evaluate the benefit of screening for anemia in infants in relation to their previous diet. The iron status of 854 9-month old infants on 3 different feeding regimens and on a regimen including iron dextran infection was determined by analysis of hemoglobin, serum ferritin, and erythrocyte protoporphyrin levels and of serum transferrin saturation. Infants were categorized as having iron deficiency if 2 or 3 of the 3 biochemical test results were abnormal; if the hemoglobin level was 110 gm/L, then a diagnosis of iron deficiency anemia was also made. The prevalence of iron deficiency was highest in infants who were fed cow's milk formula without added iron (37.5%), intermediate in the group fed human milk (26.5%), much lower in those fed cow's milk formula with added iron (8.0%), and virtually absent in those injected with iron dextran (1.3%). The corresponding values for iron deficiency anemia were 20.2%, 14.7%, 0.6% and 0%, respectively. The use of iron supplements is therefore justified in infants who received cow's milk formula without added iron, even when there is no biochemical evidence of iron deficiency. The low prevalence of iron deficiency in the group fed iron-fortified formula appears to make it unnecessary to screen routinely for anemia in such infants. These results also support the recommendation that infants who receive human milk exclusively for 9 months require an additional source of iron after about 6 months of age.

Assuntos

Assuntos

RESUMO

Serum erythropoietin levels were measured by radioimmunoassay in 146 children and young adults with congenital heart disease to assess the relationship between erythropoietin and clinical factors (heart failure, anemia, cyanosis) and hemodynamic variables affecting oxygen delivery and utilization. Erythropoietin values were in the normal range (10 to 30 microU/mL) in 73% (58 of 80) of the patients with and 82% (54 of 66) of those without cyanosis. Elevated erythropoietin values in cyanotic patients were associated with lower mixed venous oxygen saturation and tension than in cyanotic patients with normal erythropoietin levels, even though the degree of polycythemia was similar. In contrast, most of the acyanotic patients who had elevated erythropoietin levels were anemic. Of the blood oxygen measurements, mixed venous oxygen saturation and tension had the closest inverse correlation with erythropoietin values. The normal erythropoietin values in most patients are in accord with other observations that show that an elevation in erythropoietin level in response to hypoxia will be transient if it results in a rise in hemoglobin concentration "appropriate" to the degree of hypoxia. Persistent elevation of erythropoietin in patients with congenital heart disease may indicate harmful impairment of hemoglobin production that is potentially correctable.

Assuntos

RESUMO

In this study of 467 healthy term infants seen for routine 1-year health maintenance examination, we determined the influence of mild prior infection on the concentration of hemoglobin and other laboratory evidence of iron deficiency. In addition we studied the Hgb response in 261 infants randomized to receive a 3-month course of treatment with either iron or placebo. Infants who had had one or more clinic visits because of infection during the previous 3 months or who were reported as not being entirely well during the past month or who had an elevated sedimentation rate were more likely to have anemia or "low normal" Hgb, higher erythrocyte protoporphyrin and serum ferritin values, and lower serum iron concentration than infants who had been well. Hgb response greater than or equal to 1 gm/dl after iron treatment occurred more commonly in infants who had had prior visits because of infection. The results indicate that upper respiratory and other mild antecedent infections commonly predispose to iron deficiency (probably because of a decrease in iron absorption).

Assuntos

Assuntos

RESUMO

Erythropoietin, hemoglobin, hematocrit, oxygen affinity (P50), and reticulocyte counts were measured weekly starting at 1 week of age in 10 very-low-birth-weight infants and on a single occasion in 15 healthy men. In the adults, "available oxygen" (derived from oxygen carrying capacity and P50) averaged 13.1 ml/dl blood and the mean erythropoietin level was 15.2 mU/ml. Erythropoietin levels in the infants were inversely related to concentration of hemoglobin, P50, and available oxygen. However, despite the much lower mean "available oxygen" of 9.3 ml/dl in the infants compared with that in adults (P less than 0.001), the mean erythropoietin value of 8.2 mU/ml in the infants was less than in adults (P less than 0.001). Furthermore, the erythropoietin response to decreased "available oxygen" was lowest in the least mature infants. VLBW infants often develop clinical evidence of hypoxia during the anemia of prematurity. The relatively low erythropoietin levels in relation to "available oxygen" are compatible with a decreased erythropoietin response to hypoxia compared with that in adults. Such a difference in response could be a contributing factor to the anemia of prematurity.

Assuntos

RESUMO

Iron deficiency and lead toxicity both result in increased erythrocyte protoporphyrin. The purpose of this study was to determine the differences in EP concentration, according to age and sex, obtained in the 2nd National Health and Nutrition Examination Survey of the United States and to determine the extent to which EP differences might be related to iron deficiency or lead toxicity. The highest EP concentrations were found in infants and children. Among adults, women had higher EP values than men. Lead toxicity (blood lead greater than 30 micrograms/dl) and low serum iron concentration/total iron binding capacity (Fe/TIBC less than 16%), often in combination, were associated with elevated EP values in infants and children. In women, elevated EP concentration were related primarily to low Fe/TIBC values, whereas in men there was only a weak association with elevated blood lead concentration. Age/sex differences in EP values diminished markedly when the influences of lead toxicity and iron deficiency were excluded by the above criteria.

Assuntos

RESUMO

The purpose of this study was to determine whether an inappropriately low erythropoietin response in premature infants might be a basis for the anemia of prematurity. Erythropoietin was measured by radioimmunoassay in conjunction with hemoglobin and reticulocyte count in untransfused premature infants between birth and 60 days of age. The 27 infants had a mean gestational age of 31 weeks and a mean birth weight of 1378 gm. Between 2 and 30 days, mean erythropoietin concentration was 9.7 mU/ml, significantly and substantially lower than 15.2 mU/ml in 15 concurrently studied healthy adults (P less than 0.01). Subsequently, from 30 to 60 days, values rose gradually to a mean of 17.2 mU/ml, which did not differ significantly from the mean value in adults. Hemoglobin values fell from a mean of 12.9 gm/dl during the first month to 9.0 gm/dl between 30 and 60 days. Thus, during the second postnatal month, preterm infants had essentially the same erythropoietin values as in adults despite a mean hemoglobin concentration that averaged less than two thirds the adult value. This failure to mount a greater erythropoietin response may help to explain why hemoglobin declines to such low values at 2 months of age.

Assuntos

RESUMO

This study was designed to compare the effectiveness of laboratory tests for iron deficiency (mean corpuscular volume, erythrocyte protoporphyrin, transferrin saturation, and serum ferritin) in predicting hemoglobin response to iron therapy in infants found to have low Hgb concentrations. Screening for anemia was performed on capillary blood of 1,128 healthy 1-year-old infants of United States Air Force personnel. The 25% who had Hgb values less than 11.5 gm/dl were asked to return for tests on venous blood before therapy and again after three months of therapy. Of the 188 infants completing therapy, 66 (35%) had a rise in Hgb concentration greater than or equal to 1.0 gm/dl and were designated responders. None of the confirmatory tests on venous blood reliably distinguished responders from those who subsequently showed no response. By using any one of the tests in combination with a capillary Hgb value less than 11.5 gm/dl, more than half of the infants with an abnormal value responded. But well over half of the responders would have been missed if treatment had been restricted to infants with abnormal values. Neither changes in the criteria for normality nor combinations of tests substantially improved our ability to distinguish the two groups. Because of the difficulty in distinguishing responders from nonresponders with additional laboratory tests and because of the simplicity, low cost, and relative safety of iron therapy in infants, we favor an initial therapeutic trial of iron first for determining the cause of low Hgb values in similar high-risk populations. Further costly workup can then be reserved for the small number of infants who still have unexplained Hgb concentrations less than 11.0 gm/dl after a therapeutic trial.

Assuntos

RESUMO

Initial screening for anemia was performed on a capillary blood sample in 800 apparently healthy one-year-old white infants. Twenty-six percent had a Hgb or MCV below the estimated tenth percentile of normal and were asked to return for blood counts on a venous sample. They were then started on a three-month course of oral iron. Of the 151 infants who satisfactorily completed the treatment regimen, 54 had a greater than or equal to 1 gm/dl rise in venous Hgb (2.8 infants treated/response). If conformation of the capillary by the venous values had been a prerequisite for treatment, the size of the treatment group would have decreased from 151 to 87, the response rate would have been improved to 2.0 infants treated per response, but 11 of the infants who had a greater than or equal to 1 gm/dl response would have been missed. Since toxicity from iron therapy is rare, either the use of capillary blood counts alone or in combination with venous values constitutes a satisfactory basis for a therapeutic trial of iron in similar populations. Further evaluation can then be reserved for the small number whose Hgb remains below the lower limit of normal after treatment.

Assuntos