Positive Iron Balance Research Articles

Everyone should be tested for iron disorders

Routinely measuring iron status is necessary because about 6% of Americans have negative iron balance, about 10% have a gene for positive balance, and about 1% have iron overload. Deviations from normal iron status are as follows. (a) Stage I and II negative iron balance, ie, iron depletion: In these stages iron stores are low and there is no dysfunction. In stage I negative iron balance, reduced iron absorption produces moderately depleted iron stores. Stage II negative iron balance is characterized by severely depleted iron stores. More than half of all cases of negative iron balance fall into these two stages. When persons in these stages are treated with iron, they never develop dysfunction or disease. (b) Stage III and IV negative iron balance, ie, iron deficiency: Iron deficiency is characterized by inadequate body iron for normal function, producing dysfunction and disease. In stage III negative iron balance, dysfunction is not accompanied by anemia; anemia develops in stage IV negative iron balance. (c) Stage I and II positive iron balance: Stage I positive balance usually lasts for several years with no dysfunction. Supplements of iron and/or vitamin C promote progression to dysfunction or disease. Iron removal prevents progression to disease. Iron overload disease develops in stage II positive iron balance after years of iron overload has caused progressive damage to tissues and organs. Again, iron removal stops disease progression. There are a variety of indicators of iron status. Serum ferritin is in equilibrium with body iron stores.(ABSTRACT TRUNCATED AT 250 WORDS)

Iron disorders can mimic anything, so always test for them

Routinely measuring iron status is necessary because not only are about 6% of Americans in significant negative iron balance, but about 1% have iron overload. Serum ferritin is in equilibrium with body iron stores, and is the only blood test that measures them. Barring inflammation, each one ng (0.0179 pmol) ferritin/ml of serum indicates approximately 10 mg (0.179 mmol) of body iron stores. Very early Stage I positive balance is best recognized by measuring saturation of iron binding capacity. Conversely, serum ferritin best recognizes early (Stage I and II) negative balance. Deviations from normal are: 1. 1. Both stages of iron depletion (i.e. low stores, no dysfunction). Negative iron balance Stage I is reduced iron absorption producing moderately depleted iron stores. Stage II is severely depleted stores, without dysfunction. These stages include over half of all cases of negative iron balance. Treated with iron, they never progress to dysfunction, i.e. to disease. 2. 2. Both stages of iron deficiency. Deficiency is inadequate iron for normal function, i.e. dysfunction, disease. Negative balance Stage III is dysfunction without anemia; Stage IV is with anemia. 3. 3. Positive iron balance: Stage I is a multi-year period without dysfunction. Supplements of iron and/or vitamin C promote progression to dysfunction (disease). Iron removal prevents progression. Stage II is iron overload disease, encompassing years of insidiously progressive damage to tissues and organs from iron overload. Iron removal arrests progression.

Intraperitoneal deferoxamine therapy for iron overload in children undergoing CAPD

We treated three children with renal failure and chronic iron overload with intraperitoneal deferoxamine therapy. Each child had an elevated serum ferritin level, a dense liver as measured by computerized tomography (Hounsfield Units) and one had dialysis related porphyria cutanea tarda. Deferoxamine therapy (10 to 17.5 mg/kg) was given in the overnight exchange for three to six months. Prior to therapy, iron was not detected in the dialysate; during the course of therapy, daily dialysate iron removal averaged 5652 micrograms, 2241 micrograms and 4028 micrograms in the three children. The serum ferritin level fell during the course of therapy in two children who were estimated to be in negative iron balance, and was unchanged in the third who was estimated to be in positive iron balance due to frequent transfusions. In 10 children with chronic renal failure, there was a linear correlation (r = 0.855; P less than 0.01) between the serum ferritin and the liver density, suggesting that an increased serum ferritin correlates with hepatic iron content. Interestingly, in each of the three children who received deferoxamine therapy, the liver density increased during therapy regardless of the estimated iron balance and the change in the serum ferritin level. We conclude that intraperitoneal deferoxamine therapy results in substantial iron losses in peritoneal dialysate, can result in negative iron balance but, in this study, did not result in lower liver iron content as measured by density on computerized tomography scan.

The effect of erythroid hyperplasia on iron balance

Measurements of erythropoiesis and iron balance were made in eight normal and 32 anemic subjects. The latter consisted of 12 individuals with ineffective erythropoiesis (beta-thalassemia/hemoglobin E), 13 subjects with ineffective erythropoiesis and hemolytic anemia (hemoglobin H), and seven subjects with hemolytic anemia (hereditary spherocytosis). A consistent relationship within each group existed between the degree of erythropoiesis and radioiron absorption. Although the effect of erythropoiesis on iron absorption was of similar magnitude in the two thalassemia groups, the effect in hereditary spherocytosis was much less. There was agreement between absorption and ferritin or magnetic susceptibility (SQUID) measurements of iron stores in thalassemia, but in hereditary spherocytosis a discrepancy existed between absorption and ferritin. It is concluded that, although increased erythropoiesis is associated with increased iron absorption, some additional factor associated with red cell breakdown is more directly responsible for the positive iron balance in thalassemia.

The Effect of Erythroid Hyperplasia on Iron Balance

Measurements of erythropoiesis and iron balance were made in eight normal and 32 anemic subjects. The latter consisted of 12 individuals with ineffective erythropoiesis (beta-thalassemia/hemoglobin E), 13 subjects with ineffective erythropoiesis and hemolytic anemia (hemoglobin H), and seven subjects with hemolytic anemia (hereditary spherocytosis). A consistent relationship within each group existed between the degree of erythropoiesis and radioiron absorption. Although the effect of erythropoiesis on iron absorption was of similar magnitude in the two thalassemia groups, the effect in hereditary spherocytosis was much less. There was agreement between absorption and ferritin or magnetic susceptibility (SQUID) measurements of iron stores in thalassemia, but in hereditary spherocytosis a discrepancy existed between absorption and ferritin. It is concluded that, although increased erythropoiesis is associated with increased iron absorption, some additional factor associated with red cell breakdown is more directly responsible for the positive iron balance in thalassemia.

Iron overload and desferrioxamine chelation therapy in beta-thalassemia intermedia.

This study on serum ferritin levels in urinary iron excretion after 12h subcutaneous infusion of desferrioxamine in 10 thalassemia intermedia patients shows that even nontransfusion-dependent patients may have positive iron balance resulting in iron overload from 5 years of age. However, the iron overload found in these patients appears to be much lower than in age matched patients with transfusion-dependent thalassemia major. Iron overload increases with advancing age, as shown by increasing serum ferritin levels and desferrioxamine-induced urinary iron elimination. After a six month trial of 12h continuous subcutaneous desferrioxamine administration there was a significant decline in serum ferritin levels. From this study it seems that iron chelation is indicated in thalassemia intermedia patients over 5 years of age in order to prevent iron accumulation. However, the appropriate treatment schedule should be tailored to the individual needs of each patients, established by close monitoring of serum ferritin levels and desferrioxamine-induced urinary iron elimination.

A Question About a Committee Statement

The Committee on Nutrition is to be commended for the excellence of "Iron Supplementation for Infants" (Pediatrics 58:765, November 1976). This modification and modernization of their 1969 and 1971 recommendations is invaluable to practicing pediatricians. I would appreciate clarification of the article "Iron Sufficiency in Breast-Fed Infants and the Availability of Iron From Human Milk" by McMillan et al. (Pediatrics 58:686, November 1976). The authors' carefully stated conclusion is that "human milk ... was adequate to preserve a positive iron balance in four infants."

Dietary iron absorption in pregnancy - a longitudinal study with repeated measurements of non-haeme iron absorption from whole diet.

In 22 healthy women the non-haeme iron absorption (bone-marrow smears and haematological parameters) was studied at the 12th, the 24th and the 36th week of gestation and two months after delivery. In eight non-pregnant women and in seven pregnant women (at the 36th week of gestation) the absorption of food iron was measured from different types of meals. The iron absorption was measured from radioiron-labelled test meals using a whole-body counter with a very high sensitivity. During pregnancy the non-haeme iron absorption increased continuously from less than 1 % in early pregnancy to almost 15 % in late pregnancy. Calculations indicated that the amount of iron absorbed from the diet covered only about half of the demands. The increasing absorption of food iron during pregnancy seems to be related to the still more increasing demands. However, the very low absorption values in early pregnancy was quite unexpected. The amount of iron absorbed was actually below the basal demands, which means that even in early pregnancy, for reasons unknown, there is a negative iron balance. Further studies are necessary to elucidate the significance of this finding. Two months after delivery the absorption of iron from the diet was increased compared to in non-pregnant women and exceeded the demands at that phase thus indicating that a positive iron balance was achieved.

Iron Deficiency Anemia among High School Students

During adolescence, various factors such as rapid growth of the body and iron depletion due to menstrual bleeding or other causes increase the iron requirement. For instance, Bothwell and Finch1) indicated that the average daily iron requirement is 1.0mg for adolescent males compared to 0.6mg for adult males, and 1.5mg for .adolescent females compared to 1.2mg for adult females. Therefore, if males or females in adolescence do not have adequate diets to support positive iron balance as aforementioned, they might easily develop iron deficiency anemia. Although various problems concerning iron deficiency anemia in late adolescence have been reported by several investigators, 1-4) few papers have been published concerning iron deficiency anemia in early adolescence. Therefore, various findings covering iron deficiency anemia in a group of high school students in Japan are presented in this paper.

INCREASED IRON ABSORPTION DURING LIVER REGENERATION INDUCED BY PARTIAL HEPATECTOMY.

ATTENTION was drawn to the fact by Moore¹and Bothwell²and his co-workers that the rate of red blood cell production influences the quantity of iron absorbed from the gastrointestinal tract. Our studies^3,4have also shown that iron absorption varies directly with the rate of red blood cell production and, that this effect is additive, in some degree, to the effects exerted by anemia and alterations in body iron content on intestinal iron transport. While these factors, acting in concert, seem to be the most significant that have been identified to explain the regulation of iron absorption under normal circumstances and in some disease states,⁵there remains a group of conditions in which iron absorption is increased for reasons not readily explainable by the factors first considered. These conditions include the positive iron balance that is seen during periods of growth,⁶the increased iron absorption

Meat in the diet of premature infants. II. Influence on red cell volume and hemoglobin mass.

There is an almost inevitable development of anemia and iron deficiency in premature infants during the first year of life. Some observations 1,2 have suggested that the introduction of medicinal iron in early weeks of life will relieve part of the condition; other studies 3,4 have not supported this view. It has been demonstrated that meat protein is as well absorbed and utilized as cow's milk protein by the premature infant, 5 and in the same study it was observed that the addition of meat to the diet resulted in a positive iron balance. An isocaloric milk diet did not. However, the measurement of iron balance presents disputable evidence because of its technical difficulties, and definite conclusions cannot be drawn from it. The present investigation was undertaken to determine if meat would be an effective source of iron in the diet of premature infants. Experiments were planned to assess the

The Importance of Nutritional Factors in the Pathogenesis of Iron-Deficiency Anemia

Nutritional factors are of major importance in the production or prevention of iron-deficiency anemia. Healthy persons probably maintain a positive iron balance by a narrower margin than was formerly believed. Approximately 5 to 10 per cent food iron seems to be assimilated by normal adults; daily retention on a diet containing 12 to 15 mg. of iron, therefore, may be estimated to be about 0.6 to 1.5 mg. The amount of iron lost from the body each day, in all ways except as blood, seems to be between 0.5 and 1 mg. The added requirements of children and young women to compensate for growth needs and menstrual flow Place them in a precarious state of iron balance, so that poor diet or poor absorption can readily lead to the production of hypochromic anemia. In adult men or post-menopausal women, however, nutritional factors appear to be of less importance in the pathogenesis of iron deficiency. If purely nutritional iron deficiency ever occurs in these people, many years would be required for its production. It is more likely that occult, intermittent bleeding, often difficult to detect, must also be present along with inadequate diet or malabsorption before severe degrees of iron deficiency develop.