Berit Borch-Iohnsen

Low iron stores are related to higher blood concentrations of manganese, cobalt and cadmium in non-smoking, Norwegian women in the HUNT 2 study

Low iron (Fe) stores may influence absorption or transport of divalent metals in blood. To obtain more knowledge about such associations, the divalent metal ions cadmium (Cd), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn) and lead (Pb) and parameters of Fe metabolism (serum ferritin, haemoglobin (Hb) and transferrin) were investigated in 448 healthy, menstruating non-smoking women, age 20-55 years (mean 38 years), participating in the Norwegian HUNT 2 study. The study population was stratified for serum ferritin: 257 were iron-depleted (serum ferritin < 12 microg/L) and 84 had iron deficiency anaemia (serum ferritin < 12 microg/L and Hb < 120 g/L). The low ferritin group had increased blood concentrations of Mn, Co and Cd but normal concentrations of Cu, Zn and Pb. In multiple regression models, ferritin emerged as the main determinant of Mn, Co and Cd (p < 0.001), while no significant associations with Cu, Zn and Pb were found. Adjusted r(2) for the models were 0.28, 0.48 and 0.34, respectively. Strong positive associations between blood concentrations of Mn, Co and Cd were observed, also when controlled for their common association with ferritin. Apart from these associations, the models showed no significant interactions between the six divalent metals studied. Very mild anaemia (110 < or = Hb < 120 g/L) did not seem to have any effect independent of low ferritin. Approximately 26% of the women with iron deficiency anaemia had high concentrations of all of Mn, Co and Cd as opposed to 2.3% of iron-replete subjects. The results confirm that low serum ferritin may have an impact on body kinetics of certain divalent metal ions, but not all. Only a fraction of women with low iron status exhibited an increased blood concentration of divalent metals, providing indication of complexities in the bodys handling of these metals.

Iron status in a group of Norwegian children aged 6-24 months

An adequate iron status is of vital importance for health and development in infancy and early childhood. Iron status was evaluated in a group of full‐term Norwegian children followed longitudinally, at the ages of 6 mo (n= 278), 12 mo (n= 249) and 24 mo (n= 231) by measuring haemoglobin (Hb), mean cell volume (MCV) and serum ferritin. At 6, 12 and 24 mo of age, 3, 10 and 12%, respectively, had iron deficiency anaemia (IDA) defined as Hb <110 g/l in combination with ferritin <15 μg/l. With more restrictive criteria for defining IDA 10 μg/l) increased from 2 to 3% at 6 mo, from 5 to 7% at 12 mo and from 9 to 13% at 24 mo.

Headache prevalence related to haemoglobin and ferritin. The HUNT Study

As clinic-based studies show an association between headache and both high and low levels of haemoglobin, we analysed this relationship in a population-based cross-sectional study (the HUNT Study). A total of 2385 women aged 20-55 years responded to a headache questionnaire and gave blood samples for measuring haemoglobin and ferritin. In the multivariate analyses, adjusting for age and education, there was a linear trend of decreasing prevalence of headache (P = 0.02) and migraine (P = 0.01) with decreasing haemoglobin. In particular, migraine was less likely among women with low haemoglobin (values < 11.5 g/dl) (odds ratio 0.4, confidence interval 0.2, 0.9). There was no correlation between headache prevalence and ferritin. The present findings may be relevant for the headache reported in polycythaemia and chronic altitude sickness.

Oxidative capacity of tissues contributing to thermogenesis in eider (Somateria mollissima) ducklings: changes associated with hatching

Summary1.The development of liver and skeletal muscle oxidative capacities during hatching of the common eider (Somateria mollissima) in the Arctic has been investigated by monitoring tissue cytochrome c oxidase activity.2.The specific activity of the liver enzyme did not change as the embryo underwent hatching, nor during subsequent growth of the duckling into adulthood.3.Thigh muscle enzyme specific activity increased by a factor of 3.4 during the 24 h prehatching period, remained elevated for at least 48 h after hatching, and then returned to the embryonic (−24 h) level in adults.4.Histochemically visualized NADH-tetrazolium reductase of a typical red thigh muscle, M. vastus lateralis, showed a distinct increase in activity as the hatching process progressed to completion.5.Electron microscopy of sectioned M. vastus lateralis revealed a dramatic increase in the density of the myofibrillar structure (number of mitochondrial profiles per unit area), and in the surface area of mitochondrial crista membranes in the course of the 48 h interval from 1 day prehatching to 1 day after hatching.6.The significance of these changes for the scaling of thermoregulatory heat generation in the newly hatched eider duckling is discussed.

Iron status among 3005 women aged 20–55 years in Central Norway: The Nord‐Trøndelag Health Study (the HUNT Study)

Objective. To describe the iron status of Norwegian women of fertile age, to show the prevalence of iron‐deficiency anemia and iron overload, and to demonstrate possible factors connected to and/or influencing iron status. Material and methods. The diagnostic criteria were: (a) anemia: hemoglobin (Hb) <120, <117, or <115 g/l; (b) depleted iron stores: serum ferritin (SF)<10 or 12 µg/l; iron‐deficiency anemia: (a)+(b). Iron overload: SF ⩾110 µg/l. The study was conducted in Central Norway where a total of 3005 women aged 20 to 55 years were enrolled in a health survey program (the HUNT Study). None of the women were pregnant and none had been blood donors in the two previous years. Results. Median SF was 31.0 µg/l. Depleted iron stores were present in 10.9 and 15.1%, respectively. The Hb 2.5%tile among the iron‐replete women was 117 g/l. With this cut‐off value, anemia was present in 4.7% and iron‐deficiency anemia in about 3%. Iron overload was present among 5.2%, and homozygous primary hemochromatosis among 0.4%. Conclusions. The prevalence of iron‐deficiency anemia was relatively low and similar to that found earlier in small groups of Norwegian women. The prevalence is comparable with results from other developed countries.

Selective iron supplementation based on serum ferritin values early in pregnancy: are the Norwegian recommendations satisfactory?

Background.  The aims of the present study were to evaluate the recommendations by comparing compliance and adequacy of iron status at 6 weeks postpartum between one group given advice only and one group given advice plus iron supplement. In the latter group the efficacies of two iron preparations of different strengths and types were compared.

Chemical and morphological studies of liver from eider (Somateria mollissima) in Svalbard with special reference to the distribution of copper

Specimens of male and brooding female eider (Somateria mollissima) were collected in Svalbard. Chemical analyses revealed hepatic copper concentrations ranging from 20 to 1050 micrograms per g wet weight. This is in agreement with previous results. The selenium, zinc and cadmium values were equal to or slightly higher than previously recorded. It is suggested that the wide variation in copper concentration is a result of differences in intake of copper-containing food among the birds. High selenium intake may enhance copper accumulation. Starvation influences the concentration of zinc and also copper. Zinc concentrations were significantly higher in females. This may be secondary to starvation. The percentage of copper recovered among the soluble proteins was inversely related to the copper content. The distribution of the soluble proteins reflects a normal copper metabolism. Microscopic studies showed prominent dark granules, positive with the rubeanic acid test for copper, confined to hepatocytes. By electron microscopy, the granules appeared as large irregular, electron-dense bodies that, by X-ray microanalysis, were found to contain copper. There were no signs of liver injuries such as necrosis and fibrosis. Apparently, the eider has evolved a high capacity for copper storage.

Influence of season and diet on liver and kidney content of essential elements and heavy metals in svalbard reindeer

Samples of liver (n=78) and kidney (n=60) from Svalbard reindeer (Rangifer tarandus platyrhynchus Vrolik) collected at four different seasons in Svalbard were analysed for their content of Cd, Pb, Cu, Zn, Mn, and Se. The study shows that when animals are exposed to large seasonal variations in both the quality and quantity of food, it is crucial to relate element concentrations to the physiological condition of the animal, e.g., to look at seasonal fluctuations in the total element content of the different organs.

Mössbauer spectroscopic studies of haemosiderins from different sources

Mössbauer spectra obtained from the haemosiderin isolated from ironoverloaded horse and reindeer spleen and liver show superparamagnetic behaviour with a much lower transition temperature than haemosiderin from iron-overloaded human spleen. These data clearly indicate the existence of different forms of haemosiderin, which are primarily distinguishable by Mössbauer spectroscopy.

Regulation of the iron metabolism

BACKGROUND The regulation of iron absorption has previously been considered <<an enigma>>. Recent research has given us interesting information on the regulation of the iron metabolism and pathological iron overload; the present article aims at providing an overview of these topics. MATERIALS AND METHODS The article is based on a review of literature retrieved from PubMed. RESULTS The peptide hepcidin binds to ferroportin on membranes of enterocytes, macrophages and hepatocytes. The complex is internalised and degraded and this results in decreased export of iron to the circulation, and thus a lower level of plasma iron. Hepcidin production is up-regulated in iron overload and down-regulated with iron deficiency. The liver proteins human haemochromatosis protein (HFE), transferrin receptor 2 (TfR2), haemojuvelin (HJV) and bone morphogenetic protein (BNP) are necessary regulators for activation of the hepcidin synthesis. Lack of or mutations in the genes for these proteins, e.g. the HFE mutation C282Y in primary haemochromatosis, reduces the synthesis of hepcidin. Iron regulatory proteins (IRP) may bind to iron responsive elements (IRE) of ferritin-mRNA and transferritin-mRNA and regulate the protein synthesis. INTERPRETATION Regulation of uptake, utilization, release and storage of iron occurs at the gene level. Hepcidin is currently considered to be the <<key regulator>> of the iron balance. Intracellular iron balance is maintained by iron regulating proteins. Synthesis of ferritin increases with high iron levels, while synthesis of TfR1 is reduced. The opposite occurs with a low iron level.