Association Between High Serum Ferritin Levels and Carotid Atherosclerosis in the Study of Health in Pomerania (SHIP)

Low total and nonheme iron intakes are associated with a greater risk of hypertension

The relationship between iron intake and blood pressure (BP) status has not been well established. Only 1 cross-sectional study has suggested an inverse association of dietary total iron intake and nonheme iron intake with BP. We investigated the relationship between total, heme, and nonheme iron intakes, markers of iron status, 5.4-y changes in BP, and the incidence of hypertension. A total of 2895 participants included in the Supplémentation en Vitamines et Minéraux Antioxydants cohort were followed up for 5.4 y. At least 3 repeated 24-h dietary records were performed at baseline and 5.4 y later. Hemoglobin and serum ferritin concentrations were assessed at baseline. Low nonheme iron intake at baseline was associated with a greater increase in systolic BP (SBP) and pulse pressure over time after adjustment for multiple possible confounding factors (P-trend = 0.002 and 0.0005, respectively). Conversely, participants in the 3rd tertile of nonheme iron intake at baseline had a 37% lower risk of hypertension after 5.4 y of follow-up compared with those in the first tertile (P-trend = 0.04). Heme iron intake was not associated with BP changes or risk of hypertension. Meat intake was positively associated with an increase in SBP (P-trend = 0.04). However, that relation became nonsignificant after adjusting for dietary pattern scores. Baseline hemoglobin and ferritin concentrations were not associated with changes in BP or incidental hypertension. Our data support a possible role of low nonheme iron intake, independent of heme iron intake, in the development of hypertension.

The effect of dietary iron intake on the development of iron overload among homozygotes for haemochromatosis

Objective

To quantify the role of dietary Fe in total body Fe (TBI) accumulation among homozygotes for theHFEgene associated with haemochromatosis.

Design

A Monte Carlo model was built to simulate Fe accumulation based on findings from human feeding experiments and national dietary surveys. A hypothetical cohort of 1000 homozygotes with starting age 25 years was used in 39-year simulations. The impact of reducing dietary Fe intake on Fe accumulation was tested.

Results

In the baseline model without any dietary intervention, by age 64, the percentage of males with TBI > 10 g, >15 g and >20 g was 93·2 %, 49·6 % and 14·7 %, respectively. When the Fe intake of individuals in the cohort was reduced to ≤200 % of the recommended dietary allowance (RDA), the corresponding percentages were 92·0 %, 40·5 % and 10·2 %, respectively. The corresponding figures were 91·0 %, 40·0 % and 9·3 % for Fe defortification and 70·3 %, 21·3 % and 4·1 % when Fe intake was capped at 100 % RDA. Similar trends were seen with sexes combined, although the impact of interventions was less. Sensitivity analysis revealed that the rate of Fe accumulation and the impact of dietary interventions are highly dependent on assumptions concerning Fe absorption rates.

Conclusions

Variation in Fe intake as currently observed in the USA contributes to variation in Fe accumulation among homozygotes, when continued over an extended period. Lifelong dietary habits and national fortification policy can affect the rate of Fe accumulation, although the magnitude of the effect varies by gender, the TBI level of interest and factors affecting the Fe absorption rate.

Association between cholesterols, homocysteine and silent brain infarcts

BACKGROUND

The aim of this study was to assess the relationship between total plasma homocysteine, cholesterol levels, vitamin B(12), folate, thyroid hormones, urea, ferritin, uric acid, C-reactive protein, cardiovascular risk factors and silent brain infarct (SBI) in patients without any neurological disorder. Whether the factors of interest were associated with SBI is investigated.

METHODS

One hundred and forty-two subjects with a mean age of 52.1 +/- 13.1 years (21-87 years) without any history of stroke, transient ischaemic attack and neurological abnormality were enrolled in this cross-sectional study. The subjects underwent brain magnetic resonance imaging and blood chemistry determinations. Student's t-test was used to compare differences in means of laboratory results between the groups with and without SBI. The chi(2)-test was used for categorized variables. Multiple logistic regression analysis was used to determine the independent predictors of SBI.

RESULTS

The group comprised 56 men and 86 women. SBI were found in 40 patients (28%). The low-density lipoprotein levels were significantly higher in the infarct group (P = 0.019), homocysteine concentrations were significantly higher in the men-infarct group (P = 0,029) and total cholesterol levels were significantly higher in the women-infarct group than the women non-infarct group (P = 0.006).

CONCLUSION

Serum low-density lipoprotein, total cholesterol and homocysteine levels were associated with SBI.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Interferon β therapy increases serum ferritin levels in patients with relapsing-remitting multiple sclerosis

Serum ferritin levels have been found to be increased in patients with active progressive multiple sclerosis (MS). However, its levels are reported to be unchanged in stable and in active relapsing-remitting (RR) form of the disease. No research to date has assessed the influence of interferon β (IFN-β) on ferritin concentrations. In this study, serum ferritin levels were measured in 43 individuals with RR-MS and 38 age- and sex-matched control volunteers. There were no significant differences between controls and patients under stable and untreated conditions. In patients at 12 months after the beginning of IFN-β therapy, ferritin levels were higher in women and in men, in comparison with baseline (71.4 ± 58.6 vs 43.4 ± 29.9 ng/mL, P = 0.0006 and 216.0 ± 124.3 vs 127.8 ± 74.9 ng/mL, P = 0.0022, respectively). These results suggest that larger prospective studies are required to evaluate the role of serum ferritin in MS and its potential usefulness in monitoring responses to immunomodulatory therapies.

Iron and thrombosis

Although essential for cell physiology, an increase or depletion of body iron has harmful effects on health. Apart from iron deficiency anemia and iron overload-related organ tissue damage, there are increasing evidences that body iron status is implicated in atherosclerotic cardiovascular diseases. The hypothesis formulated in 1981 that iron depletion may protect against cardiovascular events is intriguing and has generated a significant debate in the last two decades. Indeed, to study this phenomenon, several investigators have tried to design appropriate experimental and clinical studies and to identify useful biochemical and genetic markers of iron status. The results of the literature on the effect of iron deficiency and overload on vascular health are critically reviewed in this study from a pathogenic and clinical point of view.

HFE genotype influences erythropoiesis support requirement in hemodialysis patients: a prospective study

BACKGROUND/AIMS

HFE protein controls iron absorption and cycling, and HFE mutations influence iron status. The aim was to evaluate the effect of the HFE genotype on the need for iron and erythropoietin in Italian hemodialysis patients.

METHODS

Ninety-six prevalent patients were evaluated at the time of enrolment and prospectively followed for 3 years. Patients were given r-HuEPO and Fe3+-gluconate according to guidelines. The HFE genotype was determined by restriction analysis.

RESULTS

Three patients (3%) carried the C282Y mutation, 4 (4%) were homozygous and 18 (19%) heterozygous for the H63D mutation, and 71 (74%) were negative for both. At enrolment, subjects positive for HFE mutations had higher iron stores (ferritin 617 +/- 663 vs. 423 +/- 386 ng/ml, p = 0.05), were receiving less iron (82.5 +/- 66 vs. 110 +/- 154 mg/month, p = 0.05) and a lower r-HuEPO dosage (98 +/- 83 vs. 142 +/- 138 U/kg/week, p = 0.03). Consistently during the study period, patients positive for HFE mutations received a lower amount of r-HuEPO (94.5 +/- 63 vs. 186 +/- 344 U/kg/week, p = 0.01) and iron (97 +/- 63 vs. 121 +/- 68 mg/month, p = 0.07). Upon Cox regression analysis, after adjustment for confounding variables, the presence of HFE mutations was associated with a reduced risk of death (HR 0.6, 95% CI 0.34-1.03, p = 0.06).

CONCLUSION

HFE mutations reduce the amount of r-HuEPO and iron necessary to support erythropoiesis in hemodialysis.

Dietary iron intake and serum ferritin in relation to 7.5 years structure and function of large arteries in the SUVIMAX cohort

AIM

Few studies have investigated the relationship between iron stores and measures of atherosclerosis. Most of these studies were cross-sectional and yielded conflicting results. We aimed to assess the relationship between serum ferritin concentrations and dietary iron intake measured at baseline and 7.5 year pulse wave velocity (PWV), intima-media thickness (IMT) and plaques in a group of 824 men and women without known CVD, cancer or hemochromatosis.

METHODS

The SUVIMAX study is a randomized double-blind, placebo-controlled primary prevention trial designed to test the effect of antioxidant supplementation in reducing ischemic cardiovascular diseases and cancer.

RESULTS

In multivariate analyses, no association was found between baseline serum ferritin levels and IMT 7 years later (beta (95% CI)=0.003 (-0.005;0.011) in men; -0.005 (-0.013;0.004) and -0.001 (-0.011;0.009) in women, before and after menopause, respectively), plaques (OR (95% CI)=1.09 (0.88;1.34) in men; 0.93 (0.66;1.31) and 0.95 (0.70;1.29) in women, before and after menopause, respectively) or PWV (beta (95% CI)=0.078 (-0.154;0.310) in men; -0.018 (-0266;0.231) in women before and after menopause). Results for dietary iron intake were similar.

CONCLUSION

Our results do not support the hypothesis that dietary iron intake and body iron stores are deleterious to the structure and function of large arteries in subjects free of CVD, cancer or hemochromatosis.

HFE gene mutations and oxidative stress influence serum ferritin, associated with vascular damage, in hemodialysis patients

BACKGROUND/AIMS

Hyperferritinemia has been associated with cardiovascular mortality in hemodialysis patients. The aim of this study was to evaluate whether serum ferritin was affected by iron and oxidative status and by genetic factors (HFE mutations and the Ala9Val MnSOD polymorphism), and to assess the association between ferritin and cardiovascular damage evaluated by ecocolor-Doppler.

METHODS

63 hemodialysis patients were tested for HFE and MnSOD genotype by restriction analysis and oxidative status; vascular damage was assessed by measuring intima-media thickness, and by detecting plaques at carotid and femoral arteries.

RESULTS

Ferritin was correlated with transferrin saturation (p = 0.003), decreased iron-specific serum antioxidant activity (p = 0.01), age (p = 0.03), and C282Y and H63D HFE mutations (p = 0.05), but not with the MnSOD polymorphism. Ferritin was associated with advanced vascular damage, as evaluated by the presence of plaques, both at carotid (p = 0.03) and femoral arteries (p = 0.001), the other risk factors being age and low albumin. Low iron-specific antioxidant activity was associated with carotid plaques (p = 0.03).

CONCLUSION

In hemodialysis patients, hyperferritinemia reflects a relative increase in iron availability and a decrease in iron-specific antioxidant activity, is favored by HFE mutations, and represents a risk factor for advanced cardiovascular damage.

Effects of soy isoflavones and phytate on homocysteine, C-reactive protein, and iron status in postmenopausal women

BACKGROUND

Soy protein or its components may protect against the atherosclerotic cardiovascular disease (CVD) risk factors total homocysteine (tHcy), C-reactive protein (CRP), and excess body iron, which generally increase with menopause.

OBJECTIVE

The primary objective of this study was to determine the independent effect of the soy protein components isoflavones and phytate on CVD risk factors in postmenopausal women. The secondary objective was to identify factors [blood lipids, oxidative stress indexes, serum ferritin, plasma folate, plasma vitamin B-12, and body mass index (BMI)] contributing to tHcy and CRP concentrations.

DESIGN

In a double-blind, 6-wk study, 55 postmenopausal women aged 47-72 y were randomly assigned to 1 of 4 soy protein (40 g/d) isolate treatments: native phytate and native isoflavone (n = 14), native phytate and low isoflavone (n = 13), low phytate and native isoflavone (n = 14), or low phytate and low isoflavone (n = 14). We measured iron indexes, tHcy, CRP, and BMI.

RESULTS

Soy protein with native phytate significantly reduced tHcy (P = 0.017), transferrin saturation (P = 0.027), and ferritin (P = 0.029), whereas soy protein with native isoflavones had no effect on any variables. At baseline, BMI was highly correlated with tHcy (r = 0.39, P = 0.003) and CRP (r = 0.55, P < 0.0001), whereas HDL cholesterol was correlated with CRP (r = -0.30, P = 0.02). Multiple regression analysis showed that LDL cholesterol and BMI contributed significantly (R2= 19.9%, P = 0.003) to the overall variance in tHcy.

CONCLUSION

Consuming phytate-rich foods and maintaining a healthy weight may reduce atherosclerotic CVD risk factors in postmenopausal women.

Serum ferritin, cardiovascular risk factors and ischaemic heart diseases: a prospective analysis in the SU.VI.MAX (SUpplementation en VItamines et Minéraux AntioXydants) cohort

BACKGROUND

Iron has been suggested to play a role in the development of cardiovascular disease (CVD) through its pro-oxidant properties. However, epidemiological studies on iron status and the risk of CVD have yielded conflicting results. We therefore carried out a prospective study to evaluate the relationship between iron status and CVD in a middle-aged French population.

METHODS

In total, 9917 subjects (3223 men aged 45-60 years and 6694 women aged 35-60 years) included in the SU.VI.MAX (SUpplementation en VItamines et Minéraux AntioXydants) cohort were followed prospectively for 7.5 years. All cases of ischaemic heart disease (IHD) were identified and validated. CVD risk factors, haemoglobin and serum ferritin concentrations were measured at baseline.

FINDINGS

Of men 4.3%, and of women 37.8%, presented at baseline a serum ferritin concentration <30 microg l(-1). During the follow-up, 187 subjects (148 men, 39 women) developed IHD. Serum ferritin was positively associated with total cholesterol, serum triglycerides, systolic and diastolic blood pressure, body mass index and haemoglobin. No linear association was found between serum ferritin and IHD risk in men or in women.

CONCLUSION

Our data do not support a major role of iron status in the development of IHD in a healthy general population.

Multiple polymorphic loci determine basal hepatic and splenic iron status in mice

Polymorphisms of genes linked to iron metabolism may account for individual variability in hemochromatosis and iron status connected with liver and cardiovascular diseases, cancers, toxicity, and infection. Mouse strains exhibit marked differences in levels of non-heme iron, with C57BL/6J and SWR showing low and high levels, respectively. The genetic basis for this variability was examined using quantitative trait loci (QTL) analysis together with expression profiling and chromosomal positions of known iron-related genes. Non-heme iron levels in liver and spleen of C57BL/6J x SWR F2 mice were poorly correlated, indicating independent regulation. Highly significant (P < .01) polymorphic loci were found on chromosomes 2 and 16 for liver and on chromosomes 8 and 9 for spleen. With sex as a covariate, additional significant or suggestive (P < 0.1) QTL were detected on chromosomes 7, 8, 11, and 19 for liver and on chromosome 2 for spleen. A gene array showed no clear association between most loci and differential iron-related gene expression. The gene for transferrin and a transferrin-like gene map close to the QTL on chromosome 9. Transferrin saturation was significantly lower in C57BL/6J mice than in SWR mice, but there was no significant difference in the serum level of transferrin, hepatic expression, or functional change in cDNA sequence. beta2-Microglobulin, which, unlike other loci, was associated with C57BL/6J alleles, is a candidate for the chromosome 2 QTL for higher iron. In conclusion, the findings show the location of polymorphic genes that determine basal iron status in wild-type mice. Human equivalents may be pertinent in predisposition to hepatic and other disorders.

Thyroid function and serum ferritin levels: the study of health in Pomerania

OBJECTIVE

Serum ferritin levels are assumed to be an atherosclerotic risk factor. Ferritin production is increased in individuals with activated liver production, which has been shown in hyperthyroid conditions. An association between subclinical hyperthyroidism and serum ferritin levels would add an explanation to the relation between low serum thyrotropin levels and mortality. The aim of the present analysis was to investigate an association between thyroid function and serum ferritin levels. We hypothesized low serum thyrotropin to be related to high serum ferritin levels.

DESIGN

The Study of Health in Pomerania (SHIP) is a population-based study comprising male and female adults aged 20 to 79 years. Data of 4111 subjects (2071 females) were available for the present analysis. Serum ferritin levels were determined by an immunoturbidimetric assay. Multivariable analyses were performed to investigate an independent relation between thyroid function and serum ferritin levels.

MAIN OUTCOME

Age-adjusted and gender-stratified analyses revealed no association between thyroid function and serum ferritin levels, neither in females nor in males. This finding remained stable after adjustment for potential confounders and in sensitivity analyses.

CONCLUSION

There was no association between thyroid function and serum ferritin levels. We conclude that serum ferritin levels do not account for the relation between subclinical hyperthyroidism and vascular mortality.

Endothelial nitric oxide synthase Glu298→Asp polymorphism, carotid atherosclerosis and intima-media thickness in a general population sample

The Glu298→Asp (E298D; 894G→T) polymorphism of eNOS (endothelial nitric oxide synthase) has been related with cardiovascular disease. In the present study, we investigated the association of Glu298→Asp with atherosclerotic plaques in different carotid vessel segments and with carotid IMT (intima-media thickness). The Glu298→Asp eNOS polymorphism was determined by 5′-exonuclease assay among 2448 participants of the SHIP (Study of Health in Pomerania). Mean and maximum common carotid IMT, as well as carotid atherosclerosis, were measured by high-resolution ultrasound. The Asp/Asp298 genotype was associated with an increased risk of atherosclerotic plaques at the level of the common carotid arteries [multivariate odds ratio, 1.57 and 95% CI (confidence interval), 1.05–2.34; P=0.025], but not in the carotid bifurcations or internal or external carotid arteries. Glu298→Asp genotype was not associated with carotid IMT in the whole sample. However, the Asp/Asp298 genotype was independently associated with both higher mean [adjusted increase by 0.046 mm (95% CI, 0.013–0.078); P=0.006] and maximum carotid IMT [0.137 mm (95% CI, 0.064–0.209); P<0.001] in the low-risk group of subjects without carotid atherosclerosis. In conclusion, the Asp/Asp298 genotype is associated with atherosclerosis in the common carotid arteries and, in a low-risk group, also with carotid IMT. This suggests that the association of the Glu298→Asp genotype with atherosclerosis in the carotid arteries is site-specific and is modified by overall cardiovascular risk.

Relation of Parity With Common Carotid Intima-Media Thickness Among Women of the Study of Health in Pomerania

Background and Purpose— Metabolic and hormonal changes associated with pregnancy and childbirth are assumed to contribute to the development of cardiovascular disease among women. We analyzed the association of parity with common carotid intima-media thickness (IMT), which has a predictive value of subsequent myocardial infarction and stroke.

Methods— The Study of Health in Pomerania (SHIP), an epidemiological study of the general population in the northeast of Germany, included 1195 women aged 45 to 79 years. Mean and maximum far-wall IMT of the common carotid arteries were assessed by high-resolution ultrasound. All women were comprehensively characterized as to their reproductive history as well as to socioeconomic, behavioral, and biological risk factors.

Results— There was a U-shaped association between the number of children (from 0 to ≥4) and mean and maximum IMT. Nulliparous women had the highest age-adjusted mean (0.81 mm [95% CI, 0.78 to 0.84]) and maximum IMT (1.04 mm [95% CI, 1.00 to 1.09]), and women with single parity the lowest (mean IMT, 0.73 [95% CI, 0.72 to 0.74]; maximum IMT, 0.91 mm [95% CI, 0.89 to 0.93]; P <0.001 versus nulliparity for both parameters). Stepwise multivariate adjustment for socioeconomic factors, lifestyle variables, and biological variables attenuated the magnitude of this association yet significance remained.

Conclusions— Nulliparity and higher number of children are associated with increased carotid IMT. These findings add support to the hypothesis of a link between the reproductive history of women and cardiovascular disease.

Ferritin in atherosclerosis

Iron, an essential element for many important cellular functions in all living organisms, can catalyze the formation of potentially toxic free radicals. Excessive iron is sequestered by ferritin in a nontoxic and readily available form in a cell. Ferritin is composed of 24 subunits of different proportions of two functionally distinct subunits: ferritin H and L. The former is involved in ferroxidase activity necessary for iron uptake and oxidation of ferrous iron, while the latter is involved in nucleation of the iron core. The expression of ferritin is under delicate control and is regulated at both the transcriptional and posttranscriptional levels by iron, cytokines and oxidative stress. Elevated ferritin levels are associated with an increased risk of atherosclerotic coronary artery disease (CAD), the leading cause of death and illness in developed countries. Serum ferritin levels are a good indicator of iron stores in the body. In fact, epidemiological studies have suggested that elevated serum ferritin levels are associated with an increased risk of CAD and myocardial infarction (MI), though inconsistent results were obtained in some other studies. Moreover, recent proteomics and molecular biology studies have shown that ferritin levels in arteries are increased in diseased tissues, which further supports the link of ferritin to CAD/MI. Future studies will determine whether increased ferritin levels can serve as a distinct biomarker for the incidence of CAD/MI and distinguish whether increased ferritin levels are a cause of CAD or a consequence of the disease process.

Candidate-based proteomics in the search for biomarkers of cardiovascular disease

The key concept of proteomics (looking at many proteins at once) opens new avenues in the search for clinically useful biomarkers of disease, treatment response and ageing. As the number of proteins that can be detected in plasma or serum (the primary clinical diagnostic samples) increases towards 1000, a paradoxical decline has occurred in the number of new protein markers approved for diagnostic use in clinical laboratories. This review explores the limitations of current proteomics protein discovery platforms, and proposes an alternative approach, applicable to a range of biological/physiological problems, in which quantitative mass spectrometric methods developed for analytical chemistry are employed to measure limited sets of candidate markers in large sets of clinical samples. A set of 177 candidate biomarker proteins with reported associations to cardiovascular disease and stroke are presented as a starting point for such a 'directed proteomics' approach.

Intracellular Labile Iron Modulates Adhesion of Human Monocytes to Human Endothelial Cells

OBJECTIVE

Elevated iron stores and high plasma iron concentration have been linked to an increased risk of atherosclerosis. Iron may thereby affect the interaction of monocytes to endothelium, an initial event in the formation of atherosclerotic plaques.

METHODS AND RESULTS

Addition of 10 mumol/L non-transferrin-bound iron to the incubation medium caused a 2-fold increase in monocyte adhesion to human umbilical vein endothelial cells (HUVECs). A concordant increase in the expression of the following adhesion molecules was observed: vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and endothelial selectin on HUVECs as well as very late antigen-4, and lymphocyte function-associated antigen-1 on monocytes. The inclusion of either deferiprone or salicylaldehyde isonicotinoylhydrazone counteracted these effects. Intracellular iron chelation by deferoxamine was completed only after 10 hours of incubation, shown by reversal of iron-quenched intracellular calcein signal, and concurrently the effects of iron were blunted. The membrane-impermeable chelator, diethylenetriamine pentaaceticacid, failed to negate iron effects, even after 48 hours of treatment. Furthermore, only membrane-permeable superoxide or hydroxyl radical scavengers were capable of preventing HUVEC activation by iron.

CONCLUSIONS

Non-transferrin-bound iron increases the level of intracellular labile iron, which promotes monocyte recruitment to endothelium and may thereby contribute to the pathogenesis of atherosclerosis. Iron-induced adhesion molecule expression was observed, and this event may involve the production of oxygen radicals.

A decrease in iron status in young healthy women after long–term daily consumption of the recommended intake of fibre–rich wheat bread

BACKGROUND

Fibrerich bread and cereals are included in the recommendations of a healthy diet.

OBJECTIVE

To measure the effects of long-term consumption of the recommended intake of fibre-rich wheat bread on the iron status of young healthy women with adequate iron stores.

DESIGN

Four-months intervention study including healthy female subjects assigned into two groups provided daily with 300 g of fibre-rich wheat bread, prepared with or without phytase as a supplement to their habitual diet.

SUBJECTS

Forty-one women aged 24.8 +/- 3.8 years (mean +/- SD) and an average BMI of 22.0 +/- 2.9 kg/m2 participated. Baseline values for serum ferritin were 45 microg/L, 22-83 (geometric mean, range) and for haemoglobin 132 g/L, 119-148 (arithmetic mean, range), respectively.

RESULTS

Distribution of energy intake from protein, fat and carbohydrate, and daily intake of dietary fibre and iron were similar in the two groups and within the recommended levels. There was no effect of the phytase added to the wheat bread on the iron status of the subjects, but an effect of the intervention period. Serum ferritin and haemoglobin levels were significantly reduced by 12 +/- 1.1 microg/L (27%) (P < 0.001) and 2 +/- 0.8 g/l (1.5%) (mean +/- SE) (P < 0.05) respectively, after four months of intervention.

CONCLUSIONS

The present long-term study indicates that consumption of the recommended daily intake of fibre-rich wheat bread results in an impairment of iron status in women with initially sufficient iron stores. Reduction of the phytic acid concentration in the bread was not sufficient to maintain iron status.

Oxidized low-density lipoprotein, iron stores, and haptoglobin polymorphism

BACKGROUND

In vitro experimental studies demonstrated that iron promotes free radical-induced low-density lipoprotein (LDL) oxidation.

OBJECTIVE

To test the hypothesis that circulating oxidized LDL (oxLDL) levels might be associated with body iron stores (serum ferritin) and iron-related genetic markers (hemochromatosis gene C282Y mutation, haptoglobin polymorphism).

METHODS

We investigated 381 (176 males, 205 females, age 45 +/- 6 years) healthy Caucasians. Serum oxLDL, assayed by a mAb-4E6-based enzyme-linked immunosorbent assay (ELISA), was expressed as oxLDL/LDL ratio to adjust for serum LDL-cholesterol concentration. Hemochromatosis gene C282Y mutation analysis was performed by a Taqman-based polymerase chain reaction (PCR) assay. Haptoglobin (Hp) phenotypes (Hp 1-1, Hp 2-1, Hp 2-2) were determined by starch gel electrophoresis.

RESULTS

In stepwise multivariate regression analysis, gender (P < 0.0001), current smoking (P < 0.0001), HDL-cholesterol (P = 0.0001), ferritin (P = 0.0051), body mass index (BMI) (P = 0.0063), and Hp phenotype (P = 0.0331) independently predicted oxLDL/LDL ratio in the total group. In men, smoking (P < 0.0001), ferritin (P = 0.0052), Hp phenotype (P = 0.0063), and HDL-cholesterol (P = 0.0127) were independent determinants of oxLDL/LDL ratio. In women, only body mass index (P < 0.0001), HDL-cholesterol (P = 0.0005), and smoking (P = 0.0025) were significantly associated with oxLDL/LDL ratio. The C282Y mutation (wild-type versus C282Y heterozygotes) was not associated with oxLDL/LDL ratio in both sexes.

CONCLUSION

Serum ferritin concentration and Hp polymorphism are independently associated with circulating oxLDL levels in males.