Iron status in Danish women, 1984-1994: a cohort comparison of changes in iron stores and the prevalence of iron deficiency and iron overload

Prevalence of Iron Deficiency Using 3 Definitions Among Women in the US and Canada

Importance

The prevalence of iron deficiency varies widely according to how it is defined.

Objective

To compare the prevalence of iron deficiency among women using 3 different definitions.

Design, Setting, and Participants

The cross-sectional Hemochromatosis and Iron Overload Screening Study (HEIRS; 2000-2006) evaluated the prevalence, determinants, and outcomes of hemochromatosis and other iron-related disorders. Multiethnic, primary care-based screening (2001-2003) was performed at 5 field centers (4 in the US and 1 in Canada). Volunteer women aged 25 years and older were recruited at primary care venues associated with the field centers. Data were analyzed from June to December 2023.

Main Outcomes and Measures

Measures included transferrin saturation, serum ferritin level, and self-reported age, pregnancy, and race and ethnicity. Three iron deficiency definitions were studied: (1) combined transferrin saturation less than 10% and serum ferritin less than 15 ng/mL (HEIRS), (2) serum ferritin less than 15 ng/mL (World Health Organization [WHO]), and (3) serum ferritin less than 25 ng/mL (a threshold for iron-deficient erythropoiesis [IDE]).

Results

Among 62 685 women (mean [SD] age, 49.58 [14.27] years), 1957 women (3.12%) had iron deficiency according to the HEIRS definition, 4659 women (7.43%) had iron deficiency according to the WHO definition, and 9611 women (15.33%) had iron deficiency according to the IDE definition. Among 40 381 women aged 25 to 54 years, 1801 women (4.46%) had iron deficiency according to HEIRS, 4267 women (10.57%) had iron deficiency according to WHO, and 8573 women (21.23%) had iron deficiency according to IDE. Prevalence rates of iron deficiency among 2039 women aged 25 to 44 years who reported pregnancy were 5.44% (111 women) according to HEIRS, 18.05% (368 women) according to WHO, and 36.10% (736 women) according to IDE. Iron deficiency prevalence by the 3 respective definitions increased significantly in each racial and ethnic group and was significantly higher among Black and Hispanic participants than Asian and White participants. The relative iron deficiency prevalence among the 62 685 women increased 2.4-fold (95% CI, 2.3-2.5; P < .001) using the WHO definition and increased 4.9-fold (95% CI, 4.7-5.2; P < .001) using the IDE definition.

Conclusions and Relevance

Three definitions of iron deficiency were associated with significantly different prevalence of iron deficiency in women, regardless of self-reported age, pregnancy, or race and ethnicity. Using higher serum ferritin thresholds to define iron deficiency could lead to diagnosis and treatment of more women with iron deficiency and greater reduction of related morbidity.

Association of hysterectomy with nonalcoholic fatty liver disease among US women

BACKGROUND

A postmenopausal rise in the rates of nonalcoholic fatty liver disease (NAFLD) has been reported in women. This study thus sought to further probe the association of hysterectomy with NAFLD.

METHODS

The data utilized in this investigation were attained from the 2017-March 2020 cycle of the National Health and Nutrition Examination Survey (NHANES), reflecting a strategic utilization of comprehensive health and nutrition information in the US population, to conduct a cross-sectional examination of the relationship between self-reported hysterectomy and NAFLD. Subjects included in this study were women aged 20 years or older. The multivariable logistic regression methodologies were utilized to determine the pertinent odds ratios (ORs) and their associated 95% confidence intervals (CIs).

RESULTS

Of the 2,868 subjects enrolled in this study (mean age: 51.3 years, 95%CI: 50.0-52.6 years), 22.1% (95%CI: 19.7-24.7%) reported having undergone a hysterectomy, while 31.1% (95%CI: 28.1-34.1%) exhibited elastographic evidence of NAFLD, and 3.8% (95%CI: 2.6-5.6%) exhibited clinically significant fibrosis (CSF). Relative to women with no history of hysterectomy, those that had undergone hysterectomy exhibited a higher odd of NAFLD (OR:1.66, 95%CI: 1.24-2.21) in a multivariable model fully adjusted for age, ethnicity, body mass index, female hormone use, oophorectomy, diabetes, hyperlipidemia, and smoking status. Subgroup analyses revealed a stronger association among women who were not obese (OR:2.23, 95%CI:1.61-3.11), women who were not affected by diabetes (OR:1.76, 95%CI: 1.25-2.46), and without hyperlipidemia (OR: 1.87, 95%CI: 1.10-3.16). No significant association of hysterectomy with NAFLD encompassing CSF was identified.

CONCLUSIONS

The results of the present nationally representative analysis suggested an association between hysterectomy and increased NAFLD prevalence among US women. Knowledge of this relationship may better aid clinical efforts to screen for and manage NAFLD.

Toenail and serum levels as biomarkers of iron status in pre- and postmenopausal women: correlations and stability over eight-year follow-up

Iron status is often assessed in epidemiologic studies, and toenails offer a convenient alternative to serum because of ease of collection, transport, and storage, and the potential to reflect a longer exposure window. Very few studies have examined the correlation between serum and toenail levels for trace metals. Our aim was to compare iron measures using serum and toenails on both a cross-sectional and longitudinal basis. Using a subset of the US-wide prospective Sister Study cohort, we compared toenail iron measures to serum concentrations for iron, ferritin and percent transferrin saturation. Among 146 women who donated both blood and toenails at baseline, a subsample (59%, n = 86) provided specimens about 8 years later. Cross-sectional analyses included nonparametric Spearman's rank correlations between toenail and serum biomarker levels. We assessed within-woman maintenance of rank across time for the toenail and serum measures and fit mixed effects models to measure change across time in relation to change in menopause status. Spearman correlations at baseline (follow-up) were 0.08 (0.09) for serum iron, 0.08 (0.07) for transferrin saturation, and - 0.09 (- 0.17) for ferritin. The within-woman Spearman correlation for toenail iron between the two time points was higher (0.47, 95% CI 0.30, 0.64) than for serum iron (0.30, 95% CI 0.09, 0.51) and transferrin saturation (0.34, 95% CI 0.15, 0.54), but lower than that for ferritin (0.58, 95% CI 0.43, 0.73). Serum ferritin increased over time while nail iron decreased over time for women who experienced menopause during the 8-years interval. Based on cross-sectional and repeated assessments, our evidence does not support an association between serum biomarkers and toenail iron levels. Toenail iron concentrations did appear to be moderately stable over time but cannot be taken as a proxy for serum iron biomarkers and they may reflect physiologically distinct fates for iron.

Associations of blood trace elements with bone mineral density: a population-based study in US adults

BACKGROUND

This study aimed to investigate the association between blood trace elements and bone mineral density (BMD) and to determine the association between blood trace elements and the risk of low BMD/osteoporosis among US adults.

METHODS

We performed a cross-sectional study using data from National Health and Nutrition Examination Survey (NHANES, 2011-2016). Multivariable linear regression models were employed to assess the associations of BMD in lumbar spine (LS-BMD), pelvic (PV-BMD) and total femur (TF-BMD) with blood trace elements, including Fe, Zn, Cu, Se, Mn, Cd, Pb, Hg. Additionally, the associations of low BMD/osteoporosis with blood trace elements were also evaluated using multivariable logistic regression.

RESULTS

Higher blood Pb levels were found associated with decreased LS-BMD (p for trend < 0.001), PV-BMD (p for trend = 0.007), and TF-BMD (p for trend = 0.003) in female, while higher blood Se levels were associated with increased PV-BMD in female (p for trend = 0.042); no linear association between BMD and other blood trace element was observed. Also, significant associations were found between Pb levels and the prevalence of low BMD (p for trend = 0.030) and the prevalence of osteoporosis (p for trend = 0.036), while association between other blood trace elements and low BMD/osteoporosis was not observed.

CONCLUSION

This study provides comprehensive insight into the association between blood trace elements and BMD and supports a detrimental effect of blood Pb levels on bone mass in women. Considering our analysis from a representative US general population, further study is warranted for the extreme levels of blood trace elements on bone metabolism.

Changes in Iron Status Biomarkers with Advancing Age According to Sex and Menopause: A Population-Based Study

BACKGROUND

The risk of chronic diseases increases markedly with age and after menopause. An increase in bodily iron following menopause could contribute to this phenomenon of increased risk of chronic diseases. We aimed to investigate how various iron biomarkers change with advancing age, according to sex and menopausal status.

METHODS

We enrolled community-dwelling individuals with available information on ferritin, transferrin, iron, hepcidin, and soluble transferrin receptor levels from the Prevention of Renal and Vascular Endstage Disease study. The association of the iron biomarkers with age, sex, and menopausal status was investigated with linear regression models.

RESULTS

Mean (SD) age of the 5222 individuals (2680 women [51.3%], among whom 907 [33.8%] were premenopausal, 529 [19.7%] perimenopausal, and 785 [29.3%] postmenopausal), was 53.4 (12.0) years. Iron biomarkers showed a constant increase in women throughout their life course, in some cases at older ages surpassing values in men who, in turn, showed consistently higher levels of iron status compared to women in most age categories. Ferritin, hepcidin, and transferrin saturation levels were 3.03, 2.92, and 1.08-fold (all p < 0.001) higher in postmenopausal women compared to premenopausal.

CONCLUSIONS

We found that iron accumulates differently depending on sex, age, and menopausal status. An increased iron status was identified in women, especially during and after menopause.

Early menopause and cardiovascular risk factors: a cross-sectional and longitudinal study

OBJECTIVE

The aim of the study is to evaluate the cross-sectional and longitudinal association of early natural menopause with changes in cardiovascular risk factors (CVRFs).

METHODS

Postmenopausal women from the Swiss CoLaus study, reporting age at natural menopause (ANM) and having CVRFs measurements (blood lipids, blood pressure, glucose, homeostatic model assessment for insulin resistance [HOMA-IR], and inflammatory markers) at baseline (2003-2006) and first follow-up (2009-2012) were eligible for analysis. Age at natural menopause was analyzed as a continuous variable and in categories (ANM <45 and ≥45 y old). Linear regression analysis and linear mixed models were used to assess whether ANM is associated cross-sectionally and longitudinally with changes in CVRFs. Models were adjusted for demographic characteristics, lifestyle-related factors, time since menopause, medication, and clinical conditions.

RESULTS

We analyzed 981 postmenopausal women. The cross-sectional analysis showed that women with ANM younger than 45 years had lower diastolic blood pressure (β = -3.76 mm Hg; 95% confidence interval [CI] = -5.86 to -1.65) compared with women whose ANM was 45 years or older. In the longitudinal analysis, ANM younger than 45 years was associated with changes in log insulin (β = 0.26; 95% CI = 0.08 to 0.45) and log homeostatic model assessment for insulin resistance levels (β = 0.28; 95% CI = 0.08 to 0.48). No associations were found between ANM and other CVRFs.

CONCLUSIONS

Early menopause may be associated with changes in glucose metabolism, while it may have little to no impact on other CVRFs. Larger longitudinal studies are needed to replicate our findings.

Managing Genetic Hemochromatosis: An Overview of Dietary Measures, Which May Reduce Intestinal Iron Absorption in Persons With Iron Overload

Genetic hemochromatosis causes iron overload by excess absorption of dietary iron, due to a decreased expression of hepcidin. The objective was to elaborate dietary recommendations that can reduce intestinal iron absorption in hemochromatosis patients, based on our present knowledge of the iron contained in nutrients and the mechanisms of iron uptake. This is a narrative review. Literature search in PubMed and Google Scholar of papers dealing with iron absorption from the diet was conducted. Most important proposed dietary recommendations are: 1) Choose a varied vegetarian, semi-vegetarian or flexitarian diet. A “veggie-lacto-ovo-poultry-pescetarian” diet seems optimal. Avoid iron enriched foods and iron supplements. 2) Eat many vegetables and fruits, at least 600 g per day. Choose protein rich pulses and legumes (e.g., kidney- and soya beans). Fresh fruits should be eaten between meals. 3) Abstain from red meat from mammals and choose the lean, white meat from poultry. Avoid processed meat, offal and blood containing foods. Eat no more than 200 g meat from poultry per week. Choose fish, eggs, vegetables and protein rich legumes the other days. Eat fish two to four times a week as main course, 350 - 500 g fish per week, of which half should be fat fish. 4) Choose whole grain products in cereals and bread. Avoid iron enriched grains. Choose non-sourdough, yeast-fermented bread with at least 50% whole grain. 5) Choose vegetable oils, and low-fat dairy products. 6) Eat less sugar and salt. Choose whole foods and foods with minimal processing and none or little added sugar or salt. 7) Quench your thirst in water. Drink green- or black tea, coffee, or low-fat milk with the meals, alternatively water or non-alcoholic beer. Fruit juices must be consumed between meals. Abstain from alcoholic beverages. Drink soft drinks, non-alcoholic beer, or non-alcoholic wine instead. These advices are close to the official Danish dietary recommendations in 2021. In the management of hemochromatosis, dietary modifications that lower iron intake and decrease iron bioavailability may provide additional measures to reduce iron uptake from the foods and reduce the number of phlebotomies. However, there is a need for large, prospective, randomized studies that specifically evaluate the effect of dietary interventions.

Wheat flour fortification with iron and other micronutrients for reducing anaemia and improving iron status in populations

BACKGROUND

Anaemia is a condition where the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body's physiological needs. Fortification of wheat flour is deemed a useful strategy to reduce anaemia in populations.

OBJECTIVES

To determine the benefits and harms of wheat flour fortification with iron alone or with other vitamins and minerals on anaemia, iron status and health-related outcomes in populations over two years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, 21 other databases and two trials registers up to 21 July 2020, together with contacting key organisations to identify additional studies.

SELECTION CRITERIA

We included cluster- or individually-randomised controlled trials (RCTs) carried out among the general population from any country, aged two years and above. The interventions were fortification of wheat flour with iron alone or in combination with other micronutrients. We included trials comparing any type of food item prepared from flour fortified with iron of any variety of wheat DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results and assessed the eligibility of studies for inclusion, extracted data from included studies and assessed risks of bias. We followed Cochrane methods in this review.

MAIN RESULTS

Our search identified 3538 records, after removing duplicates. We included 10 trials, involving 3319 participants, carried out in Bangladesh, Brazil, India, Kuwait, Philippines, South Africa and Sri Lanka. We identified two ongoing studies and one study is awaiting classification. The duration of interventions varied from 3 to 24 months. One study was carried out among adult women and one trial among both children and nonpregnant women. Most of the included trials were assessed as low or unclear risk of bias for key elements of selection, performance or reporting bias. Three trials used 41 mg to 60 mg iron/kg flour, three trials used less than 40 mg iron/kg and three trials used more than 60 mg iron/kg flour. One trial used various iron levels based on type of iron used: 80 mg/kg for electrolytic and reduced iron and 40 mg/kg for ferrous fumarate. All included studies contributed data for the meta-analyses. Iron-fortified wheat flour with or without other micronutrients added versus wheat flour (no added iron) with the same other micronutrients added Iron-fortified wheat flour with or without other micronutrients added versus wheat flour (no added iron) with the same other micronutrients added may reduce by 27% the risk of anaemia in populations (risk ratio (RR) 0.73, 95% confidence interval (CI) 0.55 to 0.97; 5 studies, 2315 participants; low-certainty evidence). It is uncertain whether iron-fortified wheat flour with or without other micronutrients reduces iron deficiency (RR 0.46, 95% CI 0.20 to 1.04; 3 studies, 748 participants; very low-certainty evidence) or increases haemoglobin concentrations (in g/L) (mean difference MD 2.75, 95% CI 0.71 to 4.80; 8 studies, 2831 participants; very low-certainty evidence). No trials reported data on adverse effects in children (including constipation, nausea, vomiting, heartburn or diarrhoea), except for risk of infection or inflammation at the individual level. The intervention probably makes little or no difference to the risk of Infection or inflammation at individual level as measured by C-reactive protein (CRP) (mean difference (MD) 0.04, 95% CI -0.02 to 0.11; 2 studies, 558 participants; moderate-certainty evidence). Iron-fortified wheat flour with other micronutrients added versus unfortified wheat flour (nil micronutrients added) It is unclear whether wheat flour fortified with iron, in combination with other micronutrients decreases anaemia (RR 0.77, 95% CI 0.41 to 1.46; 2 studies, 317 participants; very low-certainty evidence). The intervention probably reduces the risk of iron deficiency (RR 0.73, 95% CI 0.54 to 0.99; 3 studies, 382 participants; moderate-certainty evidence) and it is unclear whether it increases average haemoglobin concentrations (MD 2.53, 95% CI -0.39 to 5.45; 4 studies, 532 participants; very low-certainty evidence). No trials reported data on adverse effects in children. Nine out of 10 trials reported sources of funding, with most having multiple sources. Funding source does not appear to have distorted the results in any of the assessed trials.

AUTHORS' CONCLUSIONS

Fortification of wheat flour with iron (in comparison to unfortified flour, or where both groups received the same other micronutrients) may reduce anaemia in the general population above two years of age, but its effects on other outcomes are uncertain. Iron-fortified wheat flour in combination with other micronutrients, in comparison with unfortified flour, probably reduces iron deficiency, but its effects on other outcomes are uncertain. None of the included trials reported data on adverse side effects except for risk of infection or inflammation at the individual level. The effects of this intervention on other health outcomes are unclear. Future studies at low risk of bias should aim to measure all important outcomes, and to further investigate which variants of fortification, including the role of other micronutrients as well as types of iron fortification, are more effective, and for whom.

Iron deficiency and pruritus: A cross-sectional analysis to assess its association and relationship

Background:

As generalized pruritus can be a symptom of a systemic disease, iron deficiency may be the underlying internal cause of its symptoms. Because data on the relationship between iron deficiency and generalized chronic pruritus are limited, more research is needed to ensure proper diagnosis and management.

Aims:

To evaluate the prevalence of iron deficiency in patients with generalized chronic pruritus in the southeast region of Rajasthan and to assess the correlation of serum ferritin with iron deficiency variables.

Materials and Methods:

An observational, analytical study was conducted among a total of 200 patients complaining of itching all across the body without any skin lesions for more than 6 weeks and enrolled in the outdoor and indoor Dermatology, Venereology, and Leprology departments of the Government Medical College, Kota. The duration of the study experiment was 1 year from June 2018 to May 2019.

Results:

Females (108; 54%) were more than males (92; 46%) with a ratio of 1.17:1. The mean age of the patients was 37.35 ± 13.56. S. ferritin was found to be below 15 g/L in 58 (29%) patients. Significant correlation was found between S. ferritin and hemoglobin, MCV, MCH, and MCHC, and the P value was <0.05. Maximum number of patients (70; 35%) achieved visual analog scale (VAS) scores between 4 and 9, followed by 50 (25%) patients obtaining scores >9. Similarly, a correlation was found between the VAS score and hemoglobin, MCV, MCH, and MCHC and a statistically significant P value was obtained.

Limitations:

The sample size was small in the study. The overall levels of iron and serum transferrin were not checked, keeping patients' compliance in mind.

Conclusion:

Although statistically significant results were found, limitations were also present in our study; so, further studies for proper diagnosis and management should be conducted in greater depth.

Dietary Iron Intakes in Men in Europe Are Distinctly Above the Recommendations: A Review of 39 National Studies From 20 Countries in the Period 1995 - 2016

The objective of this review was to assess whether dietary iron intake in men in Europe is in symphony with the dietary recommendations. A literature search of national dietary surveys reporting the intake of iron using PubMed, Google Scholar, National Nutrient Databases and previous literature on dietary reviews was performed. The subjects were men aged 18 - 70 years. A total of 39 national dietary surveys in 20 European countries in the period 1995 - 2016 were included. There were considerable differences between median/mean iron dietary intake in the 20 countries. Seven countries/regions, UK-Northern Ireland, UK-Wales, Sweden, Belgium, UK-Scotland, UK-England and Serbia reported median/mean iron intake ranging from 10.5 to 11.6 mg/day. Ten countries, Norway, Finland, Lithuania, Italy, Hungary, Portugal, The Netherlands, Denmark, Iceland and Austria reported iron intake from 12.0 to 13.5 mg/day. France, Germany, Ireland and Spain reported iron intake from 14.8 to 16.0 mg/day, while Poland and Slovakia reported the highest intake of 17.2 and 22.7 mg/day. In surveys from France and The Netherlands, intake of heme iron constituted 11% of total dietary iron intake. Nutrient density for iron, reported in five countries, varied from median 11.6 mg iron/10 MJ in Denmark to 16.0 in France. In all countries, the majority of men had a dietary iron intake markedly above a recommended intake of 9 mg/day. In Europe, 75-87% of men have a dietary iron intake above 9 mg/day. A high iron intake together with relatively high intakes of meat and alcohol contributes to a high iron status and a high frequency of body iron overload in many men. We need consensus on common European standardized dietary methods, uniform dietary reference values and uniform statistical methods to perform inter-country comparisons.

Wheat flour fortification with iron for reducing anaemia and improving iron status in populations

BACKGROUND

Anaemia is a condition where the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body's physiologic needs. Fortification of wheat flour is deemed a useful strategy to reduce anaemia in populations.

OBJECTIVES

To determine the benefits and harms of wheat flour fortification with iron alone or with other vitamins and minerals on anaemia, iron status and health-related outcomes in populations over two years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and other databases up to 4 September 2019.

SELECTION CRITERIA

We included cluster- or individually randomised controlled trials (RCT) carried out among the general population from any country aged two years and above. The interventions were fortification of wheat flour with iron alone or in combination with other micronutrients. Trials comparing any type of food item prepared from flour fortified with iron of any variety of wheat were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results and assessed the eligibility of studies for inclusion, extracted data from included studies and assessed risk of bias. We followed Cochrane methods in this review.

MAIN RESULTS

Our search identified 3048 records, after removing duplicates. We included nine trials, involving 3166 participants, carried out in Bangladesh, Brazil, India, Kuwait, Phillipines, Sri Lanka and South Africa. The duration of interventions varied from 3 to 24 months. One study was carried out among adult women and one trial among both children and nonpregnant women. Most of the included trials were assessed as low or unclear risk of bias for key elements of selection, performance or reporting bias. Three trials used 41 mg to 60 mg iron/kg flour, two trials used less than 40 mg iron/kg and three trials used more than 60 mg iron/kg flour. One trial employed various iron levels based on type of iron used: 80 mg/kg for electrolytic and reduced iron and 40 mg/kg for ferrous fumarate. All included studies contributed data for the meta-analyses. Seven studies compared wheat flour fortified with iron alone versus unfortified wheat flour, three studies compared wheat flour fortified with iron in combination with other micronutrients versus unfortified wheat flour and two studies compared wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with the same micronutrients (but not iron). No studies included a 'no intervention' comparison arm. None of the included trials reported any other adverse side effects (including constipation, nausea, vomiting, heartburn or diarrhoea). Wheat flour fortified with iron alone versus unfortified wheat flour (no micronutrients added) Wheat flour fortification with iron alone may have little or no effect on anaemia (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.61 to 1.07; 5 studies; 2200 participants; low-certainty evidence). It probably makes little or no difference on iron deficiency (RR 0.43, 95% CI 0.17 to 1.07; 3 studies; 633 participants; moderate-certainty evidence) and we are uncertain about whether wheat flour fortified with iron increases haemoglobin concentrations by an average 3.30 (g/L) (95% CI 0.86 to 5.74; 7 studies; 2355 participants; very low-certainty evidence). No trials reported data on adverse effects in children, except for risk of infection or inflammation at the individual level. The intervention probably makes little or no difference to risk of Infection or inflammation at individual level as measured by C-reactive protein (CRP) (moderate-certainty evidence). Wheat flour fortified with iron in combination with other micronutrients versus unfortified wheat flour (no micronutrients added) Wheat flour fortified with iron, in combination with other micronutrients, may or may not decrease anaemia (RR 0.95, 95% CI 0.69 to 1.31; 2 studies; 322 participants; low-certainty evidence). It makes little or no difference to average risk of iron deficiency (RR 0.74, 95% CI 0.54 to 1.00; 3 studies; 387 participants; moderate-certainty evidence) and may or may not increase average haemoglobin concentrations (mean difference (MD) 3.29, 95% CI -0.78 to 7.36; 3 studies; 384 participants; low-certainty evidence). No trials reported data on adverse effects in children. Wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with same micronutrients (but not iron) Given the very low certainty of the evidence, the review authors are uncertain about the effects of wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with same micronutrients (but not iron) in reducing anaemia (RR 0.24, 95% CI 0.08 to 0.71; 1 study; 127 participants; very low-certainty evidence) and in reducing iron deficiency (RR 0.42, 95% CI 0.18 to 0.97; 1 study; 127 participants; very low-certainty evidence). The intervention may make little or no difference to the average haemoglobin concentration (MD 0.81, 95% CI -1.28 to 2.89; 2 studies; 488 participants; low-certainty evidence). No trials reported data on the adverse effects in children. Eight out of nine trials reported source of funding with most having multiple sources. Funding source does not appear to have distorted the results in any of the assessed trials.

AUTHORS' CONCLUSIONS

Eating food items containing wheat flour fortified with iron alone may have little or no effect on anaemia and probably makes little or no difference in iron deficiency. We are uncertain on whether the intervention with wheat flour fortified with iron increases haemoglobin concentrations improve blood haemoglobin concentrations. Consuming food items prepared from wheat flour fortified with iron, in combination with other micronutrients, has little or no effect on anaemia, makes little or no difference to iron deficiency and may or may not improve haemoglobin concentrations. In comparison to fortified flour with micronutrients but no iron, wheat flour fortified with iron with other micronutrients, the effects on anaemia and iron deficiency are uncertain as certainty of the evidence has been assessed as very low. The intervention may make little or no difference to the average haemoglobin concentrations in the population. None of the included trials reported any other adverse side effects. The effects of this intervention on other health outcomes are unclear.

Dietary Iron Intake in Women of Reproductive Age in Europe: A Review of 49 Studies from 29 Countries in the Period 1993-2015

OBJECTIVE

Assessment of dietary iron intake in women of reproductive age in Europe.

DESIGN

Review.

SETTING

Literature search of dietary surveys reporting intake of iron using PubMed, Internet browsers, and national nutrient databases in the period 1993-2015.

SUBJECTS

Women of reproductive age.

RESULTS

49 dietary surveys/studies in 29 European countries were included. Belgium, Bosnia, Denmark, Hungary, Italy, Northern Ireland, Serbia, Scotland, Sweden, Switzerland, United Kingdom/England, and Wales reported a median/mean iron intake of 7.6-9.9 mg/day. Finland, Iceland, Ireland, the Netherlands, Norway, Poland, and Spain reported an intake of 10.0-10.7 mg/day. Austria, Estonia, France, and Russia reported an intake of 11.0-11.9 mg/day. Latvia and Germany reported an intake of 12.0-12.2 mg/day. Croatia, Lithuania, Portugal, and Slovakia reported an intake of 15.9-19.0 mg/day. The percentage of dietary iron consisting of heme iron, reported in 7 studies, varied from 4.3% in United Kingdom to 25% in Spain. Nutrient density for iron (mg iron/10 MJ, median/mean) varied from 11.8 in Sweden to 23.0 in Lithuania. The correlation between nutrient density and dietary iron was significant (p=0.0006). In most countries, the majority of women had a dietary iron intake below 15 mg/day. In Belgium, Denmark, Hungary, and Sweden, 91-95% of women had an intake below 15 mg/day. In Ireland and Germany, 61-78% had an intake below 15 mg/day.

CONCLUSIONS

In Europe, 61-97% of women have a dietary iron intake below 15 mg/day. This contributes to a low iron status in many women. We need common European standardized dietary methods, uniform dietary reference values, and uniform statistical methods to perform intercountry comparisons.

Measurement of liver iron by magnetic resonance imaging in the UK Biobank population

The burden of liver disease continues to increase in the UK, with liver cirrhosis reported to be the third most common cause of premature death. Iron overload, a condition that impacts liver health, was traditionally associated with genetic disorders such as hereditary haemochromatosis, however, it is now increasingly associated with obesity, type-2 diabetes and non-alcoholic fatty liver disease. The aim of this study was to assess the prevalence of elevated levels of liver iron within the UK Biobank imaging study in a cohort of 9108 individuals. Magnetic resonance imaging (MRI) was undertaken at the UK Biobank imaging centre, acquiring a multi-echo spoiled gradient-echo single-breath-hold MRI sequence from the liver. All images were analysed for liver iron and fat (expressed as proton density fat fraction or PDFF) content using LiverMultiScan. Liver iron was measured in 97.3% of the cohort. The mean liver iron content was 1.32 ± 0.32 mg/g while the median was 1.25 mg/g (min: 0.85 max: 6.44 mg/g). Overall 4.82% of the population were defined as having elevated liver iron, above commonly accepted 1.8 mg/g threshold based on biochemical iron measurements in liver specimens obtained by biopsy. Further analysis using univariate models showed elevated liver iron to be related to male sex (p<10⁻¹⁶, r² = 0.008), increasing age (p<10⁻¹⁶, r² = 0.013), and red meat intake (p<10⁻¹⁶, r² = 0.008). Elevated liver fat (>5.6% PDFF) was associated with a slight increase in prevalence of elevated liver iron (4.4% vs 6.3%, p = 0.0007). This study shows that population studies including measurement of liver iron concentration are feasible, which may in future be used to better inform patient stratification and treatment.

Influence of Iron on Bone Homeostasis

Bone homeostasis is a complex process, wherein osteoclasts resorb bone and osteoblasts produce new bone tissue. For the maintenance of skeletal integrity, this sequence has to be tightly regulated and orchestrated. Iron overload as well as iron deficiency disrupt the delicate balance between bone destruction and production, via influencing osteoclast and osteoblast differentiation as well as activity. Iron overload as well as iron deficiency are accompanied by weakened bones, suggesting that balanced bone homeostasis requires optimal-not too low, not too high-iron levels. The goal of this review is to summarize our current knowledge about how imbalanced iron influence skeletal health. Better understanding of this complex process may help the development of novel therapeutic approaches to deal with the pathologic effects of altered iron levels on bone.

Investigation and management of a raised serum ferritin

Serum ferritin level is one of the most commonly requested investigations in both primary and secondary care. Whilst low serum ferritin levels invariably indicate reduced iron stores, raised serum ferritin levels can be due to multiple different aetiologies, including iron overload, inflammation, liver or renal disease, malignancy, and the recently described metabolic syndrome. A key test in the further investigation of an unexpected raised serum ferritin is the serum transferrin saturation. This guideline reviews the investigation and management of a raised serum ferritin level. The investigation and management of genetic haemochromatosis is not dealt with however and is the subject of a separate guideline.

Utility of zinc protoporphyrin in management of whole blood donors

BACKGROUND

Deferral for low hemoglobin (Hb) increases the likelihood that donors do not return for future donations. Zinc protoporphyrin (ZPP) has been described as a sensitive marker of iron-deficient erythropoiesis, before Hb decreases. It is a relatively cheap, rapid, and easy-to-perform measurement in a drop of whole blood. To assess the utility of ZPP measurement in donor management we examined whether ZPP and Hb levels among first-time donors differ from repeat donors. We further explored whether ZPP increases over subsequent donations at a donor population level and whether increasing ZPP levels coincide with decreasing Hb levels and donor deferral.

STUDY DESIGN AND METHODS

We included first-time (n = 4983) and repeat (n = 3533) whole blood donors from the ZPP and Iron in the Netherlands Cohort (ZINC) study. ZPP and Hb were measured at each subsequent donation during a 4-year period after inclusion in the study.

RESULTS

Median ZPP levels were higher in repeat than in first-time donors. In first-time donors, especially women, ZPP levels were increased with a corresponding decline in Hb levels over subsequent donations. ZPP levels were increased among first-time donors deferred for low Hb.

CONCLUSION

Our results suggest that adding ZPP to Hb measurements in the daily blood collection setting, especially for first-time donors and first-time female donors may add to the identification of a donor subpopulation with low functional iron stores.

HFE p.C282Y homozygosity predisposes to rapid serum ferritin rise after menopause: A genotype-stratified cohort study of hemochromatosis in Australian women

BACKGROUND AND AIM

Women who are homozygous for the p.C282Y mutation in the HFE gene are at much lower risk of iron overload-related disease than p.C282Y homozygous men, presumably because of the iron-depleting effects of menstruation and pregnancy. We used data from a population cohort study to model the impact of menstruation cessation at menopause on serum ferritin (SF) levels in female p.C282Y homozygotes, with p.C282Y/p.H63D simple or compound heterozygotes and those with neither p.C282Y nor p.H63D mutations (HFE wild types) as comparison groups.

METHODS

A sample of the Melbourne Collaborative Cohort Study was selected for the "HealthIron" study (n = 1438) including all HFE p.C282Y homozygotes plus a random sample stratified by HFE-genotype (p.C282Y and p.H63D). The relationship between the natural logarithm of SF and time since menopause was examined using linear mixed models incorporating spline smoothing.

RESULTS

For p.C282Y homozygotes, SF increased by a factor of 3.6 (95% CI (1.8, 7.0), P < 0.001) during the first 10 years postmenopause, after which SF continued to increase but at less than half the previous rate. In contrast, SF profiles for other HFE genotype groups increase more gradually and did not show a distinction between premenopausal and postmenopausal SF levels. Only p.C282Y homozygotes had predicted SF exceeding 200 μg/L postmenopause, but the projected SF did not increase the risk of iron overload-related disease.

CONCLUSIONS

These data provide the first documented evidence that physiological blood loss is a major factor in determining the marked gender difference in expression of p.C282Y homozygosity.

Iron, human growth, and the global epidemic of obesity

Iron is an essential nutrient utilized in almost every aspect of cell function and its availability has previously limited life. Those same properties which allow iron to function as a catalyst in the reactions of life also present a threat via generation of oxygen-based free radicals. Accordingly; life exists at the interface of iron-deficiency and iron-sufficiency. We propose that: (1) human life is no longer positioned at the limits of iron availability following several decades of fortification and supplementation and there is now an overabundance of the metal among individuals of many societies; (2) this increased iron availability exerts a positive effect on growth by targeting molecules critical in regulating the progression of the cell cycle; there is increased growth in humans provided greater amounts of this metal; and indices of obesity can positively correlate with body stores of iron; and (3) diseases of obesity reflect this over-abundance of iron. Testing potential associations between iron availability and both obesity and obesity-related diseases in populations will be difficult since fortification and supplementation is so extensively practiced.

Exploring the relationship between maternal iron status and offspring's blood pressure and adiposity: a Mendelian randomization study

Background

Iron deficiency is the most common micronutrient deficiency worldwide. Experimental animal studies suggest that mothers deficient in iron during pregnancy are more likely to have offspring who become obese with high blood pressure. C282Y mutation carriers are more likely to have higher iron stores.

Methods

We undertook an instrumental variable (IV) analysis, using maternal C282Y as an indicator for the mother’s iron status, to examine its association with offspring blood pressure (BP), waist circumference (WC), and body mass index (BMI), and compared the results to that of ordinary least squares (OLS) regression. Offspring of a sub-cohort of mothers from the UK Women’s Cohort Study (UKWCS) were recruited in 2009–2010 (n = 348, mean age = 41 years). Their blood pressure, height, and weight were measured at their local general medical practice, and they were asked to self-measure their waist circumference. About half were offspring of C282Y carriers. Maternal ferritin was used as a biomarker of maternal iron status.

Results

Maternal C282Y was strongly associated with maternal ferritin (mean difference per allele = 84 g/L, 95% confidence interval: 31–137, P = 0.002). Using IV analyses, maternal ferritin was not linked to offspring’s BP, BMI, or WC. The first stage F-statistic for the strength of the instrument was 10 (Kleibergen–Paap rk LM P = 0.009). Maternal ferritin was linked to offspring diastolic BP, WC, and BMI in univariable, but not in multivariable OLS analysis. There was no difference between the OLS and the IV models coefficients for any of the outcomes considered.

Conclusion

We found no association between maternal iron status and adult offspring’s BP and adiposity using both multivariable OLS and IV modeling. To our knowledge, this is the first study examining this relationship. Further exploration in larger studies that have genetic variation assessed in both mother and offspring should be considered.

Changes in iron measures over menopause and associations with insulin resistance

OBJECTIVES

No longitudinal studies have examined how iron measures change over menopause. Our objectives were to examine iron measures in individual women at premenopause and at postmenopause and, secondarily, to determine if any changes contributed to insulin resistance.

METHODS

In a subset of participants (n=70) in a longitudinal study of menopause, we measured ferritin, transferrin, and soluble transferrin receptor (sTfR) once in the premenopause and once in the postmenopause. We also examined associations between menopausal status and change in iron markers after adjustment for age at menopause, race/ethnicity, and waist circumference. In linear regression models, we examined associations between premenopause iron measures and changes in iron markers over menopause with homeostasis model assessment of insulin resistance (HOMA-IR) changes over menopause, before and after adjustment for age at menopause, race/ethnicity, changes in waist circumference, C-reactive protein (CRP), and sex hormone-binding globulin (SHBG) levels.

RESULTS

Women had lower ferritin (p<0.01), higher sTfR:ferritin levels (p<0.01), lower HOMA-IR (p=0.022), and lower glucose (p=0.05) in premenopause compared to postmenopause. After adjustment, lower premenopausal iron levels (sTfR:ferritin levels β=11.0, 95% confidence interval [CI] 0.017-22.0) and larger increases in iron over menopause (changes in sTfR:ferritin β=13.6, 95% CI 0.93-26.3) were associated with larger increases in HOMA-IR.

CONCLUSIONS

From premenopause to postmenopause, women on average have increases in measures of iron stores. Women who had the greatest changes in iron over menopause (lower measures of premenopausal iron and greater increases in iron measures over the menopause) had the strongest associations between changes in iron and changes in insulin resistance.

Association of serum ferritin with metabolic syndrome and diabetes mellitus in the South Korean general population according to the Korean National Health and Nutrition Examination Survey 2008

We examined the association of serum ferritin levels with metabolic syndrome (MS) and diabetes mellitus in a representative sample of the adult South Korean population using data from the 2008 Korean National Health and Nutrition Examination Survey. We conducted a cross-sectional study of 6311 adults older than 20 years who participated in the 2008 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined as the presence of at least 3 of the following: elevated blood pressure, low high-density lipoprotein cholesterol, elevated serum triglycerides, elevated plasma glucose, and abdominal obesity. Diabetes mellitus was defined as fasting glucose of at least 126 mg/dL. Insulin resistance was determined using the homeostasis model assessment estimate of insulin resistance. In a representative sample of the adult Korean population, MS was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in women following adjustments for age, education, smoking, alcohol intake, body mass index, aspartate aminotransferase, and alanine aminotransferase. Diabetes mellitus was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in premenopausal women and men. The geometric means of fasting insulin and insulin resistance determined using the homeostasis model assessment of insulin resistance in the fourth serum ferritin quartiles of postmenopausal women and men were significantly higher compared with those in the first quartile of the respective groups. The present study demonstrates that elevated serum ferritin concentrations are associated with an increased risk of MS and diabetes mellitus in a representative sample of the adult South Korean population.

Impact of hemochromatosis gene (HFE) mutations on epithelial ovarian cancer risk and prognosis

Cancer cells require large amounts of micronutrients, particularly iron, for their rapid growth and frequent divisions. Cellular iron uptake is regulated by the transferrin receptor and the hemochromatosis protein (HFE) system. Two frequent mutations in the HFE gene, H63D and C282Y, are associated with hemochromatosis type I, an inherited iron overload disease and, possibly, with cancer. In this study, we evaluated the frequency of the H63D and C282Y mutations in a cohort of 677 consecutive cases of woman with gynecological pathologies. Cases included 80 women with tumor-free pathologies normal ovary (NOV), 124 with benign ovarian tumors (BOV), 96 with epithelial ovarian cancer (EOC) tumors of low malignant potential (LPM), 264 with invasive tumors of the ovary (TOV) and 113 with endometrial cancer. We found that the C282Y allele frequency in EOC patients was higher than that in the control NOV group (5.8% vs. 1.3%, p < 0.001) and was associated with an increased risk of ovarian cancer (OR = 4.88; 95% CI 1.15-20.61; p = 0.018). The effect of the two HFE mutations on patient survival was also analyzed. Kaplan-Meier analyses did not find any significant association between the H63D allele and patient survival. However, EOC patients with at least one C282Y allele had a decreased overall survival compared to those with no C282Y allele (p = 0.001). These results indicate that the C282Y mutation may increase the risk of developing ovarian cancer and may be further associated with poor outcomes.

Anemia--still a major health problem in many parts of the world!

Anemia is a major global health problem, especially in developing countries. This fundamental health issue still has not been solved and continues to exist affecting the health, quality of life, and working capacity in billions of people all over the world. This paper gives a review on the prevalence and major causes of anemia seen on a global scale. Most cases of anemia are due to iron deficiency, which often work in symphony with folate deficiency and/or vitamin B12 deficiency as well as with infections. More efforts should be dedicated to tackle this massive problem--we have the tools, and we know the ways. Iron fortification of appropriate food items combined with iron supplements in specific population groups has proven to be efficient. Initially, the efforts should be centered on the specific risk groups for iron deficiency anemia, i.e., young children, adolescent females, women of reproductive age, as well as pregnant women and postpartum lactating mothers.

Association between iron deficiency and A1C Levels among adults without diabetes in the National Health and Nutrition Examination Survey, 1999-2006

OBJECTIVE

Iron deficiency has been reported to elevate A1C levels apart from glycemia. We examined the influence of iron deficiency on A1C distribution among adults without diabetes.

RESEARCH DESIGN AND METHODS

Participants included adults without self-reported diabetes or chronic kidney disease in the National Health and Nutrition Examination Survey 1999-2006 who were aged > or =18 years of age and had complete blood counts, iron studies, and A1C levels. Iron deficiency was defined as at least two abnormalities including free erythrocyte protoporphyrin >70 microg/dl erythrocytes, transferrin saturation <16%, or serum ferritin < or =15 microg/l. Anemia was defined as hemoglobin <13.5 g/dl in men and <12.0 g/dl in women.

RESULTS

Among women (n = 6,666), 13.7% had iron deficiency and 4.0% had iron deficiency anemia. Whereas 316 women with iron deficiency had A1C > or =5.5%, only 32 women with iron deficiency had A1C > or =6.5%. Among men (n = 3,869), only 13 had iron deficiency and A1C > or =5.5%, and only 1 had iron deficiency and A1C > or =6.5%. Among women, iron deficiency was associated with a greater odds of A1C > or =5.5% (odds ratio 1.39 [95% CI 1.11-1.73]) after adjustment for age, race/ethnicity, and waist circumference but not with a greater odds of A1C > or =6.5% (0.79 [0.33-1.85]).

CONCLUSIONS

Iron deficiency is common among women and is associated with shifts in A1C distribution from <5.5 to > or =5.5%. Further research is needed to examine whether iron deficiency is associated with shifts at higher A1C levels.

Hair iron and other minerals' level in breast cancer patients

Little is known about hair minerals in cancer patients, and serum iron level has been shown to be elevated in breast cancer patients. Therefore, the aim of this study was to evaluate hair iron and hair minerals' level related to hair iron in breast cancer patients compared to controls. We compared hair mineral analysis data of 40 breast cancer subjects with age and body mass index-matched normal control data (n = 144) by cross-sectional analysis. All breast cancer patients were newly diagnosed at one Breast Cancer Center in Ajou University and had their hair cut before anti-cancer chemotherapy, and the normal controls (without breast cancer) also had their hair cut for various reasons in out-patient clinics of the Department of Family Practice and Community Health. Breast cancer patients had low calcium, magnesium, iron, copper, manganese, and zinc, whereas they had high arsenic, sodium, and potassium compared with the normal control. The hair iron level was positively correlated with hair calcium (r = 0.761, P < 0.001), magnesium (r = 0.643, P < 0.001), and manganese (r = 0.550, P < 0.001) and negatively correlated with arsenic (r = -0.537, P < 0.001). The hair iron level was significantly associated with the hair calcium (beta = 0.778, P < 0.001) and manganese (beta = 0.240, P < 0.001) by using multiple linear regression analysis. We observed different hair mineral patterns in breast cancer patients compared to normal controls. Especially, hair iron level was significantly reduced and associated with hair calcium and manganese levels.

Iron metabolism in heterozygotes for hemoglobin E (HbE), alpha-thalassemia 1, or beta-thalassemia and in compound heterozygotes for HbE/beta-thalassemia

BACKGROUND

Despite large populations carrying traits for thalassemia in countries implementing universal iron fortification, there are few data on the absorption and utilization of iron in these persons.

OBJECTIVE

We aimed to determine whether iron absorption or utilization (or both) in women heterozygous for beta-thalassemia, alpha-thalassemia 1, or hemoglobin E (HbE) differed from that in control subjects and compound HbE/beta-thalassemia heterozygotes.

DESIGN

In Thai women (n = 103), red blood cell indexes, iron status, non-transferrin-bound iron, and growth differentiation factor 15 were measured, and body iron was calculated. Fractional iron absorption was measured from meals fortified with isotopically labeled ((57)Fe) Fe sulfate, and iron utilization was measured by the infusion of ((58)Fe) Fe citrate.

RESULTS

Iron utilization was approximately 15% lower in alpha-thalassemia 1 or beta-thalassemia heterozygotes than in controls. When corrected for differences in serum ferritin, absorption was significantly higher in the alpha- and beta-thalassemia groups, but not the HbE heterozygotes, than in controls. HbE/beta-thalassemia compound heterozygotes had lower iron utilization and higher iron absorption and body iron than did controls. Nontransferrin-bound iron and growth differentiation factor 15 were higher in the compound heterozygotes, but not in the other groups, than in the controls.

CONCLUSIONS

In alpha-thalassemia 1 and beta-thalassemia heterozygotes with ineffective erythropoesis, dietary iron absorption is not adequately down-regulated, despite a modest increase in body iron stores. In populations with a high prevalence of these traits, a program of iron fortification could include monitoring for possible iron excess and for iron deficiency.

Does iron have a role in breast cancer?

Oestrogen and family history are two of the most important risk factors for breast cancer. However, these risk factors cannot explain the differences in the incidence and recurrence of breast cancer between premenopausal and postmenopausal women. In this paper I propose that, in premenopausal women, an iron deficiency caused by menstruation stabilises hypoxia inducible factor-1alpha, which increases the formation of vascular endothelial growth factor. This mechanism results in premenopausal women being more susceptible to angiogenesis and, consequently, leads to a high recurrence of breast cancer. Conversely, increased concentrations of iron in postmenopausal women, as a result of menstrual cessation, contribute to a high incidence of breast cancer via oxidative-stress pathways. Although the focus of this Personal View is on iron, this by no means negates the roles of other known risk factors in breast-cancer development. Characterisation of the role of iron in breast cancer could potentially benefit patients by decreasing recurrence and incidence and increasing overall survival.

Interpreting indicators of iron status during an acute phase response--lessons from malaria and human immunodeficiency virus

Iron status is influenced by inflammation when the normal control of iron metabolism is reorganized by the primary mediators of the acute phase response, tumour necrosis factor-alpha and interleukin-1. The objective of this review is to show how indices of iron status, particularly haemoglobin, serum ferritin and soluble transferrin receptor concentrations relate to changes in the acute phase proteins during inflammation. The pattern of acute phase response after elective surgery, not preceded by infection, is used to demonstrate the time course of stimulation of the acute phase proteins. The changes in the concentrations of serum acute phase protein and markers of iron status during treatment for infection are used to demonstrate inter-relationships between the indicators. In many developing countries, asymptomatic malaria and human immunodeficiency virus (HIV) are common and may affect the interpretation of iron indicators during population assessments. Malaria produces an acute phase response and relationships between acute phase protein and indices of iron status indicate an influence of inflammation in both symptomatic and asymptomatic malaria, except when the parasitaemia is less than 1000/microL of blood when ferritin appears to be unaffected. HIV-1 impacts on haemopoiesis and anaemia. Anaemia increases in severity as the disease progresses and it is often a negative prognostic indicator. However, in individuals infected with HIV there may be an atypical acute phase response in the absence of opportunistic infections. Tentative conclusions are drawn concerning the inter-relationships between ferritin and the acute phase proteins, C-reactive protein and alpha-1-acid glycoprotein during an acute phase response.

Roles of hormone replacement therapy and iron in proliferation of breast epithelial cells with different estrogen and progesterone receptor status

Estrogen and iron play critical roles in a female body development and were investigated in the present study in relation to in vitro cell proliferation. Prempro, a hormone replacement therapy drug, and 17beta-estradiol (E2) were shown to increase cell proliferations in estrogen receptor positive (ER+) cells independent of progesterone receptor (PR) status. For example, increased cell proliferation was observed in ER+/PR+ human breast cancer MCF-7, its matching non-cancerous human breast epithelial MCF-12A, and ER+/PR+ murine mammary cancer MXT+ cells, but not in ER-/PR- MDA-MB-231, its matching non-cancerous MCF-10A, and MXT- (ER-/PR+) cells. By mimicking post-menopausal conditions of high estrogen in local breast tissue and increased iron levels due to cessation of menstrual periods, E2 and iron were shown to exert synergistic effects on proliferation of MCF-7 cells and significantly increased Ki67 and proliferating cell nuclear antigen. Western blotting of E2-treated ER+ but not ER- cells showed that E2 also increased transferrin receptor (TfR). Further studies are needed to assess the mitogenic effects of iron and estrogen in normal post-menopausal breast.

The potential effect of iron defortification on iron-deficiency anaemia in the US population

Objective

To quantify the potential effect of iron defortification in the USA on iron-deficiency anaemia (IDA).

Methods

Monte Carlo models were built to simulate iron nutrition in the US population. A hypothetical cohort of 15 000 persons from the general population was used in 15-year simulations to compare the prevalence of IDA with and without fortification.

Results

With iron fortification, the prevalence of IDA was 2.4% for children aged 3–5 years, 5.4% for women aged 20–49 years, and 0.14% for men aged 20–49 years. The corresponding IDA estimates under iron defortification were 4.5%, 8.2% and 0.46%, respectively. Defortification had little effect on the distribution of iron indicators at or above the 50th percentile within each of these three groups and little effect on the distributions of iron indicators among adult men.

Conclusion

Iron defortification is likely to increase IDA among children and women of reproductive age, but is not likely to have meaningful effects on the iron status of men or the majority of women and children.

Does excess iron play a role in breast carcinogenesis? An unresolved hypothesis

Free iron is a pro-oxidant and can induce oxidative stress and DNA damage. The carcinogenicity of iron has been demonstrated in animal models, and epidemiologic studies have shown associations with several human cancers. However, a possible role of excess body iron stores or of elevated iron intake in breast carcinogenesis has received little attention epidemiologically. We propose that iron overload and the disruption of iron homeostasis with a resulting increase in free iron may contribute to the development of breast cancer, and we summarize the relevant evidence from mechanistic studies, animal experiments, and studies in humans. Over time a high intake of iron can lead to iron overload. Furthermore, body iron stores increase in women following menopause. Reactive oxygen species produced by normal aerobic cellular metabolism can lead to the release of free iron from ferritin. In the presence of superoxide radical and hydrogen peroxide, stored ferric iron (Fe(3+)) is reduced to ferrous iron (Fe(2+)), which catalyzes the formation of the hydroxyl radical (*OH). *OH in turn can promote lipid peroxidation, mutagenesis, DNA strand breaks, oncogene activation, and tumor suppressor inhibition, increasing the risk of breast cancer. In addition to its independent role as a proxidant, high levels of free iron may potentiate the effects of estradiol, ethanol, and ionizing radiation - three established risk factors for breast cancer. In order to identify the role of iron in breast carcinogenesis, improved biomarkers of body iron stores are needed, as are cohort studies which assess heme iron intake. Ultimately, it is important to determine whether iron levels in the breast and iron-induced pathology are higher in women who go on to develop breast cancer compared to women who do not.

Evaluation of iron deficiency in young women in relation to oral contraceptive use

BACKGROUND

The purpose of this study was to identify the optimal measures for diagnosing iron deficiency (ID) in oral contraceptive (OC) users and nonusers, and to estimate ID frequency in relation to OC use.

STUDY DESIGN

Conventional biomarkers of iron status - serum ferritin, iron, transferrin (Tf) and transferrin saturation (TfS) - were compared with serum soluble Tf receptor (sTfR) and the sTfR/log ferritin ratio (sTfR-F index). Two hundred two healthy menstruating white Italian women (aged 24+/-4.8 years) were analyzed. Serum ferritin concentrations <12 microg/L were considered as ID.

RESULTS

ID was detected in 29.7% (60/202) of the study women. Fifty-nine women were OC users (59/202, 29.2%). OC use did not significantly affect ID prevalence (p=.24). However, OC use markedly increased Tf in OC users, who had an odds ratio (OR) of 9.3 (CI 3.8-22.7, p<.001) for elevated Tf >330 mg/dL. No other iron status measure was affected by OC. Of the markers for ID adjunctive to ferritin, an elevated sTfR-F index >or =1.5 showed the best performance. Specifically in OC users, the elevated sTfR-F index had better sensitivity (81.0% vs. 33.3%), specificity (94.7% vs. 92.1%), efficiency (89.8% vs. 71.2%), positive predictive value (89.5% vs. 70.0%) and negative predictive value (90.0% vs. 71.1%) than a TfS <15%. Additionally, the sTfR-F index allowed the identification of low iron stores in 4.5% (9/202) of women with ferritin > or =12 microg/L.

CONCLUSION

Among healthy OC users and non-OC users, the sTfR-F index had the highest performance for diagnosing ID compared with other serum markers adjunctive to ferritin measurements, whereas sTfR by itself had a low sensitivity. We showed that neither the sTfR nor sTfR-F index was affected by third-generation OC use. The sTfR measurement is useful in the diagnosis of ID, especially in women using OC, where Tf and TfS tests may be misleading.

Nutritional iron deficiency

Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming monotonous plant-based diets. The high prevalence of iron deficiency in the developing world has substantial health and economic costs, including poor pregnancy outcome, impaired school performance, and decreased productivity. Recent studies have reported how the body regulates iron absorption and metabolism in response to changing iron status by upregulation or downregulation of key intestinal and hepatic proteins. Targeted iron supplementation, iron fortification of foods, or both, can control iron deficiency in populations. Although technical challenges limit the amount of bioavailable iron compounds that can be used in food fortification, studies show that iron fortification can be an effective strategy against nutritional iron deficiency. Specific laboratory measures of iron status should be used to assess the need for fortification and to monitor these interventions. Selective plant breeding and genetic engineering are promising new approaches to improve dietary iron nutritional quality.

Ferritin and transferrin are associated with metabolic syndrome abnormalities and their change over time in a general population: Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

OBJECTIVE

The aim of this work was to study cross-sectional and longitudinal relations between iron stocks (ferritin) and the iron transport protein (transferrin) with the metabolic syndrome and its abnormalities.

RESEARCH DESIGN AND METHODS

A total of 469 men and 278 premenopausal and 197 postmenopausal women from the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort, aged 30-65 years, were followed over 6 years.

RESULTS

Higher concentrations of both ferritin and transferrin were associated with the International Diabetes Federation (IDF) and the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults Adult Treatment Panel III original and revised definitions of the metabolic syndrome at baseline: for the IDF definition of the metabolic syndrome, the standardized, age-adjusted odds ratios (95% CI) for log(ferritin) were 1.49 (1.14-1.94) for men, 2.10 (1.27-3.48) for premenopausal women, and 1.80 (1.21-2.68) for postmenopausal women; for transferrin they were, respectively, 1.94 (1.53-2.47), 2.22 (1.32-3.75), and 2.14 (1.47-3.10). After 6 years of follow-up, the change in the presence of the metabolic syndrome was associated with higher baseline values in all three groups: log(ferritin), 1.46 (1.13-1.89), 1.28 (0.85-1.94), and 1.62 (1.10-2.38); and transferrin, 1.41 (1.10-1.81), 1.63 (1.05-2.52), and 1.51 (1.02-2.22). Among syndrome components, hypertriglyceridemia at 6 years was the component most strongly associated with baseline ferritin and transferrin. The odds of an incident IDF-defined metabolic syndrome after 6 years was more than fourfold higher when ferritin and transferrin values were both above the group-specific top tertile, in comparison with participants with both parameters below these thresholds.

CONCLUSIONS

This is the first prospective study associating ferritin and transferrin with the metabolic syndrome and its components. When both markers of the iron metabolism are elevated, the incidence of the metabolic syndrome is increased in men and both pre- and postmenopausal women.

Reliability of serum assays of iron status in postmenopausal women

PURPOSE

The aim of the study is to determine the reliability during a 2-year period of several newly developed iron-related assays to assess their potential for use in prospective epidemiologic studies.

METHODS

We assessed the temporal reliability of several iron-related assays by using three serum samples collected at yearly intervals from 50 postmenopausal participants in a large prospective study.

RESULTS

We observed high reliability coefficients for ferritin (0.78; 95% confidence interval [CI], 0.67-0.86), soluble transferrin receptor (sTfR; 0.79; 95% CI, 0.69-0.87), sTfR/ferritin ratio (0.74; 95% CI, 0.62-0.83), and hepcidin (0.89; 95% CI, 0.84-0.94). In a subset of 30 women, lower reliability was observed for serum iron (0.50; 95% CI, 0.29-0.70), unsaturated iron-binding capacity (0.55; 95% CI, 0.34-0.73), total iron-binding capacity (0.60; 95% CI, 0.40-0.76), and serum transferrin saturation rate (0.44; 95% CI, 0.22-0.65). The reliability of anti-5-hydroxymethyl-2'-deoxyuridine autoantibody titers, a biomarker of oxidized DNA damage, one of the mechanisms by which iron is thought to impact disease risk, was very high (0.97, 95% CI, 0.5-0.99).

CONCLUSIONS

Our results show that some newly developed iron-related assays could be useful tools to assess iron-disease associations in prospective cohorts that collect a single blood sample.

Iron supplement use among Danish pregnant women

OBJECTIVES

To evaluate compliance with the national recommendation on supplemental iron to all pregnant women in Denmark and to explore differences between compliers and non-compliers with respect to dietary habits and other lifestyle factors.

DESIGN

Intake of supplemental iron from pure iron supplements and from multivitamin and mineral preparations was estimated in mid-pregnancy.

SETTING

Nationwide cohort study, the Danish National Birth Cohort (DNBC), comprising more than 100,000 women recruited in early pregnancy.

SUBJECTS

Information on diet and dietary supplements was available for 54,371 women. Of these, information on lifestyle factors was available for 50,902 women.

RESULTS

A high compliance with the recommendation was found, as approximately 77% of the women reported use of iron supplements during pregnancy. However, many of the compliers did not obtain the recommended doses of iron, which can partly be explained by the lack of iron preparations of appropriate doses available on the Danish market. Compliance with the recommendation was associated with age above 20 years, primiparity, body mass index<30 kg m- 2, non-smoking and long education. No major differences were seen in dietary intake between compliers and non-compliers.ConclusionOverall, a high compliance rate was found among participants of the DNBC but a clarification on daily dose is needed, and more concern should be paid to vulnerable groups such as young, smoking women and women with no or short education.

Influence of human genetic variation on nutritional requirements

Genetic variation is known to affect food tolerances among human subpopulations and may also influence dietary requirements, giving rise to the new field of nutritional genomics and raising the possibility of individualizing nutritional intake for optimal health and disease prevention on the basis of an individual's genome. However, because gene-diet interactions are complex and poorly understood, the use of genomic knowledge to adjust population-based dietary recommendations is not without risk. Whereas current recommendations target most of the population to prevent nutritional deficiencies, inclusion of genomic criteria may indicate subpopulations that may incur differential benefit or risk from generalized recommendations and fortification policies. Current efforts to identify gene alleles that affect nutrient utilization have been enhanced by the identification of genetic variations that have expanded as a consequence of selection under extreme conditions. Identification of genetic variation that arose as a consequence of diet as a selective pressure helps to identify gene alleles that affect nutrient utilization. Understanding the molecular mechanisms underlying gene-nutrient interactions and their modification by genetic variation is expected to result in dietary recommendations and nutritional interventions that optimize individual health.

Correct assessment of iron depletion and iron deficiency anemia

OBJECTIVE

Iron deficiency anemia is caused by decreased production of red blood cells (RBCs) and is characterized by a reduction in either the hematocrit (Ht) or the concentration of hemoglobin (Hb). It is detected by blood iron status measures that are below population reference standards and also below the "usual or normal" levels for an individual. In some medicine practices, usually only hemoglobin and hematocrit are routinely measured with a full blood count, without measuring the indicators of iron status. Biochemical measures that are collected on single occasion are difficult to interpret in individuals, and normal ranges of hemoglobin and hematocrit do not necessarily confirm an iron deficiency condition, because they decrease only when severe iron depletion is present and are often unreliable or misleading. Thus, iron-depleted individuals can quickly develop iron deficiency if not detected early.

METHODS

Information from hematological laboratory tests records on female patients at reproductive ages were collected and analysed.

RESULTS

In this study, measurement of general test for anemia in some individuals revealed normal levels of RBCs count, Hb, Ht, mean corpuscular volume (MCV), mean cell hemoglobin concentration (MCHC), and cell morphology, whereas the levels of parameters of iron depletion and iron deficiency anemia such as serum iron and ferritin showed reduced values. The results indicate that individuals who are ordered cell blood count (CBC) measures alone without examining the indicators of iron status (Group C vs Group D) may not be correctly assessed with a definitive diagnosis and categorized as normal individuals. But in fact, they are susceptible to iron depletion and could develop iron deficiency anemia.

CONCLUSIONS

In evaluation of iron deficiency status it is important that total CBC test be accompanied by the other tests of iron status to pinpoint true iron deficiency. Otherwise, many cases may be missed out and misdiagnosed as normal individuals.

A safe strategy for addition of vitamins and minerals to foods

Addition of vitamins and minerals to foods must be done without health risk to any consumer group. International expert groups have aimed at establishing tolerable upper intake levels (ULs) for vitamins and minerals although lack of solid data on their safety is a major obstacle to this work. In this paper, we summarize the existing ULs and suggest the use of guidance levels (GLs) set by others and temporary guidance levels (TGLs) proposed here, whenever no consensus UL has been established for adults. We suggest the use of body surface area ratios to establish similar levels for younger age groups. The levels are applied in a model for calculation of safe fortification levels for all ages. We have estimated the upper 95(th) percentile intake of vitamins and minerals from food in various Danish age and gender groups and suggest that a daily multivitamin-mineral pill is included in the calculation of total dietary intake levels of all vitamins and minerals. By subtracting this dietary intake level from the UL, GL or TGL, we calculate the amount that can be safely used for fortification. Since safety must be assured for all age groups, the smallest difference relative to energy intake calculated for any age group is proposed as the maximal allowance (MA) for fortification with each nutrient. We suggest that the MA should be expressed in weight units per energy unit in order to distribute it equally between potentially fortifiable food groups according to their usual contribution to total energy intakes.

Diet and genetic factors associated with iron status in middle-aged women

BACKGROUND

Gene mutations associated with iron overload have been identified. How food and nutrient intakes affect iron status in persons who may be at risk of iron overload because their genetic status is unknown.

OBJECTIVE

The objective was to determine the relation between food and nutrient intakes, HFE genotype, and iron status. Foods and nutrients associated with iron stores, with adjustment for gene mutations associated with hemochromatosis, were explored.

DESIGN

A prospective cohort of women aged 35-69 y (the UK Women's Cohort Study) provided information on diet through a questionnaire and food diary; 6779 women in the cohort provided cheek cell samples, blood samples, or both, which were genotyped for C282Y and H63D mutations, and 2489 women also had their iron status assessed. Relations between serum ferritin and iron intake were investigated by using multiple linear regression, with adjustment for potential confounders.

RESULTS

The strongest dietary association with serum ferritin concentration was a positive association with heme iron and not with nonheme or total iron. Weaker positive associations were seen with red and white meat, and negative associations were seen with total energy and white and brown whole-meal bread, independent of genotype and other potential confounders. The effect of genotype on ferritin concentrations primarily occurred after menopause, at which time a strong interaction between genotype and heme iron intake was observed. Other factors associated with serum ferritin concentrations were age, body mass index, blood donation, menopausal status, and HFE genotype.

CONCLUSIONS

Postmenopausal women eating a diet rich in heme iron and who were C282Y homozygotes had the highest serum ferritin concentrations.