Risk of iron overload among middle-aged women

Cross-sectional and longitudinal associations of Iron biomarkers and cardiovascular risk factors in pre- and postmenopausal women: leveraging repeated measurements to address natural variability

BACKGROUND

The association between iron biomarkers and cardiovascular disease risk factors (CVD-RFs) remains unclear. We aimed to (1) evaluate the cross-sectional and longitudinal associations between iron biomarkers (serum ferritin, transferrin saturation (TSAT), transferrin) and CVD-RFs among women, and (2) explore if these associations were modified by menopausal status.

METHOD

Cross-sectional and longitudinal analyses including 2542 and 1482 women from CoLaus cohort, respectively. Multiple linear regression and multilevel mixed models were used to analyse the associations between Iron biomarkers and CVD-RFs. Variability of outcomes and iron markers between surveys was accessed using intraclass correlation (ICC).

RESULTS

After multivariable adjustment, elevated serum ferritin levels were associated with increased insulin and glucose levels, while higher transferrin levels were linked to elevated glucose, insulin and total cholesterol, and systolic and diastolic blood pressure (p < 0.05). No association was observed between CVD-RFs and TSAT (p > 0.05). Iron biomarkers demonstrated low reliability across reproductive stages but exhibited stronger associations in the perimenopausal group. In longitudinal analysis, we found association only for transferrin with lower glucose levels [β = - 0.59, 95% CI (- 1.10, - 0.08), p = 0.02] and lower diastolic blood pressure [β = - 7.81, 95% CI (- 15.9, - 0.56), p = 0.04].

CONCLUSION

In cross-sectional analysis, transferrin was associated with several CVD-RFs, and the associations did not change according to menopausal status. Conversely, in the longitudinal analyses, changes in transferrin were associated only with lower glucose and diastolic blood pressure levels. These differences might stem from the substantial longitudinal variation of iron biomarkers, underscoring the need for multiple iron measurements in longitudinal analyses.

Mangiferin attenuates osteoporosis by inhibiting osteoblastic ferroptosis through Keap1/Nrf2/SLC7A11/GPX4 pathway

BACKGROUND

Ferroptosis is a crucial contributor to impaired osteoblast function in osteoporosis. Mangiferin, a xanthonoid glucoside isolated from mangoes, exhibits anti-osteoporosis effects. However, its potential mechanism is not fully understood.

PURPOSE

This study explores the potencies of mangiferin on osteoblastic ferroptosis and deciphers its direct target in the context of solute carrier family 7-member 11 (SLC7A11)/glutathione peroxidases 4 (GPX4) pathway.

METHODS

In vivo models include bilateral ovariectomy induced osteoporosis mice, iron-dextran induced iron-overloaded mice, and nuclear factor-erythroid 2-related factor 2 (Nrf2)-knockout mice. Mice are orally administrated mangiferin (10, 50 or 100 mg.kg-1.d-1) for 12 weeks. In vitro osteoblast models include iron-dextran induced iron-overloaded cells, erastin induced ferroptosis cells, and gene knockout cells. RNA sequencing is applied for investigating the underlying mechanisms. The direct target of mangiferin is studied using a cellular thermal shift assay, silico docking, and surface plasmon resonance.

RESULTS

Mangiferin promotes bone formation and inhibits ferroptosis in vivo models (osteoporosis mice, iron-overloaded mice) and in vitro models (ferroptosis osteoblast, iron-overloaded osteoblasts). Mechanismly, mangiferin directly binds to the kelch-like ECH-associated protein 1 (Keap1) and activates the downstream Nrf2/SLC7A11/GPX4 pathway in both the in vivo and in vitro models. Mangiferin failed to restore the osteoporosis and ferroptosis in Nrf2-knockout mice. Silencing Nrf2, SLC7A11 or GPX4 abolished the anti-ferroptosis effect of mangiferin in erastin-induced cells. Addition of the ferroptosis agonist RSL-3 also blocked the protective effects of mangiferin on iron-overloaded cells. Furthermore, mangiferin had better effects on osteogenesis than the ferroptosis inhibitor (ferrostatin-1) and the Nrf2 agonists (sulforaphane, dimethyl fumarate, and bardoxolone).

CONCLUSIONS

We identify for the first time mangiferin as a ferroptosis inhibitor and a direct Keap1 conjugator that promotes bone formation and alleviates osteoporosis. This work also provides a potentially practical pharmacological approach for treating ferroptosis-driven diseases.

The influence of iron on bone metabolism disorders

Iron is a necessary trace element in the human body, and it participates in many physiological processes. Disorders of iron metabolism can cause lesions in many tissues and organs, including bone. Recently, iron has gained attention as an independent factor influencing bone metabolism disorders, especially the involvement of iron overload in osteoporosis. The aim of this review was to summarize the findings from clinical and animal model research regarding the involvement of iron in bone metabolism disorders and to elucidate the mechanisms behind iron overload and osteoporosis. Lastly, we aimed to describe the association between bone loss and iron overload. We believe that a reduction in iron accumulation can be used as an alternative treatment to assist in the treatment of osteoporosis, to improve bone mass, and to improve the quality of life of patients.

The impact of soy products, isoflavones, and Lactobacillus acidophilus on iron status and morphological parameters in healthy female rats

BACKGROUND

Isoflavones and probiotics are two major factors involved in bone health. Osteoporosis and disturbances in iron (Fe) levels are common health problems in aging women. This study aimed to analyze how soybean products, daidzein, genistein, and Lactobacillus acidophilus (LA) affect Fe status and blood morphological parameters in healthy female rats.

METHODS

A total of 48 Wistar rats aged 3 months were randomly divided into six groups. The control group (K) received a standard diet (AIN 93 M). The remaining five groups received a standard diet supplemented with the following: tempeh flour (TP); soy flour (RS); daidzein and genistein (DG); Lactobacillus acidophilus DSM20079 (LA); as well as a combination of daidzein, genistein, and L. acidophilus DSM20079 (DGLA). After 8 weeks of intervention, blood samples of the rats were collected for morphological analysis, whereas tissue samples were collected and kept at -80 °C until Fe analysis. Red blood cells, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets (PLTs), red cell distribution width, white blood cells, neutrophils (NEUT), lymphocytes (LYM), monocytes, eosinophils (EOS), and basophils were measured for blood morphological analysis. Fe concentrations were determined using flame atomic spectrometry. For statistical analysis, an ANOVA test for significance at the 5 % level was used. The relationship between tissue Fe levels and blood morphological parameters was determined using Pearson's correlation.

RESULTS

Although no significant differences were observed in the Fe content between all diets, the TP group showed significantly higher levels of NEUT and lower levels of LYM than the control group. Compared with the DG and DGLA groups, the TP group showed a dramatically higher PLT level. In addition, the RS group showed significantly higher Fe concentrations in the spleen compared with the standard diet. Compared with the DG, LA, and DGLA groups, the RS group also showed significantly higher Fe concentrations in the liver. Compared with the TP, DG, LA, and DGLA groups, the RS group showed dramatically higher Fe concentrations in the femur. Pearson's correlations between blood morphological parameters and Fe levels in tissues were observed, especially a negative correlation between the Fe level in the femur and the NEUT concentration (-0.465) and a strong positive correlation between the Fe level in the femur and the LYM concentration (0.533).

CONCLUSION

Soybean flour was found to increase Fe levels in rats, whereas tempeh may alter anti-inflammatory blood parameters. Isoflavones and probiotics did not affect Fe status in healthy female rats.

Iron Status and Associated Factors among Canadian Women: Results from the Canadian Health Measures Survey

BACKGROUND

Iron deficiency and overload may negatively impact women's health. There has been limited assessment of iron status and its associated factors among Canadian women.

OBJECTIVES

This study investigated associations of various sociodemographic, lifestyle, medication, and dietary factors with body iron stores among pre- and postmenopausal women in Canada.

METHODS

Analyses were conducted using cross-sectional, nationally representative survey and biomarker data from women aged 20-79 y (n = 6362) in the Canadian Health Measures Survey (2009-2017). Body iron stores were assessed by measuring serum concentrations of ferritin (SF). Information on potential correlates was collected during an in-home interview. Multivariable linear regression analyses were performed to evaluate associations with SF concentration, and logistic regression was used to estimate associations with iron deficiency (SF <15 μg/L) or elevated iron stores (SF >150 μg/L).

RESULTS

Geometric mean SF concentrations were significantly higher in postmenopausal than in premenopausal women (73.2 versus 33.8 μg/L; P < 0.001). The prevalence of iron deficiency among pre- and postmenopausal women was 16.0% and 4.0%, respectively, whereas that of elevated iron stores was 2.7% and 21.0%, respectively. After simultaneous adjustment for multiple factors, including high-sensitivity CRP (inflammation marker), we found that age, East/Southeast Asian (versus White) race/ethnicity, alcohol, and red meat consumption were positively associated with SF concentration among pre- and postmenopausal women. In addition, aspirin use and dairy consumption were inversely associated with SF concentration among postmenopausal women only. Similar patterns were observed for associations with elevated iron stores among postmenopausal women, whereas higher grain consumption was associated with an increased prevalence of iron deficiency among premenopausal women.

CONCLUSIONS

Sociodemographic, lifestyle, medication, and dietary factors are correlated with iron status determined by SF concentration among Canadian women. The findings may have implications for intervention strategies aimed at optimizing body iron stores in pre- and postmenopausal women.

Maternal micronutrient disturbance as risks of offspring metabolic syndrome

Metabolic syndrome (MetS) is defined as a constellation of individual metabolic disturbances, including central obesity, hypertension, dyslipidemia, and insulin resistance. The established pathogenesis of MetS varies extensively with gender, age, ethnic background, and nutritional status. In terms of nutritional status, micronutrients are more likely to be discounted as essential components of required nutrition than macronutrients due to the small amount required. Numerous observational studies have shown that pregnant women frequently experience malnutrition, especially in developing and low-income countries, resulting in chronic MetS in the offspring due to the urgent and increasing demands for micronutrients during gestation and lactation. Over the past few decades, scientific developments have revolutionized our understanding of the association between balanced maternal micronutrients and MetS in the offspring. Examples of successful individual, dual, or multiple maternal micronutrient interventions on the offspring include iron for hypertension, selenium for type 2 diabetes, and a combination of folate and vitamin D for adiposity. In this review, we aim to elucidate the effects of maternal micronutrient intake on offspring metabolic homeostasis and discuss potential perspectives and challenges in the field of maternal micronutrient interventions.

Association Between Dietary Iron Intake and Serum Ferritin and Severe Headache or Migraine

Background: Dietary iron intake and serum ferritin in relation to severe headache or migraine remain largely unknown. Therefore, we investigated the associations between dietary iron intake and serum ferritin with severe headache or migraine among American adults. Methods: This cross-sectional study included 7,880 adults (≥20 years) from the National Health and Nutrition Examination Surveys (NHANES) of America from 1999 to 2004. We performed multivariable logistic regression and restricted cubic spline (RCS) regression to assess the association of dietary iron and serum ferritin with severe headache or migraine. Results: Most women aged 20-50 years consumed less dietary iron than their recommended dietary allowances. Dietary iron intake was inversely associated with severe headache or migraine in women aged 20-50 years. For women over 50 years, serum ferritin was negatively associated with severe headache or migraine. For men, there was no significant relationship between dietary iron and serum ferritin, and severe headache or migraine. Conclusions: Dietary iron intake has different effects on migraine in women of different ages, and this different effect may be due to age-related menstrual changes. Women aged 20-50 years should have a higher awareness of RDA and increase their dietary iron intake if needed, which may play an important role in preventing severe headache or migraine. Higher serum ferritin levels in women aged 50 and above may have a protective effect against migraine.

Iron accumulation regulates osteoblast apoptosis through lncRNA XIST/miR-758-3p/caspase 3 axis leading to osteoporosis

Postmenopausal osteoporosis (PMOP) is mainly caused by multiple factors. Recent studies have suggested that iron accumulation (IA) was closely related to PMOP. However, the detailed molecular mechanisms have not been well demonstrated. We constructed the IA mouse model by intraperitoneal injections of ferric ammonium citrate (FAC) and cell model by culturing with the medium containing FAC. Osteoporosis was confirmed in mouse bone tissues using H&E staining, and the level of serum ferritin, alkaline phosphatase (ALP), procollagen-1 N-terminal peptide (P1NP), and osteocalcin in mice was examined by ELISA. The expressions of XIST and miR-758-3p were detected by qRT-PCR. Cell proliferation and apoptosis were measured by CCK-8, TUNEL, and flow cytometry. The expression levels of apoptotic-related proteins were evaluated by western blot. Dual luciferase reporter assay was used to examine the molecular interaction. The expressions of ALP, P1NP, and osteocalcin, and the H&E staining of bone tissues in mice were analyzed to confirm the biological function of XIST and miR-758-3p in vivo. XIST was up-regulated while miR-758-3p was down-regulated in IA mouse and cell models. XIST knockdown significantly reduced FAC-induced osteoblast apoptosis, which was mimicked by transfection with miR-758-3p mimics. XIST acted as a sponge of miR-758-3p, which targeted caspase 3. IA led to the high expression of XIST and promoted osteoblast apoptosis through miR-758-3p/caspase 3. Transfection with shXIST or miR-758-3p mimics alleviated IA-induced mouse osteoporosis. IA regulated osteoblast apoptosis through XIST/miR-758-3p/caspase 3 axis, which might provide alternative targets for the treatment of osteoporosis.

Comparison of Serum Iron, Zinc, and Selenium Levels in Premenopausal and Postmenopausal Women in Ekpoma, Nigeria: A Descriptive Study

Background: Estrogen deficiency following menopause creates an imbalance in plasma micronutrient resulting in several degenerative pathological conditions, including hypertension, cardiovascular disease, osteoporosis, etc. Objectives: The present study was designed to compare zinc (Zn), iron (Fe), and selenium (Se) concentrations between premenopausal and postmenopausal women. Methods: In this descriptive study a total of 200 participants were classified into two groups of postmenopausal (age range: 46-75 years, served as experimental) and premenopausal (age range: 30-45 years, served as control). Each group consisted of 100 subjects. After obtaining informed consent from all participants, blood samples were collected from the antecubital fossa vein of each participant by venipuncture. The concentrations of Fe, Zn, and Se in each blood sample were determined using Atomic Absorption Spectrophotometer. Results: No significant difference (P>0.05) was observed in serum Fe (114.24 ± 26.79 µg/dL), Zn (83.11 ± 20.45 µg/dL), and Se (41.99 ± 9.78 µg/dL) levels between the control and experimental groups. However, serum Fe and Zn showed progressive significant (P=0.04, 0.03, respectively) increase with increasing postmenopausal age. Conversely, serum Se concentration decreased significantly (P=0.03) with increasing menopausal age. Conclusion: Although no significant difference was observed in serum levels of Fe, Zn, and Se between pre- and post-menopausal women, the progressive significant increase in the serum Fe and Zn levels as well as significant decrease in serum Se level with advancing post-menopausal age portend a great risk.

Establishing Ghanaian adult reference intervals for hematological parameters controlling for latent anemia and inflammation

Background

In Ghana, diagnostic laboratories rely on reference intervals (RIs) provided by manufacturers of laboratory analyzers which may not be appropriate. This study aimed to establish RIs for hematological parameters in adult Ghanaian population.

Methods

This cross‐sectional study recruited 501 apparently healthy adults from two major urban areas in Ghana based on the protocol by IFCC Committee for Reference Intervals and Decision Limits. Whole blood was tested for complete blood count (CBC) by Sysmex XN‐1000 analyzer, sera were tested for iron and ferritin by Beckman‐Coulter/AU480, for transferrin, vitamin‐B12, and folate was measured by Centaur‐XP/Siemen. Partitioning of reference values by sex and age was guided by “effect size” of between‐subgroup differences defined as standard deviation ratio (SDR) based on ANOVA. RIs were derived using parametric method with application of latent abnormal values exclusion method (LAVE), a multifaceted method of detecting subjects with abnormal results in related parameters.

Results

Using SDR ≥ 0.4 as a threshold, RIs were partitioned by sex for platelet, erythrocyte parameters except mean corpuscular constants, and iron markers. Application of LAVE had prominent effect on RIs for majority of erythrocyte and iron parameters. Global comparison of Ghanaian RIs revealed lower‐side shift of RIs for leukocyte and neutrophil counts, female hemoglobin and male platelet count, especially compared to non‐African countries.

Conclusion

The LAVE effect on many hematological RIs indicates the need for deliberate secondary exclusion for proper derivation of RIs. Obvious differences in Ghanaian RIs compared to other countries underscore the importance of country‐specific RIs for improved clinical decision‐making.

Trace Elements, PPARs, and Metabolic Syndrome

Metabolic syndrome (MetS) is a constellation of metabolic derangements, including central obesity, insulin resistance, hypertension, glucose intolerance, and dyslipidemia. The pathogenesis of MetS has been intensively studied, and now many factors are recognized to contribute to the development of MetS. Among these, trace elements influence the structure of proteins, enzymes, and complex carbohydrates, and thus an imbalance in trace elements is an independent risk factor for MetS. The molecular link between trace elements and metabolic homeostasis has been established, and peroxisome proliferator-activated receptors (PPARs) have appeared as key regulators bridging these two elements. This is because on one hand, PPARs are actively involved in various metabolic processes, such as abdominal adiposity and insulin sensitivity, and on the other hand, PPARs sensitively respond to changes in trace elements. For example, an iron overload attenuates hepatic mRNA expression of Ppar-α; zinc supplementation is considered to recover the DNA-binding activity of PPAR-α, which is impaired in steatotic mouse liver; selenium administration downregulates mRNA expression of Ppar-γ, thereby improving lipid metabolism and oxidative status in the liver of high-fat diet (HFD)-fed mice. More importantly, PPARs' expression and activity are under the control of the circadian clock and show a robust 24 h rhythmicity, which might be the reasons for the side effects and the clinical limitations of trace elements targeting PPARs. Taken together, understanding the casual relationships among trace elements, PPARs' actions, and the pathogenesis of MetS is of great importance. Further studies are required to explore the chronopharmacological effects of trace elements on the diurnal oscillation of PPARs and the consequent development of MetS.

Icariin protects against iron overload-induced bone loss via suppressing oxidative stress

Iron overload is common in patients with diseases such as hemoglobinopathies, hereditary hemochromatosis or elderly men and postmenopausal women. This disorder is frequently associated with bone loss and recently has been considered as an independent risk factor for osteoporosis. By excess reactive oxygen species (ROS) production through Fenton reaction, iron could induce osteoblast apoptosis, inhibit osteoblast osteogenic differentiation. Moreover, Iron could also promote osteoclasts differentiation and bone absorption. The goal of the study is to investigate whether icariin could reverse iron overload-induced bone loss in vitro and in vivo. Icariin is the major active ingredient of Herba Epimedii and has antioxidant, antiosteoporosis functions. In the current study, we demonstrated that oral administration of icariin significantly prevented bone loss in iron overloaded mice. Icariin could protect against iron overload-induced mitochondrial membrane potential dysfunction and ROS production, promote osteoblast survival and reverse the reduction of Runx2, alkaline phosphatase, and osteopontin expression induced by iron overload. Icariin also inhibited osteoclasts differentiation and function. Moreover, we also found that icariin remarkably reduced iron accumulation in bone marrow, suggesting that icariin has the ability to regulate systemic iron metabolism in vivo. These results indicated that icariin could be a potential natural resource for developing medicines to prevent or treat iron overload-induced osteoporosis.

Ferritin: A potential serum marker for lymph node metastasis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer in the world, yet current treatment options are associated with limited success. The aim of the present study was to investigate the expression of ferritin in HNSCC and clarify whether it may serve as a biomarker for predicting HNSCC metastasis. The chemiluminescent immunoassay method was used to investigate the differences in the serum ferritin (SF) levels between patients with and without tumors, and between HNSCC with and without lymph node metastasis. The iron content and expression levels of ferritin were detected to verify the differences between tumor and normal tissues, and between HNSCC without and with lymph node metastasis. Data from the Gene Expression Omnibus (GEO) dataset was used to support the aforementioned results. No statistically significant difference in the SF level was observed between patients with and without tumors. Iron content and expression levels of ferritin heavy chain (FTH) and ferritin light chain (FTL) were higher in tumor tissues compared with normal tissues. The iron content and expression levels of SF, FTH and FTL were increased in HNSCC with metastasis compared with HNSCC without metastasis. The GEO dataset further verified the results and reported that the expression level of FTH was correlated with the prognosis of patients with HNSCC. Ferritin may not be a biomarker for the early diagnosis of HNSCC. However, an association exists between the expression level of ferritin and HNSCC cervical metastasis. SF may be a potential biomarker for predicting cervical lymph node metastasis in patients with HNSCC.

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.

Is Higher Consumption of Animal Flesh Foods Associated with Better Iron Status among Adults in Developed Countries? A Systematic Review

Iron deficiency (ID) is the most prevalent nutrient deficiency within the developed world. This is of concern as ID has been shown to affect immunity, thermoregulation, work performance and cognition. Animal flesh foods provide the richest and most bioavailable source of dietary (haem) iron, however, it is unclear whether low animal flesh diets contribute to ID. This systematic review aimed to investigate whether a higher consumption of animal flesh foods is associated with better iron status in adults. CINAHL, Cochrane, EMBASE and MEDLINE were searched for published studies that included adults (≥18 years) from developed countries and measured flesh intakes in relation to iron status indices. Eight experimental and 41 observational studies met the inclusion criteria. Generally, studies varied in population and study designs and results were conflicting. Of the seven high quality studies, five showed a positive association between animal flesh intake (85-300 g/day) and iron status. However, the optimum quantity or frequency of flesh intake required to maintain or achieve a healthy iron status remains unclear. Results show a promising relationship between animal flesh intake and iron status, however, additional longitudinal and experimental studies are required to confirm this relationship and determine optimal intakes to reduce ID development.

Cardiovascular benefits of phlebotomy: relationship to changes in hemorheological variables

Renewed interest in the age-old concept of “bloodletting”, a therapeutic approach practiced until as recently as the 19th century, has been stimulated by the knowledge that blood loss, such as following regular donation, is associated with significant reductions in key hemorheological variables, including whole blood viscosity (WBV), plasma viscosity, hematocrit and fibrinogen. An elevated WBV appears to be both a strong predictor of cardiovascular disease and an important factor in the development of atherosclerosis. Elevated WBV through wall shear stress is the most direct physiological parameter that influences the rupture and erosion of vulnerable plaques. In addition to WBV reduction, phlebotomy may reduce an individual’s cardiovascular risk through reductions in excessive iron, oxidative stress and inflammation. Reflecting these findings, blood donation in males has shown significant drops in the incidence of cardiovascular events, as well as in procedures such as percutaneous transluminal coronary angioplasty and coronary artery bypass grafting. Collectively, the available data on the benefits of therapeutic phlebotomy point to the importance of monitoring WBV as part of a cardiovascular risk factor, along with other risk-modifying measures, whenever an increased cardiovascular risk is detected. The development of a scanning capillary tube viscometer allows the measurement of WBV in a clinical setting, which can prove to be valuable in providing an early warning sign of an increased risk of cardiovascular disease.

Elevated serum ferritin concentrations in prediabetic subjects

BACKGROUND

Few data are available on the association of variables of the insulin resistance syndrome and serum ferritin, an indicator of body iron stores. We examined the relationship between serum ferritin levels and impaired fasting glucose, a pre-diabetes stage associated with insulin resistance, in this study.

SUBJECTS & METHODS

One hundred and eighty seven people, including 91 subjects with impaired fasting glucose (IFG) and 96 healthy people who were well matched for age and sex, were enrolled. Body mass index (BMI) and blood pressure of the participants were measured and serum cholesterol, triglyceride, white blood cells (WBC) count, C-reactive protein (CRP) and ferritin were evaluated. All the data were analysed by t-test, chi2 test and analysis of variance.

RESULTS

The IFG group had higher serum ferritin concentrations (85.5+/-6.6 microg/L vs. 49.4+/-3.7 microg/L, p=0.001). A positive correlation was found between fasting plasma glucose and serum ferritin (r=0.29, p=0.001). Using multiple regression analysis, we found an association between serum ferritin and blood pressure (0.15, p=0.01), FPG (0.29, p=0.001), triglyceride (0.08, p=0.01) and cholesterol (0.07, p=0.03). The odds ratio for the association of IFG in male subjects with a high serum ferritin level was 8.3 (95% CI: 1.2-11.9, p=0.01) and for females was 3.06 (95% CI: 0.58-15, p=0.1).

CONCLUSION

Based on the data from our study, aelevation in serum ferritin can be seen in pre-diabetes stage, before the occurrence of an overt diabetes mellitus.

Age-associated Iron Accumulation in Bone: Implications for Postmenopausal Osteoporosis and a New Target for Prevention and Treatment by Chelation

Iron accumulation in tissues is believed to be a characteristic of aged humans and a risk factor for some chronic diseases. However, it is not known whether age-associated iron accumulation is part of the pathogenesis of postmenopausal osteoporosis that affects approximately one out three women worldwide. Here, we confirmed that this accumulation of iron was associated with osteopenia in ovariectomized (OVX) rats (a model of peri- and postmenopausal osteoporosis due to estrogen deficiency). To further investigate whether the increased iron level plays a causal role in the onset of bone loss, we treated OVX rats with an orally active and bone targeted chelator that prevented iron accumulation in their skeletal tissues. The results showed that this treatment mitigated the loss of bone mass and the deterioration of bone micro-architecture. We also found that one possible mechanism of the protective action of iron chelation was to significantly reduce bone resorption. Thus, these findings provide a novel target and a potentially useful therapeutic strategy for the prevention and treatment of postmenopausal osteoporosis and perhaps other age-related diseases.

HFE genotypes and dietary heme iron: no evidence of strong gene-nutrient interaction on serum ferritin concentrations in middle-aged women

BACKGROUND AND AIM

Hereditary hemochromatosis (HH) is a disorder characterized by inappropriately high intestinal iron absorption. In populations of Northern European descent, HH is most commonly caused by mutations (C282Y/H63D) in the HFE gene.

METHODS AND RESULTS

We investigated the effects of dietary heme iron intake and HFE mutations on serum ferritin concentrations in a population-based random sample of 1611 women aged >50 years using analysis of covariance (ANCOVA). Higher heme iron intake was associated with significantly higher serum ferritin concentrations (P(trend) < 0.001). Also, women with the compound or C282Y homozygous genotype had significantly higher serum ferritin concentrations (geometric mean 115.2 microg/L (95% CI 81.4-162.9 microg/L) than women carrying normal alleles (geometric mean 76.6 microg/L (95% CI 72.5-80.9 microg/L). We observed the highest serum ferritin concentrations among postmenopausal women who are compound heterozygous or C282Y homozygous, and who consume relatively high amounts of heme iron (geometric mean 183.9 microg/L (95% CI 97.2-347.8 microg/L).

CONCLUSIONS

Even when there are currently no clinical signs, women with the compound or C282Y homozygous genotype may still be at risk for developing iron overload sometime after menopause.

Evaluation of Iron Overload in Healthy Adult Residents of Mexico City

BACKGROUND

We described the effects of age, gender and body mass index (BMI) on the prevalence of iron overload (IO) in blood donors from Mexico City.

METHODS

A cross-sectional study of clinically healthy adults was performed. We evaluated serum ferritin (SF) concentration to allow us to establish groups with normal iron stores (SF >30 microg/L) and with IO (SF >200 microg/L and >300 microg/L for women and men), in the following ages groups: 18-29 years, 30-49 years, and 50-64 years, divided by gender.

RESULTS

The study included 1757 subjects. Prevalence of IO was 12% in men and 4.8% in women, and prevalence increased in parallel with increasing age (15.6, 25.0 and 29.9% and 3.5, 5.2 and 9.6%, for men and women, respectively). Regression analysis showed that in men there was a significant association of SF and IO with age, BMI and recent blood donation (p <0.01). In women, no differences were seen for BMI and recent blood donation.

CONCLUSIONS

IO is highly prevalent in blood donors residing in Mexico City, more so in men than in women. Age, gender and BMI had a positive association with iron stores. This report is the initial contribution towards the study of IO in the Mexican population.

Micronutrient intakes, micronutrient status and lipid profiles among young people consuming different amounts of breakfast cereals: further analysis of data from the National Diet and Nutrition Survey of Young People aged 4 to 18 years

OBJECTIVE

To examine associations between breakfast cereal consumption and the dietary habits, nutrient intakes and nutritional status of young people, considering both nutrient adequacy and safety issues (fortification).

METHODS

Using archived data from 1688 children in the (British) National Diet and Nutrition Survey of Young People aged 4 to 18 years, nutrient intakes and status were compared across thirds of breakfast cereal consumption (T1 to T3), adjusted for age and energy intake. Cereals provided on average 2%, 6% and 12% of energy in T1, T2 and T3, respectively, for boys; 1%, 4% and 10%, respectively, for girls.

RESULTS

Intakes of iron, B vitamins and vitamin D were around 20-60% higher in T3 compared with T1, with significant linear relationships observed for iron, thiamin, riboflavin and folate (T1<T2<T3). After excluding low energy reporters and the unwell, 14% of girls had iron intakes below the Lower Reference Nutrient Intake and this varied fivefold between T1 and T3 (27%, 12% and 5%; P=0.0001). High consumers of breakfast cereals (T3) had better folate, vitamin B12 and riboflavin status and lower total and low-density lipoprotein cholesterol. There was also an association with thiamin and vitamin B6 status in girls. However, iron status (haemoglobin, ferritin and transferrin saturation) was not significantly different between groups, possibly due to lower meat intakes in T3. Total iron intakes were within tolerable levels (maximum of 32 mg day(-1) in one girl taking supplements).

CONCLUSIONS

The nutritional benefits of breakfast cereals are demonstrated in status measurements as well as in nutrient intakes in this study. Concerns about excessive iron intakes from fortification appear unjustified.

Body iron stores and their determinants in healthy postmenopausal US women

BACKGROUND

Data on the determinants of body iron stores in middle-aged women are sparse.

OBJECTIVE

We prospectively evaluated nondietary and dietary determinants of iron stores.

DESIGN

Using blood samples collected in 1989-1990, we measured plasma ferritin concentrations in 620 healthy postmenopausal women aged 44-69 y who participated in the Nurses' Health Study. Food-frequency questionnaires completed in 1980, 1984, and 1986 were used to calculate average dietary intakes. Generalized linear regression and multiple logistic regression models were used to assess the association between plasma ferritin and its determinants.

RESULTS

Among these postmenopausal women, the median plasma ferritin concentration was 73.8 ng/mL (interquartile range: 41.6-125.8 ng/mL), 2.7% were iron depleted (ferritin concentration < 12 ng/mL), and 9.8% had an elevated ferritin concentration (> 200 ng/mL). Age, time since menopause, time since the last postmenopausal hormone (PMH) use, body mass index, iron supplement use, and alcohol and heme-iron intakes were positively associated with ferritin concentrations, whereas PMH use, physical activity, aspirin use, and gastrointestinal ulcer were inversely related. The association between heme-iron intake and ferritin was most apparent among the women who consumed > 30 g alcohol/d.

CONCLUSIONS

Our prospective data confirm that in postmenopausal women, intakes of heme iron, supplemental iron, and alcohol are dietary determinants of plasma ferritin, and age, PMH use, body mass index, physical activity, aspirin use, and gastrointestinal ulcer are nondietary determinants.