Obesity promotes alterations in iron recycling

Absolute and functional iron deficiency: Biomarkers, impact on immune system, and therapy

Iron is essential for numerous physiological processes and its deficiency often leads to anemia. Iron deficiency (ID) is a global problem, primarily affecting reproductive-age women and children, especially in developing countries. Diagnosis uses classical biomarkers like ferritin or transferrin saturation. Recent advancements include using soluble transferrin receptor (sTfR) or hepcidin for improved detection and classification of absolute and functional iron deficiencies, though mostly used in research. ID without anemia may present symptoms like asthenia and fatigue, even without relevant clinical consequences. ID impacts not only red-blood cells but also immune system cells, highlighting its importance in global health and immune-related comorbidities. Managing ID, requires addressing its cause and selecting appropriate iron supplementation. Various improved oral and intravenous products are available, but further research is needed to refine treatment strategies. This review updates on absolute and functional iron deficiencies, their relationships with the immune system and advancements in diagnosis and therapies.

Schizandrin A enhances the sensitivity of gastric cancer cells to 5-FU by promoting ferroptosis

Schizandrin A (Sch A) exert anticancer and multidrug resistance-reversing effects in a variety of tumors, but its effect on 5-fluorouracil (5-Fu) in gastric cancer (GC) cells remains unclear. The aim of the present study was to examine the resistance-reversing effect of Schizandrin A and assess its mechanisms in 5-Fu-resistant GC cells.5-Fu-sensitive GC cells were treated with 5-Fu and 5-Fu-resistant GC cells AGS/5-Fu and SGC7901/5-Fu were were established. These cells were stimulated with Schizandrin A alone or co-treated with 5-Fu and their effect on tumor cell growth, proliferation, migration, invasion and ferroptosis-related metabolism were investigated both in vitro and in vivo. A number of additional experiments were conducted in an attempt to elucidate the molecular mechanism of increased ferroptosis. The results of our study suggest that Schizandrin A in combination with 5-Fu might be useful in treating GC by reverse drug resistance. It was shown that Schizandrin A coadministration suppressed metastasis and chemotherapy resistance in 5-Fu-resistant GC cells through facilitating the onset of ferroptosis, which is an iron-dependent form of cell death, which was further demonstrated in a xenograft nude mouse model. Mechanistically, Schizandrin A co-administration synergistically increased the expression of transferin receptor, thus iron accumulates within cells, leading to lipid peroxidation, which ultimately results in 5-Fu-resistant GC cells death. The results of this study have provided a novel strategy for increasing GC chemosensitivity, indicating Schizandrin A as a novel ferroptosis regulator. Mechanistically, ferroptosis is induced by Schizandrin A coadministration via increasing transferrin receptor expression.

Prevalence of Overweight/Obesity Associated With Anemia Among Female Medical Students at Umm Al-Qura University in Makkah, Saudi Arabia: A Cross-Sectional Study

Introduction The obesity epidemic has been linked to a wide range of health and nutritional problems, including anemia, which is often caused by impaired iron metabolism. The World Health Organization considers anemia and obesity to be global health issues among adolescent girls and women experiencing menstruation. This study aims to examine the association between iron deficiency anemia and obesity/overweight among female medical students. Methodology This cross-sectional descriptive study conducted as an online self-administered questionnaire. Furthermore, blood samples were collected from 206 students to evaluate the complete blood count, iron and lipid profile. Results The convenience sampling technique was used and a total of 206 students were enrolled in the study. The average body mass index (BMI) was 22.51 ± 3.25, with 83.5% (n = 172) falling within the normal weight range, 12.6% (n = 26) as overweight, and 3.9% (n = 8) as obese. Anemia was present in 16.0% (n = 33) of the participants overall. Higher prevalence of anemia was observed among overweight participants with 10 out of 26 (38.5%) subjects compared to obese with two out of eight (25.0%) and normal weight 21 out of 172 (12.2%); this difference was highly significant (P = 0.005). Individuals with anemia exhibited a significant association with those experiencing a diet full of unhealthy fats and carbohydrates (P = 0.05) and a diet containing all essential nutrients (P = 0.01). There is no statistically significant correlation between anemia prevalence and participants' response to the presence of signs of anemia, physical activity or other dietary habits. Obese participants had a significantly higher mean value of triglycerides (129.5 ± 20.5) compared to normal weight and overweight participants (74.5 ± 12.02 and 51.2 ± 15.04), respectively (P = 0.001). Conclusion A dependable assembly exists between obesity and overweight in cases of iron deficient anemia. The prevalence of iron deficiency anemia was substantially higher among overweight/obese females, highlighting that overweight/obesity signifies both quantitative and qualitative malnutrition. A high BMI was associated with elevated triglycerides, typically considered indicators of obesity. This association may suggest compromised iron homeostasis.

The role of iron metabolism in chronic diseases related to obesity

Obesity is one of the major public health problems threatening the world, as well as a potential risk factor for chronic metabolic diseases. There is growing evidence that iron metabolism is altered in obese people, however, the highly refined regulation of iron metabolism in obesity and obesity-related complications is still being investigated. Iron accumulation can affect the body’s sensitivity to insulin, Type 2 diabetes, liver disease and cardiovascular disease. This review summarized the changes and potential mechanisms of iron metabolism in several chronic diseases related to obesity, providing new clues for future research.

Influence of Sex and Strain on Hepatic and Adipose Tissue Trace Element Concentrations and Gene Expression in C57BL/6J and DBA/2J High Fat Diet Models

The objective of this study was to determine the influence of sex and strain on the dysregulation of trace element concentration and associative gene expression due to diet induced obesity in adipose tissue and the liver. Male and female C57BL/6J (B6J) and DBA/2J (D2J) were randomly assigned to a normal-fat diet (NFD) containing 10% kcal fat/g or a mineral-matched high-fat diet (HFD) containing 60% kcal fat/g for 16 weeks. Liver and adipose tissue were assessed for copper, iron, manganese, and zinc concentrations and related changes in gene expression. Notable findings include three-way interactions of diet, sex, and strain amongst adipose tissue iron concentrations (p = 0.005), adipose hepcidin expression (p = 0.007), and hepatic iron regulatory protein (IRP) expression (p = 0.012). Cd11c to Cd163 ratio was increased in adipose tissue due to HFD amongst all biological groups except B6J females, for which tissue iron concentrations were reduced due to HFD (p = 0.002). Liver divalent metal transporter 1 (DMT-1) expression was increased due to HFD amongst B6J males (p < 0.005) and females (p < 0.004), which coincides with the reduction in hepatic iron concentrations found in these biological groups (p < 0.001). Sex, strain, and diet affected trace element concentration, the expression of genes that regulate trace element homeostasis, and the expression of macrophages that contribute to tissue iron-handling in adipose tissue. These findings suggest that sex and strain may be key factors that influence the adaptive capacity of iron mismanagement in adipose tissue and its subsequent consequences, such as insulin resistance.

The Dark Side of Iron: The Relationship between Iron, Inflammation and Gut Microbiota in Selected Diseases Associated with Iron Deficiency Anaemia—A Narrative Review

Iron is an indispensable nutrient for life. A lack of it leads to iron deficiency anaemia (IDA), which currently affects about 1.2 billion people worldwide. The primary means of IDA treatment is oral or parenteral iron supplementation. This can be burdened with numerous side effects such as oxidative stress, systemic and local-intestinal inflammation, dysbiosis, carcinogenic processes and gastrointestinal adverse events. Therefore, this review aimed to provide insight into the physiological mechanisms of iron management and investigate the state of knowledge of the relationship between iron supplementation, inflammatory status and changes in gut microbiota milieu in diseases typically complicated with IDA and considered as having an inflammatory background such as in inflammatory bowel disease, colorectal cancer or obesity. Understanding the precise mechanisms critical to iron metabolism and the awareness of serious adverse effects associated with iron supplementation may lead to the provision of better IDA treatment. Well-planned research, specific to each patient category and disease, is needed to find measures and methods to optimise iron treatment and reduce adverse effects.

Iron Chelation Remits Memory Deficits Caused by the High-Fat Diet in a Mouse Model of Alzheimer’s Disease

Background: Obesity is a worldwide health problem that has been implicated in many diseases, including Alzheimer’s disease (AD). AD is one of the most common neurodegenerative disorders and is characterized by two pathologies, including extracellular senior plaques composed of amyloid-β (Aβ) and intracellular neurofibrillary tangles (NFTs) consisting of abnormally hyperphosphorylated tau. According to current research, a high-fat diet (HFD) could exacerbate Aβ accumulation, oxidative damage, and cognitive defects in AD mice. However, the accurate role of HFD in the pathogenesis of AD is far more unclear. Objective: To explore the accurate role of HFD in the pathogenesis of AD. Methods: Open Field, Barns Maze, Elevated zero-maze, Contextual fear condition, Tail suspension test, western blotting, immunofluorescence, Fluoro-Jade C Labeling, Perls’ Prussian blue staining, and ELISA were used. Results: HFD caused nonheme iron overload in the brains of APPswe/PS1dE9 (APP/PS1) mice. Furthermore, the administration of M30 (0.5 mg/kg) for iron chelation once every 2 days per os (p.o.) for 1 month remitted memory deficits caused by HFD in APP/PS1 mice. Notably, a variety of hematological parameters in whole blood had no difference after iron chelation. In addition, iron chelation effectively reduced synaptic impairment in hippocampus and neuronal degeneration in cortex in the HFD-fed APP/PS1 mice. Meanwhile, iron chelation decreased Aβ 1–40 and Aβ 1–42 level as well as neuroinflammation in HFD-fed APP/PS1 mice. Conclusion: These data enhance our understanding of how HFD aggravates AD pathology and cognitive impairments and might shed light on future preclinical studies.

Anthropometric Markers and Iron Status of 6-12-Year-Old Thai Children: Associations and Predictors

Introduction

Obesity may be associated with poor iron status. The objective of this study was to investigate the association between different indices of iron status and anthropometric measurements in Thai children.

Materials and Methods

Anthropometry (weight, height, waist circumference (WC), and body composition assessed by bioelectrical impedance analysis) and iron indices were measured in 336 Thai children aged 6-12 years. Iron deficiency (ID) was defined using two or more of the following: (1) %transferrin saturation (%Tsat) < 16%; (2) serum ferritin (SF) < 15 μg/mL; and (3) soluble transferrin receptor (sTfR) > 5 mg/L. Iron deficiency anaemia (IDA) was defined as haemoglobin < WHO age cutoff combined with ID. Overweight and obesity were defined as body mass index (BMI) standard deviation score (SDS) ≥ +1 SDS or +2 SDS, respectively (WHO growth reference).

Results

BMI SDS was significantly positively correlated with sTfR and SF (sTfR, r: 0.209, p < 0.001; SF, r: 0.214, p < 0.001) and negatively correlated with %Tsat (r: -0.132, p = 0.013). Correlations between WC SDS and %fat mass and each iron marker were similar. The percentage with low SF was significantly lower than that using other individual markers. ID prevalence was not significantly different between normal-weight and overweight/obesity groups although a significantly higher proportion of overweight/obese children had sTfR >5 mg/L. Puberty and menarche were significant predictors of ID (puberty adjusted OR: 2.20, 95% CI: 0.43, 11.25; menarche adjusted OR: 6.11, 95% CI: 1.21, 30.94).

Conclusion

Greater adiposity was associated with poorer iron status. However, SF may not be a good indicator of iron status in Thai children, particularly in those who are overweight/obese, whereas sTfR merits further investigation.

Diet-Induced Obesity Disrupts Trace Element Homeostasis and Gene Expression in the Olfactory Bulb

The aim of this study was to determine the impact of diet-induced obesity (DIO) on trace element homeostasis and gene expression in the olfactory bulb and to identify potential interaction effects between diet, sex, and strain. Our study is based on evidence that obesity and olfactory bulb impairments are linked to neurodegenerative processes. Briefly, C57BL/6J (B6J) and DBA/2J (D2J) male and female mice were fed either a low-fat diet or a high-fat diet for 16 weeks. Brain tissue was then evaluated for iron, manganese, copper, and zinc concentrations and mRNA gene expression. There was a statistically significant diet-by-sex interaction for iron and a three-way interaction between diet, sex, and strain for zinc in the olfactory bulb. Obese male B6J mice had a striking 75% increase in iron and a 50% increase in manganese compared with the control. There was an increase in zinc due to DIO in B6J males and D2J females, but a decrease in zinc in B6J females and D2J males. Obese male D2J mice had significantly upregulated mRNA gene expression for divalent metal transporter 1, alpha-synuclein, amyloid precursor protein, dopamine receptor D2, and tyrosine hydroxylase. B6J females with DIO had significantly upregulated brain-derived neurotrophic factor expression. Our results demonstrate that DIO has the potential to disrupt trace element homeostasis and mRNA gene expression in the olfactory bulb, with effects that depend on sex and genetics. We found that DIO led to alterations in iron and manganese predominantly in male B6J mice, and gene expression dysregulation mainly in male D2J mice. These results have important implications for health outcomes related to obesity with possible connections to neurodegenerative disease.

A high-fructose diet in rats induces systemic iron deficiency and hepatic iron overload by an inflammation mechanism

Nonalcoholic fatty liver disease (NAFLD) correlates with the high intake of fructose-rich soft drinks. Both inflammation and dysregulated iron metabolism are pathogenic factors in the development of NAFLD. The present investigation assessed the effects of a high-fructose diet (HF diet) on inflammation and iron metabolism. In this study, rats were fed a control or HF diet for 4, 8, or 12 weeks, after which insulin resistance, transaminases levels, serum and liver lipid profiles, inflammatory factors, and iron metabolism-related molecules were evaluated. The activities of the hepatic inflammation-associated pathways, IKKβ/NF-κB, and JAK2/STAT3, were detected by western blot. Result showed that the HF diet-fed animals developed a time-dependent serum lipid increase and hepatic lipid accumulation as well as insulin resistance. Serum iron (SI), serum ferritin (SF), and transferrin saturation (TS) decreased while total iron-binding capacity (TIBC) and serum transferrin (s-TF) increased at 8 and 12 weeks in the HF diet group. The HF diet led to increased transaminases levels at 8 and 12 weeks, and iron deposition was observed in the liver, accompanied by an upregulation of ferritin light chain (FTL), hepcidin (HEPC), transferrin (TF), transferrin receptor 1 (TfR1), iron regulatory protein 1 (IRP1), hemojuvelin (HJV), and divalent metal transporter 1 (DMT1). Moreover, ferroportin (FPN1) levels were downregulated, as expected from the increased HEPC. A progressive inflammation phenotype was apparent, with increased inflammatory factors, MDA, IL-1β, IL-6, and TNF-α, in the serum and liver tissue. Concomitantly, the hepatic IKKβ/NF-κB and JAK2/STAT3 pathways were activated. In summary, we verified that HF diet induces systemic iron deficiency and hepatic iron accumulation, likely due to the activation of inflammation via the NF-κB and JAK2/STAT3 pathways. PRACTICAL APPLICATIONS: As increasing numbers of individuals consume HF diets, the health implications of this type of over nutrition become globally relevant. Using a high-fructose diet rat model, our present study reveals inflammation as the link between a HF diet and dysregulated iron metabolism. Importantly, both inflammation and disrupted iron metabolism have been shown to be pathogenic factors in nonalcoholic fatty liver disease (NAFLD). The iron regulatory hormone, HEPC, is a link between the liver, inflammation, and iron metabolism. As fructose-rich foods become increasingly abundant and people's fructose intake increases, the impact of high fructose on health requires increased attention. Little research has been conducted on the effects of fructose on iron metabolism. Our study provides useful insights into the prevention and treatment of iron metabolism disorders arising from metabolic syndrome.

Chronic intermittent hypobaric hypoxia improves markers of iron metabolism in a model of dietary-induced obesity

BACKGROUND

Obesity, a risk factor for many chronic diseases, is a potential independent risk factor for iron deficiency. Evidence has shown that chronic intermittent hypobaric hypoxia (CIHH) has protective or improved effects on cardiovascular, nervous, metabolic and immune systems. We hypothesized that CIHH may ameliorate the abnormal iron metabolism in obesity. This study was aimed to investigate the effect and the underlying mechanisms of CIHH on iron metabolism in high-fat-high-fructose-induced obese rats.

METHODS

Six to seven weeks old male Sprague-Dawley rats were fed with different diet for 16 weeks, and according to body weight divided into four groups: control (CON), CIHH (28-day, 6-h daily hypobaric hypoxia treatment simulating an altitude of 5000 m), dietary-induced obesity (DIO; induced by high fat diet and 10% fructose water feeding), and DIO + CIHH groups. The body weight, systolic arterial pressure (SAP), Lee index, fat coefficient, blood lipids, blood routine, iron metabolism parameters, interleukin6 (IL-6) and erythropoietin (Epo) were measured. The morphological changes of the liver, kidney and spleen were examined. Additionally, hepcidin mRNA expression in liver was analyzed.

RESULTS

The DIO rats displayed obesity, increased SAP, lipids metabolism disorders, damaged morphology of liver, kidney and spleen, disturbed iron metabolism, increased IL-6 level and hepcidin mRNA expression, and decreased Epo compared to CON rats. But all the aforementioned abnormalities in DIO rats were improved in DIO + CIHH rats.

CONCLUSIONS

CIHH improves iron metabolism disorder in obese rats possibly through the down-regulation of hepcidin by decreasing IL-6 and increasing Epo.

The Association between Excess Body Mass and Disturbances in Somatic Mineral Levels

BACKGROUND

Obesity and excess body weight are significant epidemiological issues, not only because they are costly to treat, but also because they are among the leading causes of death worldwide. In 2016, an estimated 40% of the global population was overweight, reflecting the importance of the issue. Obesity is linked to metabolism malfunction and concomitantly with altered mineral levels in the body. In this paper, we review alterations in somatic levels of iron, calcium, magnesium, copper, iodine, chromium, selenium, and zinc in relation to excess body mass.

METHODOLOGY

An electronic literature search was performed using PubMed. Our search covered original English research articles published over the past five years, culminating in 63 papers included for study.

RESULTS

The reviewed papers presented correlation between obesity and hypomagnesemia and hypozincemia. They also indicated that patients with excess body mass present increased body copper levels. Studies have similarly indicated that obesity appears to be associated with lower selenium levels in both blood and urine, which may be correlated with the decline and weakening of defenses against oxidative stress. It has been found that decreased level of chromium is connected with metabolic syndrome. Chromium supplementation influences body mass, but the effect of the supplementation depends on the chemical form of the chromium. It is hypothesized that obesity poses a risk of iodine deficiency and iodine absorption may be disrupted by increased fat intake in obese women. A range of studies have suggested that obesity is correlated with iron deficiency. On the other hand, some reports have indicated that excess body mass may coexist with iron excess. The relation between obesity and body iron level requires further investigation. Calcium signaling seems to be disturbed in obesity, due to the increased production of reactive oxygen species and low level of fast troponin isoform responsible for mediating calcium sensitivity of muscle relaxation. Correlation between excess body mass and calcium levels needs further research.

CONCLUSIONS

Excess body mass is associated with alterations in mineral levels in the body, in particular hypomagnesemia and decreased selenium (Se) and zinc (Zn) levels. Chromium (Cr) deficiency is associated with metabolic syndrome. Obese patients are at risk of iodine deficiency. Excess body mass is associated with elevated levels of copper (Cu). Data on the association between obesity and iron (Fe) levels are contradictory. Obesity coexists with disturbed calcium (Ca) signaling pathways. The association between obesity and body Ca levels has not been investigated in detail.

Assessment of Iron Metabolism-Related Parameters in Obese Children

Objectives: The aim of the study was to assess the possible associations among biochemical parameters that may be correlated with the possible mechanisms of iron metabolism in healthy children with normal body mass index (BMI), along with morbid obese (MO) children with and without metabolic syndrome (MetS). Methods: To this end, children aged 6-18 years with no history of any acute or chronic diseases were selected as the population of this prospective case-control study. Thirty MO children (with BMI higher than 99th percentile and without MetS findings), 28 MO children (with BMI higher than 99th percentile and with MetS), and 30 healthy children (with BMI values between 15th and 85th percentiles) participated in the study. Then, anthropometric measurements were recorded, followed by performing the complete blood count and serum iron profile. In addition, ferritin, transferrin, hepcidin, irisin, ferroportin, brain-derived neurotrophic factor (BDNF), WISP1, and PTP1/fortilin levels were measured using ELISA. Finally, statistical analyses were performed and P<0.05 was considered as the level of statistical significance. Results: Significant differences were obtained among the groups regarding anthropometric measurements, blood pressures, triacylglycerols, and high-density lipoprotein cholesterol levels. Further, there was a tendency toward an iron deficiency in both MO groups while an increase in ferritin levels was significant in the MetS group. However, BDNF, hepcidin, and ferroportin demonstrated no significant difference among the groups. Eventually, although the above-mentioned parameters were statistically insignificant, fortilin levels indicated a gradual decrease whereas irisin levels represented an increase from control group toward morbid obesity and MetS. Conclusion: In our study, obesity severity and the tendency toward iron deficiency were in accordance with each other. Particularly, different WISP-1 levels in the groups may help predict future complications, along with its use in diagnosing obesity.

Increased adiposity by feeding growing rats a high-fat diet results in iron decompartmentalisation

The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue 'i' to tissue 'j') adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ${k_{i,j}} = a \times {M^b}$. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.

Extrahepatic hepcidin production: The intriguing outcomes of recent years

Hepcidin is the hyposideremic hormone regulating iron metabolism. It is a defensin-like disulfide-bonded peptide with antimicrobial activity. The main site of hepcidin production is the liver where its synthesis is modulated by iron, inflammation and erythropoietic signaling. However, hepcidin locally produced in several peripheral organs seems to be an important actor for the maintenance of iron homeostasis in these organs. This review highlights the presence of peripheral hepcidin and its potential functions. Understanding the role of extrahepatic hepcidin could be of great physiological and therapeutic importance for several specific pathologies.

Links Between Iron and Lipids: Implications in Some Major Human Diseases

Maintenance of iron homeostasis is critical to cellular health as both its excess and insufficiency are detrimental. Likewise, lipids, which are essential components of cellular membranes and signaling mediators, must also be tightly regulated to hinder disease progression. Recent research, using a myriad of model organisms, as well as data from clinical studies, has revealed links between these two metabolic pathways, but the mechanisms behind these interactions and the role these have in the progression of human diseases remains unclear. In this review, we summarize literature describing cross-talk between iron and lipid pathways, including alterations in cholesterol, sphingolipid, and lipid droplet metabolism in response to changes in iron levels. We discuss human diseases correlating with both iron and lipid alterations, including neurodegenerative disorders, and the available evidence regarding the potential mechanisms underlying how iron may promote disease pathogenesis. Finally, we review research regarding iron reduction techniques and their therapeutic potential in treating patients with these debilitating conditions. We propose that iron-mediated alterations in lipid metabolic pathways are involved in the progression of these diseases, but further research is direly needed to elucidate the mechanisms involved.

Serum Hepcidin Concentration in Individuals with Sickle Cell Anemia: Basis for the Dietary Recommendation of Iron

Dietary iron requirements in patients with sickle cell disease (SCD) remain unclear. SCD is a neglected hemoglobinopathy characterized by intense erythropoietic activity and anemia. Hepcidin is the hormone mainly responsible for iron homeostasis and intestinal absorption. Intense erythropoietic activity and anemia may reduce hepcidin transcription. By contrast, iron overload and inflammation may induce it. Studies on SCD have not evaluated the role of hepcidin in the presence and absence of iron overload. We aimed to compare serum hepcidin concentrations among individuals with sickle cell anemia, with or without iron overload, and those without the disease. Markers of iron metabolism and erythropoietic activity such as hepcidin, ferritin, and growth differentiation factor 15 were evaluated. Three groups participated in the study: the control group, comprised of individuals without SCD (C); those with the disease but without iron overload (SCDw); and those with the disease and iron overload (SCDio). Results showed that hepcidin concentration was higher in the SCDio > C > SCDw group. These data suggest that the dietary iron intake of the SCDio group should not be reduced as higher hepcidin concentrations may reduce the intestinal absorption of iron.

Hepatic iron content is independently associated with serum hepcidin levels in subjects with obesity

BACKGROUND & AIMS

Serum hepcidin concentration is known to increase in parallel to circulating markers of iron stores. We aimed to investigate whether this is reflected at the tissue level in subjects with obesity.

METHODS

Serum hepcidin and ferritin levels (ELISA) and hepatic iron content (using magnetic resonance imaging) were analyzed longitudinally in 44 participants (19 without obesity and 25 with obesity). In a subgroup of 16 participants with obesity, a weight loss intervention was performed.

RESULTS

Serum hepcidin, ferritin and hepatic iron content (HIC) were significantly increased in participants with obesity. Age- and gender-adjusted serum hepcidin was positively correlated with BMI, hsCRP, ferritin and HIC. In addition, age- and gender-adjusted serum hepcidin was positively correlated with ferritin and HIC in both non-obese and obese participants. In multivariate regression analysis, hepatic iron content (p < 0.01) and serum ferritin (p < 0.001) contributed independently to circulating hepcidin concentration variation after controlling for age, gender, BMI and hsCRP. Diet intervention-induced weight loss led to decreased serum hepcidin (p = 0.01), serum ferritin concentration (p = 0.01) and HIC (p = 0.002). Of note, the percent change of serum hepcidin strongly correlated with the percent change of serum ferritin (r = 0.69, p = 0.01) and HIC (r = 0.61, p = 0.03) even after controlling for age and gender.

CONCLUSIONS

Serum hepcidin is a reliable marker of the hepatic iron content in subjects with obesity.