Iron Metabolism in Obesity and Metabolic Syndrome

Associations of non-essential metal/metalloids and their mixture with liver function in Chinese older adults: the mediating roles of lipid profiles

The liver is vulnerable to damage from environmental pollutants, but evidence on the effects of non-essential metal/metalloid (NEM) mixture on liver function and their mechanisms remains limited. The study aimed to explore the correlations between individual NEMs and their combinations with liver function, and the mediating roles of lipid profiles. The research involved 2642 individuals aged 60 and older in China. Urine concentrations of arsenic (As), cesium (Cs), barium (Ba), thallium (Tl), and cadmium (Cd) were analyzed using ICP-MS. Liver function was assessed based on the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB). To evaluate the individual and combined effects of these NEMs on liver function, linear regression, restricted cubic splines (RCS), weighted quantile sum (WQS), quantile g-computation (QGC), and Bayesian kernel machine regression (BKMR) models were utilized. Mediation analyses were conducted to explore the potential role of lipid profiles in NEM-liver function relations. Adjusted linear regression revealed positive associations of Tl with ALT (β = 0.044, 95 % CI: 0.022 to 0.066) and AST (β = 0.019, 95 % CI: 0.004 to 0.035), and negative associations of Cs (β = -0.015, 95 % CI: -0.020 to -0.010), Tl (β = -0.010, 95 % CI: -0.015 to -0.005), and Cd (β = -0.019, 95 % CI: -0.024 to -0.014) with ALB. The RCS model confirmed these linear relationships. Mixture models consistently demonstrated a positive association between the NEM mixture and ALT/AST, primarily driven by Tl, and a negative association with ALB, predominantly influenced by Cd. Mediation analyses suggested triglycerides and total cholesterol partially mediated the associations between Tl, the NEM mixture, and liver function. In conclusion, the NEM mixture, mainly driven by Tl and Cd, is linked to liver function impairment, with lipid profiles potentially mediating these effects. More research is needed to confirm these findings and clarify the mechanisms.

A molecular sensor for selective recognition of Fe3+ by a functional seven-nuclear Zn(II) cluster compound formed from a quinoline-modified half-salamo-type Precursor

In this paper, we designed and synthesized a novel based on quinoline modification half-salamo-type Zn(II) complex([Zn7(L)6(μ3-OCH3)6]·(ClO4)2), namely ZP. The structure of ZP was determined by X-ray single-crystal diffraction, in which the Zn(II) ions displayed in two different coordination modes, ultimately forming a highly symmetric heptanuclear structure. The Zn(II) complex probe modified by quinoline luminescent group has excellent luminescence properties and selectively recognizes Fe3+ in aqueous solution. When Fe3+ is added to the aqueous solution of ZP, ZP exhibits an obvious fluorescence quenching effect in a relatively short period of time, with a high sensitivity. The lowest detection limit of ZP for Fe3+ was further determined by fluorescence titration to be 5.8 × 10-8 M-1. In order to further explore the mechanism of Fe3+ quenching on ZP fluorescence, we performed fluorescence titration experiments, XPS as well as ESI-MS characterization, which proved that the recognition of Fe3+ by ZP is the substitution of metal ions leading to fluorescence quenching. At the same time, we also examined the practical application of ZP in life, and found that ZP can quantitatively detect the content of Fe3+ in drugs and actual water samples, and the experimental results were highly consistent with test result of ICP-MS, which further demonstrated that the detection of ZP was highly accurate. In addition, the detection of Fe3+ by ZP can be applied over a wide pH range without interference from other metal ions.

The Interplay Between Iron Metabolism and Insulin Resistance: A Key Factor in Optimizing Obesity Management in Children and Adolescents

Iron plays a vital role in insulin signaling, regulating molecular mechanisms that influence cellular insulin responses. This review explores the link between iron metabolism and insulin resistance (IR) in children and adolescents with obesity. A connection between iron metabolism, iron deficiency (ID), and IR is well-documented, but further longitudinal studies are needed to better understand how iron metabolism influences insulin resistance during childhood and adolescence. This connection warrants attention due to its significant public health implications, as optimizing obesity management could help prevent both ID and metabolic complications in children. Current evidence does not suggest that dietary factors are primary contributors to ID in children. However, there is scientific evidence that weight reduction can restore iron homeostasis in people with obesity. Therefore, efforts should focus on improving dietary habits, increasing awareness of iron's importance, and implementing strategies to address both ID and obesity.

Establishing the relationships between obesity and genetically predicted serum micronutrient levels: a multivariable Mendelian randomization analysis

BACKGROUND

Previous observational studies have indicated that circulating micronutrients may influence obesity risk. This study aimed to explore the causal relationship between micronutrient levels and obesity through multivariable Mendelian randomization (MR) analysis.

METHODS

Single nucleotide polymorphisms (SNPs) significantly associated with 15 micronutrients (selenium, zinc, copper, calcium, beta-carotene, folate, iron, magnesium, potassium, and vitamins A, B6, B12, C, D, and E) from published genome-wide association studies (GWAS) were used as instrumental variables (IVs). Three obesity-related datasets were obtained from the GWAS. Inverse variance weighted (IVW) is the main method used for MR analysis. Leave-one-out analysis, MR-Pleiotropy Residual Sum and Outlier method (MR-PRESSO), weighted median, and MR-Egger method were used to assess pleiotropy and heterogeneity.

RESULTS

Genetically predicted levels of circulating selenium and calcium are causally related to the risk of obesity (calcium odds ratio [OR]: 1.478, 95% confidence interval [CI] 1.128-1.935, p = 0.005; selenium OR: 1.478, 95% CI 1.128-1.935, p = 0.005). Multivariate MR analysis suggested a causal relationship between circulating selenium and calcium levels and obesity risk (calcium OR: 1.625, 95% CI 1.260-2.097; selenium OR: 1.080, 95% CI 1.003-1.163, p = 0.041). The p-value obtained in the Cochrane Q test, MR-Egger intercept test, and MR-PRESSO were > 0.05, suggesting no significant evidence of pleiotropy or heterogeneity.

CONCLUSION

Our study revealed, for the first time, a positive correlation between elevated circulating calcium and selenium levels and an increased obesity risk. These findings provide valuable insights into obesity's underlying mechanisms. Nevertheless, further large-scale clinical studies are required to confirm our results.

LEVEL OF EVIDENCE

Level III, Mendelian randomization.

Plasma N-Glycoproteomics in monozygotic twin pairs discordant for body mass index reveals an obesity signature related to inflammation and iron metabolism

BACKGROUND

N-glycosylation is a complex, post-translational modification which influences protein function and is sensitive to physiological changes. Obesity is associated with alterations in protein function; however, little is known about the glycoproteome in obesity beyond observations of association with types and structures of selected glycopeptides. Most often, due to technical challenges, glycan composition and structure information are missing. Here, we combined label-free data-independent proteomics and targeted quantitative glycoproteomics to study N-glycosylation of plasma proteins in obesity. Using a monozygotic twin study design, we controlled for genetic variation and focused only on the acquired effects of obesity.

METHODS

Using plasma samples of 48 monozygotic twin pairs discordant for BMI (intrapair difference > 2.5 kg/m2), we identified using mass spectrometry, differential protein and glycopeptide levels between heavier and leaner co-twins. We used a within-twin paired analysis model and considered p < 0.05 as significant.

RESULTS

We identified 48 protein and 33 N-glycosylation expression differences (p < 0.05) between co-twins. These differences occurred either both in the protein expression and glycoprotein (sometimes in opposing directions) or independently from each other. Haptoglobin protein was upregulated (Fold Change = 1.10, p = 0.001) in heavier co-twins along with seven upregulated glycan compositions at N-glycosylation site Asn241. The complement protein C3 was upregulated (Fold Change = 1.08, p = 0.014) along with one upregulated glycopeptide at Asn85. Additionally, many glycopeptides were upregulated despite non-significant differences in protein-backbone plasma levels.

CONCLUSION

Differential protein expression related to cholesterol biosynthesis and acute phase signalling as well as N-glycosylation of proteins related to iron metabolism and inflammation can be linked to acquired obesity.

Epithelial-mesenchymal transition promotes metabolic reprogramming to suppress ferroptosis

Epithelial-mesenchymal transition (EMT) is a cellular de-differentiation process that provides cells with the increased plasticity and stem cell-like traits required during embryonic development, tissue remodeling, wound healing and metastasis. Morphologically, EMT confers tumor cells with fibroblast-like properties that lead to the rearrangement of cytoskeleton (loss of stiffness) and decrease of membrane rigidity by incorporating high level of poly-unsaturated fatty acids (PUFA) in their phospholipid membrane. Although large amounts of PUFA in membrane reduces rigidity and offers capabilities for tumor cells with the unbridled ability to stretch, bend and twist in metastasis, these PUFA are highly susceptible to lipid peroxidation, which leads to the breakdown of membrane integrity and, ultimately results in ferroptosis. To escape the ferroptotic risk, EMT also triggers the rewiring of metabolic program, particularly in lipid metabolism, to enforce the epigenetic regulation of EMT and mitigate the potential damages from ferroptosis. Thus, the interplay among EMT, lipid metabolism, and ferroptosis highlights a new layer of intricated regulation in cancer biology and metastasis. Here we summarize the latest findings and discuss these mutual interactions. Finally, we provide perspectives of how these interplays contribute to cellular plasticity and ferroptosis resistance in metastatic tumor cells that can be explored for innovative therapeutic interventions.

Worldwide prevalence of the double burden of malnutrition in children and adolescents at the individual level: systematic review and meta-regression

OBJECTIVE

This study aimed to assess the prevalence of the double burden of malnutrition (DBM) at the individual level in children and adolescents through a comprehensive literature review.

SOURCES

Electronic databases, including PubMed, Scopus, and Web of Science, were searched for articles published up until September 9, 2022. Studies reporting individual-level DBM in children and adolescents were included, and meta-regression models were used to investigate potential causes of heterogeneity across studies.

SUMMARY OF THE FINDINGS

Of the 784 articles initially retrieved, 11 met the inclusion criteria. The overweight/obesity prevalence ranges from 8.1 % to 37.0 %, and the undernutrition (stunting, micronutrient deficiency, or anemia) from 4.2 % and 73.0 %. The prevalence of DBM ranged from 1 % to 35.4 %, with the highest rates observed in low- and middle-income countries. Among children, Asia reported the highest DBM prevalence, while in adolescents, Latin America had the highest rates. The review revealed significant variability in DBM prevalence across studies, with a notable increase in research on this topic over the past decade (2013-2022).

CONCLUSION

These findings underscore the concerning global prevalence of the double burden of malnutrition in children and adolescents, particularly in low- and middle-income countries. Standardized definitions and methods are urgently needed to improve comparability, along with further research to identify the specific drivers of DBM and inform effective prevention strategies. CRD42022333424.

Moderate static magnetic field modulated lipid metabolism abnormalities induced by continuous artificial light in Caenorhabditis elegans: Role of iron ions

Excessive use of artificial light sources has led to a significant increase in light pollution, which has raised serious concerns due to its serious adverse effects on lipid metabolism. Although moderate static magnetic fields (SMFs) have shown potential in health intervention and treatment as non-invasive and highly permeable physical field, the influence of SMFs on lipid metabolic disturbance induced by lights remains largely unknown. In this study, we explored the lipid metabolism of Caenorhabditis elegans (C. elegans) under varying wavelengths of light ranging from 395 nm to 635 nm, both in the presence and absence of a 0.5 T SMF, and elucidated their underlying mechanisms. Exposure of C. elegans to artificial light at 200 lux resulted in a shortened lifespan while significantly increasing fat accumulation in a wavelength-dependent manner. The presence of 0.5 T SMF significantly extended the lifespan and reduced the size of fat droplets, as well as the content of triglyceride in light exposed worms. These effects were achieved by upregulating the expression of genes related to lipolysis and downregulating the expression of genes related to lipid synthesis. Moreover, the 0.5 T SMF alleviated abnormalities in lipid metabolism caused by light through the regulation of iron ions. Our findings provided clear evidence that moderate SMFs have significant protective effects on lipid metabolism abnormalities induced by artificial light via mediating iron homeostasis, which might contribute to a better understanding of the combined photomagnetic effects in living organisms.

Emerging biomarkers in type 2 diabetes mellitus

Diabetes mellitus is a chronic condition caused by high blood glucose resulting from insufficient insulin production or cellular resistance to insulin action or both. It is one of the fastest-growing public health concerns worldwide. Development of long-term nephropathy, retinopathy, neuropathy, and cardiovascular disease are some of the complications commonly associated with poor blood glycemic control. Type 2 diabetes mellitus (T2DM), the most prevalent type of diabetes, accounts for around 95 % of all cases globally. Although middle-aged or older adults are more likely to develop T2DM, its prevalence has grown in children and young people due to increased obesity, sedentary lifestyle and poor nutrition. Furthermore, it is believed that more than 50 % of cases go undiagnosed annually. Routine screening is essential to ensure early detection and reduce risk of life-threatening complications. Herein, we review traditional biomarkers and highlight the ongoing pursuit of novel and efficacious biomarkers driven by the objective of achieving early, precise and prompt diagnoses. It is widely acknowledged that individual biomarkers will inevitably have certain limitations necessitating the need for integrating multiple markers in screening.

Preventing and Managing Pre- and Postoperative Micronutrient Deficiencies: A Vital Component of Long-Term Success in Bariatric Surgery

Bariatric surgery (BS) is an effective treatment for severe obesity and its related comorbidities, such as type 2 diabetes and hypertension. However, the anatomical and physiological changes associated with these procedures significantly increase the risk of preoperative and postoperative micronutrient deficiencies, which can lead to severe complications such as anemia, osteoporosis, and neurological disorders. This narrative review examines the prevalence and clinical implications of micronutrient deficiencies in BS patients, as well as evidence-based strategies for their prevention and management. The most common deficiencies include iron, vitamin B12, folate, calcium, vitamin D, and fat-soluble vitamins (A, E, and K). Procedures with a hypoabsorptive component, such as Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion with duodenal switch (BPD/DS), pose higher risks of deficiencies compared to restrictive procedures like sleeve gastrectomy (SG). Effective strategies involve the preoperative correction of deficiencies, continuous monitoring, and tailored supplementation. However, long-term adherence to supplementation tends to decrease over time, influenced by behavioral and socioeconomic factors. Hence, preventing and managing micronutrient deficiencies are crucial for the long-term success of BS. While current guidelines provide valuable recommendations, many are based on low-certainty evidence, underscoring the need for more robust studies. A multidisciplinary approach, combined with innovative strategies, such as telemedicine, can enhance adherence and achieve sustainable clinical outcomes.

The relationship between physical activity level, dietary patterns, and metabolic syndrome: An empirical study in Saudi Arabia

BACKGROUND

Metabolic syndrome, a cluster of conditions increasing the risk of heart disease, stroke, and diabetes, is a growing concern globally. In Saudi Arabia, lifestyle factors such as physical activity and dietary patterns play a significant role in the prevalence of metabolic syndrome.

STUDY PURPOSE

This study aims to explore the relationship between physical activity levels, dietary patterns, and the prevalence of metabolic syndrome among adults in Saudi Arabia.

METHODS

A cross-sectional study was conducted using purposive and convenience sampling techniques. A total of 468 participants completed questionnaires assessing their physical activity levels and dietary patterns. Metabolic syndrome was determined based on clinical measurements of waist circumference, blood pressure, fasting glucose, and lipid levels.

RESULTS

The analysis revealed a significant association between lower physical activity levels and poor dietary patterns with higher prevalence rates of metabolic syndrome. The analysis revealed that participants with low physical activity levels had a higher prevalence of metabolic syndrome (p < 0.01). Similarly, those with unhealthy dietary patterns (high in saturated fats and sugars) showed a metabolic syndrome risk (p < 0.01), compared to those with healthy dietary patterns.

CONCLUSION

The findings underscore the critical role of physical activity and dietary patterns in the development of metabolic syndrome in Saudi Arabia. Public health interventions targeting lifestyle modifications could be essential in mitigating metabolic syndrome and improving overall health.

Optimizing Nutritional Management Before and After Bariatric Surgery: A Comprehensive Guide for Sustained Weight Loss and Metabolic Health

Obesity is associated with multiple comorbidities that contribute to increased mortality among affected individuals. There are multiple treatments for this condition, including nutritional interventions, pharmacological therapies, and surgical procedures. Within these, bariatric surgery is an effective treatment option that requires a multidisciplinary approach, both before and after surgery. Nutritional management prior to surgery aims to achieve metabolic control and reduce comorbidities associated with the procedure. Postoperative nutritional management focuses on preventing complications, ensuring adequate nourishment, and providing necessary supplementation for optimal recovery and long-term success. This narrative review examines all these critical aspects of nutritional management in bariatric surgery, including preoperative nutrition, postoperative nutrition and physical activity recommendation, different nutritional aspects according to the type of bariatric surgery, and future directions for investigation.

Physical activities and cardiometabolic profiles of African overweight and obese pregnant women

BACKGROUND

Pregnancy triggers physiological adjustments through hormonal changes, supporting foetal growth and preparation for labour. Becoming more pronounced with excessive weight, these changes may trigger pathophysiological changes and unmask pre-existing disease conditions. In developing countries, many pregnant women experience either inadequate or excessive weight gain and may present with perturbed metabolism. Lifestyle interventions, including regular physical activity, are important but often overlooked in these settings. Context-specific data on physical activity and cardiometabolic profile of overweight and obese pregnant women are limited in sub-Saharan Africa, specifically Tanzania. The current analysis aimed to determine the relationship between pre-pregnancy overweight/obesity, pregnancy physical activity and cardiometabolic factors among pregnant women.

METHODS

This cross-sectional study involving 243 pregnant women aged 18-35 was conducted in selected antenatal clinics in Dodoma, of whom 37% (n = 91) were overweight or obese. The current analysis assessed physical activity, anthropometric, and cardiometabolic parameters and compared between overweight/obese and normal-weight participants.

RESULTS

Overweight and obese pregnant women demonstrated significantly lower levels of physical activity across various domains, including overall physical activity (p < 0.001) and median METs (metabolic equivalent of tasks) minutes per week (p < 0.001) compared with their normal weight counterparts. In particular, they had lower median METs obtained from the occupational domain (p = 0.037). Additionally, the same group engaged less in exercise or leisure time physical activities (p = 0.014), with a lower percentage of contribution to total METs minutes per week obtained from these activities (p = 0.002). Furthermore, overweight or obese participants exhibited higher systolic blood pressure (p < 0.001), diastolic blood pressure (p = 0.008), haemoglobin levels (p < 0.001), fasting blood glucose levels (p = 0.005), serum triglycerides levels (p = 0.012), and total cholesterol levels (t(234) = 1.98, p = 0.048) than their normal-weight counterparts.

CONCLUSION AND RECOMMENDATIONS

Overweight and obese pregnant women showed lower physical activity levels, with low levels of both occupational and leisure time (exercise) physical activities, possibly explaining the observed cardio metabolic perturbation in this group. An intervention aiming at promoting physical activity and enhancing cardiometabolic health among this group is necessary.

Advances in Oral Biomacromolecule Therapies for Metabolic Diseases

Metabolic diseases like obesity and diabetes are on the rise, and therapies with biomacromolecules (such as proteins, peptides, antibodies, and oligonucleotides) play a crucial role in their treatment. However, these drugs are traditionally injected. For patients with chronic diseases (e.g., metabolic diseases), long-term injections are accompanied by inconvenience and low compliance. Oral administration is preferred, but the delivery of biomacromolecules is challenging due to gastrointestinal barriers. In this article, we introduce the available biomacromolecule drugs for the treatment of metabolic diseases. The gastrointestinal barriers to oral drug delivery and strategies to overcome these barriers are also explored. We then discuss strategies for alleviating metabolic defects, including glucose metabolism, lipid metabolism, and energy metabolism, with oral biomacromolecules such as insulin, glucagon-like peptide-1 receptor agonists, proprotein convertase subtilisin/kexin type 9 inhibitors, fibroblast growth factor 21 analogues, and peptide YY analogues.

Iron-Mediated Regulation in Adipose Tissue: A Comprehensive Review of Metabolism and Physiological Effects

PURPOSE OF REVIEW

Review the latest data regarding the intersection of adipose tissue (AT) and iron to meet the needs of AT metabolism and the progression of related diseases.

RECENT FINDINGS

Iron is involved in fundamental biological metabolic processes and is precisely fine-tuned within the body to maintain cellular, tissue and even systemic iron homeostasis. AT not only serves as an energy storage depot but also represents the largest endocrine organ in the human body, maintaining systemic metabolic homeostasis. It is involved in physiological processes such as energy storage, insulin sensitivity regulation and lipid metabolism. As a unique iron-sensing tissue, AT expresses related regulatory factors, including the classic hepcidin, ferroportin (FPN), iron regulatory protein/iron responsive element (IRP/IRE) and ferritin. Consequently, the interaction between AT and iron is intricately intertwined. Imbalance of iron homeostasis produces the potential risks of steatosis, impaired glucose tolerance and insulin resistance, leading to AT dysfunction diseases, including obesity, type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). Despite the role of AT iron has garnered increasing attention in recent years, a comprehensive review that systematically organizes the connection between iron and AT remains lacking. Given the necessity of iron homeostasis, emphasizing its potential impact on AT function and metabolism regulation provides valuable insights into physiological effects such as adipocyte differentiation and thermogenesis. Futhermore, regulators including adipokines, mitochondria and macrophages have been mentioned, along with analyzing the novel perspective of iron as a key mediator influencing the fat-gut crosstalk.

Serum Iron Levels, Dietary Iron Intake, and Supplement Use in Relation to Metabolic Syndrome in Adolescents: A Cross-Sectional Study

The objective of this study was to investigate the potential associations between serum iron levels, dietary iron intake, and iron supplementation, and the prevalence of metabolic syndrome (MetS) in adolescents A cross-sectional analysis was conducted, utilizing data from adolescents participating in the 2003-2018 cycle of the National Health and Nutrition Examination Survey (NHANES). Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) pertaining to serum iron, dietary iron, and iron supplementation were derived through multivariate logistic regression models. Additionally, a restricted cubic spline (RCS) regression model was applied to explore the nonlinear relationship between dietary iron and serum iron concerning MetS. The study encompassed 4858 American adolescents aged 12 to 19, among whom 413 (8.5%) manifested MetS. The study cohort exhibited an average age of 15.52 years, comprising 2551 males (52.51%) and 2307 females (47.49%). Relative to individuals in the lowest serum iron quartile, those in the highest quartile for serum iron (OR = 0.33, 95% CI 0.21-0.50), the highest quartile for dietary iron (OR = 0.53, 95% CI 0.32-0.89), and those utilizing iron supplements (OR = 0.61, 95% CI 0.37-0.99) evinced a diminished prevalence of MetS, even post adjustment for potential confounding variables. A non-linear relationship was discerned between serum iron and MetS, exhibiting a statistically significant negative correlation when serum iron concentrations exceeded the inflection point (serum iron = 8.66 µmol/L, P for nonlinear < 0.001). This investigation reveals that higher levels of serum iron, increased dietary iron intake, and the use of iron supplements are linked to a lower prevalence of MetS in US adolescents. These findings suggest that dietary modifications could play a role in promoting the health of adolescents.

High-iron diet damages brown adipose tissue mitochondria and exacerbates metabolic hazards of a high-fat diet

Metabolic diseases may be prevented by reducing carbohydrate intake and replacing plant-based diets with animal-based ones low in carbohydrates but high in protein, fat, and iron. While the effects of sugars on metabolic diseases are well-known, the role of iron remains unclear. This study aimed to explore the effects of a high-fat high-iron animal diet on body metabolism in mice. Micro-PET imaging was used to assess 18-F-labelled glucose uptake in BAT, and the morphology, respiratory function, and oxidative stress of BAT mitochondria were examined. The underlying mechanisms were elucidated by analyzing the expression of UCP-1, PGC-1α and PPARα. The high-iron high-fat diet increased appetite, impaired glucose tolerance, and reduced insulin sensitivity. Additionally, the high-iron diet promoted gluconeogenesis only in the absence of high-fat levels. Both high-iron and high-fat diets suppressed BAT activity, increased mitochondrial oxidative stress, decreased mitochondrial respiratory function, and lowered thermogenic gene expression. Weight loss strategies focusing solely on reducing carbohydrates and increasing animal foods, like ketogenic diets, may have long-term detrimental effects on metabolic health. Prioritizing dietary diversity and monitoring overall caloric intake is advisable for optimal outcomes.

The relationship between non-HDL cholesterol to HDL cholesterol ratio (NHHR) and anemia: A cross-sectional study of NHANES, 2009 to 2016

The non-HDL cholesterol to HDL cholesterol ratio (NHHR) is a newly developed metric that represents the ratio of non-HDL cholesterol to HDL cholesterol. Anemia is a prevalent public health concern affecting all age groups. Our purpose is to investigate the connection between NHHR and the prevalence of anemia, as well as to explore their potential interactions. A total of 17,019 participants were incorporated into this research. NHHR was calculated as the scale of non-HDL cholesterol to HDL cholesterol. According to WHO criteria, anemia at sea level is diagnosed with a hemoglobin level (g/dL) of <12 for women and <13 for men. This study utilized multivariate linear regression, threshold effect analysis, smooth curve fitting, multivariate logistic regression as well as subgroup analysis, to investigate the linkage between the NHHR and anemia. After complete adjustment, the model indicated a strong inverse relationship between NHHR and the prevalence of anemia (the odds ratio [OR] was 0.82 with a 95% confidence interval of 0.78-0.86), suggesting that an incremental increase in NHHR correlates with an 18% decrease in the prevalence of anemia. Segmenting NHHR into quartiles maintained this significant association. The prevalence of anemia was 51% lower among participants in the highest NHHR quartile compared to those in the lowest quartile, with an OR of 0.49 (95% CI: 0.41-0.59; P for trend < .0001). Subsequent analysis revealed a significant improvement in the threshold effect value to 4.28 for the potential relationship between NHHR and anemia. Subgroup analysis showed an inverse correlation in some subgroups. Alcohol consumption significantly affects the relationship between NHHR and anemia (interaction P < .05). Our study revealed that NHHR is inversely proportional to the prevalence of anemia in U.S. adults.

Low serum hepcidin levels in women with polycystic ovary syndrome: evidence from meta-analysis

BACKGROUND

Iron metabolism plays a significant role in the development of metabolic disorders in women with polycystic ovary syndrome (PCOS). Despite the importance of hepcidin, a key iron regulator, current research on serum hepcidin levels in PCOS patients shows conflicting results.

METHODS

PubMed, Embase, Web of Science, Cochrane Library and the China National Knowledge Infrastructure (CNKI) database were systematically searched from their inception to 9 September 2023. The search aimed to identify studies in English and Chinese that examined hepcidin levels in women with PCOS compared to healthy control subjects. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (95% CIs) were calculated to evaluate the difference in serum hepcidin levels between women with and without PCOS.

RESULTS

The meta-analysis included a total of 10 eligible studies, which encompassed 499 PCOS patients and 391 control subjects. The pooled analysis revealed a significant reduction in serum hepcidin levels among the PCOS patients compared to the healthy controls (SMD = -3.49, 95% CI: -4.68 to -2.30, p < .05). There was no statistically significant difference in serum hepcidin levels between PCOS patients with a body mass index (BMI) < 25 and those with a BMI ≥ 25 (p > .05).

CONCLUSION

The serum hepcidin levels of women with PCOS were significantly lower than those of healthy controls, which suggests that serum hepcidin could be a potential biomarker for PCOS.

Inverted U-Shaped Association of Soluble Transferrin Receptor Concentrations with Risks of Cardiovascular Diseases in Overweight Individuals: A Cross-Sectional Study

Background

Iron metabolism may play a role in cardiovascular disease (CVD) pathogenesis. The association between iron metabolism and CVD has yet to be fully investigated. This study evaluated whether iron metabolism was associated with CVD risk and whether the body mass index (BMI) of US adults varied the association.

Methods

A cross-sectional study was performed using the National Health and Nutrition Examination Survey (NHANES), conducted from 2017 to 2018. Generalized additive models (GAMs) and multivariable logistic regression were adopted to analyze the association between iron metabolism (serum iron (SI), serum ferritin (SF), transferrin saturation (TSAT), and soluble transferrin receptor (sTfR)) and CVD risk. Further, stratified analysis was conducted to identify patients with high CVD risk.

Results

Participants with CVD tended to have significantly increased levels of sTfR (p < 0.001) and decreased levels of TSAT (p < 0.001) and SI (p < 0.001). After adjusting for confounding factors, sTfR levels had a significant positive association with CVD risk (Q1 as reference, Q4 odds ratio (OR) 2.1, 95% CI 1.54-2.87, p < 0.001). Notably, the association between sTfR and CVD risk differed in the BMI subgroup (p for interaction < 0.05). We identified an inverted U-shaped relationship between sTfR and the CVD risk in the group of overweight individuals (non-linear p < 0.001). When the sTfR level was below the turning point (sTfR = 5.35 mg/L), a per unit increase in the sTfR level was correlated with a 78% greater adjusted OR of CVD risk (OR, 1.78 [1.44, 2.19]).

Conclusions

Increased sTfR levels were non-linearly related to the CVD risk in the overweight population.

Integrated approach to reducing polypharmacy in older people: exploring the role of oxidative stress and antioxidant potential therapy

Increased life expectancy, attributed to improved access to healthcare and drug development, has led to an increase in multimorbidity, a key contributor to polypharmacy. Polypharmacy is characterised by its association with a variety of adverse events in the older persons. The mechanisms involved in the development of age-related chronic diseases are largely unknown; however, altered redox homeostasis due to ageing is one of the main theories. In this context, the present review explores the development and interaction between different age-related diseases, mainly linked by oxidative stress. In addition, drug interactions in the treatment of various diseases are described, emphasising that the holistic management of older people and their pathologies should prevail over the individual treatment of each condition.

Relationship of serum iron and thyroid hormone in obesity and after laparoscopic sleeve gastrectomy

BACKGROUND

Iron is an essential element for thyroid function. However, no study focuses on the association between iron and thyroid in individuals with obesity. Our research aimed to investigate the iron status in relation to baseline thyroid hormone levels and after laparoscopic sleeve gastrectomy (LSG).

METHODS

A total of 216 subjects with obesity were enrolled and divided into low and high iron groups depending on the median value. The association between iron and thyroid hormone was analyzed and compared before and after LSG at the 6-month follow-up in patients who underwent LSG.

RESULTS

1) In all, Total Triiodothyronine (TT3) was significantly higher in high iron than low iron group (P = 0.008). TT3 and thyroid stimulating hormone (TSH) were significantly higher in high iron than low iron group (1.92 ± 0.61 vs. 1.69 ± 0.28 nmol/l, P = 0.029; 2.93 ± 1.66 vs. 1.88 ± 1.03 mU/l, P = 0.002) in females while not in males (all P > 0.05). 2) Iron was significantly positively associated with free triiodothyronine (FT3), free thyroxine (FT4), TT3 and TSH (all P < 0.05). Adjusted for body mass index (BMI), total cholesterol (TCH), high-density lipoprotein cholesterol (HDL-C), fasting insulin (FINS) and homeostatic model assessment of insulin resistance (HOMA-IR), FT3, FT4 and TSH were still significantly associated with iron (all P < 0.05). 3). Regression analysis showed that iron was significantly associated with FT4 (β = 0.338, P = 0.038). 3) LSG led to decreased FT3, FT3, TT3, total thyroxine (TT4) and TSH at 6 months follow-up (all P < 0.05). Changed FT4 was significantly associated with changed iron (r = 0.520, P = 0.009). Subjects with iron decreased had more significant decreased TT4 than subjects without iron decreased (P = 0.021).

CONCLUSION

Serum iron overload is significantly associated with impaired thyroid function in subjects with obesity. LSG led to improved thyroid function which is associated with a change in iron.

TRIAL REGISTRATION

NCT04548232 registration date is on October 9, 2022, registered in https://register.

CLINICALTRIALS

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Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Serum iron status is associated with all-cause mortality in metabolic dysfunction-associated steatotic liver disease: a prospective, observational study

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading chronic liver disease worldwide. Emerging evidence suggests a close crosstalk between iron status and metabolic syndrome. Therefore, this cohort study aimed to investigate the relationship between serum iron status and all-cause mortality in individuals with MASLD.

Methods

A total of 3393 subjects with MASLD identified by ultrasound from the Third National Health and Nutrition Examination Survey (NHANES III) were included in the analysis. Iron status indicators included serum iron, ferritin, transferrin saturation, total iron binding capacity, hemoglobin concentration, mean corpuscular hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin concentration. Cox proportional hazards models and restricted cubic spline models with adjustment for multiple confounders were applied. Stratified analyses were performed by sex and age.

Results

During a median of 26.08 years of follow-up, high serum iron and transferrin saturation were significantly associated with reduced all-cause mortality in a linear pattern (P overall<0.001). Compared with the lowest quartile, individuals with serum iron and transferrin saturation in the third or fourth quartile intervals had a 20-40% reduction in long-term mortality. However, there was no independent association of serum ferritin, total iron binding capacity, and red blood cell indices with all-cause mortality in MASLD.

Conclusion

This study suggests that serum iron and transferrin saturation have the potential to serve as independent biomarkers of all-cause mortality in patients with MASLD and implies the therapeutic potential of modifying iron status.

Enhanced cytokine signaling and ferroptosis defense interplay initiates obesity-associated pancreatic ductal adenocarcinoma

Obesity is a significant risk factor for various cancers, including pancreatic cancer (PC), but the underlying mechanisms are still unclear. In our study, pancreatic ductal epithelial cells were cultured using serum from human subjects with diverse metabolic statuses, revealing that serum from patients with obesity alters inflammatory cytokine signaling and ferroptosis, where a mutual enhancement between interleukin 34 (IL-34) expression and ferroptosis defense was observed in these cells. Notably, oncogenic KRASG12D amplified their interaction and this leads to the initiation of pancreatic ductal adenocarcinoma (PDAC) in diet-induced obese mice via macrophage-mediated immunosuppression. Single-cell RNA sequencing (scRNA-seq) of human samples showed that cytokine signaling, ferroptosis defense, and immunosuppression are correlated with the patients' body mass index (BMI) during PDAC progression. Our findings provide a mechanistic link between obesity, inflammation, ferroptosis defense, and pancreatic cancer, suggesting novel therapeutic targets for the prevention and treatment of obesity-associated PDAC.

Probing erythrocytes as sensitive and reliable sensors of metabolic disturbances in the crosstalk between childhood obesity and insulin resistance: findings from an observational study, in vivo challenge tests, and ex vivo incubation assays

BACKGROUND

Although insulin resistance (IR) is among the most frequent and pathogenically relevant complications accompanying childhood obesity, its role in modulating and exacerbating obesity pathophysiology has not yet been completely clarified.

METHODS

To get deeper insights into the interplay between childhood obesity and IR, we leveraged a comprehensive experimental design based on a combination of observational data, in vivo challenge tests (i.e., oral glucose tolerance test), and ex vivo assays (i.e., incubation of erythrocytes with insulin) using a population comprising children with obesity and IR, children with obesity without IR, and healthy controls, from whom plasma and erythrocyte samples were collected for subsequent metabolomics analysis.

RESULTS

Children with concomitant IR showed exacerbated metabolic disturbances in the crosstalk between endogenous, microbial, and environmental determinants, including failures in energy homeostasis, amino acid metabolism, oxidative stress, synthesis of steroid hormones and bile acids, membrane lipid composition, as well as differences in exposome-related metabolites associated with diet, exposure to endocrine disruptors, and gut microbiota. Furthermore, challenge tests and ex vivo assays revealed a deleterious impact of IR on individuals' metabolic flexibility, as reflected in blunted capacity to regulate homeostasis in response to hyperinsulinemia, at both systemic and erythroid levels.

CONCLUSIONS

Thus, we have demonstrated for the first time that metabolite alterations in erythrocytes represent reliable and sensitive biomarkers to disentangle the metabolic complexity of IR and childhood obesity. This study emphasizes the crucial need of addressing inter-individual variability factors, such as the presence of comorbidities, to obtain a more accurate understanding of obesity-related molecular mechanisms.

Iron supplementation and iron accumulation promote adipocyte thermogenesis through PGC1α-ATGL-mediated lipolysis

Iron homeostasis is essential for maintaining metabolic health and iron disorder has been linked to chronic metabolic diseases. Increasing thermogenic capacity in adipose tissue has been considered as a potential approach to regulate energy homeostasis. Both mitochondrial biogenesis and mitochondrial function are iron-dependent and essential for adipocyte thermogenic capacity, but the underlying relationships between iron accumulation and adipose thermogenesis is unclear. Firstly, we confirmed that iron homeostasis and the iron regulatory markers (e.g., Tfr1 and Hfe) are involved in cold-induced thermogenesis in subcutaneous adipose tissues using RNA-seq and bioinformatic analysis. Secondly, an Hfe (Hfe-/-)-deficient mouse model, in which tissues become overloaded with iron, was employed. We found iron accumulation caused by Hfe deficiency enhanced mitochondrial respiratory chain expression in subcutaneous white adipose in vivo and resulted in enhanced tissue thermogenesis with upregulation of PGC-1α and adipose triglyceride lipase, mitochondrial biogenesis and lipolysis. To investigate the thermogenic capacity in vitro, stromal vascular fraction from adipose tissues was isolated, followed with adipogenic differentiation. Primary adipocyte from Hfe-/- mice exhibited higher cellular oxygen consumption, associated with enhanced expression of mitochondrial oxidative respiratory chain protein, while primary adipocytes or stromal vascular fractions from WT mice supplemented with iron citrate) exhibited similar effect in thermogenic capacity. Taken together, these findings indicate iron supplementation and iron accumulation (Hfe deficiency) can regulate adipocyte thermogenic capacity, suggesting a potential role for iron homeostasis in adipose tissues.

Iron Homeostasis-Related Parameters and Hepcidin/Ferritin Ratio: Emerging Sex-Specific Predictive Markers for Metabolic Syndrome

Metabolic syndrome (MetS) is a worldwide public health challenge. Accumulating evidence implicates elevated serum ferritin and disruptions in iron metabolism as potential elements linked to an increased risk of MetS. This study investigates the relationship between iron homeostasis-including hepcidin levels, serum iron concentration, unsaturated iron-binding capacity (UIBC), and the hepcidin/ferritin (H/F) ratio-and MetS. In this descriptive cross-sectional study, 209 participants aged 24-70 were categorized into two groups: 103 with MetS and 106 without MetS. All participants underwent medical assessment, including anthropometric measures, indices of glycemic control, lipid profiles, and iron-related parameters. Participants were further stratified by the Homeostasis Model Assessment-Insulin Resistance index into three subgroups: insulin-sensitive (IS) (<1.9), early insulin resistance (EIR) (>1.9 to <2.9), and significant insulin resistance (SIR) (>2.9). Notable increments in serum ferritin and hepcidin were observed in the SIR group relative to the IS and EIR groups, with a significant association between metabolic parameters. The UIBC and serum ferritin emerged as significant predictors of MetS, particularly in men, with an area under the curve (AUC) of 0.753 and 0.792, respectively (p ≤ 0.001). In contrast, hepcidin was notably correlated with MetS in women, with an AUC of 0.655 (p = 0.007). The H/F ratio showed superior predictive capability for MetS across both sexes (at cutoff level = 0.67). Among women, this ratio had an AUC of 0.639 (p = 0.015), and for men, it had an AUC of 0.792 (p < 0.001). Hypertension proved an independent risk factor for MetS, affirming its role in metabolic dysregulation. The findings highlight a significant interconnection between iron homeostasis parameters and MetS, with sex-specific variations underscoring the importance of personalized diagnostic criteria. The crucial role of the H/F ratio and the UIBC as emerging predictive markers for MetS indicates their potential utility in identifying at-risk individuals. Further longitudinal research is essential to establish causality and explore the interplay between these biomarkers and MetS.

Is oxidative stress - antioxidants imbalance the physiopathogenic core in pediatric obesity?

Despite the early recognition of obesity as an epidemic with global implications, research on its pathogenesis and therapeutic approach is still on the rise. The literature of the 21st century records an excess weight found in up to 1/3 of children. Both the determining factors and its systemic effects are multiple and variable. Regarding its involvement in the potentiation of cardio-vascular, pulmonary, digestive, metabolic, neuro-psychic or even dermatological diseases, the information is already broadly outlined. The connection between the underlying disease and the associated comorbidities seems to be partially attributable to oxidative stress. In addition to these, and in the light of the recent COVID-19 pandemic, the role played by oxidative stress in the induction, maintenance and potentiation of chronic inflammation among overweight children and adolescents becomes a topic of interest again. Thus, this review's purpose is to update general data on obesity, with an emphasis on the physiopathological mechanisms that underlie it and involve oxidative stress. At the same time, we briefly present the latest principles of pathology diagnosis and management. Among these, we will mainly emphasize the impact played by endogenous and exogenous antioxidants in the evolutionary course of pediatric obesity. In order to achieve our objectives, we will refer to the most recent studies published in the specialized literature.

Association between childhood obesity, trace elements, and heavy metals: Recent discoveries and future perspectives

Trace elements and heavy metals play pivotal roles in health status by regulating a myriad of vital biological functions. Abnormal metal homeostasis has been linked to a constellation of pathogenic complications, including oxidative stress, inflammatory processes, dyslipidemia, and impaired insulin-mediated metabolism of carbohydrates, thereby increasing the odds of developing childhood obesity and related comorbidities. Herein, we provide a comprehensive revision of recent literature on the association between childhood obesity, trace elements, and heavy metals. Further, we emphasize on the crucial importance of addressing the influence that interindividual variability factors (e.g., sex, age, genetic determinants, concomitance of comorbidities, and environmental factors) may have in modulating the susceptibility to disease development. Altogether, this review article represents a concise guide to better understand the involvement of metals in childhood obesity pathogenesis and discusses future needs with the aim of establishing robust biomarkers in the context of precision medicine.

The Role of Iron Metabolism in Sepsis-associated Encephalopathy: a Potential Target

Sepsis-associated encephalopathy (SAE) is an acute cerebral dysfunction secondary to infection, and the severity can range from mild delirium to deep coma. Disorders of iron metabolism have been proven to play an important role in a variety of neurodegenerative diseases by inducing cell damage through iron accumulation in glial cells and neurons. Recent studies have found that iron accumulation is also a potential mechanism of SAE. Systemic inflammation can induce changes in the expression of transporters and receptors on cells, especially high expression of divalent metal transporter1 (DMT1) and low expression of ferroportin (Fpn) 1, which leads to iron accumulation in cells. Excessive free Fe2+ can participate in the Fenton reaction to produce reactive oxygen species (ROS) to directly damage cells or induce ferroptosis. As a result, it may be of great help to improve SAE by treatment of targeting disorders of iron metabolism. Therefore, it is important to review the current research progress on the mechanism of SAE based on iron metabolism disorders. In addition, we also briefly describe the current status of SAE and iron metabolism disorders and emphasize the therapeutic prospect of targeting iron accumulation as a treatment for SAE, especially iron chelator. Moreover, drug delivery and side effects can be improved with the development of nanotechnology. This work suggests that treating SAE based on disorders of iron metabolism will be a thriving field.

A high reticulocyte count is a risk factor for the onset of metabolic dysfunction-associated steatotic liver disease: Cross-sectional and prospective studies of data of 310,091 individuals from the UK Biobank

Background and Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) poses a considerable health risk. Nevertheless, its risk factors are not thoroughly comprehended, and the association between the reticulocyte count and MASLD remains uncertain. This study aimed to explore the relationship between reticulocyte count and MASLD. Methods: A total of 310,091 individuals from the UK Biobank were included in this cross-sectional study, and 7,316 individuals were included in this prospective study. The cross-sectional analysis categorized reticulocyte count into quartiles, considering the sample distribution. Logistic regression models examined the connection between reticulocyte count and MASLD. In the prospective analysis, Cox analysis was utilized to investigate the association. Results: Our study findings indicate a significant association between higher reticulocyte count and an elevated risk of MASLD in both the cross-sectional and prospective analyses. In the cross-sectional analysis, the adjusted odds ratios (ORs) of MASLD increased stepwise over reticulocyte count quartiles (quartile 2: OR 1.22, 95% CI 1.17-1.28, p < 0.001; quartile 3: OR 1.44; 95% CI 1.38-1.51, p < 0.001; quartile 4: OR 1.66, 95% CI 1.59-1.74, p < 0.001). The results of prospective analyses were similar. Conclusion: Increased reticulocyte count was independently associated with a higher risk of MASLD. This discovery offers new insights into the potential of reticulocytes as biomarkers for MASLD.

Iron metabolism and ferroptosis in nonalcoholic fatty liver disease: what is our next step?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with increasing prevalence worldwide. NAFLD could develop from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH), NASH-related fibrosis, cirrhosis, and even hepatocellular carcinoma. However, the mechanism of NAFLD development has not yet been fully defined. Recently, emerging evidence shows that the dysregulated iron metabolism marked by elevated serum ferritin, and ferroptosis are involved in the NAFLD. Understanding iron metabolism and ferroptosis can shed light on the mechanisms of NAFLD development. Here, we summarized studies on iron metabolism and the ferroptosis process involved in NAFLD development to highlight potential medications and therapies for treating NAFLD.

Liver steatosis in patients with transfusion-dependent thalassaemia

We evaluated the prevalence and the clinical associations of liver steatosis (LS) in patients with transfusion-dependent thalassaemia (TDT). We considered 301 TDT patients (177 females, median age = 40.61 years) enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 25 healthy subjects. Magnetic resonance imaging was used to quantify iron overload and hepatic fat fraction (FF) by T2* technique and cardiac function by cine images. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Hepatic FF was significantly higher in TDT patients than in healthy subjects (median value: 1.48% vs. 0.55%; p = 0.013). In TDT, hepatic FF was not associated with age, gender, serum ferritin levels or liver function parameters, but showed a weak inverse correlation with high-density lipoprotein cholesterol. The 36.4% of TDT patients showed LS (FF >3.7%). Active hepatitis C virus (HCV) infection, increased body mass index and hepatic iron were independent determinants of LS. A hepatic FF >3.53% predicted the presence of an abnormal OGTT. Hepatic FF was not correlated with cardiac iron, biventricular volumes or ejection fractions, but was correlated with left ventricular mass index. In TDT, LS is a frequent finding, associated with iron overload, increased weight and HCV, and conveying an increased risk for the alterations of glucose metabolism.

Whole genome sequencing of mouse lines divergently selected for fatness (FLI) and leanness (FHI) revealed several genetic variants as candidates for novel obesity genes

BACKGROUND

Analysing genomes of animal model organisms is widely used for understanding the genetic basis of complex traits and diseases, such as obesity, for which only a few mouse models exist, however, without their lean counterparts.

OBJECTIVE

To analyse genetic differences in the unique mouse models of polygenic obesity (Fat line) and leanness (Lean line) originating from the same base population and established by divergent selection over more than 60 generations.

METHODS

Genetic variability was analysed using WGS. Variants were identified with GATK and annotated with Ensembl VEP. g.Profiler, WebGestalt, and KEGG were used for GO and pathway enrichment analysis. miRNA seed regions were obtained with miRPathDB 2.0, LncRRIsearch was used to predict targets of identified lncRNAs, and genes influencing adipose tissue amount were searched using the IMPC database.

RESULTS

WGS analysis revealed 6.3 million SNPs, 1.3 million were new. Thousands of potentially impactful SNPs were identified, including within 24 genes related to adipose tissue amount. SNP density was highest in pseudogenes and regulatory RNAs. The Lean line carries SNP rs248726381 in the seed region of mmu-miR-3086-3p, which may affect fatty acid metabolism. KEGG analysis showed deleterious missense variants in immune response and diabetes genes, with food perception pathways being most enriched. Gene prioritisation considering SNP GERP scores, variant consequences, and allele comparison with other mouse lines identified seven novel obesity candidate genes: 4930441H08Rik, Aff3, Fam237b, Gm36633, Pced1a, Tecrl, and Zfp536.

CONCLUSION

WGS revealed many genetic differences between the lines that accumulated over the selection period, including variants with potential negative impacts on gene function. Given the increasing availability of mouse strains and genetic polymorphism catalogues, the study is a valuable resource for researchers to study obesity.

Crosstalk between intestinal flora and human iron metabolism: the role in metabolic syndrome-related comorbidities and its potential clinical application

The interaction of iron and intestinal flora, both of which play crucial roles in many physiologic processes, is involved in the development of Metabolic syndrome (MetS). MetS is a pathologic condition represented by insulin resistance, obesity, dyslipidemia, and hypertension. MetS-related comorbidities including type 2 diabetes mellitus (T2DM), obesity, metabolism-related fatty liver (MAFLD), hypertension polycystic ovary syndrome (PCOS), and so forth. In this review, we examine the interplay between intestinal flora and human iron metabolism and its underlying mechanism in the pathogenesis of MetS-related comorbidities. The composition and metabolites of intestinal flora regulate the level of human iron by modulating intestinal iron absorption, the factors associated with iron metabolism. On the other hand, the iron level also affects the abundance, composition, and metabolism of intestinal flora. The crosstalk between these factors is of significant importance in human metabolism and exerts varying degrees of influence on the manifestation and progression of MetS-related comorbidities. The findings derived from these studies can enhance our comprehension of the interplay between intestinal flora and iron metabolism, and open up novel potential therapeutic approaches toward MetS-related comorbidities.

Icariin, astragaloside a and puerarin mixture attenuates cognitive impairment in APP/PS1 mice via inhibition of ferroptosis-lipid peroxidation

Alzheimer's disease (AD) is a neurodegenerative disease that seriously threatens the quality of life of the elderly. Its pathogenesis has not yet been fully elucidated. Ferroptosis, a cell death caused by excessive accumulation of iron-dependent lipid peroxides, has been implicated in the pathogenesis of AD. Uncontrolled lipid peroxidation is the core process of ferroptosis, and inhibiting lipid peroxidation of ferroptosis may be an important therapeutic target for AD. Based on previous studies, we mixed standards of icariin, astragaloside IV, and puerarin, named the standard mixture YHG, and investigated the effect of YHG on ferroptosis -lipid peroxidation in APP/PS1 mice. DFX, a ferroptosis inhibitor, was used as a control drug. In this study, APP/PS1 mice were used as an AD animal model, and behavioral experiments, iron level detection, Transmission electron microscopy (TEM) observation, lipid peroxidation level detection, antioxidant capacity detection, immunofluorescence, Western blot and real-time qPCR were performed. It was found that YHG could reduce body weight, significantly improve abnormal behaviors and the ultrastructure of hippocampal neurons in APP/PS1 mice. The results of biochemical tests showed that YHG reduced the contents of iron, malondialdehyde (MDA) and lipid peroxide (LPO) in brain tissue and serum, and increased the levels of superoxide dismutase (SOD) and reduced glutathione (GSH). Immunofluorescence, WesternBlot and real-time qPCR results showed that YHG could promote the expression of solute carrier family 7 member 11 (SLC7A11), solute carrier family 3 member 2 (SLC3A2) and glutathione peroxidase 4(GPX4). Inhibited the expression of long-chain acyllipid coenzyme a synthetase 4(ACSL4) and lysophosphatidyltransferase 3 (LPCAT3). This study suggests that the mechanism by which YHG improves cognitive dysfunction in APP/PS1 mice may be related to the inhibition of ferroptosis-lipid peroxidation.

Application of Deferoxamine in Tissue Regeneration Attributed to Promoted Angiogenesis

Deferoxamine, an iron chelator used to treat diseases caused by excess iron, has had a Food and Drug Administration-approved status for many years. A large number of studies have confirmed that deferoxamine can reduce inflammatory response and promote angiogenesis. Blood vessels play a crucial role in sustaining vital life by facilitating the delivery of immune cells, oxygen, and nutrients, as well as eliminating waste products generated during cellular metabolism. Dysfunction in blood vessels may contribute significantly to the development of life-threatening diseases. Anti-angiogenesis therapy and pro-angiogenesis/angiogenesis strategies have been frequently recommended for various diseases. Herein, we describe the mechanism by which deferoxamine promotes angiogenesis and summarize its application in chronic wounds, bone repair, and diseases of the respiratory system. Furthermore, we discuss the drug delivery system of deferoxamine for treating various diseases, providing constructive ideas and inspiration for the development of new treatment strategies.

Transferrin Saturation, Serum Ferritin, and C-Reactive Protein vs. Serum Ferritin for an optimal Iron Deficiency Diagnosis in Candidates for Bariatric Surgery

INTRODUCTION

Iron has different physiological processes and is regulated by hepcidin that is also an acute phase reactant, which increases with inflammation. Obesity produces a pro-inflammatory state, affecting directly the normal regulation of iron, causing ferritin (FER) deficiency. FER is used as the only indicator of the status of iron in patients with obesity, so the majority of them would be underdiagnosed, leading to a high prevalence of iron deficiency (ID) and anemia. The aim of this study is to evaluate the diagnostic tests: transferrin saturation (TS), FER, and C-reactive protein (CRP) vs. FER with the objective of analyzing the most accurate variable for the diagnosis of ID.

MATERIALS AND METHODS

We present a cross-sectional, analytical, and retrospective study, evaluating the diagnostic tests in 96 patients, to whom two methods were applied for the diagnosis of ID: method 1 (FER < 30 ng/mL) and method 2 divided into 2A (FER < 30 ng/mL), 2B (FER 30-100 ng/mL + CRP ≥ 5 mg/L), 2C (FER 100-300 ng/mL + CRP ≥ 5 mg/L + TS < 20%), and 2D (TS < 20%).

RESULTS

The prevalence of ID obtained using method 1 was 30.2% while 69.8% presented ID using total method 2, confirming an underdiagnosis of 39.6%.

CONCLUSION

The inflammatory state in patients with obesity must be considered in the diagnosis of ID. The use of TS, FER, and CRP has greater validity than the use of serum FER for the diagnosis of ID in patients with obesity.

Sipyimigwanjung-tang, a traditional herbal medication, alleviates weight gain in a high-fat diet-induced obese mice model

Obesity leads to the development of metabolic syndrome and comorbidities. Overweight and obesity continue to be a relentless global issue. Sipyimigwanjung-tang (SGT), a traditional herbal medication, was first mentioned in Dongui Sasang Shinpyun and has been used to treat edema, meteorism, and jaundice, which are common findings associated with obesity. The main physiological feature of obesity is expanded adipose tissue, which causes several impairments in liver metabolism. Therefore, this study aimed to investigate the anti-obesity effects of SGT in the epididymal white adipose tissue (eWAT) and livers of high-fat diet (HFD)-induced obese mice. SGT significantly blocked HFD-induced weight gain in C57BL/6N mice. In addition, SGT effectively reduced the increased weight and adipocyte size in eWAT of HFD-induced obese C57BL/6 N mice. Moreover, SGT significantly decreased the elevated gene expression of Peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, and Sterol regulatory element-binding protein 1 in the eWAT of HFD-induced obese mice. Furthermore, SGT significantly decreased lipid accumulation in the livers of HFD-induced obese mice and differentiated 3T3-L1 adipocytes. Hence, the present study provides substantial evidence that SGT has potential therapeutic effects on obesity.

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.

Parental obesity predisposes to exacerbated metabolic and inflammatory disturbances in childhood obesity within the framework of an altered profile of trace elements

BACKGROUND

Family history of obesity is known to increase the odds of developing childhood obesity in the offspring, but its influence in underlying molecular complications remains unexplored.

SUBJECTS/METHODS

Here, we investigated a population-based cohort comprising children with obesity, with and without parental obesity (PO+, N = 20; PO-, N = 29), and lean healthy children as controls (N = 30), from whom plasma and erythrocyte samples were collected to characterize their multi-elemental profile, inflammatory status, as well as carbohydrate and lipid metabolisms.

RESULTS

We found parental obesity to be associated with unhealthier outcomes in children, as reflected in increased blood insulin levels and reduced insulin sensitivity, unfavorable lipid profile, and pro-inflammatory milieu. This was accompanied by moderate alterations in the content of trace elements, including increased copper-to-zinc ratios and iron deficiency in circulation, as well as metal accumulation within erythrocytes.

CONCLUSIONS

Therefore, we hypothesize that family history of obesity could be an important risk factor in modulating the characteristic multi-elemental alterations behind childhood obesity, which in turn could predispose to boost related comorbidities and metabolic complications.

Prevalence and Characteristics of Metabolic Hyperferritinemia in a Population-Based Central-European Cohort

BACKGROUND

Hyperferritinemia (HF) is a common finding and can be considered as metabolic HF (MHF) in combination with metabolic diseases. The definition of MHF was heterogenous until a consensus statement was published recently. Our aim was to apply the definition of MHF to provide data on the prevalence and characteristics of MHF in a Central-European cohort.

METHODS

This study was a retrospective analysis of the Paracelsus 10,000 study, a population-based cohort study from the region of Salzburg, Austria. We included 8408 participants, aged 40-77. Participants with HF were divided into three categories according to their level of HF and evaluated for metabolic co-morbidities defined by the proposed criteria for MHF.

RESULTS

HF was present in 13% (n = 1111) with a clear male preponderance (n = 771, 69% of HF). Within the HF group, 81% (n = 901) of subjects fulfilled the metabolic criteria and were defined as MHF, of which 75% (n = 674) were characterized by a major criterion. In the remaining HF cohort, 52% (n = 227 of 437) of subjects were classified as MHF after application of the minor criteria.

CONCLUSION

HF is a common finding in the general middle-aged population and the majority of cases are classified as MHF. The new classification provides useful criteria for defining MHF.

Association between minerals intake and childhood obesity: A cross-sectional study of the NHANES database in 2007-2014

BACKGROUND

The roles of minerals in obesity received increasing attention recently due to its oxidant or antioxidant functions and effects on insulin and glucose metabolism that may be associated with obesity. Herein, this study aims to explore the association between minerals and obesity and body mass index (BMI) in children with different ages, and hope to provide some references for prevention and management in children with high-risk of obesity.

METHODS

Data of children aged 2-17 years old were extracted from the National Health and Nutrition Examination Survey (NHANES) database in 2007-2014 in this cross-sectional study. Weighted univariate and multivariate logistic regression and liner regression analyses were used to screen covariates, and explore the association between minerals [including calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), sodium (Na), potassium (K) and selenium (Se)] and childhood obesity and BMI. The evaluation indexes were β, odds ratios (ORs) and 95% confidence intervals (CIs). These relationships were also investigated in age subgroups.

RESULTS

Among 10,450 eligible children, 1,988 (19.02%) had obesity. After adjusting for covariates, we found the highest quartile of dietary Fe [OR = 0.74, 95%CI: (0.58, 0.95)] and Zn [OR = 0.70, 95%CI: (0.54, 0.92)] intakes were associated with low odds of childhood obesity, while that of dietary Na intake seemed to be positively linked to childhood obesity [OR = 1.35, 95%CI: (1.05, 1.74)]. High dietary intakes of Ca, Na and K were positively associated with children's BMI, on the contrary, dietary Fe and Zn consumptions had a negative one (all P<0.05). Additionally, these associations were also found in children with different age (all P<0.05).

CONCLUSION

Dietary Fe and Zn intakes played positive roles in reducing childhood obesity or BMI, while the intakes of Na should be controlled suitably.

Childhood obesity, metabolic syndrome, and oxidative stress: microRNAs go on stage

The incidence of childhood obesity and metabolic syndrome has grown notably in the last years, becoming major public health burdens in developed countries. Nowadays, oxidative stress is well-recognized to be closely associated with the onset and progression of several obesity-related complications within the framework of a complex crosstalk involving other intertwined pathogenic events, such as inflammation, insulin disturbances, and dyslipidemia. Thus, understanding the molecular basis behind these oxidative dysregulations could provide new approaches for the diagnosis, prevention, and treatment of childhood obesity and associated disorders. In this respect, the transcriptomic characterization of miRNAs bares great potential because of their involvement in post-transcriptional modulation of genetic expression. Herein, we provide a comprehensive literature revision gathering state-of-the-art research into the association between childhood obesity, metabolic syndrome, and miRNAs. We put special emphasis on the potential role of miRNAs in modulating obesity-related pathogenic events, with particular focus on oxidative stress.

Induction of Browning in White Adipocytes: Fucoidan Characterization and Gold Nanoparticle Synthesis from Undaria pinnatifida Sporophyll Extract

Seaweed extracts and their specific polysaccharides are widely known for their ability to act as reducing and capping agents during nanoparticle synthesis. Their application is highly favored in green synthesis methods, owing to their eco-friendliness, cost-effectiveness, and remarkable time and energy efficiency. In this study, fucoidan extracted from Undaria pinnatifida sporophyll (UPS) is introduced as a polysaccharide that effectively serves as a dual-function reducing and capping agent for the synthesis of gold nanoparticles (AuNPs). Results from various analyses indicate that AuNPs derived from UPS extract display a uniform spherical shape with an average size of 28.34 ± 1.15 nm and a zeta potential of -37.49 ± 2.13 mV, conclusively confirming the presence of Au. The FT-IR spectra distinctly revealed the characteristic fucoidan bands on the stabilized UPS-AuNPs surface. A 1H-NMR analysis provided additional confirmation by revealing the presence of specific fucoidan protons on the UPS-AuNPs surface. To comprehensively evaluate the impact of UPS extract, UPS-AuNPs, and fucoidan on the biological properties of adipocytes, a rigorous comparative analysis of lipid droplet formation and morphology was conducted. Our findings revealed that adipocytes treated with UPS extract, fucoidan, and UPS-AuNPs, in that order, exhibited a reduction in the total lipid droplet surface area, maximum Ferret diameter, and overall Nile red staining intensity when compared to mature white adipocytes. Furthermore, our analysis of the effects of UPS extracts, UPS-AuNPs, and fucoidan on the expression of key markers associated with white adipose tissue browning, such as UCP1, PGC1a, and PRDM16, demonstrated increased mRNA and protein expression levels in the following order: UPS-AuNPs > fucoidan > UPS extracts. Notably, the production of active mitochondria, which play a crucial role in enhancing energy expenditure in beige adipocytes, also increased in the following order: UPS-AuNPs > fucoidan > UPS extract. These findings underscore the pivotal role of UPS extract, fucoidan, and UPS-AuNPs in promoting adipocyte browning and subsequently enhancing energy expenditure.

Pyrroloquinoline quinone inhibits PCSK9-NLRP3 mediated pyroptosis of Leydig cells in obese mice

Abnormal lipid metabolism and chronic low-grade inflammation are the main traits of obesity. Especially, the molecular mechanism of concomitant deficiency in steroidogenesis-associated enzymes related to testosterone (T) synthesis of obesity dominated a decline in male fertility is still poorly understood. Here, we found that in vivo, supplementation of pyrroloquinoline quinone (PQQ) efficaciously ameliorated the abnormal lipid metabolism and testicular spermatogenic function from high-fat-diet (HFD)-induced obese mice. Moreover, the transcriptome analysis of the liver and testicular showed that PQQ supplementation not only inhibited the high expression of proprotein convertase subtilisin/Kexin type 9 (PCSK9) but also weakened the NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis, which both played a negative role in T synthesis of Leydig Cells (LCs). Eventually, the function and the pyroptosis of LCs cultured with palmitic acid in vitro were simultaneously benefited by suppressing the expression of NLRP3 or PCSK9 respectively, as well the parallel effects of PQQ were affirmed. Collectively, our data revealed that PQQ supplementation is a feasible approach to protect T synthesis from PCSK9-NLRP3 crosstalk-induced LCs' pyroptosis in obese men.

The effect of chronic intermittent hypobaric hypoxia improving liver damage in metabolic syndrome rats through ferritinophagy

Studies have confirmed that hepatic iron overload is one of the important factors causing liver damage in the metabolic syndrome (MS). As a special form of autophagy, ferritinophagy is involved in the regulation of iron metabolism. Our previous studies have shown that chronic intermittent hypobaric hypoxia (CIHH) can improve the iron metabolism disorder. The aim of this study was to investigate how CIHH improves liver damage through ferritinophagy in MS rats. Male Sprague-Dawley rats aged 8-10 weeks were randomly divided into four groups: control (CON), CIHH (exposed to hypoxia at a simulated altitude of 5000 m for 28 days, 6 h daily), MS model (induced by a 16-week high-fat diet and 10% fructose water feeding), and MS + CIHH (exposed to CIHH after a 16-week MS inducement) groups. Liver index, liver function, iron content, tissue morphology, oxidative stress, ferritinophagy, ferroptosis, and iron metabolism-related protein expression were measured, and the ferritinophagy flux in the liver was further analyzed. Compared with CON rats, MS rats had an increased liver index, damaged liver tissue and function, increased iron content and iron deposition, disrupted iron metabolism, significantly increased oxidative stress indicators in the liver, significantly upregulated expression of ferroptosis-related proteins, and downregulated expression of nuclear receptor coactivator 4 (NCOA4) and ferritinophagy flux. After CIHH treatment, the degree of liver damage and various abnormal indicators in MS rats were significantly improved. CIHH may improve liver damage by promoting NCOA4-mediated ferritinophagy, reducing iron overload and oxidative stress, and thereby alleviating ferroptosis in MS rats.

The effects of spirulina supplementation on serum iron and ferritin, anemia parameters, and fecal occult blood in adults with ulcerative colitis: A randomized, double-blinded, placebo-controlled trial

BACKGROUND & AIMS

The present clinical trial aimed to evaluate the efficacy of spirulina administration on serum iron, ferritin, anemia parameters, and fecal occult blood test (FOBT) in adults with ulcerative colitis (UC).

METHODS

Eighty participants with UC were randomly assigned to take, either 1 g/day (two 500 mg capsules) spirulina (n = 40) or placebo (n = 40) in a double-blinded clinical trial for eight weeks. Dietary intake, physical activity status, serum iron and ferritin levels, anemia parameters, and FOBT were assessed in each participant at baseline and following the intervention. Seventy-three participants completed the trial.

RESULTS

Our results indicated significantly increased (p = 0.04) serum iron after eight weeks of spirulina supplementation compared to the placebo group. The spirulina group also demonstrated significantly increased mean corpuscular volume (p = 0.004) whereas red blood cell count (p = 0.01) and hematocrit (p = 0.03) were significantly lowered in the placebo group. No significant changes in FOBT outcomes were seen between groups at baseline (p = 0.12) and the end of the trial (p = 0.34). Eight weeks of 1 g/day spirulina supplementation improved anemia parameters in adults with UC compared to placebo.

CONCLUSIONS

These outcomes suggest that spirulina administration may be beneficial in the management of anemia in UC. Further clinical trials of longer duration are necessary to corroborate and expand our findings. Registered at: http://www.IRCT.ir (code: IRCT20170802035460N3).