Iron metabolism and the polycystic ovary syndrome

Effect of Chromium Supplementation on Element Distribution in a Mouse Model of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder and one of the most common causes of anovulatory infertility. In addition, insulin resistance is commonly associated with PCOS and contributed to pathophysiology connected to dietary minerals including chromium (Cr), copper (Cu), iron (Fe), and zinc (Zn). The aims of this study were to explore whether PCOS in mice alters levels of these elements and determine if Cr supplementation resolves changes. Twenty-four female BALB/c mice were divided into three groups of eight mice [normal control (NC), PCOS+placebo milk (PP), and PCOS+Cr-containing milk (PCr)]. Each group received a high-fat diet for 4 weeks. Our results show significantly higher levels of dehydroepiandrosterone (DHEA) (p<0.001), fasting glucose (p<0.05), and fasting insulin (p<0.05) in the PP group compared with both NC and PCr group. However, Cr levels were significantly lower in muscle, bone, and serum in the PP group (p<0.05) compared with NC and PCr groups. In liver, bone, and serum, Fe levels were significantly higher in the PP group compared with the NC group (p<0.05). In addition, we found significant correlations between Cu/Zn ratio and fasting insulin in all mice (r=0.61; p=0.002). Given that significant research shows that Cr supplementation improves fasting glucose, fasting insulin, and metal metabolism disorders for PCOS mice, our data suggest that trace element levels can serve as biomarkers to prescribe therapeutic supplementation to maintain a healthy metabolic balance and treat disease conditions.

Identification, prevention and treatment of iron deficiency during the first 1000 days

Iron deficiency is a global problem across the life course, but infants and their mothers are especially vulnerable to both the development and the consequences of iron deficiency. Maternal iron deficiency during pregnancy can predispose offspring to the development of iron deficiency during infancy, with potentially lifelong sequelae. This review explores iron status throughout these "first 1000 days" from pregnancy through two years of age, covering the role of iron and the epidemiology of iron deficiency, as well as its consequences, identification, interventions and remaining research gaps.

Low-grade chronic inflammation in pregnant women with polycystic ovary syndrome: a prospective controlled clinical study

CONTEXT

Polycystic ovary syndrome (PCOS) and pregnancy are conditions characterized by an increased low-grade chronic inflammation state. A higher incidence of pregnancy complications has been detected in pregnant PCOS women.

OBJECTIVE

The objective of the study was to test the hypothesis that the low-grade chronic inflammation state typical of PCOS patients persists during gestation and is exacerbated by pregnancy and contributes to the increased risk of obstetric/neonatal complications.

DESIGN

This was a prospective controlled clinical study.

SETTING

The study was conducted at the Academic Department of Obstetrics and Gynecology of the "Pugliese-Ciaccio" Hospital of Catanzaro (Catanzaro, Italy).

PATIENTS

One hundred fifty pregnant PCOS women and 150 age- and body mass index-matched healthy pregnant controls participated in the study.

INTERVENTIONS

INTERVENTIONS included serial clinical, biochemical, and ultrasonographic assessments before and throughout pregnancy.

MAIN OUTCOME MEASURES

Serum levels of white blood cell count (WBC), C-reactive protein (CRP), and ferritin were measured.

RESULTS

Pregnant women with PCOS had higher WBC, CRP, and ferritin levels at study entry and at all gestational ages than controls. Changes in serum WBC and ferritin levels were significantly higher in PCOS than in controls starting from the 12th week of gestation whereas those in CRP from the 20th week of gestation. By multivariable Cox proportional hazard analysis, in the PCOS group, a significant association with the risk of adverse obstetric/neonatal outcomes was found for WBC [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.31-1.64; P = .010], CRP (HR 1.19, 95% CI 1.06-1.34; P = .019), and ferritin levels (HR 1.12, 95% CI 1.03-1.26; P = .011).

CONCLUSIONS

In PCOS patients, the low-grade chronic inflammation persists during gestation and is exacerbated by pregnancy, and it is associated with adverse pregnancy outcomes.

The impact of obesity and insulin resistance on iron and red blood cell parameters: a single center, cross-sectional study

Objective: Obesity and iron deficiency (ID) are the 2 most common nutritional disorders worldwide causing significant public health implications. Obesity is characterized by the presence of low-grade inflammation, which may lead to a number of diseases including insulin resistance (IR) and type 2 diabetes. Increased levels of acute-phase proteins such as C-reactive protein (CRP) have been reported in obesity-related inflammation. The aim of this study was to investigate the impact of obesity/IR on iron and red blood cell related parameters.

Materials and Methods: A total of 206 patients and 45 control subjects of normal weight were included in this cross-sectional study. Venous blood samples were taken from each patient to measure hemoglobin (Hb), serum iron (Fe), iron-binding capacity (IBC), ferritin, CRP, fasting blood glucose, and fasting insulin. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated for each patient. IR was determined using the HOMA-IR formula.

Results: Subjects were divided into 3 groups according to BMI. There were 152 severely obese (BMI: 42.6±10.1), 54 mildly obese (BMI: 32.4±2.1), and 45 normal-weight (BMI: 24.3±1.3) patients. Hb levels in severely obese patients and normal controls were 12.8±1.3 g/dL and 13.6±1.8 g/dL, respectively. We found decreasing Fe levels with increasing weight (14.9±6.9 µmol/L, 13.6±6.3 µmol/L, and 10.9±4.6 µmol/L for normal controls and mildly and severely obese patients, respectively). Hb levels were slightly lower in patients with higher HOMA-IR values (13.1±1.5 g/dL vs. 13.2±1.2 g/dL; p=0.36). Serum iron levels were significantly higher in the group with low HOMA-IR values (13.6±5.9 µmol/L vs. 11.6±4.9 µmol/L; p=0.008). IBC was found to be similar in both groups (60.2±11.4 µmol/L vs. 61.9±10.7 µmol/L; p=0.23). Ferritin was slightly higher in patients with higher HOMA-IR values (156.1±209.5 pmol/L vs. 145.3±131.5 pmol/L; p=0.62).

Conclusion: Elevated BMI and IR are associated with lower Fe and hemoglobin levels. These findings may be explained by the chronic inflammation of obesity and may contribute to obesity-related co-morbidities. People with IR may present with ID without anemia.

Testosterone perturbs systemic iron balance through activation of epidermal growth factor receptor signaling in the liver and repression of hepcidin

Gender-related disparities in the regulation of iron metabolism may contribute to the differences exhibited by men and women in the progression of chronic liver diseases associated with reduced hepcidin expression, e.g., chronic hepatitis C, alcoholic liver disease, or hereditary hemochromatosis. However, their mechanisms remain poorly understood. In this study we took advantage of the major differences in hepcidin expression and tissue iron loading observed between Bmp6-deficient male and female mice to investigate the mechanisms underlying this sexual dimorphism. We found that testosterone robustly represses hepcidin transcription by enhancing Egfr signaling in the liver and that selective epidermal growth factor receptor (Egfr) inhibition by gefitinib (Iressa) in males markedly increases hepcidin expression. In males, where the suppressive effects of testosterone and Bmp6-deficiency on hepcidin expression are combined, hepcidin is more strongly repressed than in females and iron accumulates massively not only in the liver but also in the pancreas, heart, and kidneys.

CONCLUSION

Testosterone-induced repression of hepcidin expression becomes functionally important during homeostatic stress from disorders that result in iron loading and/or reduced capacity for hepcidin synthesis. These findings suggest that novel therapeutic strategies targeting the testosterone/EGF/EGFR axis may be useful for inducing hepcidin expression in patients with iron overload and/or chronic liver diseases.

Relationship between leptin receptor and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, which is involved in the multi-system disease, and its etiology is still not clearly understood. It is currently considered that not only the genetic factors but also the environment factors play a crucial role in the pathogenesis of PCOS. Obesity plays an important role through the insulin, leptin and endocannabinoid system in the pathological process of PCOS, leading to more severe clinical manifestations. The aim of our present study is to investigate whether there is association between single nucleotide polymorphisms (SNPs) of Gln223Arg and Pro1019Pro in the leptin receptor gene (LEPR) and PCOS in a Korean population. Interestingly, a significant association was found between the Pro1019Pro in LEPR gene and PCOS, and a highly significant association was found between the Gln223Arg in LEPR gene and PCOS (P=0.033, OR=1.523, 95% confidence interval and P<0.0001, OR=0.446, 95% confidence interval). Moreover, genotype combination and haplotype analyses indicate that Gln223Arg and Pro1019Pro polymorphisms of LEPR are significantly associated with the risk of PCOS.

Proteomic and metabolomic approaches to the study of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is considered a complex multifactorial disorder resulting from the interaction of genetic, environmental, and lifestyle influences. Nontargeted proteomics and metabolomics have been used in the past years with the aim of identifying molecules potentially involved in the pathophysiology of this frequent disorder. The biomolecules identified so far participate in many metabolic pathways, including energy metabolism (glucose and lipid metabolism), protein metabolic processes and protein folding, cytoskeleton structure, immune response, inflammation and iron metabolism, fibrinolysis and thrombosis, oxidative stress and intracellular calcium metabolism. These molecules provide key information about molecular functions altered in PCOS and raise questions concerning their precise role in the pathogenesis of this syndrome. The biomolecules identified by nontargeted proteomic and metabolomic approaches should be considered as candidates in future studies aiming to define specific molecular phenotypes of PCOS.