Role of decreased circulating hepcidin concentrations in the iron excess of women with the polycystic ovary syndrome

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.

Broadening horizons: the role of ferroptosis in polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is a common heterogeneous reproductive endocrine metabolic disorder in women of reproductive age characterized by clinical and biochemical hyperandrogenemia, ovulation disorders, and polycystic ovarian morphology. Ferroptosis is a novel type of cell death driven by iron accumulation and lipid peroxidation. Ferroptosis plays a role in maintaining redox balance, iron metabolism, lipid metabolism, amino acid metabolism, mitochondrial activity, and many other signaling pathways linked to diseases. Iron overload is closely related to insulin resistance, decreased glucose tolerance, and the occurrence of diabetes mellitus. There is limited research on the role of ferroptosis in PCOS. Patients with PCOS have elevated levels of ferritin and increased reactive oxygen species in ovarian GCs. Studying ferroptosis in PCOS patients is highly important for achieving personalized treatment. This article reviews the progress of research on ferroptosis in PCOS, introduces the potential connections between iron metabolism abnormalities and oxidative stress-mediated PCOS, and provides a theoretical basis for diagnosing and treating PCOS.

Chromosome Segregation-1-like Gene Participates in Ferroptosis in Human Ovarian Granulosa Cells via Nucleocytoplasmic Transport

Premature ovarian insufficiency (POI) is defined as the depletion of ovarian function before the age of 40 years. The global prevalence of POI is 3.5%. To date, genetic factors account for 23.5% of the etiology of POI. Herein, a previously uncharacterized pathogenic homozygous variant of the chromosome segregation-1-like gene (CSE1L) was identified in POI patients via targeted panel sequencing. It is reported that dysregulated iron metabolism is involved in many reproductive endocrine disorders; however, its precise role in POI remains obscure. In this study, we identified CSE1L as a potential candidate gene that plays an important role in maintaining iron homeostasis. Deficiency of CSE1L led to ferroptosis in human granulosa cells, which was confirmed by transmission electron microscopy. Mechanistically, coimmunoprecipitation identified the direct interaction between CSE1L and FoxO1. Inhibition of CSE1L led to the excessive accumulation of FoxO1 in the nucleus via nucleocytoplasmic transport. Then, FoxO1 bound to the promoter region of NCOA4 and promoted its transcription, which was verified by a chromatin immunoprecipitation assay. Moreover, inhibition of CSE1L in cumulus cell monolayer could impede oocyte maturation, which might be associated with oxidative stress. Consequently, our study first revealed that CSE1L participated in ferroptosis in human ovarian granulosa cells via nucleocytoplasmic transportation, which might be helpful in revealing the molecular mechanism of CSE1L in the development of POI. Importantly, these findings might provide new insights into the application of ferroptosis inhibitors in the treatment of POI.

Effects of Hypoxia and Inflammation on Hepcidin Concentration in Non-Anaemic COVID-19 Patients

Background/Objectives: This study aimed to explore the influence of hypoxia, inflammation, and erythropoiesis on hepcidin and other iron status parameters in non-anaemic COVID-19 patients admitted to the emergency unit before the introduction of therapeutic interventions. Methods: Ninety-six COVID-19 patients and 47 healthy subjects were recruited. Patients were subdivided into hypoxic or normoxic groups and, after follow-up, into mild and moderate, severe or critical disease severity groups. Iron, unsaturated iron-binding capacity (UIBC), ferritin, C-reactive protein (CRP), and interleukin 6 (IL-6) were measured on automatic analysers. ELISA kits were used for hepcidin and erythropoietin (EPO) determination. We calculated total iron-binding capacity (TIBC) and ratios of hepcidin with parameters of iron metabolism (ferritin/hepcidin, hepcidin/iron), inflammation (hepcidin/CRP, hepcidin/IL-6), and erythropoietic activity (hepcidin/EPO). Results: Hepcidin, ferritin, EPO, CRP, IL-6, ferritin/hepcidin, and hepcidin/iron were increased, while UIBC, TIBC, hepcidin/CRP, and hepcidin/IL-6 were decreased in hypoxic compared to normoxic patients as well as in patients with severe or critical disease compared to those with mild and moderate COVID-19. Regarding predictive parameters of critical COVID-19 occurrence, in multivariable logistic regression analysis, a combination of EPO and ferritin/hepcidin showed very good diagnostic performances and correctly classified 88% of cases, with an AUC of 0.838 (0.749-0.906). Conclusions: The hypoxic signal in our group of patients was not strong enough to overcome the stimulating effect of inflammation on hepcidin expression. EPO and ferritin/hepcidin might help to identify on-admission COVID-19 patients at risk of developing a critical form of the disease.

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.

The emerging role of ferroptosis in female reproductive disorders

Iron, as an essential trace element for the organism, is vital for maintaining the organism's health. Excessive iron can promote reactive oxygen species (ROS) accumulation, thus damaging cells and tissues. Ferroptosis is a novel form of programmed cell death distinguished by iron overload and lipid peroxidation, which is unique from autophagy, apoptosis and necrosis, more and more studies are focusing on ferroptosis. Recent evidence suggests that ferroptosis is associated with the development of female reproductive disorders (FRDs), including polycystic ovary syndrome (PCOS), premature ovarian insufficiency (POI), endometriosis (EMs), ovarian cancer (OC), preeclampsia (PE) and spontaneous abortion (SA). Pathways and genes associated with ferroptosis may participate in processes that regulate granulosa cell proliferation and secretion, oocyte development, ovarian reserve function, early embryonic development and placental oxidative stress. However, its exact mechanism has not been fully revealed. Therefore, our review systematically elaborates the occurrence mechanism of ferroptosis and its research progress in the development of FRDs, with a view to providing literature references for clinical targeting of ferroptosis -related pathways and regulatory factors for the management of FRDs.

Correlation Between Hemoglobin Levels and Polycystic Ovary Syndrome Metabolic Disorder

Objective

The purpose of this study was to explore the relationship between hemoglobin levels and metabolic disorders in patients with PCOS.

Methods

A total of 573 patients were selected, based on the hemoglobin level; 342 patients with PCOS were divided into two groups as follows: Group A (normal Hb group, n = 269) and Group B (high Hb group, n = 73); 231 non-PCOS patients were divided into two groups as follows: Group C (normal Hb group, n = 199), and Group D (high Hb group, n = 32). The general information, glucose and lipid metabolism indicators, and uric acid levels of all patients were compiled for data analysis.

Results

(1) Hb, HGB concentration in mean red blood cells and RDW in PCOS patients were higher than those in non-PCOS patients, and MCV was lower than that in non-PCOS patients (P < 0.05); (2) Compared with Group A, patients in Group B had higher BMI, Hb, 2-hPG, FINS, 2-hINS, HOMA-IR, LDL-C, and uric acid levels while the QUICKI was lower; in Group C, the age, FSH, HDL-C, and LDL-C were higher, and AMH, BMI, T, TG, and uric acid level were lower (P<0.05); compared with Group D, AMH, BMI, FINS, HOMA-IR, TG, uric acid level increased, while age, FSH, and QUICKI decreased in Group B; and Hb and T decreased in Group C (P<0.05); (3) Pearson's correlation analysis indicated that Hb in PCOS patients was positively correlated with BMI, FPG, 2-hPG, FINS, 2-hINS, and HOMA-IR, and negatively correlated with the QUICKI (P<0.05); (4) Multi-factor logistic regression analysis suggested that the high Hb level in PCOS patients was an independent risk factor of IR (P<0.05).

Conclusion

Hb level in patients with PCOS was associated with BMI and glucose metabolism indicators; a high Hb level may be an independent risk factor for IR.

Physiological effect of iron status on patients with polycystic ovary syndrome in Basrah city

Polycystic ovary syndrome (PCOS) is one of the most common gynecological diseases that affect the fertility in women in Basra governorate. The current study was designed in order to assess iron aberrations in PCOS patients by measuring the related parameters and their relationship with sex hormones in patients with PCOS. Serum samples were collected from 45 PCOS patients and 45 controls from a private women's clinic and were measured by ELISA in a private medical laboratory. The results showed a significant decrease in the level of hepcidin, transferrin and estradiol versus a significant increase in iron, ferritin, progesterone and testosterone. The current study showed a clear imbalance in the level of iron and its serum regulating parameters in in PCOS women, and there is an effective correlation between iron status and sex hormones.

1,25-Dihydroxyvitamin D3 alleviates hyperandrogen-induced ferroptosis in KGN cells

PURPOSE

Hyperandrogenism, one of the most frequent causes of anovulation in women, increases the risk of metabolic disorders in patients with polycystic ovary syndrome (PCOS). Ferroptosis, characterized by iron-dependent lipid peroxidation, has provided new insight into the progression of PCOS. 1,25-dihydroxyvitamin D3 (1,25D3) may play a role in reproduction because its receptor, VDR, which contributes to the inhibition of oxidative stress, is primarily located in the nuclei of granulosa cells. This study has therefore investigated whether 1,25D3 and hyperandrogenism affect granulosa-like tumor cells (KGN cells) through ferroptosis.

METHODS

KGN cells were treated with dehydroepiandrosterone (DHEA) or pretreated with 1,25D3. Cell viability was evaluated with the cell counting kit-8 (CCK-8) assay. The mRNA and protein expression levels of ferroptosis-related molecules, including glutathione peroxidase 4 (GPX4), solute carrier family 7 member (SLC7A11), and long-chain acyl-CoA synthetase 4 (ACSL4), were assessed via qRT-PCR and western blot. The concentration of malondialdehyde (MDA) was measured by ELISA. The rates of reactive oxygen species (ROS) production and lipid peroxidation were assessed via photometric methods.

RESULTS

Decreased cell viability, suppression of GPX4 and SLC7A11 expression, increased expression of ACSL4, elevated levels of MDA, accumulation of ROS, and increased lipid peroxidation, which are changes representative of ferroptosis, were observed in KGN cells after treatment with DHEA. Pretreatment with 1,25D3 in KGN cells significantly prevented these changes.

CONCLUSIONS

Our findings demonstrate that 1,25D3 attenuates hyperandrogen-induced ferroptosis of KGN cells. This finding might lead to new insights into the pathophysiology and therapy of PCOS and provides new evidence for the treatment of PCOS with 1,25D3.

Polycystic ovary syndrome and iron overload: biochemical link and underlying mechanisms with potential novel therapeutic avenues

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in women with components of significant genetic predisposition and possibly multiple, but not yet clearly defined, triggers. This disorder shares several clinical features with hemochromatosis, a genetically defined inheritable disorder of iron overload, which includes insulin resistance, increased adiposity, diabetes, fatty liver, infertility, and hyperandrogenism. A notable difference between the two disorders, however, is that the clinical symptoms in PCOS appear at much younger age whereas they become evident in hemochromatosis at a much later age. Nonetheless, noticeable accumulation of excess iron in the body is a common finding in both disorders even at adolescence. Hepcidin, the iron-regulatory hormone secreted by the liver, is reduced in both disorders and consequently increases intestinal iron absorption. Recent studies have shown that gut bacteria play a critical role in the control of iron absorption in the intestine. As dysbiosis is a common finding between PCOS and hemochromatosis, changes in bacterial composition in the gut may represent another cause for iron overload in both diseases via increased iron absorption. This raises the possibility that strategies to prevent accumulation of excess iron with iron chelators and/or probiotics may have therapeutic potential in the management of polycystic ovary syndrome.

Effect of Iron Depletion by Bloodletting vs. Observation on Oxidative Stress Biomarkers of Women with Functional Hyperandrogenism Taking a Combined Oral Contraceptive: A Randomized Clinical Trial

Women with functional hyperandrogenism show both increased markers of oxidative stress and a mild iron overload. Combined oral contraceptives (COC) may worsen redox status in the general population. Since iron depletion ameliorates oxidative stress in other iron overload states, we aimed to address the changes in the redox status of these women as a consequence of COC therapy and of bloodletting, conducting a randomized, controlled, parallel, open-label clinical trial in 33 adult women with polycystic ovary syndrome or idiopathic hyperandrogenism. After three months of treatment with a COC, participants were randomized (1:1) to three scheduled bloodlettings or observation for another nine months. After taking a COC, participants showed a mild decrease in their plasma electrochemical antioxidant capacity, considering fast-acting antioxidants [MD: −1.51 (−2.43 to −0.60) μC, p = 0.002], and slow-acting antioxidants [MD: −1.90 (−2.66 to −1.14) μC, p < 0.001]. Women submitted to bloodletting showed a decrease in their non-enzymatic antioxidant capacity levels (NEAC) throughout the trial, whereas those individuals in the control arm showed a mild increase in these levels at the end of the study (Wilks’ λ: 0.802, F: 3.572, p = 0.041). Decreasing ferritin and plasma hemoglobin during the trial were associated with worse NEAC levels. COC may impair redox status in women with functional hyperandrogenism. Decreasing iron stores by scheduled bloodletting does not override this impairment.

Bloodletting has no effect on the blood pressure abnormalities of hyperandrogenic women taking oral contraceptives in a randomized clinical trial

Normoferritinemic women with functional hyperandrogenism show a mild iron overload. Iron excess, hyperandrogenism, and cardioautonomic dysfunction contribute to blood pressure (BP) abnormalities in these patients. Furthermore, combined oral contraceptives (COC) prescribed for hyperandrogenic symptoms may worse BP recordings. Iron depletion by phlebotomy appears to lower BP in other acquired iron overload conditions. We aimed to determine the effect of iron depletion on the office BP, ambulatory BP monitoring, and frequency of hypertension in patients with functional hyperandrogenism submitted to standard therapy with COC. We conducted a phase 2 randomized, controlled, parallel, open-label clinical trial (NCT02460445) in adult women with functional hyperandrogenism including hyperandrogenic polycystic ovary syndrome and idiopathic hyperandrogenism. After a 3-month run-in period of treatment with 35 µg ethinylestradiol plus 2 mg cyproterone acetate, participants were randomized (1:1) to three scheduled bloodlettings or observation for another 9 months. Main outcome measures were the changes in office BP, 24-h-ambulatory BP, and frequency of hypertension in both study arms. From June 2015 to June 2019, 33 women were included in the intention-to-treat analyses. We observed an increase in mean office systolic BP [mean of the differences (MD): 2.5 (0.3–4.8) mmHg] and night-time ambulatory systolic BP [MD 4.1 (1.4–6.8) mmHg] after 3 months on COC. The percentage of nocturnal BP non-dippers also increased, from 28.1 to 92.3% (P < 0.001). Office and ambulatory BP did not change throughout the experimental period of the trial, both when considering all women as a whole or as a function of the study arm. The frequency of the non-dipping pattern in BP decreased during the experimental period [OR 0.694 (0.577–0.835), P < 0.001], regardless of the study arm. Decreasing iron stores by scheduled bloodletting does not override the BP abnormalities caused by COC in women with functional hyperandrogenism.

Iron Overload in Functional Hyperandrogenism: In a Randomized Trial, Bloodletting Does Not Improve Metabolic Outcomes

CONTEXT

Functional hyperandrogenism may be associated with a mild increase in body iron stores. Iron depletion exerts a beneficial effect on metabolic endpoints in other iron overload states.

OBJECTIVES

(i) To determine the effect of iron depletion on the insulin sensitivity and frequency of abnormal glucose tolerance in patients with functional hyperandrogenism submitted to standard therapy with combined oral contraceptives (COC). ii) To assess the overall safety of this intervention.

DESIGN

Randomized, parallel, open-label, clinical trial.

SETTING

Academic hospital.

PATIENTS

Adult women with polycystic ovary syndrome or idiopathic hyperandrogenism.

INTERVENTION

After a 3-month run-in period of treatment with 35 μg ethinylestradiol plus 2 mg cyproterone acetate, participants were randomized (1:1) to 3 scheduled bloodlettings or observation for another 9 months.

MAIN OUTCOME MEASURES

Changes in insulin sensitivity index and frequency of prediabetes/diabetes, and percentage of women in whom bloodletting resulted in plasma hemoglobin <120 g/L and/or hematocrit <0.36.

RESULTS

From 2015 to 2019, 33 women were included by intention-to-treat. During the follow-up, insulin sensitivity did not change in the whole group of women or between study arms [mean of the differences (MD): 0.0 (95%CI: -1.6 to 1.6)]. Women in the experimental arm showed a similar odds of having prediabetes/diabetes than women submitted to observation [odds ratio: 0.981 (95%CI: 0.712 to 1.351)]. After bloodletting, 4 (21.1%) and 2 women (10.5%) in the experimental arm had hemoglobin (Hb) levels <120 g/L and hematocrit (Hct) values <0.36, respectively, but none showed Hb <110 g/L or Hct <0.34.

CONCLUSIONS

Scheduled bloodletting does not improve insulin sensitivity in women with functional hyperandrogenism on COC.

Serum Trace Elements in Patients With Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is reported to be associated with certain trace elements. However, previous data are inconsistent and potentially biased due to small sample sizes. The potential utility of trace element levels for screening of PCOS remains to be established. The aim of this meta-analysis was to investigate the potential relationships between PCOS and serum levels of zinc (Zn), copper (Cu), magnesium (Mg), iron (Fe) and ferritin. We carried out a literature search of PubMed, EMBASE, and Web of Science for relevant cross-sectional/case-control studies published prior to October 2019. Random-effect models were used to estimate the overall standard mean differences (SMDs) between PCOS and healthy control subjects. The screening value of potential microelement biomarkers for PCOS was assessed using the receiver operating characteristic (ROC) curve. Twenty-one studies featuring 2,173 women with PCOS and 1,897 healthy women were selected for analysis. Our results showed that Cu and ferritin levels were significantly higher in women with PCOS than healthy controls, with SMDs of 0.52 [95% confidence interval (CI): 0.38-0.67, I2 = 47.6%] and 1.05 (95% CI: 0.25-1.86, I2 = 97.0%), respectively. The serum ferritin concentration was distinguished as a potential biomarker for PCOS based on the high area under ROC curve value of 0.71 (95% CI: 0.57-0.86). Although we did not identify a statistical association between serum Zn concentration and PCOS overall, the concentration of Zn in PCOS women with insulin resistance (IR) was lower than that in healthy women (SMD = -0.89, 95% CI: -1.73 to -0.06). Furthermore, the concentrations of Mg (SMD = 0.31, 95% CI: -0.32-0.94, I2 = 95.4%) and Fe (SMD = -0.59, 95% CI: -1.29-0.12, I2 = 97.2%) were not statistically significant between the PCOS and control groups. We generated hypothetical pathways for associations among serum Cu, ferritin and PCOS. The serum concentrations of both Cu and ferritin were significantly higher in women with PCOS, and ferritin was identified as a potential early indicator for PCOS screening. Further studies are essential to determine the specific underlying mechanisms.

Metformin versus the combined oral contraceptive pill for hirsutism, acne, and menstrual pattern in polycystic ovary syndrome

BACKGROUND

Metformin has been proposed as possibly a safer and more effective long-term treatment than the oral contraceptive pill (OCP) in women with polycystic ovary syndrome (PCOS). It is important to directly compare the efficacy and safety of metformin versus OCP in the long-term treatment of women with PCOS. This is an update of a Cochrane Review comparing insulin sensitising agents with the OCP and only includes studies on metformin.

OBJECTIVES

To assess the effectiveness and safety of metformin versus the OCP (alone or in combination) in improving clinical, hormonal, and metabolic features of PCOS.

SEARCH METHODS

In August 2019 we searched the Cochrane Gynaecology and Fertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and CINAHL, the trial registers, handsearched references of the identified articles, and contacted experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of the use of metformin versus the OCP (alone or in combination) for women with PCOS.

DATA COLLECTION AND ANALYSIS

We used standard methods recommended by Cochrane. The primary review outcomes were the clinical parameters of hirsutism and adverse events, both severe (requiring stopping of medication), and minor. In the presence of substantial heterogeneity (I2 statistic > 50), which could be explained by pre-specified subgroup analyses on the basis of BMI, we reported the subgroups separately.

MAIN RESULTS

This is a substantive update. We identified 38 additional studies. We included 44 RCTs (2253 women), which comprised 39 RCTs on adult women (2047 women) and five RCTs on adolescent women (206 women). Evidence quality ranged from very low to low. The main limitations were risk of bias, imprecision and inconsistency. Metformin versus the OCP In adult women, we are uncertain of the effect of metformin compared to the OCP on hirsutism in subgroup body mass index (BMI) < 25 kg/m2 (mean difference (MD) 0.38, 95% confidence interval (CI) -0.44 to 1.19, 3 RCTs, n = 134, I2 = 50%, very low-quality evidence) and subgroup BMI > 30 kg/m2 (MD -0.38, 95% CI -1.93 to 1.17; 2 RCTs, n = 85, I2 = 34%, low-quality evidence). Metformin may be less effective in improving hirsutism compared to the OCP in the subgroup BMI 25 kg/m2 to 30 kg/m2 (MD 1.92, 95% CI 1.21 to 2.64, 5 RCTs, n = 254, I2 = 0%, low-quality evidence). Metformin may increase severe gastro-intestinal adverse events rate compared to the OCP (Peto odds ratio (OR) 6.42, 95% CI 2.98 to 13.84, 11 RCTs, n = 602, I2 = 0%, low-quality evidence). Metformin may decrease the incidence of severe other adverse events compared to the OCP (Peto OR 0.20, 95% CI 0.09 to 0.44, 8 RCTs, n = 363, I2 = 0%, low-quality evidence). There were no trials reporting on minor adverse events. In adolescents, we are uncertain whether there is a difference between Metformin and the OCP, on hirsutism and adverse events. Metformin versus metformin combined with the OCP In adult women, metformin may be less effective in improving hirsutism compared to Metformin combined with the OCP (MD 1.36, 95% CI 0.62 to 2.11, 3 RCTs, n = 135, I2= 9%, low-quality evidence). We are uncertain if there was a difference between metformin and metformin combined with the OCP for severe gastro-intestinal adverse events (OR 0.74, 95% CI 0.21 to 2.53, 3 RCTs, n = 171, I2 = 0%, low-quality evidence), or for severe other adverse events (OR 0.56, 95% CI 0.11 to 2.82, 2 RCTs, n = 109, I2 = 44%, low-quality evidence). There were no trials reporting on minor adverse events. In adolescents, there were no trials for this comparison. The OCP versus metformin combined with the OCP In adult women, the OCP may be less effective in improving hirsutism compared to metformin combined with the OCP (MD 0.54, 95% CI 0.20 to 0.89, 6 RCTs, n = 389, I2= 1%, low-quality evidence). The OCP may decrease the incidence of severe gastro-intestinal adverse events compared to metformin combined with the OCP (OR 0.20, 95% CI 0.06 to 0.72, 5 RCTs, n = 228, I2 = 0%, low-quality evidence). We are uncertain if there is a difference between the OCP and metformin combined with the OCP for severe other adverse events (OR 1.61, 95% CI 0.49 to 5.37, 4 RCTs, n = 159, I2 = 12%, low-quality evidence). The OCP may decrease the incidence of minor (gastro-intestinal) adverse events compared to metformin combined with the OCP (OR 0.06, 95% CI 0.01 to 0.44, 2 RCTs, n = 98, I2 = 0%, low-quality evidence). In adolescents, we are uncertain whether there is a difference between the OCP, compared to metformin combined with the OCP, on hirsutism or adverse events.

AUTHORS' CONCLUSIONS

In adult women with PCOS, metformin may be less effective in improving hirsutism compared to the OCP in the subgroup BMI 25 kg/m2 to 30 kg/m2 but we are uncertain if there was a difference between metformin and the OCP in subgroups BMI < 25 kg/m2 and BMI > 30kg/m2. Compared to the OCP, metformin may increase the incidence of severe gastro-intestinal adverse events and decrease the incidence of severe other adverse events with no trials reporting on minor adverse events. Either metformin alone or the OCP alone may be less effective in improving hirsutism compared to metformin combined with the OCP. We are uncertain whether there is a difference between the OCP alone and metformin alone compared to metformin combined with the OCP for severe or minor adverse events except for the OCP versus metformin combined with the OCP where the OCP may decrease the incidence of severe and minor gastro-intestinal adverse events. In adolescent women with PCOS, we are uncertain whether there is a difference between any of the comparisons for hirsutism and adverse events due to either no evidence or very low-quality evidence. Further large well-designed RCTs that stratify for BMI are needed to evaluate metformin versus the OCP and combinations in women with PCOS, in particular adolescent women.

Iron Consumption Is Not Consistently Associated with Fecundability among North American and Danish Pregnancy Planners

BACKGROUND

Infertility is an important public health problem with few known modifiable risk factors. Dietary factors including folic acid have been associated with improved fertility, but the association between iron and fertility is understudied. One study among US nurses found a 40% lower risk of ovulatory infertility with higher intake of nonheme iron and iron supplements.

OBJECTIVES

The aim of this study was to determine the extent to which iron intake from diet and supplements reported on structured questionnaires is associated with fecundability.

METHODS

We conducted parallel analyses that used data from 2 prospective cohort studies of pregnancy planners from Denmark (Snart Foraeldre; n = 1693) and North America (PRESTO; n = 2969) during 2013-2018. Follow-up comprised menstrual cycles at risk until pregnancy or censoring for fertility treatment, stopped trying to conceive, withdrawal, loss to follow-up, or 12 cycles of attempt. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs, adjusting for confounders.

RESULTS

We found little association between dietary heme iron intake and fecundability in either cohort. The FR for nonheme iron intake (≥11 mg/d compared with <9 mg/day) was 1.11 for Snart Foraeldre participants (95% CI: 0.92, 1.34) and 1.01 for PRESTO participants (95% CI: 0.89, 1.14). The FR for iron-containing supplements was 1.01 in Snart Foraeldre (95% CI: 0.90, 1.13) and 1.19 in PRESTO (95% CI: 1.03, 1.38). In PRESTO, but not Snart Foraeldre, stronger positive associations were found for nonheme iron intake and iron supplement use among women with heavy menses or short menstrual cycles.

CONCLUSIONS

Overall, dietary intake of iron was not consistently associated with fecundability, although there was some evidence for a positive association among women with risk factors for iron deficiency. We also found a small positive association between supplemental iron intake and fecundability among North American, but not Danish, pregnancy planners.

Effect of phlebotomy versus oral contraceptives containing cyproterone acetate on the clinical and biochemical parameters in women with polycystic ovary syndrome: a randomized controlled trial

BACKGROUND

Reduction of the body iron stores can improve hyperandrogenemia and insulin resistance. This study aimed to compare clinical and para-clinical responses to the treatment of phlebotomy using oral contraceptive pills (OCs) containing cyproterone acetate in women with PCOS.

METHODS

In this randomized clinical trial, 64 patients with PCOS were randomly assigned to the phlebotomy and OCs groups (n = 32 in each group). The intervention group, using a single treatment procedure, underwent venesection of 450 mL of whole blood at the early follicular phase of the spontaneous or progesterone-induced menstrual cycle. The control group received OCs pills for 3 months from the 1th day of spontaneous or progesterone-induced menstrual cycle onwards for 3 weeks, followed by a pill-free interval of 7 days. The women were evaluated after the 3-month intervention. The primary outcome measure was a change in the HOMA-IR and free androgen index (FAI). Secondary outcomes were changes in the Ferriman-Gallwey (FG) score and other clinical, biochemical and hormonal changes from the baseline (pre-treatment) to week 12.

RESULTS

In the phlebotomy group, 27 (84.3%) and in the OCs group 30 (93.7%) of the women completed the 3-month follow-up. The median HOMA-IR significantly decreased from 3.5 to 2.7 in the phlebotomy, and from 3.1 to 2.8 in the OCs group, and the changes were comparable between the groups. Median changes in the FAI significantly decreased in both groups, but the differences were not statistically significant between the groups (P = 0.061). With regard to secondary outcomes, mean FG scores in both groups significantly decreased [from 16.8 (6) to 13.3 (7.4), P < 0.028] in the phlebotomy group and [from 14.3 (7) to 9.8 (7.6) in the OCs group, P = 0.001] after 3 months of treatment, but such changes had no statistically significant differences between the groups. During treatment, menstrual cycles became regular in all women in the OCs group and in 12.27 (44.4%) of the women in the phlebotomy group, and the difference was statistically significant (P = 0.001). Despite no statistically significant differences in lipid profiles between the groups at the baseline, triglycerides were significantly higher in the OCs group compared to the phlebotomy at end of follow up (p = 0.019).

CONCLUSION

Both treatment modalities had similar beneficial effects on insulin resistance and on androgenic profiles. However, OCs was reported more effective in treating menstrual irregularities and phlebotomy had less adverse effects on triglyceride concentrations.

TRIAL REGISTRATION

Code: IRCT2013080514277N1 .

Serum ferritin as a candidate diagnostic biomarker of polycystic ovarian syndrome: a meta-analysis

Objective: In this study, we investigated about the potential of serum ferritin as a complementary diagnostic biomarker of polycystic ovarian syndrome (PCOS) by performing a meta-analysis of existing literature. Materials and methods: Eleven studies written in English were retrieved up to 30 June 2018. Data were extracted from the selected studies by two of the authors and was subjected to statistical analysis. Levels of serum ferritin were compared between women with PCOS and controls using the standardized mean difference (SMD) and 95% confidence interval (CI). Subgroup analysis was also performed and stratified by ethnicity (Asians versus Caucasians). Results: Overall post-outlier outcomes indicated that elevated serum ferritin is strongly associated with PCOS (SMD: 0.52; 95% CI: 0.40-0.64; P^A = 10^-5). Subgroup analysis by ethnicity showed no significant difference between Asian and Caucasian population. Post-outlier receiving operations characteristics curve were plotted and showed that values for serum ferritin showed good potential in discriminating patients with and without PCOS (AUC = 0.827, p = 0.006). Conclusion: Our findings suggest that high serum ferritin level is significantly associated with PCOS and its potential as a biomarker is evident in its high diagnostic accuracy. However, additional studies are needed to confirm our claims.

Regulators of hepcidin expression

Iron, an essential nutrient, is required for many biological processes but is also toxic in excess. The lack of a mechanism to excrete excess iron makes it crucial for the body to regulate the amount of iron absorbed from the diet. This regulation is mediated by the hepatic hormone hepcidin. Hepcidin also controls iron release from macrophages that recycle iron and from hepatocytes that store iron. Hepcidin binds to the only known iron export protein, ferroportin, inducing its internalization and degradation and thus limiting the amount of iron released into the plasma. Important regulators of hepcidin, and therefore of systemic iron homeostasis, include plasma iron concentrations, body iron stores, infection and inflammation, hypoxia and erythropoiesis, and, to a lesser extent, testosterone. Dysregulation of hepcidin production contributes to the pathogenesis of many iron disorders: hepcidin deficiency causes iron overload in hereditary hemochromatosis and non-transfused β-thalassemia, whereas overproduction of hepcidin is associated with iron-restricted anemias seen in patients with chronic inflammatory diseases and inherited iron-refractory iron-deficiency anemia. The present review summarizes our current understanding of the molecular mechanisms and signaling pathways contributing to hepcidin regulation by these factors and highlights the issues that still need clarification.

Pharmacotherapeutic management of comorbid polycystic ovary syndrome and diabetes

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women. Insulin resistance and glucose intolerance are very prevalent metabolic complications in women with PCOS, especially in those presenting with weight excess. Therapeutic strategies targeting insulin resistance in PCOS are of interest because of their overall safety and their beneficial effects on metabolic and reproductive features.

AREAS COVERED

The authors review systematically all of the available therapeutic interventions targeting insulin resistance and/or disturbances of glucose metabolism in women with PCOS.

EXPERT OPINION

The diagnosis of glucose tolerance disorders in women with PCOS requires an oral glucose tolerance test. Strategies addressing weight excess and abdominal adiposity, from lifestyle modification to insulin sensitizers, may improve insulin resistance and glucose tolerance in women with PCOS. However, amelioration of signs and symptoms of PCOS usually requires the loss of large amounts of weight for it to be noticeable. Bariatric surgery has emerged as the most successful approach for obese patients with PCOS, because glucose intolerance, diabetes, and PCOS resolve in most cases through follow-ups. At present, the role of novel drugs targeting insulin resistance and/or diabetes such as inositols, berberine, resveratrol, and incretin-based therapies are yet to be properly established.

Combined oral contraceptives and/or antiandrogens versus insulin sensitizers for polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Androgen excess is a key pathogenetic mechanism in polycystic ovary syndrome (PCOS), although hyperinsulinism also contributes to androgen secretion. Therapeutic approaches for adult patients not seeking fertility include combined oral contraceptives (COC), antiandrogens (AA) and/or insulin sensitizers, although these practices are supported by limited high-quality evidence.

OBJECTIVE AND RATIONALE

We aimed to assess the efficacy and safety of these common treatments for PCOS by conducting a meta-analysis of RCTs with the following review questions: Which is the more appropriate therapeutic approach for hyperandrogenic symptoms, hyperandrogenemia, and ovulatory dysfunction in adult women with PCOS not seeking fertility; What is the impact on classic cardiometabolic risk factors of the more common treatments used in those women; Does the combination of the antiandrogenic therapy plus metformin have any impact on efficacy or cardiometabolic profile?

SEARCH METHODS

We searched PubMed and EMBASE for articles published up to 16 September 2017. After deleting duplicates, the abstracts of 1522 articles were analysed. We subsequently excluded 1446 articles leaving 76 studies for full-text assessment of eligibility. Of them, 43 articles were excluded. Hence, 33 studies and 1521 women were included in the quantitative synthesis and in the meta-analyses. Meta-analyses calculated mean differences (MD), standardized mean differences (SMD), odds ratio (OR) and 95% CIs. Heterogeneity and inconsistency across studies was assessed by χ2 test and Higgins's I2 statistics. Quality and risk of bias of individual studies were assessed according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0. We then used the approach recommended by the Grading of Recommendations, Assessments, Development, and Evaluation (GRADE) group to indicate the global quality of evidence for a selection of primary outcomes.

OUTCOMES

Regarding efficacy, the MD in hirsutism score between COC and/or AA and metformin were not significant. The exclusion of one single study including most women with severe hirsutism yielded a significant effect in favour of COC and/or AA. When only those studies including an AA were compared with metformin, there were significant differences favouring antiandrogenic therapy. The combination of COC and/or AA with metformin was similar to COC and/or AA therapy alone in the whole group of patients. Post-intervention OR for the presence of regular menses favoured COC therapy. In terms of cardiometabolic impact, the MD in BMI were in favour of metformin. The negative effect of COC therapy on BMI was blunted by its combination with metformin. The MD in homoeostasis model assessment of insulin resistance (HOMA-IR) were also in favour of metformin therapy compared to COC and/or AA. The combination of COC and/or AA and metformin decreased MD in HOMA with respect to antiandrogenic therapy alone. There were no significant post-intervention SMD in circulating glucose levels between COC and/or AA and metformin. However, adding metformin to COC and/or AA yielded a beneficial effect on fasting glucose levels. Post-intervention OR for abnormal glucose tolerance showed no significant differences between COC and/or AA and metformin, although after excluding studies including an AA as a comparator (without COC) a significant effect in favour of metformin therapy was observed. There were no significant differences among therapies in lipid profile, blood pressure or prevalence of hypertension. The global quality of evidence was very low when addressing the impact of the treatments explored on prevalence of hypertension and lipid profiles, low in the case of hirsutism, BMI and blood pressure values, and high for endometrial protection and glucose tolerance.

WIDER IMPLICATIONS

These data provide further scientific evidence for the choice of treatment of women with PCOS. COC and AA are more effective than metformin for hyperandrogenic symptoms and endometrial protection. Their combination with metformin adds a positive effect on BMI and glucose tolerance.

PROSPERO CRD REGISTRATION NUMBER

CRD42016053457.

Evaluation of serum hepcidin and iron levels in patients with PCOS: a case-control study

PURPOSE

Polycystic ovary syndrome (PCOS) is the most common cause of chronic anovulation with a prevalence of 5-10% in women of reproductive age. The etiology of this disease is not well known, and hepcidin is one of the factors affecting the pathogenesis of the disease. The aim of this study was to evaluate plasma levels of hepcidin in patients with PCOS and its correlation with serum iron level.

METHODS

In this case-control study, plasma levels of hepcidin, IL-6, and ferritin using ELISA method and serum iron levels using a spectrophotometric method were tested on 56 women with PCOS (case group) and 41 healthy subjects (control group). The results were analyzed using t test, General Linear Model, Binary logistic regression, and linear regression tests.

RESULTS

The mean hepcidin levels were 1.97 ± 0.53 and 2.40 ± 0.25 pg/ml in the case and control groups, respectively. The t-test results showed significant difference between the two groups (p = 0.0001). The mean serum iron levels were 72.89 ± 28.97 and 70.62 ± 31.18 g/dl in the case and control groups, respectively. The t test analysis indicated no significant difference between the two groups. The serum ferritin and iron levels had no significant relation with serum hepcidin level in two groups.

CONCLUSION

Despite the differences in the serum levels of hepcidin between the two groups, no significant relation was observed between serum iron levels and hepcidin level in this group of patients. This implies the need for more comprehensive studies on gene expression in hepcidin and iron pathways using real-time and Western techniques to investigate more precisely serum hepcidin level and its relationship with the factors mentioned.

Genetic, hormonal and metabolic aspects of PCOS: an update

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder affecting 5-10 % of women of reproductive age. It generally manifests with oligo/anovulatory cycles, hirsutism and polycystic ovaries, together with a considerable prevalence of insulin resistance. Although the aetiology of the syndrome is not completely understood yet, PCOS is considered a multifactorial disorder with various genetic, endocrine and environmental abnormalities. Moreover, PCOS patients have a higher risk of metabolic and cardiovascular diseases and their related morbidity, if compared to the general population.

Inadequate hepcidin serum concentrations predict incident type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is closely associated with elevated body iron stores. The hormone hepcidin is the key regulator of iron homeostasis. Inadequately low hepcidin levels were recently reported in subjects with manifest T2DM. We investigated whether alterations of hepcidin levels precede the manifestation of T2DM and predict T2DM development independently of established risk conditions.

METHODS

This prospective population-based study included 675 subjects aged 50-89 years, 51.9% of whom were female. Hepcidin levels were measured by gold standard tandem mass spectrometry. Diabetes was diagnosed according to American Diabetes Association criteria, and incident diabetes was recorded between baseline in 2000 and 2010.

RESULTS

The baseline hepcidin-to-ferritin ratio in subjects that subsequently developed diabetes during follow-up was reduced on average by 29.8% as compared with subjects with normal glucose tolerance (95% confidence interval, -50.7% to -0.2%; p = 0.049). After adjustment for age, sex, and serum ferritin, higher hepcidin levels were associated with reduced risk of incident diabetes (hazard ratio per 1-unit higher log2 hepcidin, 0.80; 95% confidence interval, 0.64-0.98; p = 0.035; 33 events). Additional adjustment for established diabetes risk factors and determinants of hepcidin concentration did not appreciably change these results (HR, 0.81; 95% CI, 0.66-0.99). Likewise, inadequately low hepcidin levels were also detected in subjects with prevalent T2DM (n = 76).

CONCLUSIONS

Hepcidin levels that are inadequately low in relation to body iron stores are an independent predictor for incident T2DM and may contribute to diabetes-related tissue iron overload. Copyright © 2015 John Wiley & Sons, Ltd.

GDF-15 and Hepcidin Levels in Nonanemic Patients with Impaired Glucose Tolerance

Aims. Growth Differentiation Factor-15 (GDF-15) has been suggested as one of the regulators of hepcidin, an important regulatory peptide for iron deposition. Current data is conflicting about the relationship between hepcidin and disorders of glucose metabolism. We aimed to investigate serum hepcidin and GDF-15 concentrations and their associations with each other, in nonanemic subjects with impaired glucose tolerance (IGT) in comparison with the nonanemic subjects with normal glucose tolerance (NGT). Methods. Thirty-seven subjects with IGT and 32 control subjects with NGT, who were age-, gender-, and body mass index- (BMI-) matched, were included in the study. Results. Serum GDF-15 levels were significantly higher in IGT compared to NGT. There were no differences in hepcidin, interleukin-6, and high sensitive C-reactive protein levels between the groups. We found a positive correlation between GDF-15 and hepcidin levels. There were also positive correlations between GDF-15 and age, uric acid, creatinine, and area under the curve for glucose (AUC-G). Hepcidin was correlated positively with ferritin levels. In the multiple regression analysis, GDF-15 concentrations were independently associated with age, uric acid, and AUC-G. Conclusions. Impaired glucose tolerance is associated with increased GDF-15 levels even in the absence of anemia, but the levels of hepcidin are not significantly altered in prediabetic state.

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.

Circulating hepcidin in type 2 diabetes: A multivariate analysis and double blind evaluation of metformin effects

SCOPE

Very few studies have evaluated serum hepcidin in patients with type 2 diabetes and they have reported conflicting results. In addition, the effect of antidiabetic drugs on circulating hepcidin has not been explored so far. The aims of the study were to evaluate hepcidin concentrations and hepcidin/ferritin ratio in type 2 diabetes subjects and healthy non-diabetic controls and to evaluate the effect of metformin on hepcidin concentrations.

METHODS AND RESULTS

Study 1: Cross-sectional multivariate study of 239 non-diabetic individuals and 65 people with type 2 diabetes. The multivariate analysis included covariates of chronic inflammation, BMI, pharmacological treatment, menopausal status and insulin resistance. Study 2: Randomized, double-blinded, placebo-controlled 4-month trial metformin compared to placebo among 36 type 2 diabetic patients. In both groups diet was controlled by maintaining a hypocaloric intake across the trial. Hepcidin levels were significantly lower in patients with type 2 diabetes than in non-diabetic individuals either in crude or adjusted regression models (P<0.05). Hepcidin decreased in both arms of the trial (Placebo, p = 0.004; metformin, p = 0.022).

CONCLUSION

Circulating hepcidin was significantly and independently lower in type 2 diabetes. Metformin treatment is not associated with reductions in hepcidin but hypocaloric diet could be involved.

Blocking of targeted microRNAs from next-generation sequencing libraries

Highly abundant microRNAs (miRNAs) in small RNA sequencing libraries make it difficult to obtain efficient measurements of more lowly expressed species. We present a new method that allows for the selective blocking of specific, abundant miRNAs during preparation of sequencing libraries. This technique is specific with little off-target effects and has no impact on the reproducibility of the measurement of non-targeted species. In human plasma samples, we demonstrate that blocking of highly abundant hsa-miR-16–5p leads to improved detection of lowly expressed miRNAs and more precise measurement of differential expression overall. Furthermore, we establish the ability to target a second abundant miRNA and to multiplex the blocking of two miRNAs simultaneously. For small RNA sequencing, this technique could fill a similar role as do ribosomal or globin removal technologies in messenger RNA sequencing.

Higher androgen bioactivity is associated with excessive erythrocytosis and chronic mountain sickness in Andean Highlanders: a review

Populations living at high altitudes (HA), particularly in the Peruvian Central Andes, are characterised by presenting subjects with erythrocytosis and others with excessive erythrocytosis (EE)(Hb>21 g dl(-1) ). EE is associated with chronic mountain sickness (CMS), or lack of adaptation to HA. Testosterone is an erythropoietic hormone and it may play a role on EE at HA. The objective of the present review was to summarise findings on role of serum T levels on adaptation at HA and genes acting on this process. Men at HA without EE have higher androstenedione levels and low ratio androstenedione/testosterone than men with EE, suggesting low activity of 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and this could be a mechanism of adaptation to HA. Higher conversion of dehydroepiandrosterone to testosterone in men with EE suggests nigher 17beta-HSD activity. Men with CMS at Peruvian Central Andes have two genes SENP1, and ANP32D with higher transcriptional response to hypoxia relative to those without. SUMO-specific protease 1 (SENP1) is an erythropoiesis regulator, which is essential for the stability and activity of hypoxia-inducible factor 1 (HIF-1α) under hypoxia. SENP1 reverses the hormone-augmented SUMOylation of androgen receptor (AR) increasing the transcription activity of AR.In conclusion, increased androgen activity is related with CMS.

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.

Hepcidin levels in diabetes mellitus and polycystic ovary syndrome

AIM

Increased body iron is associated with insulin resistance. Hepcidin is the key hormone that negatively regulates iron homeostasis. We hypothesized that individuals with insulin resistance have inadequate hepcidin levels for their iron load.

METHODS

Serum concentrations of the active form of hepcidin (hepcidin-25) and hepcidin:ferritin ratio were evaluated in participants with Type 2 diabetes (n = 33, control subjects matched for age, gender and BMI, n = 33) and participants with polycystic ovary syndrome (n = 27, control subjects matched for age and BMI, n = 16). To investigate whether any changes observed were associated with insulin resistance rather than insulin deficiency or hyperglycaemia per se, the same measurements were made in participants with Type 1 diabetes (n = 28, control subjects matched for age, gender and BMI, n = 30). Finally, the relationship between homeostasis model assessment of insulin resistance and serum hepcidin:ferritin ratio was explored in overweight or obese participants without diabetes (n = 16).

RESULTS

Participants with Type 2 diabetes had significantly lower hepcidin and hepcidin:ferritin ratio than control subjects (P < 0.05 and P < 0.01, respectively). Participants with polycystic ovary syndrome had a significantly lower hepcidin:ferritin ratio than control subjects (P < 0.05). There was no significant difference in hepcidin or hepcidin:ferritin ratio between participants with Type 1 diabetes and control subjects (P = 0.88 and P = 0.94). Serum hepcidin:ferritin ratio inversely correlated with homeostasis model assessment of insulin resistance (r = -0.59, P < 0.05).

CONCLUSION

Insulin resistance, but not insulin deficiency or hyperglycaemia per se, is associated with inadequate hepcidin levels. Reduced hepcidin concentrations may cause increased body iron stores in insulin-resistant states.

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.

Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl(-1)<haemoglobin (Hb)≤21 g dl(-1)) and others with excessive erythrocytosis (EE) (Hb>21 g dl(-1)). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.

Iron metabolism and the polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is associated with insulin resistance and abnormal glucose tolerance. Iron overload may lead also to insulin resistance and diabetes. Serum ferritin levels are increased in PCOS, especially when glucose tolerance is abnormal, suggesting mild iron overload. Factors contributing to potential iron overload in PCOS include the iron sparing effect of chronic menstrual dysfunction, insulin resistance, and a decrease in hepcidin leading to increased iron absorption. Enhancement of erythropoiesis by androgen excess is unlikely, because soluble transferrin receptor levels are not increased in PCOS. Future venues of research should address the long-term effects of PCOS treatment on iron overload and, conversely, the possible effects of iron lowering strategies on the glucose tolerance of patients with PCOS.

Estrogen regulates hepcidin expression via GPR30-BMP6-dependent signaling in hepatocytes

Hepcidin, a liver-derived iron regulatory protein, plays a crucial role in iron metabolism. It is known that gender differences exist with respect to iron storage in the body; however, the effects of sex steroid hormones on iron metabolism are not completely understood. We focused on the effects of the female sex hormone estrogen on hepcidin expression. First, ovariectomized (OVX) and sham-operated mice were employed to investigate the effects of estrogen on hepcidin expression in an in vivo study. Hepcidin expression was decreased in the livers of OVX mice compared to the sham-operated mice. In OVX mice, bone morphologic protein-6 (BMP6), a regulator of hepcidin, was also found to be downregulated in the liver, whereas ferroportin (FPN), an iron export protein, was upregulated in the duodenum. Both serum and liver iron concentrations were elevated in OVX mice relative to their concentrations in sham-operated mice. In in vitro studies, 17β-estradiol (E(2)) increased the mRNA expression of hepcidin in HepG2 cells in a concentration-dependent manner. E(2)-induced hepatic hepcidin upregulation was not inhibited by ICI 182720, an inhibitor of the estrogen receptor; instead, hepcidin expression was increased by ICI 182720. E(2) and ICI 182720 exhibit agonist actions with G-protein coupled receptor 30 (GPR30), the 7-transmembrane estrogen receptor. G1, a GPR30 agonist, upregulated hepcidin expression, and GPR30 siRNA treatment abolished E(2)-induced hepcidin expression. BMP6 expression induced by E(2) was abolished by GPR30 silencing. Finally, both E(2) and G1 supplementation restored reduced hepatic hepcidin and BMP6 expression and reversed the augmentation of duodenal FPN expression in the OVX mice. In contrast, serum hepcidin was elevated in OVX mice, which was reversed in these mice with E(2) and G1. Thus, estrogen is involved in hepcidin expression via a GPR30-BMP6-dependent mechanism, providing new insight into the role of estrogen in iron metabolism.

Changes in iron measures over menopause and associations with insulin resistance

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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