Regulation of adiponectin secretion by adipocytes in the polycystic ovary syndrome: role of tumor necrosis factor-{alpha}

Plasma Corin: A New Biochemical Marker for Polycystic Ovary Syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder. Atrial natriuretic peptide (ANP) is a risk factor for PCOS. Corin protein has an essential role in ANP synthesis. This study aimed to evaluate corin as a sensitive biomarker for PCOS.

MATERIALS AND METHODS

A case-control study was conducted with 70 PCOS patients and 70 healthy females. Plasma Corin levels were quantified using enzyme-linked immunosorbent assay.

RESULTS

The median plasma corin levels in PCOS patients and controls were 1785 and 822.5 pg/mL, respectively. Plasma corin levels were significantly elevated in PCOS patients than in the controls (p < 0.001). The optimal cut-off value was set at 1186 pg/mL. The sensitivity and specificity of Corin were 100% and 97.1%, respectively. Plasma corin levels were surrogate predictors for infertility in women with PCOS. It had an odds ratio of 5.9 (95% confidence interval: 1.1-32.7) (p = 0.04). Plasma corin levels were more highly detected in patients with PCOS than in the controls.

CONCLUSION

Plasma corin level has reasonable diagnostic interpretation for PCOS. Corin appears as a worthy distinct predictor of infertility in PCOS women. Therefore, Corin may be a substantial biomarker for PCOS.

Polycystic ovary syndrome

Despite affecting ~11-13% of women globally, polycystic ovary syndrome (PCOS) is a substantially understudied condition. PCOS, possibly extending to men's health, imposes a considerable health and economic burden worldwide. Diagnosis in adults follows the International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome, requiring two out of three criteria - clinical or biochemical hyperandrogenism, ovulatory dysfunction, and/or specific ovarian morphological characteristics or elevated anti-Müllerian hormone. However, diagnosing adolescents omits ovarian morphology and anti-Müllerian hormone considerations. PCOS, marked by insulin resistance and hyperandrogenism, strongly contributes to early-onset type 2 diabetes, with increased odds for cardiovascular diseases. Reproduction-related implications include irregular menstrual cycles, anovulatory infertility, heightened risks of pregnancy complications and endometrial cancer. Beyond physiological manifestations, PCOS is associated with anxiety, depression, eating disorders, psychosexual dysfunction and negative body image, collectively contributing to diminished health-related quality of life in patients. Despite its high prevalence persisting into menopause, diagnosing PCOS often involves extended timelines and multiple health-care visits. Treatment remains ad hoc owing to limited understanding of underlying mechanisms, highlighting the need for research delineating the aetiology and pathophysiology of the syndrome. Identifying factors contributing to PCOS will pave the way for personalized medicine approaches. Additionally, exploring novel biomarkers, refining diagnostic criteria and advancing treatment modalities will be crucial in enhancing the precision and efficacy of interventions that will positively impact the lives of patients.

Adipose Tissue Dysfunction in Polycystic Ovary Syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is a complex genetic trait and the most common endocrine disorder of women, clinically evident in 5% to 15% of reproductive-aged women globally, with associated cardiometabolic dysfunction. Adipose tissue (AT) dysfunction appears to play an important role in the pathophysiology of PCOS even in patients who do not have excess adiposity.

METHODS

We undertook a systematic review concerning AT dysfunction in PCOS, and prioritized studies that assessed AT function directly. We also explored therapies that targeted AT dysfunction for the treatment of PCOS.

RESULTS

Various mechanisms of AT dysfunction in PCOS were identified including dysregulation in storage capacity, hypoxia, and hyperplasia; impaired adipogenesis; impaired insulin signaling and glucose transport; dysregulated lipolysis and nonesterified free fatty acids (NEFAs) kinetics; adipokine and cytokine dysregulation and subacute inflammation; epigenetic dysregulation; and mitochondrial dysfunction and endoplasmic reticulum and oxidative stress. Decreased glucose transporter-4 expression and content in adipocytes, leading to decreased insulin-mediated glucose transport in AT, was a consistent abnormality despite no alterations in insulin binding or in IRS/PI3K/Akt signaling. Adiponectin secretion in response to cytokines/chemokines is affected in PCOS compared to controls. Interestingly, epigenetic modulation via DNA methylation and microRNA regulation appears to be important mechanisms underlying AT dysfunction in PCOS.

CONCLUSION

AT dysfunction, more than AT distribution and excess adiposity, contributes to the metabolic and inflammation abnormalities of PCOS. Nonetheless, many studies provided contradictory, unclear, or limited data, highlighting the urgent need for additional research in this important field.

Identification of key genes and miRNAs related to polycystic ovary syndrome by comprehensive analysis of microarray

BACKGROUND

We aimed to explore mechanisms of development and progression of polycystic ovary syndrome (PCOS).

METHODS

The microRNA expression microarray GSE37914 and gene expression profiles GSE43264 and GSE98421 were downloaded from the Gene Expression Omnibus database. The differentially expressed miRNAs (DEmiRNAs) and genes (DEGs) were screened using Limma package. Then, the DEGs and DEmiRNAs were combined to use for the subsequent analysis, including the functional enrichment analysis, protein-protein interaction (PPI) network and module analysis, drug-gene interaction network analysis, and DEmiRNAs-DEGs interactive network construction.

RESULTS

A total of 26 DEmiRNAs and 80 DEGs were screened. The PPI network contained 68 nodes and 259 interactions. A significant clustering module with 8 nodes and 25 interactions was obtained. Three PCOS-related overlapping pathways were obtained based on PPI-degree top10 and module genes, including prion diseases, Staphylococcus aureus infection, and Chagas disease (American trypanosomiasis). A total of 44 drug-gene interaction pairs were obtained, which included 2 up-regulated genes (LDLR and VCAM1), 4 down-regulated genes (C1QA, C1QB, IL6 and ACAN) and 26 small molecules drugs. A total of 52 nodes and 57 interactions were obtained in the DEmiRNA-DEGs regulatory network, LDLR was regulated by miR-152-3p, miR-1207-5p, miR-378a-5p and miR-150-5p.

CONCLUSIONS

Our research has identified several key genes and pathways related to PCOS. These results can improve our understanding of PCOS and provide new basis for drug target research.

Association of SNPs in the FK-506 binding protein (FKBP5) gene among Han Chinese women with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women, whose etiology remains uncertain, although it is known to be highly heterogeneous and genetically complex. PCOS often presents with hyperandrogenism symptoms. The present study aimed to determine whether polymorphisms in the FK-506 binding protein 5 (FKBP5) gene (androgen target gene) are associated with an association for PCOS and hyperandrogenism.

Methods

This is a case–control study, and association analyses were conducted. A total of 13 single-nucleotide polymorphisms (SNPs) in the FKBP5 gene were evaluated in 775 PCOS patients who were diagnosed based on the Rotterdam Standard and 783 healthy Chinese Han women. Associations between FKBP5 SNPs and hormone levels were investigated. These 13 SNPs were genotyped using the Sequenom MassARRAY system, and an association analysis between the phenotype and alleles and genotypes were conducted.

Results

The genotype frequencies for the rs1360780 and rs3800373 SNPs differed significantly between the PCOS cases and healthy controls (p = 0.025, OR is 1.63 (1.05–2.53) and p = 0.029, OR is 1.59 (1.03–2.45) respectively under co-dominant model). Moreover, the genotype frequencies and genetic model analysis for the SNPs rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037 differed significantly between the hyperandrogenism and non-hyperandrogenism groups of PCOS patients. The TT genotype of rs1360780, the TT genotype of rs9470080, the TT genotype of rs1043805 or the GG genotype of rs7705037 (ORs are 2.13 (1.03–4.39), 1.81 (1.03–3.17), 2.94 (1.32–6.53) and 1.72 (1.04–2.84) respectively) were correlated with androgen level of PCOS patients.

Conclusion

Our study showed that FKBP5 gene polymorphisms are associated with PCOS generally (rs1360780 and rs3800373) and with the hyperandrogenism subtype specifically (rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01301-0.

Brown Adipose Tissue and Novel Management Strategies for Polycystic Ovary Syndrome Therapy

Brown adipose tissue (BAT), a unique tissue, plays a key role in metabolism and energy expenditure through adaptive nonshivering thermogenesis. It has recently become a therapeutic target in the treatment of obesity and metabolic diseases. The thermogenic effect of BAT occurs through uncoupling protein-1 by uncoupling adenosine triphosphate (ATP) synthesis from energy substrate oxidation. The review discusses the recent developments and progress associated with the biology, function, and activation of BAT, with a focus on its therapeutic potential for the treatment of polycystic ovary syndrome (PCOS). The endocrine activity of brown adipocytes affects the energy balance and homeostasis of glucose and lipids, thereby affecting the association of BAT activity and the metabolic profile. PCOS is a complex reproductive and metabolic disorder of reproductive-age women. Functional abnormalities of adipose tissue (AT) have been reported in patients with PCOS. Numerous studies have shown that BAT could regulate the features of PCOS and that increases in BAT mass or activity were effective in the treatment of PCOS through approaches including cold stimulation, BAT transplantation and compound activation in various animal models. Therefore, BAT may be used as a novel management strategy for the patients with PCOS to improve women's health clinically. It is highly important to identify key brown adipokines for the discovery and development of novel candidates to establish an efficacious therapeutic strategy for patients with PCOS in the future.

Adipocyte integrin-linked kinase plays a key role in the development of diet-induced adipose insulin resistance in male mice

Objective

Increased deposition of the extracellular matrix (ECM) in adipose tissue (AT) during obesity contributes to insulin resistance. The integrin receptors transmit changes in the extracellular environment causing corresponding intracellular adaptations. Integrin-linked kinase (ILK), an adaptor protein, is a central hub for intracellular signaling of integrins. This study determined the role of ILK in adipose function and insulin resistance.

Methods

The pathogenic role of ILK in obesity and insulin resistance was studied in human adipose tissue and adipocyte-specific ILK-deficient mice (ILK^lox/loxAdCre). ILK^lox/loxAdCre mice together with wild-type littermates (ILK^lox/lox) were fed a chow diet or 60% high-fat (HF) diet for 16 weeks. In vivo insulin sensitivity was determined by hyperinsulinemic-euglycemic clamps.

Results

AT ILK expression was increased by HF diet feeding in mice and increased in visceral fat of morbidly obese humans. The HF-fed ILK^lox/loxAdCre mice displayed reduced fat mass and improved glucose tolerance relative to the HF-fed ILK^lox/lox mice. During a hyperinsulinemic-euglycemic clamp, the HF-fed ILK^lox/loxAdCre mice exhibited partially improved insulin resistance in AT. Lipolysis was suppressed to a greater extent by insulin and glucose uptake in brown AT (BAT) increased. Increased inhibition of lipolysis may have been attributed to increased vascularization in white AT, while increased glucose uptake in BAT was associated with increased Akt phosphorylation and P38/JNK dephosphorylation. Notably, AT insulin sensitivity in lean mice was not affected by ILK deletion. Moreover, reduced fat mass in the HF-fed ILK^lox/loxAdCre mice may have been attributed to decreased free fatty acid uptake into adipocytes via the downregulation of CD36 gene expression. Consistent with the results in the mice, knockdown and knockout of ILK in 3T3-L1 cells decreased lipid accumulation and CD36 gene expression during adipogenesis.

Conclusions

These data show that adipocyte ILK is important for regulating HF diet-mediated insulin resistance in AT in a manner consistent with AT function.

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ILK protein increased in visceral adipose tissue of obese humans and mice.

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Mice lacking adipocyte ILK had less fat and improved glucose tolerance in obesity.

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Adipocyte ILK deletion improved anti-lipolytic action of insulin in obese mice.

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Adipocyte ILK deletion stimulated brown adipose tissue glucose uptake in obese mice.

Brown Adipose Tissue Activation by Cold Treatment Ameliorates Polycystic Ovary Syndrome in Rat

Polycystic ovary syndrome (PCOS) is a common endocrine disease accompanied by energetic metabolic imbalance. Because the etiology of PCOS is complex and remains unclear, there is no effective and specific treatment for PCOS. It is often accompanied by various metabolic disorders such as obesity, insulin resistances, and others. Activated brown adipose tissue (BAT) consumes excess energy via thermogenesis, which has positive effects on energy metabolism. Our previous research and that of others indicates that BAT activity is decreased in PCOS patients, and exogenous BAT transplantation can improve PCOS rodents. Notably however, it is difficult to apply this therapeutic strategy in clinical practice. Therapeutic strategies of enhancing endogenous BAT activity and restoring whole-body endocrine homeostasis may be more meaningful for PCOS treatment. In the current study, the dehydroepiandrosterone-induced PCOS rat was exposed to low temperature for 20 days. The results show that cold treatment could reverse acyclicity of the estrous cycle and reduce circulating testosterone and luteinizing hormone in PCOS rats by activating endogenous BAT. It also significantly reduced the expression of steroidogenic enzymes as well as inflammatory factors in the ovaries of PCOS rats. Histological investigations revealed that cold treatment could significantly reduce ovary cystic follicles and increase corpus luteum, indicating that ovulation was recovered to a normal level. Concordant with these results, cold treatment also improved fertility in PCOS rats. Collectively, these findings suggest that cold treatment could be a novel therapeutic strategy for PCOS.

Beneficial health effects of Menaquinone-7 on body composition, glycemic indices, lipid profile, and endocrine markers in polycystic ovary syndrome patients

OBJECTIVE

The aim of this study was to investigate the effect of oral vitamin K2 (Menaquinone-7 [MK-7]) on clinical and biochemical parameters in polycystic ovary syndrome (PCOS) patients.

METHODS

In this randomized, double-blind, placebo-controlled clinical trial, 84 PCOS patients were randomly assigned into the treatment (90 µg Menaquinone-7 daily for 8 weeks) and placebo groups. Insulin resistance, lipid profile, endocrine biomarkers, and body composition of the participants were measured before and after the intervention. This study was performed in Ghadir Mother & Child Hospital affiliated to Shiraz University of Medical Sciences, Shiraz, Iran.

RESULTS

Menaquinone-7 supplementation, when compared to placebo, significantly decreased serum fasting insulin (p = .002), homeostasis model of assessment insulin resistance (p = .002), and homeostasis model of assessment β-cell function (p = .02) in addition to a significant increase in quantitative insulin sensitivity check index (p = .001). Also, MK-7 administration led to significant declines in serum triglyceride (p = .003) and dihydrotestosterone (DHT; p = .03) levels, free androgen index (p < .001), waist circumference (p = .03), and body fat mass (p < .001) as well as significant increases in skeletal muscle (p < .001) and sex hormone binding globulin (SHBG, p < .001).

CONCLUSIONS

This study highlights the beneficial effects of MK-7 on insulin resistance, fat mass, skeletal muscle, and serum levels of triglyceride, DHT, and SHBG in PCOS patients. Therefore, it seems that MK-7 supplementation might be an appropriate additive treatment for PCOS patients.

Adipocyte Insulin Resistance in PCOS: Relationship With GLUT-4 Expression and Whole-Body Glucose Disposal and β-Cell Function

CONTEXT

Impaired sensitivity to the antilipolytic action of insulin in adipose tissue (AT) may play a role in determining metabolic dysfunction in polycystic ovary syndrome (PCOS).

OBJECTIVES

To test the hypothesis that insulin resistance (IR) in AT is associated with whole-body insulin sensitivity and β-cell function in PCOS.

RESEARCH DESIGN AND SETTING

Prospective cross-sectional study.

METHODS

Eighteen participants with PCOS and 18-matched control participants underwent a modified frequently sampled intravenous glucose tolerance test (mFSIVGTT); subgroups underwent single-slice computed tomography scans determining AT distribution and adipocyte glucose transporter type 4 (GLUT-4) expression.

MAIN OUTCOME MEASURES

IR in AT in basal (by the adipose insulin resistance index [Adipo-IR]) and dynamic (mFSIVGTT-derived indices of insulin-mediated nonesterified fatty acids [NEFA] suppression [NEFAnadir, TIMEnadir, and %NEFAsupp]) states; whole-body insulin-mediated glucose uptake and insulin secretion in basal (by homeostatic model assessment [HOMA]-IR and HOMA-β%) and dynamic (mFSIVGTT-derived insulin sensitivity index [Si], acute insulin response to glucose [AIRg], and disposition index [Di]) states.

RESULTS

Participants with PCOS had higher HOMA-IR and HOMA-β%, lower Si and Di, higher longer TIMEnadir, higher Adipo-IR and NEFAnadir, and a trend toward lower GLUT-4, than the control group participants. Adipo-IR was associated with dynamic state IR in AT (NEFAnadir TIMEnadir, and %NEFAsupp), but only in PCOS, and with HOMA-IR and HOMA-β% in both groups. NEFAnadir and TIMEnadir were negatively and %NEFAsupp positively associated with Si only in PCOS, but not with AIRg and Di, or GLUT-4 expression.

CONCLUSION

Women with PCOS demonstrated increased IR in AT, which is closely associated with whole-body IR but not with dynamic state β-cell function or adipocyte GLUT-4 gene expression.

Androgen Action in Adipose Tissue and the Brain are Key Mediators in the Development of PCOS Traits in a Mouse Model

Polycystic ovary syndrome (PCOS) is a complex disorder characterized by endocrine, reproductive, and metabolic abnormalities. Despite PCOS being the most common endocrinopathy affecting women of reproductive age, the etiology of PCOS is poorly understood, so there is no cure and symptomatic treatment is suboptimal. Hyperandrogenism is the most consistent feature observed in PCOS patients, and recently aberrant neuroendocrine signaling and adipose tissue function have been proposed as playing a role in the development of PCOS. To investigate the role of adipose tissue and the brain as key sites for androgen receptor (AR)-mediated development of PCOS, we combined a white and brown adipose and brain-specific AR knockout (AdBARKO) mouse model with a dihydrotestosterone (DHT)-induced mouse model of PCOS. As expected, in wildtype (WT) control females, DHT exposure induced the reproductive PCOS traits of cycle irregularity, ovulatory dysfunction, and reduced follicle health, whereas in AdBARKO females, DHT did not produce the reproductive features of PCOS. The metabolic PCOS characteristics of increased adiposity, adipocyte hypertrophy, and hepatic steatosis induced by DHT in WT females were not evident in DHT-treated AdBARKO females, which displayed normal white adipose tissue weight and no adipocyte hypertrophy or liver steatosis. Dihydrotestosterone treatment induced increased fasting glucose levels in both WT and AdBARKO females. These findings demonstrate that adipose tissue and the brain are key loci of androgen-mediated actions involved in the developmental origins of PCOS. These data support targeting adipocyte and neuroendocrine AR-driven pathways in the future development of novel therapeutic strategies for PCOS.

Adropin as A Fat-Burning Hormone with Multiple Functions-Review of a Decade of Research

Adropin is a unique hormone encoded by the energy homeostasis-associated (Enho) gene. Adropin is produced in the liver and brain, and also in peripheral tissues such as in the heart and gastrointestinal tract. Furthermore, adropin is present in the circulatory system. A decade after its discovery, there is evidence that adropin may contribute to body weight regulation, glucose and lipid homeostasis, and cardiovascular system functions. In this review, we summarize and discuss the physiological, metabolic, and pathophysiological factors regulating Enho as well as adropin. Furthermore, we review the literature addressing the role of adropin in adiposity and type 2 diabetes. Finally, we elaborate on the role of adropin in the context of the cardiovascular system, liver diseases, and cancer.

Pregnancy Outcomes of Women With Polycystic Ovary Syndrome for the First In Vitro Fertilization Treatment: A Retrospective Cohort Study With 7678 Patients

BACKGROUND

The risk of adverse pregnancy outcomes is increased by having a polycystic ovary syndrome (PCOS) diagnosis. However, the confounders in previous studies preclude firm conclusions, and further studies are warranted.

OBJECTIVES

To investigate whether PCOS affects pregnancy outcomes and complications in infertile women undergoing their first in vitro fertilization (IVF) treatment, taking into account important confounders.

METHODS

We performed a retrospective cohort study of 7,678 infertile women, including 666 women with PCOS and 7,012 controls undergoing their first IVF treatment at a private fertility center from January 2010 to December 2017. Our main outcome was the impact of PCOS on adverse pregnancy outcomes (miscarriage, preterm delivery, pregnancy-induced hypertension) and pregnancy outcomes (live birth rate, clinical pregnancy rate, implantation rate). PCOS effects were summarized by adjusted odds ratios (aORs) with 95% confidence intervals (CIs) after controlling for maternal characteristics.

RESULTS

After adjusting for differences in maternal age, BMI, infertility duration, total dose of gonadotropin, serum E₂ and endometrial thickness on the day of hCG trigger, number of fertilized occytes, number of embryos transferred, embryo type (cleavage-stage embryo or blastocyst) and quality, women with PCOS had an increased risk of developing unfavorable pregnancy complications, including miscarriage (aOR 1.629, 95% CI 1.240-2.141), very preterm delivery (< 32 weeks) (aOR 2.072, 95% CI 1.133-3.791). For pregnancy outcomes, PCOS was associated with higher clinical pregnancy rate (aOR 1.248, 95% CI 1.038-1.501) and implantation rate (aOR 1.238, 95% CI 1.030-1.489) after adjusting for the above-mentioned confounders.

CONCLUSIONS

Women with PCOS are at increased risk of adverse pregnancy outcomes after adjusting for differences in maternal characteristics. These women may need more frequent medical consultants and management during pregnancy and parturition.

Drug development research for novel adiponectin receptor-targeted antidiabetic drugs contributing to healthy longevity

It is well recognized that the decrease of adiponectin associated with high-fat diet and lack of exercise accounts for the onset of insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease. Our research efforts have led to the identification of adiponectin receptors, AdipoR1 and AdipoR2, with the former shown to activate AMP kinase in the liver and the latter shown to activate peroxisome proliferator-activated receptor-α signaling thereby increasing fatty acid oxidation. Again, adiponectin upregulates mitochondrial function in the skeletal muscle thereby improving glucose/lipid metabolism and insulin resistance. These findings suggested that activation of adiponectin/AdipoR signaling could represent a viable therapeutic approach to lifestyle-linked diseases associated with prevalent obesity thus contributing to healthy longevity in humans. Indeed, they have led to the successful discovery of AdipoRon, a small-molecule AdipoR-activating compound. Thus far, AdipoRon has been found not only to improve insulin resistance in mice but to prolong their lifespan shortened by high-fat diet. Additionally, our structure-based drug discovery research has led to AdipoR being identified as an entirely novel structure having a zinc iron bound within its seven-transmembrane domain as well as an opposite orientation to that of G protein-coupled receptors. It is expected that increasing insight into AdipoR signaling will facilitate the structure-based optimization of candidate small-molecule AdipoR-activating compounds for human use as well as the development of molecularly targeted and calorie-limiting/exercise-mimicking agents for lifestyle-linked diseases.

Evaluation of tumor necrosis factor alpha serum level in obese and lean women with clomiphene citrate-resistant polycystic ovary disease

OBJECTIVE

The aim of this work was to investigate the level of the serum level of tumor necrosis factor alpha (TNF-α) as an inflammatory biomarker in lean and obese women with polycystic ovary disease (PCOD), who are resistant to clomiphene citrate (CCR-PCOD).

PATIENTS AND DESIGN

It is a case-controlled study, where 150 (n = 150) PCOD women (study group), who are resistant to clomiphene citrate (CCR-PCOD) had been recruited, in addition to 100 (n = 100) women with PCOD, who are not resistant to clomiphene citrate (NCCR-PCOD) as the first control group, and another 100 women (n = 100) fertile women with normal reproductive health, as the second control group. All the recruited subjects had been divided into subgroups according to the BMI: One obese group with BMI ≥ 27 and the second lean group with BMI < 27. TNF-α had been measured in all women groups recruited, in addition to the other essential, basic and PCOD-relevant biochemical and hormonal tests.

RESULTS

TNF-α level was found to be higher in all PCOD women, either the study or control PCOD groups, than the fertile control group (49.93 ± 3.39 versus 35.83 ± 2.47 pg/ml, p < 0.001). The level of TNF-α has come highest in the obese clomiphene citrate-resistant PCOD women (obese CCR-PCOD), while the lowest has come in the lean PCOD women, who are not resistant to clomiphene citrate (NCCR-PCOD). Free Androgen Index (FAI) and androgenic obesity with higher W/H ratio were clearly going with TNF-α pattern and have come higher in all PCOD compared to the fertile control group. Insulin resistance (IR) shows a positive correlation with BMI regardless off PCOD status and androgen level as well. The level of other basic and PCOD-relevant hormones like FSH, TSH and prolactin have never shown statistically significant differences between all the study and control groups, except LH serum level which has shown a nonsignificant higher level in all PCOD women included either resistant to CC or not.

CONCLUSION

TNF-α serum level has come significantly higher in all women with PCOD, especially in those resistant to CC. Androgenic obesity with higher W/H ratio has shown a positive correlation with TNF-α level, which could consider it a good severity index of PCOD status and an informative predictor of CCR before its use.

Ovarian hormones and obesity

BACKGROUND

Obesity is caused by an imbalance between energy intake, i.e. eating and energy expenditure (EE). Severe obesity is more prevalent in women than men worldwide, and obesity pathophysiology and the resultant obesity-related disease risks differ in women and men. The underlying mechanisms are largely unknown. Pre-clinical and clinical research indicate that ovarian hormones may play a major role.

OBJECTIVE AND RATIONALE

We systematically reviewed the clinical and pre-clinical literature on the effects of ovarian hormones on the physiology of adipose tissue (AT) and the regulation of AT mass by energy intake and EE.

SEARCH METHODS

Articles in English indexed in PubMed through January 2016 were searched using keywords related to: (i) reproductive hormones, (ii) weight regulation and (iii) central nervous system. We sought to identify emerging research foci with clinical translational potential rather than to provide a comprehensive review.

OUTCOMES

We find that estrogens play a leading role in the causes and consequences of female obesity. With respect to adiposity, estrogens synergize with AT genes to increase gluteofemoral subcutaneous AT mass and decrease central AT mass in reproductive-age women, which leads to protective cardiometabolic effects. Loss of estrogens after menopause, independent of aging, increases total AT mass and decreases lean body mass, so that there is little net effect on body weight. Menopause also partially reverses women's protective AT distribution. These effects can be counteracted by estrogen treatment. With respect to eating, increasing estrogen levels progressively decrease eating during the follicular and peri-ovulatory phases of the menstrual cycle. Progestin levels are associated with eating during the luteal phase, but there does not appear to be a causal relationship. Progestins may increase binge eating and eating stimulated by negative emotional states during the luteal phase. Pre-clinical research indicates that one mechanism for the pre-ovulatory decrease in eating is a central action of estrogens to increase the satiating potency of the gastrointestinal hormone cholecystokinin. Another mechanism involves a decrease in the preference for sweet foods during the follicular phase. Genetic defects in brain α-melanocycte-stimulating hormone-melanocortin receptor (melanocortin 4 receptor, MC4R) signaling lead to a syndrome of overeating and obesity that is particularly pronounced in women and in female animals. The syndrome appears around puberty in mice with genetic deletions of MC4R, suggesting a role of ovarian hormones. Emerging functional brain-imaging data indicates that fluctuations in ovarian hormones affect eating by influencing striatal dopaminergic processing of flavor hedonics and lateral prefrontal cortex processing of cognitive inhibitory controls of eating. There is a dearth of research on the neuroendocrine control of eating after menopause. There is also comparatively little research on the effects of ovarian hormones on EE, although changes in ovarian hormone levels during the menstrual cycle do affect resting EE.

WIDER IMPLICATIONS

The markedly greater obesity burden in women makes understanding the diverse effects of ovarian hormones on eating, EE and body adiposity urgent research challenges. A variety of research modalities can be used to investigate these effects in women, and most of the mechanisms reviewed are accessible in animal models. Therefore, human and translational research on the roles of ovarian hormones in women's obesity and its causes should be intensified to gain further mechanistic insights that may ultimately be translated into novel anti-obesity therapies and thereby improve women's health.

Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the presence of hyperandrogenism, ovulatory dysfunction and PCOM. Treatment should be tailored to the complaints and needs of the patient and involves targeting metabolic abnormalities through lifestyle changes, medication and potentially surgery for the prevention and management of excess weight, androgen suppression and/or blockade, endometrial protection, reproductive therapy and the detection and treatment of psychological features. This Primer summarizes the current state of knowledge regarding the epidemiology, mechanisms and pathophysiology, diagnosis, screening and prevention, management and future investigational directions of the disorder.

A possible connection between tumor necrosis factor alpha and adropin levels in polycystic ovary syndrome

CONTEXT

Adropin is a peptide hormone implicated in the regulation of insulin sensitivity and energy homeostasis. Polycystic ovary syndrome (PCOS) is a metabolic and reproductive disease associated with insulin resistance. It has been demonstrated that various inflammatory markers increased in PCOS including TNF-α. TNF-α regulates the secretion of certain peptides which play a crucial role in glucose and lipid homeostasis. There is also some evidence of a link between TNF-α and adropin.

OBJECTIVE

To ascertain whether there is an association between circulating adropin levels and TNF-α in PCOS.

PATIENTS AND DESIGN

152 women with PCOS and 152 age- and body mass index-matched controls without PCOS were recruited for this cross-sectional study.

MAIN OUTCOME MEASURES

Adropin and TNF-α levels were measured using ELISA.

RESULTS

Adropin levels were lower in the PCOS group compared with the control group (7.43 ± 0.79 vs. 9.42 ± 0.76 ng/ml, P < 0.001), whereas TNF-α levels were higher (49.93 ± 3.39 vs. 35.83 ± 2.47 pg/ml, P < 0.001). A strongly negative correlation was found between circulating adropin levels and TNF-α levels in women with PCOS (r = -0.407, P < 0.001). Binary logistic regression analysis revealed that decreased adropin levels were significantly associated with high odds of having PCOS, although, after adjustment for TNF-α, this link vanished. Additionally, multiple linear regression analysis showed that HOMA-IR and TFN-α independently predicted adropin levels.

CONCLUSIONS

Serum adropin levels are significantly decreased in PCOS and are inversely associated with TNF-α. Further dissection of the nature of this association can open new therapeutic options for metabolic diseases.

Association of fat to lean mass ratio with metabolic dysfunction in women with polycystic ovary syndrome

STUDY QUESTION

Are differences in metabolic dysfunction between polycystic ovary syndrome (PCOS) and control women related to differences in their fat to lean mass (F/L) ratio?

SUMMARY ANSWER

Compared with controls of similar body mass index (BMI), women with PCOS demonstrate adverse body composition characterized by increased whole body fat relative to lean mass (i.e. a higher F/L ratio), which is associated with differences in metabolic dysfunction between the two groups.

WHAT IS KNOWN ALREADY

Previous studies examining body composition and insulin resistance (IR) in PCOS have yielded conflicting results. Excess total fat mass (i.e. fat mass index [fat BMI]) correlates with IR, whereas increased total lean mass (i.e. lean BMI) has been associated with higher insulin sensitivity. However, the role of the F/L ratio, which integrates the antagonistic effects of both fat and lean mass depots, on IR in PCOS, has not been investigated.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective cross-sectional study of 120 women between the ages of 22-44 years to study the relation of the F/L ratio with measures of insulin action and secretion in both steady and dynamic states.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sixty PCOS (by NIH, 1990 criteria) and 60 control (age, race and BMI-matched) women were prospectively studied for body composition (by bioelectrical impedance analysis [BIA]) and basal IR and insulin secretion by the homeostasis model assessment (HOMA-IR and HOMA-%β-cell function, respectively) in a tertiary care academic referral center. A subset of 12 PCOS and 12 matched control women also underwent a modified frequently sampled intravenous glucose tolerance test (FSIVGTT) to determine glucose uptake and insulin secretion in dynamic state.

MAIN RESULTS AND THE ROLE OF CHANCE

Our results indicate that women with PCOS demonstrated greater degrees of hyperandrogenism, and higher waist-to-hip ratio (WHR), %body fat, fat BMI, F/L, fasting insulin levels, and HOMA-IR and HOMA-%β-cell values, than controls. In models adjusted for WHR and free testosterone and diagnostic groups, fasting insulin levels, HOMA-IR, and HOMA-%beta cell function were positively related to the F/L ratio. A positive relationship was also found in both study groups between F/L and the FSIVGTT measures insulin sensitivity (Si) and acute insulin response to glucose (AIRg). The F/L tended to negatively correlate with glucose effectiveness or non-insulin-mediated glucose transport (Sg) only in PCOS women.

LIMITATIONS, REASONS FOR CAUTION

Regional tissue sub-compartments, which have been shown to have potential independent associations with metabolic variables, cannot be determined by bioelectrical impedance analysis (BIA).

WIDER IMPLICATIONS OF THE FINDINGS

The current results suggest that BIA could be used to assess F/L in place of dual energy X-ray absorptiometry (DXA) in research protocols, and that F/L could possibly be used as an alternative to WHR as a surrogate marker of metabolic dysfunction in clinical practice.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants R01-DK073632 and R01-HD29364 from the NIH and an endowment of the Helping Hand of Los Angeles, Inc. (to R.A.). The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Small for gestational age babies are not related to changes in markers of adipose tissue dysfunction during reproductive age

BACKGROUND

Small for gestational age (SGA) birth has been associated with adipocyte dysfunction during later phases of life. Because SGA women are at a higher risk of developing polycystic ovary syndrome (PCOS), adipocyte dysfunction detected in patients with PCOS may be associated with SGA birth.

AIMS

To determine whether SGA birth is related to altered serum markers of adipose tissue dysfunction during the third decade of life in Brazilian women. A secondary objective was to relate the presence of PCOS with serum markers of adipose tissue dysfunction.

STUDY DESIGN

Prospective cohort observational study.

SUBJECTS

A total of 384 women born at 37 to 42weeks of gestation from June 1, 1978 to May 31, 1979 in Ribeirão Preto, State of São Paulo, Brazil. After exclusion, 165 women participated in the study. Of these women, 43 were in the SGA group and 122 were in the adequate for gestational age group based on birth weight determined from cohort files.

OUTCOME MEASURES

Body mass index (BMI), arterial systolic and diastolic pressures, abdominal circumference and serum concentrations of total testosterone, fasting glucose and insulin, lipid profile, adiponectin, leptin and necrosis factor alpha tumor (TNFα).

RESULTS

BMI was an independent predictor of lower adiponectin (adjusted coefficient=-0.02, p=0.01) and higher leptin (adjusted coefficient=0.06, p=0.01) concentrations. The serum insulin concentration was associated with higher leptin (adjusted coefficient=0.03, p=0.02) and TNF-α (adjusted coefficient=0.01, p=0.03) concentrations. Having PCOS or being born SGA did not predict any markers of adipocyte dysfunction.

Supplementation with conjugated linoleic acids extends the adiponectin deficit during early lactation in dairy cows

Decreasing insulin sensitivity (IS) in peripheral tissues allows for partitioning nutrients towards the mammary gland. In dairy cows, extensive lipid mobilization and continued insulin resistance (IR) are typical for early lactation. Adiponectin, an adipokine, promotes IS. Supplementation with conjugated linoleic acids (CLA) in rodents and humans reduces fat mass whereby IR and hyperinsulinemia may occur. In dairy cows, CLA reduce milk fat, whereas body fat, serum free fatty acids and leptin are not affected. We aimed to investigate the effects of CLA supplementation on serum and adipose tissue (AT) adiponectin concentrations in dairy cows during the lactation driven and parity modulated changes of metabolism. High yielding cows (n=33) were allocated on day 1 post partum to either 100 g/day of a CLA mixture or a control fat supplement (CON) until day 182 post partum. Blood and subcutaneous (sc) AT (AT) biopsy samples were collected until day 252 post partum to measure adiponectin. Serum adiponectin decreased from day 21 pre partum reaching a nadir at calving and thereafter increased gradually. The distribution of adiponectin molecular weight forms was neither affected by time, parity nor treatment. Cows receiving CLA had decreased serum adiponectin concentrations whereby primiparous cows responded about 4 weeks earlier than multiparous cows. The time course of adiponectin concentrations in sc AT (corrected for residual blood) was similar to serum concentrations, without differences between CLA and CON. CLA supplementation attenuated the post partum increase of circulating adiponectin thus acting towards prolongation of peripartal IR and drain of nutrients towards the mammary gland.

Cancer risk and PCOS

Women with polycystic ovary syndrome (PCOS) have a 2.7-fold increased risk for developing endometrial cancer. A major factor for this increased malignancy risk is prolonged exposure of the endometrium to unopposed estrogen that results from anovulation. Additionally, secretory endometrium of some women with PCOS undergoing ovulation induction or receiving exogenous progestin exhibits progesterone resistance accompanied by dysregulation of gene expression controlling steroid action and cell proliferation. Endometrial surveillance includes transvaginal ultrasound and/or endometrial biopsy to assess thickened endometrium, prolonged amenorrhea, unopposed estrogen exposure or abnormal vaginal bleeding. Medical management for abnormal vaginal bleeding or endometrial hyperplasia consists of estrogen-progestin oral contraceptives, cyclic or continuous progestins or a levonorgestrel-releasing (Mirena) intrauterine device. Lifestyle modification with caloric restriction and exercise is appropriate to treat obesity as a concomitant risk factor for developing endometrial disease. An increased risk of ovarian cancer may also exist in some women with PCOS. There are strong data to suggest that oral contraceptive use is protective against ovarian cancer and increases with the duration of therapy. The mechanism of this protection may be through suppression of gonadotropin secretion rather than the prevention of "incessant ovulation". There is no apparent association of PCOS with breast cancer, although the high prevalence of metabolic dysfunction from obesity is a common denominator for both conditions. Recent data suggest that the use of metformin may be protective for both endometrial and breast cancer. There are insufficient data to evaluate any association between PCOS and vaginal, vulvar and cervical cancer or uterine leiomyosarcoma.

Effects of endogenous androgens and abdominal fat distribution on the interrelationship between insulin and non-insulin-mediated glucose uptake in females

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism and insulin resistance. Glucose disposal occurs via noninsulin-mediated glucose uptake (NIMGU) and insulin-mediated glucose uptake (IMGU). It is unknown whether in PCOS NIMGU increases to compensate for declining IMGU and whether androgens and fat distribution influence this relationship.

OBJECTIVES

The objective of the study was to compare in women with PCOS and controls the interrelationship between NIMGU [ie, glucose effectiveness (Sg)] and IMGU [ie, the insulin sensitivity index (Si)] and the role of androgens and fat distribution.

PARTICIPANTS

Twenty-eight PCOS (by National Institutes of Health 1990 criteria) and 28 control (age, race, and body mass index matched) women were prospectively studied. A subset of 16 PCOS subjects and 16 matched controls also underwent abdominal computed tomography.

MAIN OUTCOME MEASURES

Glucose disposal (by a frequently sampled iv glucose tolerance test), circulating androgens, and abdominal fat distribution [by waist to hip ratio and visceral (VAT) and sc (SAT) adipose tissue content] were measured.

RESULTS

PCOS women had lower mean Si and similar Sg and abdominal fat distribution compared with controls. PCOS women with Si below the PCOS median (more insulin resistant) had a lower mean Sg than controls with Si above the control median (more insulin sensitive). In PCOS only, body mass index, free T, modified Ferriman-Gallwey score, and waist to hip ratio independently predicted Sg, whereas Si did not. In PCOS, VAT and SAT independently and negatively predicted Si and Sg, respectively.

CONCLUSION

The decreased IMGU in PCOS is not accompanied by a compensatory increase in NIMGU or associated with excessive VAT accumulation. Increased general obesity, SAT, and hyperandrogenism are primary predictors of the deterioration of NIMGU in PCOS.

Ontogeny of the ovary in polycystic ovary syndrome

Activation of primordial follicles into the growing pool, selection of the dominant follicle, and its eventual ovulation require complex endocrine and metabolic interactions as well as intraovarian paracrine signals to coordinate granulosa cell proliferation, theca cell differentiation, and oocyte maturation. Early preantral follicle development relies mostly upon mesenchymal-epithelial cell interactions, intraovarian paracrine signals, and oocyte-secreted factors, whereas development of the antral follicle depends on circulating gonadotropins as well as locally derived regulators. In women with polycystic ovary syndrome (PCOS), ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and altered intrafollicular paracrine signaling perturb the activation, survival, growth, and selection of follicles, causing accumulation of small antral follicles within the periphery of the ovary, giving it a polycystic morphology. Altered adipocyte-ovarian interactions further compound these adverse events on follicle development and also can harm the oocyte, particularly in the presence of increased adiposity. Finally, endocrine antecedents of PCOS occur in female infants born to mothers with PCOS, which suggests that interactions between genes and the maternal-fetal hormonal environment may program ovarian function after birth.

Abnormal expression of genes involved in inflammation, lipid metabolism, and Wnt signaling in the adipose tissue of polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women.

OBJECTIVE

Our objective was to compare gene expression pattern in sc abdominal adipose tissue in nonobese PCOS patients vs. body mass index-matched controls.

RESEARCH DESIGN AND METHODS

Eleven PCOS subjects and 12 controls (body mass index 20-28 kg/m(2)) were recruited. Total RNA was isolated, and gene expression profiling was performed using Affymetrix Human Genome U133 arrays. Differentially expressed genes were classified by gene ontology. Microarray results for selected genes were confirmed by quantitative real-time PCR (RT-qPCR). Frequently sampled iv glucose tolerance tests were used to assess dynamic insulin sensitivity.

RESULTS

Ninety-six genes were identified with altered expression of at least 2-fold in nonobese PCOS adipose tissues. Inflammatory response genes were significantly down-regulated. RT-qPCR confirmed decreases in expression of IL6 (12.3-fold), CXCL2 (18.3-fold), and SOCS3 (22.6-fold). Lipid metabolism genes associated with insulin resistance were significantly up-regulated, with confirmed increases in DHRS9 (2.5-fold), UCLH1 (2.6-fold), and FADS1 (2.8-fold) expression. Wnt signaling genes (DKK2, JUN, and FOSB) were differentially expressed. RT-qPCR confirmed significant expression changes in DKK2 (1.9-fold increase), JUN (4.1-fold decrease), and FOSB (60-fold decrease).

CONCLUSIONS

Genes involved in inflammation, lipid metabolism, and Wnt signaling are differentially expressed in nonobese PCOS adipose tissue. Because these genes are known to affect adipogenesis and insulin resistance, we hypothesize that their dysregulation may contribute to the metabolic abnormalities observed in women with PCOS.

Polycystic ovary syndrome: etiology, pathogenesis and diagnosis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age, with a prevalence of up to 10%. Various diagnostic criteria have been proposed, generally centered around the features of hyperandrogenism and/or hyperandrogenemia, oligo-ovulation and polycystic ovarian morphology. Insulin resistance is present in a majority of cases, with compensatory hyperinsulinemia contributing to hyperandrogenism via stimulation of ovarian androgen secretion and inhibition of hepatic sex hormone-binding globulin production. Adipose tissue dysfunction has been implicated as a contributor to the insulin resistance observed in PCOS. Environmental and genetic factors also have a role in the development of PCOS. The syndrome is associated with numerous morbidities, including infertility, obstetrical complications, type 2 diabetes mellitus, cardiovascular disease, and mood and eating disorders. Despite these morbidities, PCOS may be common in our society owing to evolutionary advantages of the syndrome in ancient times, including smaller family sizes, reduced exposure to childbirth-related mortality, increased muscle mass and greater capacity to store energy. The diagnosis of PCOS hinges on establishing key features while ruling out other hyperandrogenic or oligo-ovulatory disorders. Treatment is focused on the goals of ameliorating hyperandrogenic symptoms, inducing ovulation and preventing cardiometabolic complications.

Eicosapentaenoic acid prevents and reverses insulin resistance in high-fat diet-induced obese mice via modulation of adipose tissue inflammation

We investigated the effects of eicosapentaenoic acid (EPA) on prevention (P) and reversal (R) of high saturated-fat (HF) diet-induced obesity and glucose-insulin homeostasis. Male C57BL/6J mice were fed low-fat (LF; 10% energy from fat), HF (45% energy from fat), or a HF-EPA-P (45% energy from fat; 36 g/kg EPA) diet for 11 wk. A 4th group was initially fed HF for 6 wk followed by the HF-EPA-R diet for 5 wk. As expected, mice fed the HF diet developed obesity and glucose intolerance. In contrast, mice fed the HF-EPA-P diet maintained normal glucose tolerance despite weight gain compared with the LF group. Whereas the HF group developed hyperglycemia and hyperinsulinemia, both HF-EPA groups (P and R) exhibited normal glycemia and insulinemia. Further, plasma adiponectin concentration was lower in the HF group but was comparable in the LF and HF-EPA groups, suggesting a role of EPA in preventing and improving insulin resistance induced by HF feeding. Further analysis of adipose tissue adipokine levels and proteomic studies in cultured adipocytes indicated that dietary EPA supplementation of HF diets was associated with reduced adipose inflammation and lipogenesis and elevated markers of fatty acid oxidation. In C57BL/6J mice, EPA minimized saturated fat-induced insulin resistance and this is in part mediated by its effects on fatty acid oxidation and inflammation.