The relationships of sex hormone-binding globulin, total testosterone, androstenedione and free testosterone with metabolic and reproductive features of polycystic ovary syndrome

Sex hormone-binding globulin as a biomarker for metabolic risk in European women with polycystic ovary syndrome

OBJECTIVE

Sex hormone-binding globulin (SHBG) is suggested to be a biomarker for metabolic disturbances in women with polycystic ovary syndrome (PCOS). Insulin resistance and hyperinsulinemia is common in PCOS patients. Low SHBG increases free testosterone levels, which further induces hyperinsulinemia. There is no established cutoff level for SHBG in PCOS patients. The goal of this study is to examine SHBG as a biomarker for metabolic dysregulation in European women with PCOS in relation to hyperandrogenemia.

METHODS

Retrospective data was collected from the outpatient clinic for menstrual cycle disorders at Maastricht University Medical Center+. 208 women were included, aged between 18 and 40 years old. During a one-time visit to the clinic, physical examination and vaginal ultrasound evaluation were performed as well as endocrine evaluation performed after overnight fast. The women were diagnosed with PCOS according to the European Society of Human Reproduction and Embryology (ESHRE) 2018 guideline.

RESULTS

BMI was inversely associated with SHBG (β -0.598, 95% CI [-0.710 to -0.485]) and waist circumference (β -0.604, [-0.715 to -0.492]), even after correction for HOMA-IR and testosterone. A cutoff level <40 nmol/L was significantly, and unfavorably, associated with all metabolic outcomes. Its AUROC was optimal for waist circumference (sensitivity 0.75, specificity 0.82).

CONCLUSIONS

SHBG levels <40 nmol/L are indicative for metabolic dysregulation in European women with PCOS. Waist circumference is an important predictor for SHBG, comparable to BMI. Visceral adiposity might play an important role in the expression of SHBG and etiology of PCOS.

Age and BMI-related changes in hormonal profile in women with polycystic ovary syndrome (PCOS): Association with infertility

OBJECTIVE

The aim of the study was to evaluate age- and body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters)-related changes in hormonal profile in women with PCOS and to compare hormonal changes among women with polycystic ovary syndrome (PCOS) with and without infertility.

METHODS

In this case-control study, conducted from March 2018 to January 2024, we enrolled women with PCOS with infertility (n = 265) and controls (n = 265) matched for age and BMI at the Department of Endocrinological Gynecology in University Hospital, Krakow, Poland. The assessment of anti-Müllerian hormone (AMH) along with hormonal profile including follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), androgens (testosterone, 17-hydroxyprogesterone [17-OHP], dehydroepiandrosterone sulfate [DHEA-S]) as well as sex-hormone binding globulin was performed among these women, after assignment to different age BMI groups.

RESULTS

Women with POCS and infertility showed higher AMH (+42.9%), E2 (+15.9%) and LH (+41.9%) along with increased androgen levels reflected by increased testosterone (+20%), DHEA-S (+28.7%) and lower FSH (-10.3%) in contrary to women without infertility. Younger women (≤25 years) showed higher AMH, LH and androgens levels (total testosterone and DHEA-S) with lower FSH concentration. Women with higher BMI (≥30) had lower AMH together with increased free androgen index (FAI) and decreased sex hormone binding globulin (SHBG).

CONCLUSION

Infertile women with PCOS represent higher AMH together with elevated total testosterone, DHEA-S and FAI levels in contrary to fertile ones. Higher BMI together with older age have a negative impact on AMH in women with PCOS.

The calculated and the rapid equilibrium dialyzed human serum free testosterone by LC-MS/MS and their performances in PCOS diagnosis

OBJECTIVE

To compare the calculated and the rapid equilibrium dialyzed (ED) human serum free testosterone (FT) by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and to explore their performances in polycystic ovary syndrome (PCOS) diagnosis.

METHODS

A rapid ED LC-MS/MS method for serum FT was established and validated for linearity, lower limit of the measuring interval (LLMI), imprecision, trueness, stability, dilution, matrix specificity and carryover. The validated ED LC-MS/MS (ED-FT) was compared with calculated LC-MS/MS method from Vermeulen's formula (cFT) for FT measurement in 139 PCOS patients and 100 healthy controls. The performances of total testosterone (TT), ED-FT and cFT by LC-MS/MS in PCOS diagnosis were investigated with the same cohorts.

RESULTS

The linearity range of ED-FT was 1.74-890 pmol/L, with a LLMI at 1.74 pmol/L. The intra-assay and inter-assay imprecision were < 3.8 % and < 5.9 %. The trueness was acceptable with recoveries of 92.9 %-108.2 %. The equilibrium dialysis time was 4 h. The two FT methods displayed systematic and proportional differences and cFT showed significant positive deviations compared to ED-FT. Receiver operating characteristic curve analysis proved that ED-FT outperformanced in PCOS diagnosis with the an area under the curve at 0.973, sensitivity of 89.93 % and specificity of 96.00 %.

CONCLUSIONS

This study established a rapid, accurate and sensitive ED LC-MS/MS method for serum FT. ED-FT is optimal compared to TT and cFT by LC-MS/MS in PCOS diagnosis.

Pancreastatin inhibitor PSTi8 improves ovarian health in Letrozole-HFD induced PCOS rats by ameliorating metabolic and reproductive parameters

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine and metabolic disorder associated with insulin resistance (IR) and hyperandrogenism. IR plays a crucial role in the etiology of PCOS. An insulin-sensitizing agent like metformin is most commonly used as an off-label drug for the treatment of PCOS. PSTi8 (a pancreastatin inhibitor) is known as a promising therapeutic insulin-sensitizing agent for the treatment of IR in metabolic diseases. Thus, this study evaluates the insulin-sensitizing effects of PSTi8 compared to metformin on IR, hyperandrogenism, ovarian, and metabolic dysfunction in a PCOS model. To induce PCOS, rats were administered letrozole at a dose of 2 mg/kg via oral administration and fed a 60 % high-fat diet. Metformin and PSTi8 lowered serum insulin, testosterone, luteinizing hormone (LH) levels, and the LH/follicle-stimulating hormone ratio in the blood serum and improved steroidogenic gene expression in the PCOS ovaries. Both treatments increased the levels of sex hormone-binding globulin and estrogen hormone. Metformin and PSTi8 restore ovarian and uterine histomorphometry and improve the estrous cycle in PCOS rats. Metformin and PSTi8 treatments also improve blood glucose level and increase insulin sensitivity, inflammation, reactive oxygen species accumulation, lipid parameters, body weight, and fat mass in PCOS rats. This study revealed that PSTi8 is as helpful as metformin in decreasing hyperandrogenism by improving insulin sensitivity, free testosterone level and restoring disturbed reproductive and metabolic parameters in PCOS rats. PSTi8 has potential to serve as a therapeutic molecule for preventing IR induced by a western diet in PCOS.

Sex hormone imbalance and rheumatoid arthritis in American men: a cross-sectional analysis from NHANES 2011-2016

Background

Emerging evidence suggests that sex hormones, particularly testosterone and sex hormone-binding globulin (SHBG), play a critical role in the pathophysiology of Rheumatoid arthritis (RA). However, the precise relationship between these hormonal factors and RA risk in men remains underexplored.

Methods

We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2016. A total of 3,110 male participants were included after excluding those with missing data on testosterone, SHBG, RA, or key covariates. Serum testosterone and SHBG levels were measured, and RA status was determined based on self-reported physician diagnosis. Multivariate logistic regression models were used to assess the association between testosterone, SHBG, and RA. Restricted cubic spline (RCS) regression was applied to explore nonlinear relationships. Subgroup and interaction analyses were performed to assess effect modifications by age, race/ethnicity, body mass index (BMI), hypertension, and poverty-income ratio (PIR).

Results

Of the 3,110 men analyzed, 191 were diagnosed with RA. Low testosterone levels (<300 ng/dL) were significantly associated with increased RA risk (OR = 2.30, 95% CI: 1.65-3.21, p < 0.001), and elevated SHBG levels (>57 nmol/L) were also associated with a higher risk of RA (OR = 1.65, 95% CI: 1.14-2.39, p = 0.008). RCS analysis indicated a nonlinear relationship between testosterone, SHBG, and RA risk, with sharp increases in RA risk at the lower ends of testosterone and SHBG levels. Interaction analyses revealed that age, race/ethnicity, hypertension, and PIR significantly modified the relationship between these hormonal factors and RA, while BMI did not exhibit any significant interaction.

Conclusion

This study provides evidence that low testosterone and high SHBG levels are associated with an increased risk of RA in men. These associations are nonlinear and modified by factors such as age, race/ethnicity, hypertension, and PIR. Our findings highlight the importance of considering hormonal status in RA risk assessment and suggest potential avenues for targeted therapeutic strategies aimed at hormonal regulation.

Hyperandrogenism and anthropometric parameters in women with polycystic ovary syndrome

OBJECTIVE

One of the main features of polycystic ovary syndrome (PCOS) is increased adipose tissue, which can result in hormonal disturbances. In the present study, we aimed to investigate which indicator of obesity could better associate with hormonal disturbances in PCOS women.

METHODS

In this cross-sectional analysis, women with PCOS were included according to the Rotterdam criteria. Fasting blood samples were analyzed for biochemical, metabolic, and hormonal parameters. Anthropometric measures comprised body composition indices (assessed by bioelectric impedance analysis [BIA]), waist circumference, body mass index (BMI), and waist-to-height ratio (WHtR). Linear regression modeling was used to assess the association between anthropometric indices and hormonal imbalance, adjusted for age, mensuration status, and the homeostasis model assessment-estimated insulin resistance (HOMA-IR). Receiver operating characteristics (ROC) curves were utilized to ascertain the sensitivity, specificity, and optimal cut-off points of various anthropometric indices in identifying hyperandrogenism.

RESULTS

A total of 129 PCOS women with a median (interquartile range [IQR]) age of 32.0 (23.0-32.0) years and a median BMI of 26.3 (23.00-29.70) kg/m2 were enrolled. In the adjusted linear regression model, BMI (β = 0.053, P < 0.001), waist circumference (β = 0.021, P = 0.001), WHtR (β = 3.325, P = 0.002), total fat mass (β = 0.021, P = 0.002), trunk fat mass (β = 0.038, P = 0.006), and leg fat mass (β = 0.045, P = 0.004) were positively associated with free androgen index (FAI). In addition, BMI (β=-0.017, P = 0.003), waist circumference (β=-0.008, P = 0.002), WHtR (β=-1.167, P = 0.004), total fat mass (β=-0.008, P=0.003), trunk fat mass (β=-0.017, P=0.001), and leg fat mass (β=-0.018, P=0.004) were negatively associated with the serum level of sex hormone binding globulin (SHBG). WHtR showed the greatest area under the curve (AUC) value (AUC = 0.676, P = 0.001) for identifying hyperandrogenism (FAI ≥ 4.97 or total testosterone ≥ 0.7 ng/mL) in PCOS women with corresponding sensitivity of 87.30% and specificity of 39.70%.

CONCLUSIONS

WHtR is related to hyperandrogenism in PCOS better than other anthropometric measures.

Causal relationships between modifiable risk factors and polycystic ovary syndrome: a comprehensive Mendelian randomization study

Background

Polycystic Ovary Syndrome (PCOS) is a heritable condition with an as yet unclear etiology. Various factors, such as genetics, lifestyle, environment, inflammation, insulin resistance, hyperandrogenism, iron metabolism, and gut microbiota, have been proposed as potential contributors to PCOS. Nevertheless, a systematic assessment of modifiable risk factors and their causal effects on PCOS is lacking. This study aims to establish a comprehensive profile of modifiable risk factors for PCOS by utilizing a two-sample Mendelian Randomization (MR) framework.

Methods

After identifying over 400 modifiable risk factors, we employed a two-sample MR approach, including the Inverse Variance Weighted (IVW) method, Weighted Median method, and MR-Egger, to investigate their causal associations with PCOS. The reliability of our estimates underwent rigorous examination through sensitivity analyses, encompassing Cochran's Q test, MR-Egger intercept analysis, leave-one-out analysis, and funnel plots.

Results

We discovered that factors such as smoking per day, smoking initiation, body mass index, basal metabolic rate, waist-to-hip ratio, whole body fat mass, trunk fat mass, overall health rating, docosahexaenoic acid (DHA) (22:6n-3) in blood, monounsaturated fatty acids, other polyunsaturated fatty acids apart from 18:2 in blood, omega-3 fatty acids, ratio of bisallylic groups to double bonds, omega-9 and saturated fatty acids, total lipids in medium VLDL, phospholipids in medium VLDL, phospholipids in very large HDL, triglycerides in very large HDL, the genus Oscillibacter, the genus Alistipes, the genus Ruminiclostridium 9, the class Mollicutes, and the phylum Tenericutes, showed a significant effect on heightening genetic susceptibility of PCOS. In contrast, factors including fasting insulin interaction with body mass index, sex hormone-binding globulin, iron, ferritin, SDF1a, college or university degree, years of schooling, household income, the genus Enterorhabdus, the family Bifidobacteriaceae, the order Bifidobacteriales, the class Actinobacteria, and the phylum Actinobacteria were determined to reduce risk of PCOS.

Conclusion

This study innovatively employs the MR method to assess causal relationships between 400 modifiable risk factors and the susceptibility of PCOS risk. It supports causal links between factors like smoking, BMI, and various blood lipid levels and PCOS. These findings offer novel insights into potential strategies for the management and treatment of PCOS.

Comparing Literature- and Subreddit-Derived Laboratory Values in Polycystic Ovary Syndrome (PCOS): Validation of Clinical Data Posted on PCOS Reddit Forums

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogeneous condition that affects 4% to 21% of people with ovaries. Inaccessibility or dissatisfaction with clinical treatment for PCOS has led to some individuals with the condition discussing their experiences in specialized web-based forums.

OBJECTIVE

This study explores the feasibility of using such web-based forums for clinical research purposes by gathering and analyzing laboratory test results posted in an active PCOS forum, specifically the PCOS subreddit hosted on Reddit.

METHODS

We gathered around 45,000 posts from the PCOS subreddit. A random subset of 5000 posts was manually read, and the presence of laboratory test results was labeled. These labeled posts were used to train a machine learning model to identify which of the remaining posts contained laboratory results. The laboratory results were extracted manually from the identified posts. These self-reported laboratory test results were compared with values in the published literature to assess whether the results were concordant with researcher-published values for PCOS cohorts. A total of 10 papers were chosen to represent published PCOS literature, with selection criteria including the Rotterdam diagnostic criteria for PCOS, a publication date within the last 20 years, and at least 50 participants with PCOS.

RESULTS

Overall, the general trends observed in the laboratory test results from the PCOS web-based forum were consistent with clinically reported PCOS. A number of results, such as follicle stimulating hormone, fasting insulin, and anti-Mullerian hormone, were concordant with published values for patients with PCOS. The high consistency of these results among the literature and when compared to the subreddit suggests that follicle stimulating hormone, fasting insulin, and anti-Mullerian hormone are more consistent across PCOS phenotypes than other test results. Some results, such as testosterone, sex hormone-binding globulin, and homeostasis model assessment-estimated insulin resistance index, were between those of PCOS literature values and normal values, as defined by clinical testing limits. Interestingly, other results, including dehydroepiandrosterone sulfate, luteinizing hormone, and fasting glucose, appeared to be slightly more dysregulated than those reported in the literature.

CONCLUSIONS

The differences between the forum-posted results and those published in the literature may be due to the selection process in clinical studies and the possibility that the forum disproportionally describes PCOS phenotypes that are less likely to be alleviated with medical intervention. However, the degree of concordance in most laboratory test values implied that the PCOS web-based forum participants were representative of research-identified PCOS cohorts. This validation of the PCOS subreddit grants the possibility for more research into the contents of the subreddit and the idea of undertaking similar research using the contents of other medical internet forums.

Androgen signalling in the ovaries and endometrium

Currently, our understanding of hormonal regulation within the female reproductive system is largely based on our knowledge of estrogen and progesterone signalling. However, while the important functions of androgens in male physiology are well known, it is also recognized that androgens play critical roles in the female reproductive system. Further, androgen signalling is altered in a variety of gynaecological conditions, including endometriosis and polycystic ovary syndrome, indicative of regulatory roles in endometrial and ovarian function. Co-regulatory mechanisms exist between different androgens, estrogens, and progesterone, resulting in a complex network of steroid hormone interactions. Evidence from animal knockout studies, in vitro experiments, and human data indicate that androgen receptor expression is cell-specific and menstrual cycle stage-dependent, with important regulatory roles in the menstrual cycle, endometrial biology, and follicular development in the ovaries. This review will discuss the expression and co-regulatory interactions of androgen receptors, highlighting the complexity of the androgen signalling pathway in the endometrium and ovaries, and the synthesis of androgens from additional alternative pathways previously disregarded as male-specific. Moreover, it will illustrate the challenges faced when studying androgens in female biology, and the need for a more in-depth, integrative view of androgen metabolism and signalling in the female reproductive system.

Mechanism of testicular injury induced by Di-ethylhexyl phthalate and its protective agents

Di-ethylhexyl phthalate (DEHP) is used as an important plasticizer in a wide range of products such as paints, food packaging, medical devices and children's toys. In recent years, there has been increasing interest in the toxic effects of DEHP on the male reproductive organs, the testicles. Here, we reviewed the basic pathways of testicular damage caused by DEHP. The mechanism involves oxidative stress, ferroptosis, interfering with hypothalamic-pituitary-gonadal axis (HPGA) and testosterone level. We summarized the protective agents that have been shown to be effective in repairing this type of testicular damage in recent years. This provides a new perspective and direction for future research into the health effects and molecular mechanisms of DEHP.

Assessing the androgenic and metabolic heterogeneity in polycystic ovary syndrome using cluster analysis

INTRODUCTION

Some but not all women with polycystic ovary syndrome (PCOS) develop the metabolic syndrome (MS). The objective of this study was to determine if a subset of women with PCOS had higher androgen levels predisposing them to MS and whether routinely measured hormonal parameters impacted the metabolic syndrome score (siMS).

METHODS

We included data from a discovery (PCOS clinic data) and a replication cohort (Hull PCOS Biobank) and utilized eight routinely measured hormonal parameters in our clinics (free androgen index [FAI], sex hormone-binding globulin, dehydroepiandrosterone sulphate (DHEAS), androstenedione, luteinizing hormone [LH], follicular stimulating hormone, anti-Müllerian hormone and 17 hydroxyprogesterone [17-OHP]) to perform a K-means clustering (an unsupervised machine learning algorithm). We used NbClust Package in R to determine the best number of clusters. We estimated the siMS in each cluster and used regression analysis to evaluate the effect of hormonal parameters on SiMS.

RESULTS

The study consisted of 310 women with PCOS (discovery cohort: n = 199, replication cohort: n = 111). The cluster analysis identified two clusters in both the discovery and replication cohorts. The discovery cohort identified a larger cluster (n = 137) and a smaller cluster (n = 62), with 31% of the study participants. Similarly, the replication cohort identified a larger cluster (n = 74) and a smaller cluster (n = 37) with 33% of the study participants. The smaller cluster in the discovery cohort had significantly higher levels of LH (7.26 vs. 16.1 IU/L, p < .001), FAI (5.21 vs. 9.22, p < .001), androstenedione (3.93 vs. 7.56 nmol/L, p < .001) and 17-OHP (1.59 vs. 3.12 nmol/L, p < .001). These findings were replicated in the replication cohort. The mean (±SD) siMS score was higher in the smaller cluster, 3.1 (±1.1) versus 2.8 (±0.8); however, this was not statistically significant (p = .20). In the regression analysis, higher FAI (β = .05, p = .003) and androstenedione (β = .03, p = .02) were independently associated with a higher risk of SiMS score, while higher DHEAS levels were associated with a lower siMS score (β = -.07, p = .03) CONCLUSION: We identified a subset of women in our PCOS cohort with significantly higher LH, FAI, and androstenedione levels. We show that higher levels of androstenedione and FAI are associated with a higher siMS, while higher DHEAS levels were associated with lower siMS.

Anti-Mullerian Hormone-Based Phenotyping Identifies Subgroups of Women with Polycystic Ovary Syndrome with Differing Clinical and Biochemical Characteristics

Even though polycystic ovary syndrome (PCOS) was originally defined as "amenorrhea associated with bilateral polycystic ovaries", women without PCO morphology can be included in this diagnosis. This may contribute to the clinical heterogeneity seen in PCOS. Serum anti-Mullerian hormone (AMH) correlates with the number of ovarian cysts. We investigated whether phenotyping based on serum AMH can distinguish subgroups of PCOS with different clinical and biochemical characteristics. The electronic medical records of 108 women with PCOS (Rotterdam criteria) were reviewed. The serum AMH value correlated inversely (0.03 < p < 0.0001) with age, weight, and BMI values and directly with serum total testosterone (T), free T, and bioavailable T values. When divided into quartiles based on serum AMH values, the women in the highest quartile (AMH: 18.5 ± 9.9 ng/mL; n = 27) had lower BMI (29.4 ± 6.9 vs. 34.0 ± 10.6-36.7 ± 7.2 kg/m²) but higher total T (51.3 ± 27.2 vs. 26.5 ± 10.4-35.1 ± 16.3 ng/dL), free T (7.7 ± 6.0 vs. 4.4 ± 2.3-5.7 ± 3.2 ng/dL), and bioavailable T (22.1 ± 17.0 vs. 12.2 ± 6.6-16.5 ± 8.7 ng/dL) values. The combination of high AMH and high testosterone values may point to the ovaries and reproductive etiology for PCOS in this subgroup. Thus, AMH-based phenotyping may provide a practical and cost-effective tool to explore the heterogeneity in PCOS.

Nuts and Metabolic Syndrome: Reducing the Burden of Metabolic Syndrome in Menopause

Menopause imposes a dramatic fall in estrogens, which is followed by an increase in the proportion of fat. The rising androgen/estrogen ratio along the menopause transition favors the accumulation of central fat, which contributes to insulin resistance and a series of concatenated effects, leading to a higher incidence of metabolic syndrome. The modulatory effect of diet on the metabolic syndrome phenotype has been shown for the Mediterranean diet, and nuts are key determinants of these health benefits. This review of the impact of nuts on the risk factors of the metabolic syndrome cluster examined studies—prioritizing meta-analyses and systemic reviews—to summarize the potential benefits of nut ingestion on the risk of metabolic syndrome associated with menopause. Nuts have a general composition profile that includes macronutrients, with a high proportion of unsaturated fat, bioactive compounds, and fiber. The mechanisms set in motion by nuts have shown different levels of efficacy against the disturbances associated with metabolic syndrome, but a beneficial impact on lipids and carbohydrate metabolism, and a potential, but minimal reduction in blood pressure and fat accumulation have been found.

Body weight and fat mass across the menopausal transition: hormonal modulators

BACKGROUND

The role of the menopause in weight gain is an understudied yet important field, given the rising prevalence of obesity and its associated risk of disease.

OBJECTIVE

To review the current evidence regarding the impact of the menopausal transition on changes in body composition and fat accrual in women and the hormonal mechanisms underlying the process.

METHODS

A critical appraisal of the current literature by experts in the field.

RESULTS

Menopause is associated with an overall increase in fat mass, which tends to accumulate around the waist. There is also a decrease in lean mass, particularly evident in the lower limbs. Reduced energy expenditure (EE) has been confirmed in parallel with increased food intake, the latter being more evident in experimental models. A prominent role has been found for the estrogen receptor (ER) alpha isoform in fat accrual. Human studies suggest a role for androgens in central fat accumulation and type 2 diabetes. FSH is a key factor in the process of fat accumulation, but only in rodents. Clinical studies suggest that these endocrine alterations are insufficient to explain the observed changes.

CONCLUSIONS

The menopausal transition is associated with an increase in adiposity, which accumulates preferentially in the abdominal area. Hypoestrogenism and the imbalance of the androgen/estrogen ratio are strong candidates to explain the phenomenon, although other hormonal factors probably also play a role. The impact on risk of disease is still insufficiently known, although an association with risk factors, such as an unfavorable lipid profile or insulin resistance seems likely.

A review of the hormones involved in the endocrine dysfunctions of polycystic ovary syndrome and their interactions

Polycystic ovary syndrome (PCOS) affects up to 20% of women but remains poorly understood. It is a heterogeneous condition with many potential comorbidities. This review offers an overview of the dysregulation of the reproductive and metabolic systems associated with PCOS. Review of the literature informed the development of a comprehensive summarizing 'wiring' diagram of PCOS-related features. This review provides a justification for each diagram aspect from the relevant academic literature, and explores the interactions between the hypothalamus, ovarian follicles, adipose tissue, reproductive hormones and other organ systems. The diagram will provide an efficient and useful tool for those researching and treating PCOS to understand the current state of knowledge on the complexity and variability of PCOS.