Evaluation of the Efficacy of Sex Hormone-Binding Globulin in Insulin Resistance Assessment Based on HOMA-IR in Patients with PCOS

Genetically predicted high sex hormone binding globulin was associated with decreased risk of polycystic ovary syndrome

BACKGROUND

Previous observational studies have indicated an inverse correlation between circulating sex hormone binding globulin (SHBG) levels and the incidence of polycystic ovary syndrome (PCOS). Nevertheless, conventional observational studies may be susceptible to bias. Consequently, we conducted a two-sample Mendelian randomization (MR) investigation to delve deeper into the connection between SHBG levels and the risk of PCOS.

METHODS

We employed single-nucleotide polymorphisms (SNPs) linked to serum SHBG levels as instrumental variables (IVs). Genetic associations with PCOS were derived from a meta-analysis of GWAS data. Our primary analytical approach relied on the inverse-variance weighted (IVW) method, complemented by alternative MR techniques, including simple-median, weighted-median, MR-Egger regression, and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) testing. Additionally, sensitivity analyses were conducted to assess the robustness of the association.

RESULTS

We utilized 289 SNPs associated with serum SHBG levels, achieving genome-wide significance, as instrumental variables (IVs). Our MR analyses revealed that genetically predicted elevated circulating SHBG concentrations were linked to a reduced risk of PCOS (odds ratio (OR) = 0.56, 95% confidence interval (CI): 0.39-0.78, P = 8.30 × 10-4) using the IVW method. MR-Egger regression did not detect any directional pleiotropic effects (P intercept = 0.626). Sensitivity analyses, employing alternative MR methods and IV sets, consistently reaffirmed our results, underscoring the robustness of our findings.

CONCLUSIONS

Through a genetic epidemiological approach, we have substantiated prior observational literature, indicating a potential causal inverse relationship between serum SHBG concentrations and PCOS risk. Nevertheless, further research is needed to elucidate the underlying mechanism of SHBG in the development of PCOS.

SHBG Levels Do Not Correlate with Insulin Levels in PCOS with Appropriate Fasting Insulin Sensitivity

Introduction: There are several phenotypes of polycystic ovarian syndrome (PCOS), and the different phenotypes may differ metabolically. Methods: In the present retrospective study, women with PCOS having normal fasting insulin sensitivity (n = 88) were compared with women with PCOS showing impaired insulin sensitivity (n = 46) using the HPCOS (Hungarian Polycystic ovarian syndrome) database. Results: The impaired insulin sensitivity group has significantly higher body mass index (BMI) and HOMA index than the normal fasting insulin sensitivity group (BMI (kg/m2): 22.0 vs. 28.1, p < 0.0001, HOMA index: 0.96 vs. 2.38, p < 0.0001). The sex hormone binding globulin (SHBG) level was significantly lower, and the free androgen index proved itself significantly higher in the impaired insulin sensitivity group (p < 0.05). Linear regression analysis showed a negative association of BMI with SHBG levels in both groups, while BMI had a positive correlation with insulin concentrations in both groups. However, the SHBG levels were negatively associated with insulin concentrations in the impaired insulin sensitivity group, but this inverse association could not be observed in the normal fasting insulin sensitivity group. Conclusions: The inverse linear correlation of SHBG with HOMA index and serum insulin level is not evident in all PCO syndrome phenotypes, thus SHBG has limited applicability for characterizing carbohydrate metabolism and serum insulin sensitivity.

Sex Hormone Binding Globulin is an Independent Predictor for Insulin Resistance in Male Patients with Newly Diagnosed Type 2 Diabetes Mellitus

INTRODUCTION

This study explored the correlation between sex hormones, sex hormone binding globulin (SHBG), and insulin resistance in male patients with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

A total of 48 male patients with newly diagnosed T2DM were enrolled in this study between March 2022 and December 2022. Clinical characteristics, sex hormones, and SHBG levels were collected. All enrolled subjects received intensive hypoglycemic treatment with insulin pump for 1 week to achieve glycemic control, then the steady-state glucose infusion rate (GIR), an indicator of insulin sensitivity, was determined by the hyperinsulinemic-euglycemic clamp. Correlation analysis and multivariate logistic regression analysis were performed to explore the association of clinical characteristics, sex hormones, and SHBG with insulin sensitivity. The optimal cutoff value to predict insulin resistance was calculated using receiver operating characteristic (ROC) curve.

RESULTS

According to the GIR cut-point value of 5.700 mg/(kg min), there were 40 patients with insulin resistance (IR group) and 8 patients without (non-IR group). The IR group exhibited lower testosterone and SHBG levels than the non-IR group (all p < 0.050). Correlation analysis showed that insulin sensitivity was positively associated with testosterone and SHBG, while negatively associated with body mass index, fasting blood glucose, alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride, and apolipoprotein B (all p < 0.050). Multivariate logistic regression analysis demonstrated that SHBG is an independent predictor for insulin resistance (p = 0.029). Further ROC curve analysis revealed that the optimal cutoff value of SHBG to predict insulin resistance is 17.200 nmol/L, with the corresponding area under the curve (AUC) and its 95% confidence interval (CI) being 0.813 and 0.691-0.934.

CONCLUSIONS

SHBG is an independent predictor for insulin resistance in male patients with newly diagnosed T2DM.

TRIAL REGISTRATION NUMBER

KY20220314-01.

Risk factors for insulin resistance related to polycystic ovarian syndrome in Iranian population

Polycystic ovary syndrome (PCOS) has significant metabolic sequelae linked to insulin resistance. This study aimed to compare clinical, metabolic, and hormonal characteristics of PCOS women with and without insulin resistance. The second aim was to compare the clinico-biochemical profiles of the various PCOS phenotypes. In this cross-sectional secondary analysis, we combined the baseline data from two separate randomized controlled trials (RCTs) in women diagnosed with PCOS. PCOS patients were categorized into the four Rotterdam PCOS phenotypes according to the presence of at least two criteria of oligomenorrhea/anovulation (O), hyperandrogenism (H), and polycystic ovary morphology (P): O-H-P, H-P, O-H, and O-P. Participants were categorized into two groups according to the homeostasis model assessment index of insulin resistance (HOMA-IR) levels: < 3.46, and ≥ 3.46. The correlation between the HOMA-IR and biometric, clinical, and biochemical variables was assessed in normal weight (BMI < 25) and overweight/obese (BMI ≥ 25) PCOS women. Then, the association between PCOS phenotypes and insulin resistance was investigated using logistic regression analysis. A total of 125 PCOS patients aged 18-40 years were included in the present study. Based on our results, the HOMA-IR index was positively correlated with diastolic blood pressure, free androgen index, and triglycerides levels; and negatively correlated with sex hormone-binding globulin in overweight/obese PCOS women. In addition, the HOMA-IR index was found to be positively correlated with alanine transaminase and negatively correlated with diastolic blood pressure in normal weight PCOS women. Moreover, individuals with O-H-P phenotype (odds ratio [OR] 2.52, 95% confidence interval [CI] 1.02-6.24) had about two-fold increased risk of insulin resistance. In conclusion, the full-blown PCOS (O-H-P) phenotype has an increased risk of insulin resistance. Accordingly, phenotype division may help physicians to predict adverse metabolic outcomes.

Role of CPXM1 in Impaired Glucose Metabolism and Ovarian Dysfunction in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS), a common female endocrinopathy associated with both reproductive and metabolic disorders, has an unclear etiology and unsatisfactory management methods. Carboxypeptidase X, M14 family member 1 (CPXM1) is a protein involved in follicular atresia, insulin production, and adipose tissue production, though its role in PCOS is not fully understood. We used a 60% high-fat diet (HFD) plus dehydroepiandrosterone (DHEA)-induced PCOS mouse model to determine the role of CPXM1 in abnormal glucose metabolism and ovarian dysfunction in PCOS. We found that serum CPXM1 concentrations were higher in PCOS mice and positively correlated with increased levels of serum testosterone and insulin. In both ovarian and adipose tissues of PCOS mice, CPXM1 mRNA and protein levels were significantly increased but GLUT4 levels were significantly decreased. Immunohistochemistry (IHC) staining of the ovary showed increased CPXM1 expression in PCOS. In addition, the protein expression of phosphorylated protein kinase B (p-Akt) was also significantly decreased in PCOS mice. Furthermore, mRNA levels of inflammatory markers such as TNF-α, IL-6, IFN-α, and IFN-γ were increased in ovarian and adipose tissues of PCOS mice. However, IRS-1, IRS-2, and INSR levels were significantly decreased. Our results indicated for the first time that abnormally high expression of CPXM1, increased adiposity, impaired glucose tolerance, and chronic low-grade inflammation may act together in a vicious cycle in the pathophysiology of PCOS. Our research suggests the possibility of CPXM1 as a potential therapeutic target for the treatment of PCOS.

Insulin resistance in polycystic ovary syndrome across various tissues: an updated review of pathogenesis, evaluation, and treatment

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by chronic ovulation dysfunction and overabundance of androgens; it affects 6-20% of women of reproductive age. PCOS involves various pathophysiological factors, and affected women usually have significant insulin resistance (IR), which is a major cause of PCOS. IR and compensatory hyperinsulinaemia have differing pathogeneses in various tissues, and IR varies among different PCOS phenotypes. Genetic and epigenetic changes, hyperandrogenaemia, and obesity aggravate IR. Insulin sensitization drugs are a new treatment modality for PCOS. We searched PubMed, Google Scholar, Elsevier, and UpToDate databases in this review, and focused on the pathogenesis of IR in women with PCOS and the pathophysiology of IR in various tissues. In addition, the review provides a comprehensive overview of the current progress in the efficacy of insulin sensitization therapy in the management of PCOS, providing the latest evidence for the clinical treatment of women with PCOS and IR.

Alterations of bacteriome, mycobiome and metabolome characteristics in PCOS patients with normal/overweight individuals

To characterize the gut bacteriome, mycobiome and serum metabolome profiles in polycystic ovary syndrome (PCOS) patients with normal/overweight individuals and evaluate a potential microbiota-related diagnostic method development for PCOS, 16S rRNA and ITS2 gene sequencing using 88 fecal samples and 87 metabolome analysis from serum samples are conducted and PCOS classifiers based on multiomics markers are constructed. There are significant bacterial, fungal community and metabolite differences among PCOS patients and healthy volunteers with normal/overweight individuals. Healthy individuals with overweight/obesity display less abnormal metabolism than PCOS patients and uniquely higher abundance of the fungal genus Mortierella. Nine bacterial genera, 4 predicted pathways, 11 fungal genera and top 30 metabolites are screened out which distinguish PCOS from healthy controls, with AUCs of 0.84, 0.64, 0.85 and 1, respectively. The metabolite-derived model is more accurate than the microbe-based model in discriminating normal BMI PCOS (PCOS-LB) from normal BMI healthy (Healthy-LB), PCOS-HB from Healthy-HB. Featured bacteria, fungi, predicted pathways and serum metabolites display higher associations with free androgen index (FAI) in the cooccurrence network. In conclusion, our data reveal that hyperandrogenemia plays a central role in the dysbiosis of intestinal microecology and the change in metabolic status in patients with PCOS and that its effect exceeds the role of BMI. Healthy women with high BMI showed unique microbiota and metabolic features.The priority of predictive models in discriminating PCOS from healthy status in this study were serum metabolites, fungal taxa and bacterial taxa.

The Prevalence of Fallopian Tube Occlusion in Women with Polycystic Ovary Syndrome Seems Similar to Non-Subfertile Women: A Retrospective Cohort Study

There are limited data on how non-infectious risk factors influence tubal patency in women with subfertility. With hormonal shifts influencing tubal secretions, it has been argued that subfertile women with polycystic ovary syndrome (PCOS) have lower tubal patency. In a retrospective study, 216 women, who underwent diagnostic evaluation for PCOS and infertility, were included. Fallopian tube patency was tested using HSG, HyCoSy, and laparoscopic chromopertubation in 171 (79.2%), 28 (13.0%), and 17 (7.9%), respectively. Bilateral patency was found in 193 women (89.4%), unilateral patency in 13 (6.0%) and bilateral occlusion in 10 (4.6%) patients. Women with PCOS phenotypes C (odds ratio, OR 0.179, 95% CI: 0.039–0.828) and D (OR 0.256, 95% CI: 0.069–0.947) demonstrated lower risks for Fallopian tube occlusion. In conclusion, our data suggest that about 5% of infertile women with PCOS also have bilateral tubal occlusion, which seems similar to the rate in non-subfertile women. With 11% of participants having unilateral or bilateral tubal occlusion, this should reassure women with PCOS that their hormonal challenges do not seem to increase their risk for tubal factor subfertility.

Correlation of Serum Visfatin Level in Non-obese Women with Polycystic Ovary Syndrome and Matched Control

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy affecting reproductive-age women. Visfatin, an adipocytokine, and insulin resistance (IR) marker in diabetes since PCOS and diabetes share insulin resistance as an etiological factor, this study aimed to investigate visfatin as a predictive marker for IR and hyperandrogenemia in non-obese PCOS women and test its correlation to other parameters. A cross-sectional study conducted at the University Hospital recruited 140 women, divided into two groups. Group I (70/140, study group) was PCOS patients' diagnosis based on 2003 Rotterdam criteria and Group II (70/140, healthy controls). Both were aged, and body mass index (BMI) matched. After a detailed history and general examination, the clinical, demographic, biochemical, hormonal, and metabolic parameters were taken for comparison's sake. PCOS patients were subdivided according to the clinical or hormonal evidence of hyperandrogenemia into two groups: those with hyperandrogenemia and those without. Higher serum visfatin was estimated in the PCOS group (4.4 ± 1.7) versus healthy controls (3.1 ± 0.7) ng/mL, P < 0.0001. Significantly higher visfatin was confirmed in hyperandrogenic PCOS versus non-hyperandrogenic PCOS women (5.69 ± 1.1 vs. 2.76 ± 0.51 ng/mL). A strong correlation was found between visfatin versus hemoglobin A1c and free androgen index (FAI); r = 0.784 and 0.624, respectively. BMI and free testosterone scored a modest correlation. BMI centiles' correlation with serum visfatin revealed no significant effect on serum visfatin, P = 0.62. The ROC calculated visfatin cut-off value; 4.34 ng/mL with 51.4% sensitivity and 100% specificity, and a P-value < 0.001 in discriminating PCOS cases. In conclusion, a strong positive correlation of visfatin with insulin resistance, followed by FAI in PCOS cases irrespective of BMI, suggests the intimate relation of visfatin in PCOS pathophysiology among non-obese women. Further research is warranted to explore this association's therapeutic and prognostic value.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Evaluation of Triglyceride Glucose Index and Homeostasis Model of Insulin Resistance in Patients with Polycystic Ovary Syndrome

PURPOSE

To use the triglyceride glucose (TyG) index to evaluate insulin resistance (IR) in patients with polycystic ovary syndrome (PCOS) and to explore alternative indicators for early identification of IR.

PATIENTS AND METHODS

This study included 114 patients with PCOS and 61 healthy volunteers. Pearson or Spearman correlations were calculated to compare the association between the TyG index and triglyceride glucose body mass index (TyG-BMI) with homeostatic model assessment for IR (HOMA-IR), homeostasis model assessment for β-cell function (HOMA-β), quantitative insulin sensitivity check index (QUICKI), and fasting glucose-to-insulin ratio (FG-IR). The receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of the TyG index and TyG-BMI in identifying IR (defined as HOMA-IR ≥2.5) in patients with PCOS.

RESULTS

Correlation analyses revealed that the TyG index of the PCOS group was positively correlated with HOMA-IR (r=0.515, P<0.01) and HOMA-β (r=0.348, P<0.01), but negatively correlated with QUICKI (r=-0.532, P<0.01) and FG-IR (r=-0.394, P<0.01). The ROC curve of IR defined by HOMA-IR showed that the AUC value of TyG-BMI was the highest, at 0.796 (95% confidence interval (CI): 0.710-0.866, P<0.001) when the cut-off point was 191.53, with 85.3% sensitivity and 73.9% specificity values. For the TyG index, the AUC was 0.781 (95% CI: 0.693-0.853, P<0.001) when 8.51 was the cut-off point, with a sensitivity of 63.2% and specificity of 87.0%.

CONCLUSION

This study found that the TyG index and TyG-BMI performed better than traditional lipid ratios, such as triglycerides/high density lipoprotein cholesterol (TG/HDL-C), in predicting IR and may be used as markers of IR in Chinese patients with PCOS.