To Assess the Association between Glucose Metabolism and Ectopic Lipid Content in Different Clinical Classifications of PCOS

Anthropometric, Metabolic, and Endocrine Parameters as Predictors of Estimated Average Glucose and Other Biomarkers of Dysglycemia in Women with Different Phenotypes of Polycystic Ovary Syndrome

The aim of the study was to evaluate the efficacy of anthropometric, metabolic, and endocrine abnormalities as predictors of estimated average glucose and other biomarkers of dysglycemia in women with different phenotypes of polycystic ovary syndrome (PCOS). This cross-sectional study included 648 women with PCOS and 330 controls. A single protocol of investigation was applied for all subjects. PCOS women were divided by phenotypes according to the Rotterdam criteria. Biomarkers of dysglycemia were considered dependent variables and anthropometric, lipid, and hormone alterations as independent variables using univariate and multivariate logistic regressions. Univariate logistic regression analysis, controlled for age and BMI, showed that many biomarkers of dysglycemia could be predicted by anthropometric, lipid, and endocrine variables. Multivariate logistic models showed that in non-PCOS women estimated average glucose (eAG) was predicted by lower TSH levels (OR=0.39; p=0.045); fasting glucose was predicted by increased T (OR=2.3). For PCOS, phenotype A, eAG was predicted by decreased HDL-C (OR=0.17, p=0.023) and high levels of free estradiol (OR=7.1, p<0.001). Otherwise, in PCOS, phenotype D, eAG was predicted by higher levels of HDL-C. The current study demonstrated that eAG was poorly predicted by anthropometric, lipid, and hormone parameters. Nevertheless, without adding significant benefits, it was comparable with other established markers of dysglycemia in women with different PCOS phenotypes.

Effect of pharmacological interventions on lipid profiles and C-reactive protein in polycystic ovary syndrome: A systematic review and meta-analysis

CONTEXT

Polycystic ovary syndrome (PCOS) is a heterogeneous condition affecting women of reproductive age. It is associated with dyslipidaemia and elevated plasma C-reactive protein (CRP), which increase the risks of cardiovascular disease (CVD).

OBJECTIVE

To review the existing evidence on the effects of different pharmacological interventions on lipid profiles and CRP of women with PCOS.

DATA SOURCES

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane Library, and Web of Science in April 2020 and updated the results in March 2021.

STUDY SELECTION

The study included randomized controlled trials (RCTs) and follows the 2020 Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

DATA EXTRACTION

Two independent researchers extracted data and assessed for risk of bias using the Cochrane risk of bias tool. Covidence systematic review software were used for blinded screening and study selection.

DATA SYNTHESIS

In 29 RCTs, there were significant reductions in triglycerides with atorvastatin versus placebo [mean difference (MD): -0.21 mmol/L; 95% confidence interval (CI): -0.39, -0.03, I²  = 0%, moderate grade evidence]. Significant reductions were seen for low-density lipoprotein cholesterol (LDL-C) with metformin versus placebo [standardized mean difference (SMD): -0.41; 95% CI: -0.85, 0.02, I²  = 59%, low grade evidence]. Significant reductions were also seen for total cholesterol with saxagliptin versus metformin (MD: -0.15 mmol/L; 95% CI: -0.23, -0.08, I²  = 0%, very low grade evidence). Significant reductions in C-reactive protein (CRP) were seen for atorvastatin versus placebo (MD: -1.51 mmol/L; 95% CI: -3.26 to 0.24, I²  = 75%, very low-grade evidence).

CONCLUSION

There were significant reductions in the lipid parameters when metformin, atorvastatin, saxagliptin, rosiglitazone and pioglitazone were compared with placebo or other agents. There was also a significant reduction of CRP with atorvastatin.

Metabolic syndrome and its components in different phenotypes of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting reproductive-age women. Important factors in its pathogenesis are hyperinsulinaemia and insulin resistance, which lead to higher risk of metabolic syndrome (MetS) and its complications. With the implementation of the Rotterdam diagnostic criteria in 2003, the group of PCOS patients became highly heterogeneous, with varying metabolic risk reported for different phenotypes of the syndrome. The aim of the present review is to assess the prevalence and severity of MetS and its components in patients with the four phenotypes of PCOS. A comprehensive search of Pubmed database was performed to identify studies comparing metabolic characteristics between PCOS patients with different phenotypes of the syndrome. The results of 60 studies published between 2004 and 2020 were retrieved and analysed. More adverse metabolic profile was observed in PCOS patients with hyperandrogenic phenotypes in comparison to normoandrogenic patients, as well as in classic phenotypes, defined by National Institutes of Health criteria, in comparison to newer phenotypes introduced by the Rotterdam criteria. In the majority of observations, normoandrogenic PCOS patients did not differ significantly from controls in terms of metabolic characteristics, although some East Asian studies reported more adverse metabolic profile in normoandrogenic phenotype in comparison to healthy women. In conclusion, metabolic abnormalities in PCOS seem to be associated with joint effects of hyperandrogenism, insulin resistance and visceral obesity. The differences observed between the four phenotypes of PCOS underline the need for individualised diagnostic and therapeutic approach.

Prediction of Gut Microbial Community Structure and Function in Polycystic Ovary Syndrome With High Low-Density Lipoprotein Cholesterol

Gut microbiota has been proved to be involved in the occurrence and development of many diseases, such as type 2 diabetes, obesity, coronary heart disease, etcetera. It provides a new idea for the pathogenesis of polycystic ovary syndrome (PCOS). Our study showed that the gut microbial community of PCOS with high low-density lipoprotein cholesterol (LDLC) has a noticeable imbalance. Gut microbiota of PCOS patients was significantly changed compared with CON, and these changes were closely related to LDLC. Gut microbiota may affect the metabolic level of PCOS patients through multiple metabolic pathways, and lipid metabolism disorder may further aggravate the imbalance of gut microbiota. Actinomycetaceae, Enterobacteriaceae and Streptococcaceae had high accuracy in the diagnosis of PCOS and the differentiation of subgroups, suggesting that they may play an important role in the diagnosis and treatment of PCOS in the future. Also, the model we built showed good specificity and sensitivity for distinguishing PCOS from CON (including L_CON and L_PCOS, H_CON and H_PCOS). In conclusion, this is the first report on the gut microbiota of PCOS with high LDLC, suggesting that in the drug development or treatment of PCOS patients, the difference of gut microbiota in PCOS patients with different LDLC levels should be fully considered.

Dyslipidemia involvement in the development of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is widely accepted as the most common endocrine abnormality in women of childbearing age and may be accompanied by dyslipidemia, hyperandrogenism, hyperinsulinemia, oxidative stress and infertility. Dyslipidemia is now known to play an important role in the development of PCOS. Lipid abnormalities, including elevated low-density lipoprotein and triglyceride levels and reduced high-density lipoprotein levels, are often found in women with PCOS and play an important role in PCOS; therefore, we summarize the effect of lipid abnormalities on hyperandrogenism, insulin resistance, oxidative stress and infertility in PCOS and review the effects of common lipid-lowering drugs on patients with PCOS. The purpose of this article is to elucidate the mechanisms of lipid metabolism abnormalities in the development of PCOS.

Glucagon-like peptide 1 (GLP-1) drives postprandial hyperinsulinemic hypoglycemia in pregnant women with a history of Roux-en-Y gastric bypass operation

BACKGROUND

The influential role of incretin hormones on glucose metabolism in patients with a history of Roux-en-Y gastric bypass (RYGB) has been investigated thoroughly, but there has been little examination of the effect of incretins and ectopic lipids on altered glucose profiles, especially severe hypoglycemia in pregnant women with RYGB.

METHODS

In this prospective clinical study, an oral glucose tolerance test (OGTT), an intravenous glucose tolerance test (IVGTT), and continuous glucose monitoring (CGM) were conducted in 25 women with RYGB during pregnancy, 19 of normal weight (NW) and 19 with obesity (OB) between the 24th and the 28th weeks of pregnancy, and 3 to 6 months post-partum. Post-partum, the ectopic lipid content in the liver, heart, and skeletal muscle was analyzed using ¹H-magnetic resonance spectroscopy (¹H-MRS).

RESULTS

RYGB patients presented with major fluctuations in glucose profiles, including a high occurrence of postprandial hyperglycemic spikes and hypoglycemic events during the day, as well as a high risk of hypoglycemic periods during the night (2.9 ± 1.1% vs. 0.1 ± 0.2% in the OB and vs. 0.8 ± 0.6% in the NW groups, p < 0.001). During the extended OGTT, RYGB patients presented with exaggerated expression of GLP-1, which was the main driver of the exaggerated risk of postprandial hypoglycemia in a time-lagged correlation analysis. Basal and dynamic GLP-1 levels were not related to insulin sensitivity, insulin secretion, or beta cell function and did not differ between pregnant women with and without GDM. A lower amount of liver fat (2.34 ± 5.22% vs.5.68 ± 4.42%, p = 0.015), which was positively related to insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR: rho = 0.61, p = 0.002) and beta-cell function (insulinogenic index: rho = 0.65, p = 0.001), was observed in the RYGB group after delivery in comparison to the OB group.

CONCLUSION

GLP-1 is mainly involved in the regulation of postprandial glucose metabolism and therefore especially in the development of postprandial hypoglycemia in pregnant RYGB patients, who are characterized by major alterations in glucose profiles, and thus in long-term regulation, multiple organ-related mechanisms, such as the lipid content in the liver, must be involved.

Identification of Potential Biomarkers for Urine Metabolomics of Polycystic Ovary Syndrome Based on Gas Chromatography-Mass Spectrometry

Background:

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder, and it's diagnosis is difficult. The aim of this study was to investigate the metabolic profiles of PCOS patients by analyzing urine samples and identify useful biomarkers for diagnosis of PCOS.

Methods:

This study was carried out in the Department of Obstetrics and Gynecology of the Maternal and Child Health Hospital of Hunan Province from December 2014 to July 2016. In this study, the urine samples of 21 women with PCOS and 16 healthy controls were assessed through gas chromatography-mass spectrometry to investigate the urine metabolite characteristics of PCOS and identify useful biomarkers for the diagnosis of this disorder. The Student's t-test and rank sum test were applied to validate the statistical significance of the between the two groups.

Results:

In total, 35 urine metabolites were found to be significantly different between the PCOS patients and the controls. In particular, a significant increase in the levels of lactose (10.01 [0,13.99] mmol/mol creatinine vs. 2.35 [0.16, 3.26] mmol/mol creatinine, P = 0.042), stearic acid (2.35 [1.47, 3.14] mmol/mol creatinine vs. 0.05 [0, 0.14] mmol/mol creatinine, P < 0.001), and palmitic acid (2.13 [1.07, 2.79] mmol/mol creatinine vs. 0 [0, 0] mmol/mol creatinine, P < 0.001) and a decrease in the levels of succinic acid (0 [0, 0] mmol/mol creatinine vs. 38.94 [4.16, 51.30] mmol/mol creatinine, P < 0.001) were found in the PCOS patients compared with the controls. It was possible to cluster the PCOS patients and the healthy controls into two distinct regions based on a principal component analysis model. Of the differentially expressed metabolites, four compounds, including stearic acid, palmitic acid, benzoylglycine, and threonine, were selected as potential biomarkers.

Conclusions:

This study offers new insight into the pathogenesis of PCOS, and the discriminating urine metabolites may provide a prospect for the diagnosis of PCOS.

New insights into the genic and metabolic characteristics of induced pluripotent stem cells from polycystic ovary syndrome women

Background

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder that affects female fertility. However, with the lack of a corresponding research model, the pathology mechanism of PCOS is poorly understood. Induced pluripotent stem cell (iPSC) technology has been recognized as means to generate patient-specific stem cells for disease modeling.

Methods

The mRNA abundance of iPSCs was analyzed by RNA microarray and real-time polymerase chain reaction (RT-PCR). Karyotyping of iPSCs was performed with cytogenetic analysis. The mitochondrial respiration ability and glycolytic function were measured by the Seahorse Bioscience XF extracellular flux analyzer. The expression of iPSC-associated markers was identified by immunofluorescence and RT-PCR. The teratoma formation of iPSCs was studied using immunochemistry.

Results

A PCOS patient-derived iPSC model was established from somatic cells of PCOS patients. Through comprehensive transcriptional profiling analysis of the RNA microarray, PCOS patient-derived iPSCs showed metabolic abnormalities and mitochondrial dysfunction compared with non-PCOS patient-derived iPSCs in vitro. Specifically, a total of 2904 genes were differentially expressed between the two iPSC populations, of which 1416 genes were upregulated and 1488 genes were downregulated (fold change > 2, p < 0.01). Gene Ontology (GO) term enrichment results showed that upregulated genes were enriched in metabolic processes and mitochondrial activities which participated in the tricarboxylic acid (TCA) cycle, the respiratory electron transport chain (ETC), and glycogenolysis. On the other hand, the downregulated genes were related to cell communication, glucose transport, and uptake. The differentially expressed genes were verified by RT-PCR in PCOS patient-derived iPSCs and granulosa cells from PCOS patients. The PCOS patient-derived iPSCs demonstrated decreased mitochondrial respiration ability and glycolytic function (p < 0.05) but increased mitochondrial copy numbers and biogenesis (p < 0.05). Subsequently, some genes related to glucose metabolism were rescued by treating with metformin in PCOS patient-derived iPSCs. Meanwhile, the ATP production ability of mitochondria and the glycolysis ability of PCOS patient-derived iPSCs also partially returned to normal levels. However, metformin had little effect on mitochondrial maximal respiration ability and maximal glycolytic capacity.

Conclusions

We measured differences in iPSCs from women with and without PCOS in gene transcription and mitochondrial respiratory function. PCOS patient-derived iPSCs showed abnormal expression of metabolic genes and mitochondrial dysfunction in vitro. The study provides a novel cell model in vitro for studying the clinical causes and molecular mechanisms of PCOS.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0950-x) contains supplementary material, which is available to authorized users.

Pericardial Fat Relates to Disturbances of Glucose Metabolism in Women with the Polycystic Ovary Syndrome, but Not in Healthy Control Subjects

OBJECTIVE

The objective of the present study is to investigate the relationship of cardiac fat depots with disturbances of the carbohydrate metabolism in women with PCOS.

METHODS

An oral glucose tolerance test (OGTT) was realized, and metabolic parameters were collected in 48 women with PCOS and in 20 controls. Intramyocardial fat (MYCL) and pericardial fat (PERI) were measured using ¹H-magnetic resonance spectroscopy and imaging.

RESULTS

Only in PCOS women, PERI was positively and independently related to parameters of glucose metabolism (HbA1c: p = 0.001, fasting plasma glucose: p < 0.001, stimulated glucose at 30 and 60 minutes in the OGTT). Thus, the disposition index, insulin sensitivity, and adiponectin also declined with the increase of PERI in women with PCOS; however, these results were not independent of BMI and age. In addition, PERI was positively related to atherogenic lipid profiles, BMI, waist circumference, CRP, and liver fat in women with PCOS. A negative relation of PERI with triglycerides and a positive relation with BMI and waist circumference could be observed in the controls. No relationship of MYCL with diabetes-specific parameters could be found in the study population.

CONCLUSION

PERI is related to metabolic disturbances in women with PCOS, but not in metabolically healthy lean subjects. This clinical trial was registered at ClinicalTrials.gov and has the registration number NCT03204461.

Normalizing Ovulation Rate by Preferential Reduction of Hepato-Visceral Fat in Adolescent Girls With Polycystic Ovary Syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is an increasingly prevalent disorder in adolescent girls, commonly presenting with hirsutism/oligomenorrhea, commonly treated with an oral contraceptive (OC), and commonly followed by oligoanovulatory subfertility. We tested whether an intervention targeting the reduction of hepato-visceral adiposity is followed by a higher ovulation rate than OC treatment.

METHODS

This randomized, open-label, single-center, pilot proof-of-concept study (12 months on treatment, then 12 months off) was performed in adolescent girls with hirsutism and oligomenorrhea (PCOS by National Institutes of Health; no sexual activity; N = 36; mean age 16 years, body mass index 23.5 kg/m²; 94% study completion). Compared treatments were OC (ethinylestradiol-levonorgestrel) versus low-dose combination of spironolactone 50 mg/d, pioglitazone 7.5 mg/d, and metformin 850 mg/d (SPIOMET). Primary outcome was post-treatment ovulation rate inferred from menstrual diaries and salivary progesterone (12 + 12 weeks). Secondary outcomes included body composition (dual X-ray absorptiometry), abdominal fat (magnetic resonance imaging), insulinemia (oral glucose tolerance test), and androgenemia (liquid chromatography - tandem mass spectrometry).

RESULTS

SPIOMET was followed by a 2.5-fold higher ovulation rate than OC (p ≤ .001) and by a 6-fold higher normovulatory fraction (71% vs. 12%; p ≤ .001); oligoanovulation risk after SPIOMET was 65% lower (95% confidence interval, 40%-89%) than after OC. Higher post-treatment ovulation rates related to more on-treatment loss of hepatic fat (r² = .27; p < .005). Visceral fat and insulinemia normalized only with SPIOMET; androgenemia normalized faster with OC but rebounded more thereafter. Body weight, lean mass, and abdominal subcutaneous fat mass remained stable in both groups.

CONCLUSIONS

Early SPIOMET treatment for PCOS normalized post-treatment ovulation rates more than OC. Focusing PCOS treatment on early reduction of hepato-visceral fat may prevent part of later oligoanovulatory subfertility.

Hyperandrogenemia Induced by Letrozole Treatment of Pubertal Female Mice Results in Hyperinsulinemia Prior to Weight Gain and Insulin Resistance

Women with polycystic ovary syndrome (PCOS) diagnosed with hyperandrogenism and ovulatory dysfunction have an increased risk of developing metabolic disorders, including type 2 diabetes and cardiovascular disease. We previously developed a model that uses letrozole to elevate endogenous testosterone levels in female mice. This model has hallmarks of PCOS, including hyperandrogenism, anovulation, and polycystic ovaries, as well as increased abdominal adiposity and glucose intolerance. In the current study, we further characterized the metabolic dysfunction that occurs after letrozole treatment to determine whether this model represents a PCOS-like metabolic phenotype. We focused on whether letrozole treatment results in altered pancreatic or liver function as well as insulin resistance. We also investigated whether hyperinsulinemia occurs secondary to weight gain and insulin resistance in this model or if it can occur independently. Our study demonstrated that letrozole-treated mice developed hyperinsulinemia after 1 week of treatment and without evidence of insulin resistance. After 2 weeks of letrozole treatment, mice became significantly heavier than placebo mice, demonstrating that weight gain was not required to develop hyperinsulinemia. After 5 weeks of letrozole treatment, mice exhibited blunted glucose-stimulated insulin secretion, insulin resistance, and impaired insulin-induced phosphorylation of AKT in skeletal muscle. Moreover, letrozole-treated mice exhibited dyslipidemia after 5 weeks of treatment but no evidence of hepatic disease. Our study demonstrated that the letrozole-induced PCOS mouse model exhibits multiple features of the metabolic dysregulation observed in obese, hyperandrogenic women with PCOS. This model will be useful for mechanistic studies investigating how hyperandrogenemia affects metabolism in females.