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

Endocrinology ◽  
2017 ◽  
Vol 158 (9) ◽  
pp. 2988-3003 ◽  
Author(s):  
Danalea V Skarra ◽  
Angelina Hernández-Carretero ◽  
Alissa J Rivera ◽  
Arya R Anvar ◽  
Varykina G Thackray

Abstract 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.

Author(s):  
Christine U. Lee ◽  
James F. Glockner

28-year-old woman with secondary amenorrhea and hirsutism Axial fat-suppressed 2D SSFP images (Figure 11.1.1) demonstrate multiple follicles arranged in the periphery of the ovaries bilaterally. Polycystic ovary syndrome PCOS is the most common endocrine disorder in women of reproductive age, affecting between 6% and 15%, depending on the criteria used for diagnosis. It typically presents with anovulatory or oligo-ovulatory menstrual cycles leading to oligomenorrhea, polycystic ovaries, and clinical and biochemical hyperandrogenism. PCOS is also associated with increased risk of obesity, insulin resistance, diabetes mellitus, metabolic syndrome, and infertility....


2007 ◽  
Vol 92 (11) ◽  
pp. 4191-4198 ◽  
Author(s):  
Margrit Urbanek ◽  
Susan Sam ◽  
Richard S. Legro ◽  
Andrea Dunaif

Abstract Context: Polycystic ovary syndrome (PCOS), the most common reproductive endocrine disorder of premenopausal women, is also associated with metabolic abnormalities including insulin resistance and an increased risk for diabetes mellitus. We previously mapped a PCOS susceptibility locus to chromosome 19p13.2 near the dinucleotide repeat marker D19S884. Objective: Our objective is to localize the chromosome 19p13.2 PCOS susceptibility locus and determine its impact on metabolic features of PCOS. Design: Resequencing and family-based association testing were used to examine the effect of sequence variation within 100 kb of D19S884 on the reproductive and metabolic phenotypes of PCOS. Setting: The study was conducted in an academic medical center. Subjects: Genetic analyses were performed on DNA obtained from1723 individuals in 412 families with 412 index cases and 43 affected sisters of predominantly European origin (>94%). Genotype-phenotype associations were assessed in 601 women with PCOS and 168 brothers of affected women. Results: D19S884 allele 8 (A8) within intron 55 of the fibrillin-3 (FBN3) gene showed the strongest evidence for association with PCOS of 53 variants tested (Pcorrected = 0.0037). A8 was also associated with higher levels of fasting insulin and homeostasis model assessment for insulin resistance in women with PCOS and higher fasting levels of proinsulin and proinsulin/insulin ratio in brothers. Conclusions: These findings strongly suggest that A8 of D19S884 is the chromosome 19p13.2 PCOS susceptibility locus. The association of D19S884 with markers of insulin resistance and pancreatic β-cell dysfunction suggests that the same variant contributes to the reproductive and metabolic abnormalities of PCOS in affected women and their brothers.


2019 ◽  
Vol 17 (6) ◽  
pp. 595-603 ◽  
Author(s):  
Sezcan Mumusoglu ◽  
Bulent Okan Yildiz

The metabolic syndrome (MetS) comprises individual components including central obesity, insulin resistance, dyslipidaemia and hypertension and it is associated with an increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). The menopause per se increases the incidence of MetS in aging women. The effect(s) of menopause on individual components of MetS include: i) increasing central obesity with changes in the fat tissue distribution, ii) potential increase in insulin resistance, iii) changes in serum lipid concentrations, which seem to be associated with increasing weight rather than menopause itself, and, iv) an association between menopause and hypertension, although available data are inconclusive. With regard to the consequences of MetS during menopause, there is no consistent data supporting a causal relationship between menopause and CVD. However, concomitant MetS during menopause appears to increase the risk of CVD. Furthermore, despite the data supporting the association between early menopause and increased risk of T2DM, the association between natural menopause itself and risk of T2DM is not evident. However, the presence and the severity of MetS appears to be associated with an increased risk of T2DM. Although the mechanism is not clear, surgical menopause is strongly linked with a higher incidence of MetS. Interestingly, women with polycystic ovary syndrome (PCOS) have an increased risk of MetS during their reproductive years; however, with menopausal transition, the risk of MetS becomes similar to that of non-PCOS women.


2018 ◽  
Vol 96 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Hanin Aburasayn ◽  
Rami Al Batran ◽  
Keshav Gopal ◽  
Malak Almutairi ◽  
Amina Eshreif ◽  
...  

The percentage of women who are obese at the time of conception or during pregnancy is increasing, with animal and human studies demonstrating that offspring born to obese dams or mothers are at increased risk for obesity and the metabolic syndrome. Our goal was to confirm in an experimental model of metabolic syndrome in the dam, whether the offspring would be at increased risk of obesity. Conversely, we observed that male offspring born to dams with metabolic syndrome had no alterations in their body mass profiles, whereas female offspring born to dams with metabolic syndrome were heavier at weaning, but exhibited no perturbations in energy metabolism. Moreover, they gained weight at a reduced rate versus female offspring born to healthy dams, and thus weighed less at study completion. Hence, our findings suggest that factors other than increased adiposity and insulin resistance during pregnancy are responsible for the increased risk of obesity in children born to obese mothers.


Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4071-4080 ◽  
Author(s):  
Amanda Hurliman ◽  
Jennifer Keller Brown ◽  
Nicole Maille ◽  
Maurizio Mandala ◽  
Peter Casson ◽  
...  

This study was designed to differentiate the contributions of hyperandrogenism, insulin resistance (IR), and body weight to the development of endothelial dysfunction in polycystic ovary syndrome and determine the effectiveness of insulin sensitization and antiandrogenic therapy after the establishment of vascular and metabolic dysfunction using a rat model of polycystic ovary syndrome. We hypothesized that the observed endothelial dysfunction was a direct steroidal effect, as opposed to changes in insulin sensitivity or body weight. Prepubertal female rats were randomized to the implantation of a pellet containing DHT or sham procedure. In phase 1, DHT-exposed animals were randomized to pair feeding to prevent weight gain or metformin, an insulin-sensitizing agent, from 5 to 14 weeks. In phase 2, DHT-exposed animals were randomized to treatment with metformin or flutamide, a nonsteroidal androgen receptor blocker from 12 to 16 weeks. Endothelial function was assessed by the vasodilatory response of preconstricted arteries to acetylcholine. Serum steroid levels were analyzed in phase 1 animals. Fasting blood glucose and plasma insulin were analyzed and homeostasis model assessment index calculated in all animals. Our data confirm the presence of endothelial dysfunction as well as increased body weight, hypertension, hyperinsulinemia, and greater IR among DHT-treated animals. Even when normal weight was maintained through pair feeding, endothelial dysfunction, hyperinsulinemia, and IR still developed. Furthermore, despite weight gain, treatment with metformin and flutamide improved insulin sensitivity and blood pressure and restored normal endothelial function. Therefore, the observed endothelial dysfunction is most likely a direct result of hyperandrogenism-induced reductions in insulin sensitivity, as opposed to weight gain.


2010 ◽  
Vol 207 (2) ◽  
pp. 213-223 ◽  
Author(s):  
Alison V Roland ◽  
Craig S Nunemaker ◽  
Susanna R Keller ◽  
Suzanne M Moenter

Polycystic ovary syndrome (PCOS) is a common fertility disorder with metabolic sequelae. Our laboratory previously characterized reproductive phenotypes in a prenatally androgenized (PNA) mouse model for PCOS. PNA mice exhibited elevated testosterone and LH levels, irregular estrous cycles, and neuroendocrine abnormalities suggesting increased central drive to the reproductive system. In this study, we examined metabolic characteristics of female PNA mice. PNA mice exhibited increased fasting glucose and impaired glucose tolerance (IGT) that were independent of age and were not associated with changes in body composition or peripheral insulin sensitivity. IGT was associated with defects in pancreatic islet function leading to an impaired response to high glucose, consistent with impaired insulin secretion. Exposure of isolated pancreatic islets to androgen in vitro demonstrated an impaired response to glucose stimulation similar to that in PNA mice, suggesting androgens may have activational in addition to organizational effects on pancreatic islet function. PNA mice also exhibited increased size of visceral adipocytes, suggesting androgen-programed differences in adipocyte differentiation and/or function. These studies demonstrate that in addition to causing reproductive axis abnormalities, in utero androgen exposure can induce long-term metabolic alterations in female mice.


2021 ◽  
Vol 27 ◽  
Author(s):  
Jelica Bjekić-Macut ◽  
Tamara Vukašin ◽  
Zelija Velija-Ašimi ◽  
Azra Bureković ◽  
Marija Zdravković ◽  
...  

: Polycystic ovary syndrome (PCOS) is a frequent endocrine disease in women during reproductive period. It is considered a complex metabolic disorder with long-term metabolic, as well as reproductive consequences. Main pathophysiological pathways are related to the increased androgen levels and insulin resistance. Nowadays, genetic origins of PCOS are acknowledged, with numerous genes involved in the pathogenesis of hyperandrogenemia, insulin resistance, inflammation and disturbed folliculogenesis. Rotterdam diagnostic criteria are most widely accepted and four PCOS phenotypes have been recognized. Metabolic abnormalities are more common in phenotypes 1 and 2. Women with classic PCOS are more obese and typically have central type of obesity, more prevalently displaying dyslipidemia, insulin resistance and metabolic syndrome that could be associated with an increased risk of cardiovascular complications during life. Heterogeneity of phenotypes demands an individualized approach in the treatment of women with PCOS. Metabolic therapies involve a lifestyle intervention followed by the introduction of insulin sensitizers including metformin and inositols, glucagon-like peptide 1 receptor agonists (GLP-1 RA), as recently sodium glucose contransporter-2 (SGLT2) inhibitors. Addition of an insulin sensitizer to the standard infertility therapy such as CC improves ovulation and pregnancy rates. Our current review analyzes the contemporary knowledge of PCOS etiology and etiopathogenesis, its cardiometabolic risks and their outcomes, as well as therapeutic advances for women with PCOS.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jiayu Huang ◽  
Lin Liu ◽  
Chunyan Chen ◽  
Ying Gao

Abstract Background Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder, and its pathogenesis is still under debate. Trimethylamine-N-oxide (TMAO) is a small, organic compound generated by the gut microbiome with a hypothesized relation to insulin resistance (IR) and low-grade inflammation in PCOS. By comparing plasma TMAO levels in non-PCOS participants and PCOS patients without hyperandrogenism (HA), we aimed to determine whether plasma TMAO levels correlate with PCOS without HA and to analyze their relationship with low-grade inflammation and IR. Methods A total of 27 PCOS patients without HA and 23 non-PCOS participants were enrolled in this study and subdivided into “nonobese” and “obese” arms for each group. Levels of plasma TMAO were quantified, and basic clinical characteristics and plasma biomarkers of inflammation were assessed. Results First, plasma TMAO levels, insulin levels and homeostatic model assessment of insulin resistance (HOMA-IR) values were higher in PCOS patients without HA, especially in the obese subgroup. Second, the levels of the inflammatory factors interleukin (IL)-17A, IL-18 and interferon gamma (IFN-γ) were significantly increased in obese PCOS patients without HA. Third, plasma TMAO levels were associated with body mass index (BMI) in the normal-weight groups, and the obese groups had higher fasting plasma insulin (FINS) and HOMA-IR values. Finally, logistic regression showed that the plasma levels of TMAO and luteinizing hormone/follicle-stimulating hormone (LH/FSH) were independent predictors of PCOS and indicated an increased risk of PCOS. Conclusions Elevated plasma TMAO levels may be associated with the pathogenesis of PCOS without HA and correlated with increased systemic inflammation. Further studies are needed to determine the suitability of TMAO as a predictive biomarker and to identify possible therapies for PCOS.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vruti Patel ◽  
Guillaume Bidault ◽  
Joseph E. Chambers ◽  
Stefania Carobbio ◽  
Angharad J. T. Everden ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Yi-Fei Sun ◽  
Jie Zhang ◽  
Yue-Ming Xu ◽  
Zi-Yu Cao ◽  
Yi-Zhuo Wang ◽  
...  

BackgroundThe risk of spontaneous abortion in patients with polycystic ovary syndrome (PCOS) undergoing assisted reproductive treatment (ART) is higher than that in patients without PCOS, however, no definitive risk factors have been confirmed to associate with the high spontaneous abortion rate in PCOS patients undergoing ART. This study was performed to assess the impact of relevant risk factors on spontaneous abortion in patients with PCOS. Clinical questions were formulated and organized according to the PICOS principle.MethodsA systematic review and meta-analysis were conducted on all published studies on PCOS and spontaneous abortion in Embase, PubMed, Web of Science and Cochrane Library. Related risk factors included body mass index (BMI), age, insulin resistance (IR), hyperandrogenism, and chromosome aberrations. All patients were diagnosed as PCOS using the Rotterdam criteria. The primary endpoint was miscarriage and live birth rate. Fixed-effect models were used to analyze homogeneous data, and subgroup and sensitivity analyses were performed on heterogeneous data. The source of heterogeneity was evaluated, and the random effect model was used to summarize the heterogeneity.ResultsAmong 1836 retrieved articles, 22 were eligible and included in the analysis with 11182 patients. High BMI (OR = 1.48, 95% CI [1.32, 1.67], MD = 1.35, 95% CI [0.58,2.12]) and insulin resistance (MD = 0.32, 95% CI [0.15, 0.49]) were associated with an increased risk of spontaneous abortion in PCOS patients undergoing ART. Older age (OR = 0.29, 95% CI [0.29, 0.44], MD = 2.01, 95% CI [0.04, 4.18]), embryonic chromosomal aberrations (OR = 0.75, 95%CI [0.31,1.77]), and hyperandrogenism (MD = 0.10, 95% CI [- 0.02, 0.22]) were not associated with the high spontaneous abortion rate in patients with PCOS. A subgroup analysis of BMI showed that there was no statistically significant difference in the effect between overweight and obesity on spontaneous abortion in PCOS patients undergoing ART (OR = 1.34, 95% [0.97, 1.85]).ConclusionHigh BMI and insulin resistance are two risk factors for an increased risk of spontaneous abortion in PCOS patients undergoing ART, and losing weight and mitigating insulin resistance may decrease the spontaneous abortion rate in these patients undergoing ART.


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