Enhanced Inflammation without Impairment of Insulin Signaling in the Visceral Adipose Tissue of 5α-Dihydrotestosterone-Induced Animal Model of Polycystic Ovary Syndrome

2017 ◽  
Vol 125 (08) ◽  
pp. 522-529 ◽  
Author(s):  
Danijela Milutinović ◽  
Marina Nikolić ◽  
Nataša Veličković ◽  
Ana Djordjevic ◽  
Biljana Bursać ◽  
...  

AbstractPolycystic ovary syndrome is a heterogeneous endocrine and metabolic disorder associated with abdominal obesity, dyslipidemia and insulin resistance. Since abdominal obesity is characterized by low-grade inflammation, the aim of the study was to investigate whether visceral adipose tissue inflammation linked to abdominal obesity and dyslipidemia could lead to impaired insulin sensitivity in the animal model of polycystic ovary syndrome.Female Wistar rats were treated with nonaromatizable 5α-dihydrotestosterone pellets in order to induce reproductive and metabolic characteristics of polycystic ovary syndrome. Glucose, triglycerides, non-esterified fatty acids and insulin were determined in blood plasma. Visceral adipose tissue inflammation was evaluated by the nuclear factor kappa B intracellular distribution, macrophage migration inhibitory factor protein level, as well as TNFα, IL6 and IL1β mRNA levels. Insulin sensitivity was assessed by intraperitoneal glucose tolerance test and homeostasis model assessment index, and through analysis of insulin signaling pathway in the visceral adipose tissue.Dihydrotestosterone treatment led to increased body weight, abdominal obesity and elevated triglycerides and non-esterified fatty acids, which were accompanied by the activation of nuclear factor kappa B and increase in macrophage migration inhibitory factor, IL6 and IL1β levels in the visceral adipose tissue. In parallel, insulin sensitivity was affected in 5α-dihydrotestosterone-treated animals only at the systemic and not at the level of visceral adipose tissue.The results showed that abdominal obesity and dyslipidemia in the animal model of polycystic ovary syndrome were accompanied with low-grade inflammation in the visceral adipose tissue. However, these metabolic disturbances did not result in decreased tissue insulin sensitivity.

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2494
Author(s):  
Małgorzata Kałużna ◽  
Magdalena Czlapka-Matyasik ◽  
Aleksandra Bykowska-Derda ◽  
Jerzy Moczko ◽  
Marek Ruchala ◽  
...  

Visceral adipose tissue (VAT) accumulation, is a part of a polycystic ovary syndrome (PCOS) phenotype. Dual-energy x-ray absorptiometry (DXA) provides a gold standard measurement of VAT. This study aimed to compare ten different indirect methods of VAT estimation in PCOS women. The study included 154 PCOS and 68 age- and BMI-matched control women. Subjects were divided into age groups: 18–30 y.o. and 30–40 y.o. Analysis included: body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist/height 0.5 (WHT.5R), visceral adipose index (VAI), lipid accumulation product (LAP), and fat mass index (FMI). VAT accumulation, android-to-gynoid ratio (A/G), and total body fat (TBF) was measured by DXA. ROC analysis revealed that WHtR, WHT.5R, WC, BMI, and LAP demonstrated the highest predictive value in identifying VAT in the PCOS group. Lower cut-off values of BMI (23.43 kg/m2) and WHtR (0.45) were determined in the younger PCOS group and higher thresholds of WHtR (0.52) in the older PCOS group than commonly used. Measuring either: WHtR, WHT.5R, WC, BMI, or LAP, could help identify a subgroup of PCOS patients at high cardiometabolic risk. The current observations reinforce the importance of using special cut-offs to identify VAT, dependent on age and PCOS presence.


2017 ◽  
Vol 59 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Signe Frøssing ◽  
Malin Chatarina Nylander ◽  
Elizaveta Chabanova ◽  
Caroline Kistorp ◽  
Sven O Skouby ◽  
...  

Background Polycystic ovary syndrome (PCOS) is associated with frequent overweight and abdominal obesity. Quantifying visceral adipose tissue (VAT) in PCOS patients can be a tool to assess metabolic risk and monitor effects of treatment. The latest dual-energy X-ray absorptiometry (DXA) technology can measure VAT and subcutaneous adipose tissue (SAT) in a clinical setting. Purpose To compare DXA-measurements of VAT and SAT with the gold standard MRI in women with PCOS. Material and Methods A cross-sectional study of 67 overweight women with PCOS was performed. Measurements of VAT and SAT were performed by DXA in a 5-cm thick transverse slice at the L4/L5 level and by MRI in a 1-cm thick transverse slice at the L3 level. Results Mean (SD) DXA-VAT was 81 (34) cm3, DXA-SAT was 498 (118) cm3, MRI-VAT was 117 (48) cm3, and MRI-SAT was 408 (122) cm3. MRI and DXA measures of VAT (r = 0.82, P < 0.001) and SAT (r = 0.92, P < 0.001) correlated closely, and DXA-VAT was stronger correlated with MRI-VAT than BMI (r = 0.62, P < 0.001) and waist circumference (r = 0.60, P < 0.001). DXA-VAT coefficient of variance was 6.7% and inter correlation coefficient was 0.98. Bland–Altman analyses showed DXA to slightly underestimate VAT and SAT measurements compared with MRI. Conclusion DXA and MRI measurements of VAT and SAT correlated closely despite different size of region of interest, and DXA-VAT was superior to waist circumference and BMI in estimating MRI-VAT. DXA showed high reproducibility making it is suitable for repeated measurements in the same individual over time.


2008 ◽  
Vol 159 (6) ◽  
pp. 833-839 ◽  
Author(s):  
Barbara Mlinar ◽  
Marija Pfeifer ◽  
Eda Vrtačnik-Bokal ◽  
Mojca Jensterle ◽  
Janja Marc

ObjectiveIn polycystic ovary syndrome (PCOS), insulin resistance (IR) appears with high prevalence and represents the major cause of cardiometabolic complications. Lipin 1β regulates lipid metabolism and augments insulin sensitivity. The impact of lipin 1β expression in visceral and subcutaneous adipose tissue of PCOS patients on IR was studied for the first time.MethodsEighty-five PCOS patients and 44 controls were enrolled for subcutaneous tissue biopsy, of whom 25 patients and 30 controls also underwent visceral adipose tissue biopsy. Gene expression of lipin 1β was measured, together with that of peroxisome proliferator-activated receptor γ, lipoprotein lipase, hormone-sensitive lipase, adiponectin and glucose transporter 4 in subcutaneous and visceral adipose tissue. Markers of obesity, IR and PCOS were also measured.ResultsIn PCOS patients, lipin 1β expression in both adipose depots was lower than in controls: 0.76 (0.67–0.84) vs 1.16 (0.90–1.43) for visceral and 0.91 (0.73–1.10) vs 1.30 (1.03–1.57) for s.c. depot (both P<10−4). The difference remained significant after adjustment for body mass index (BMI) and also when comparing only lean patients with lean controls. In PCOS patients, visceral adipose lipin 1β expression correlated negatively with homeostasis model assessment–IR (r=−0.474, P=0.017), BMI (r=−0.511, P=0.009) and waist circumference (r=−0.473, P=0.017), waist circumference remaining significant (P=0.027) in multiple regression. Subcutaneous lipin 1β expression in PCOS correlated negatively with BMI, waist circumference and plasma triglycerides, and positively with high density lipoprotein-cholesterol. Subcutaneous, but not visceral lipin 1β expression, correlated positively with the studied genes.ConclusionsLipin 1β appears to be involved in the pathogenesis of IR in PCOS.


2014 ◽  
Vol 99 (11) ◽  
pp. E2244-E2251 ◽  
Author(s):  
Frank González ◽  
Chang Ling Sia ◽  
Marguerite K. Shepard ◽  
Neal S. Rote ◽  
Judi Minium

Context: Excess adipose tissue is a source of inflammation. Polycystic ovary syndrome (PCOS) is a proinflammatory state and is often associated with excess abdominal adiposity (AA) alone and/or frank obesity. Objective: To determine the effect of glucose ingestion on cytokine release from mononuclear cells (MNC) in women with PCOS with and without excess AA and/or obesity. Design: A cross-sectional study. Setting: Academic medical center. Patients: Twenty-three women with PCOS (seven normal weight with normal AA, eight normal weight with excess AA, eight obese) and 24 ovulatory controls (eight normal weight with normal AA, eight normal weight with excess AA, eight obese). Intervention: Three-hour 75-g oral glucose tolerance test (OGTT). Main Outcome Measures: Body composition was measured by dual energy x-ray absorptiometry. Insulin sensitivity was derived from the OGTT (ISOGTT). TNFα, IL-6, and IL-1β release was measured in supernatants of cultured MNC isolated from blood samples drawn while fasting and 2 hours after glucose ingestion. Results: Insulin sensitivity was lower in obese subjects regardless of PCOS status and in normal-weight women with PCOS compared with normal-weight controls regardless of body composition status. In response to glucose ingestion, MNC-derived TNFα, IL-6, and IL-1β release decreased in both normal-weight control groups but failed to suppress in either normal-weight PCOS group and in obese women regardless of PCOS status. For the combined groups, the cytokine responses were negatively correlated with insulin sensitivity and positively correlated with abdominal fat and androgens. Conclusions: Women with PCOS fail to suppress MNC-derived cytokine release in response to glucose ingestion, and this response is independent of excess adiposity. Nevertheless, a similar response is also a feature of obesity per se. Circulating MNC and excess adipose tissue are separate and distinct sources of inflammation in this population.


Reproduction ◽  
2015 ◽  
Vol 149 (5) ◽  
pp. R219-R227 ◽  
Author(s):  
Poli Mara Spritzer ◽  
Sheila B Lecke ◽  
Fabíola Satler ◽  
Debora M Morsch

Polycystic ovary syndrome (PCOS), a complex condition that affects women of reproductive age, is characterized by ovulatory dysfunction and androgen excess. Women with PCOS present higher prevalence of obesity, central adiposity, and dyslipidemia, and face increased risk of type 2 diabetes. PCOS is closely linked to functional derangements in adipose tissue. Adipocytes seem to be prone to hypertrophy when exposed to androgen excess, as experienced by women with PCOS, and both adipose tissue hypertrophy and hyperandrogenism are related to insulin resistance. Hypertrophic adipocytes are more susceptible to inflammation, apoptosis, fibrosis, and release of free fatty acids. Disturbed secretion of adipokines may also impact the pathophysiology of PCOS through their influence on metabolism and on sex steroid secretion. Chronic low-grade inflammation in PCOS is also related to hyperandrogenism and to the hypertrophy of adipocytes, causing compression phenomena in the stromal vessels, leading to adipose tissue hypoperfusion and altered secretion of cytokines. Lifestyle changes are the first-line intervention for reducing metabolic risks in PCOS and the addition of an insulin-sensitizing drug might be required. Nevertheless, there is not sufficient evidence in favor of any specific pharmacologic therapies to directly oppose inflammation. Further studies are warranted to identify an adipokine that could serve as an indirect marker of adipocyte production in PCOS, representing a reliable sign of metabolic alteration in this syndrome.


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