Study of Association of Leptin and Insulin Resistance Markers in Patients of PCOS

Effect of Hyperinsulinemia on Leptin and Ghrelin Levels in Polycystic Ovarian Syndrome: A Meta-Analysis

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. Leptin and ghrelin are important markers in PCOS due to their correlation with obesity, insulin resistance, and fertility. There is currently a debate in the literature about whether altered leptin and ghrelin levels in women with PCOS are a result of the disease itself or if they are due to factors such as the hyperinsulinemic state characteristic of PCOS. This meta-analysis aims to assess if insulin levels impact leptin and ghrelin levels in PCOS.  Eight case-control studies assessing the relationship between insulin and leptin, as well as five case-control studies assessing the relationship between insulin and ghrelin, were identified in PubMed. Pearson's correlation coefficient (PCC) and the sample size were extracted, and two meta-analyses were conducted using a random-effects model. Total heterogeneity (I2) with a confidence interval of 95% was then determined. "Leave-one out" diagnostics were calculated for each case. If a study was identified as being significantly influential, the study was removed from the data set, and the trim and fill procedure was applied. Publication bias was assessed using Egger's regression test and rank correlation test.  Our results showed a moderate positive relationship (r=0.56, 95% confidence interval (CI) (0.42, 0.71), with substantial heterogeneity I2=81.35%, 95% CI (25.2799, 88.2451)) between insulin and leptin levels, and a moderate negative relationship (r=-0.33, 95% CI (-0.43, -0.24)), with low heterogeneity (I2=0.00%, 95% CI (0.0000, 80.8159)) between insulin and ghrelin levels. Therefore, there is a significant relationship between insulin and higher leptin and lower ghrelin levels in women with PCOS. Better insulin control may have a positive effect on fertility, appetite, weight, body image, and quality of life in these women. This correlation is likely multifactorial, and further studies are needed to isolate factors influencing these hormones.

A combination of gliclazide and metformin attenuates obesity-induced polycystic ovary syndrome in female Wistar rats

Presently, it is known that the progression of obesity concomitantly leads to polycystic ovary syndrome and infertility. This study aimed to evaluate the potential effects of metformin (M; insulin secretagogues) and gliclazide (G; insulin sensitizer) alone and their combination at different doses to treat obesity-induced PCOS. High high-fat diet was given to all female Wistar rats for nine weeks to induce obesity except for the normal control group which received a normal chow diet. Estradiol valerate (0.8 mg/kg) was also given to all obese rats to induce polycystic ovarian syndrome. After the induction, M (100, 300 mg/kg) and G (5, 10 mg/kg) were given orally either individually or in combination for 28 days. The notable (p < 0.0001) reduction in body weight and blood glucose level was observed in treatment groups in contrast to disease control (DCG). The marked (p < 0.05-0.0001) decrease in hemocylated hemoglobin, serum insulin, cholesterol, triglycerides, and testosterone was observed in treated groups, notably in combination groups (M100+G10 mg/kg) in contrast to DCG. There was a considerable (p < 0.01-0.0001) increase in progesterone E2, estradiol, luteinizing, and follicle-stimulating hormones in treated groups as compared to DCG. Treatment with M and G treated groups also exhibited marked (p < 0.05-0.0001) increases in SOD, CAT, and GSH while decreased in NO and MDA levels in ovary tissue as evidenced by the histological study of the ovary. Treatment with M and G alone and in combination significantly (p < 0.0001) restored the serum IL-6, NrF2, and NF-κB levels as compared to DCG. The results inveterate that the M and G combination (M100+G10, and M300+G10) was useful in treating obesity-induced infertility due to antioxidant properties, hypolipidemic effects, and modulation of inflammatory markers.

The effects of zinc supplementation on the metabolic factors in patients with non-alcoholic fatty liver disease: a randomized, double-blinded, placebo-controlled clinical trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with metabolic factors including obesity, dyslipidemia, insulin resistance, oxidative stress, and elevated inflammatory factors. Zinc (Zn) supplementation has been investigated as a potential adjunctive therapy in managing NAFLD outcomes.

METHODS

In this randomized, double-blinded, controlled clinical trial, 50 overweight or obese participants with NAFLD were randomized into 2 groups of 25 and received either 30 mg of daily Zn or a placebo for 8 weeks. Both groups were invited to follow a balanced energy-restricted diet and physical activity recommendations.

RESULTS

Based on the between-group comparison, Zn supplementation caused a significant increase in the Zn level (P < 0.001) and a significant decrease in weight (P = 0.004), body mass index (BMI) (P = 0.002), waist circumference (P = 0.010), aspartate transaminase (AST) (P = 0.033), total cholesterol (TC) (P = 0.045), and low-density lipoprotein cholesterol (LDL-C) (P = 0.014), but it had no significant effect on alanine transaminase (ALT), fasting blood sugar (FBS), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), high-density lipoprotein (HDL), triglyceride (TG), high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), and total antioxidant capacity (TAC) (P > 0.05).

CONCLUSION

The results of the present study indicated that 8-week supplementation of 30 mg daily Zn may increase the Zn serum level and decline anthropometric parameters, AST, TC, and LDL-C in NAFLD patients, so further research is suggested in the future.

TRIAL REGISTRATION

The trial was retrospectively registered at IRCT.ir as IRCT20191015045113N1 (December/8/2019).

Effects of eight-week high-intensity interval training on some metabolic, hormonal and cardiovascular indices in women with PCOS: a randomized controlled trail

BACKGROUND

Studies have revealed that high-intensity interval training (HIIT) has beneficial effect on hormonal, cardiovascular indices in women with polycystic ovary syndrome (PCOS). There, however, is still no comprehensive data on the type, intensity and duration of training for these women.

OBJECTIVE

The current study aimed to investigate the effects of high-intensity interval training (HIIT) on metabolic, hormonal and cardiovascular indices in women with PCOS compared to a control group.

METHODS

In a randomized controlled study, 28 patients (age: 23.8 ± 5.3 years, weight: 82.4 ± 9.7 kg, BMI: 30.33 ± 3.99 kg/m²) were divided into two groups including HIIT (n = 14) and the control (n = 14). The training protocol was performed with 100-110 maximum aerobic velocity (MAV), 4-6 sets, 4 laps, 3 sessions per week for eight weeks. Anthropometric indices, aerobic performance, insulin resistance and sensitivity, lipid profiles, testosterone, cortisol and hs-CRP were evaluated.

RESULTS

The HIIT intervention decreased BMI, waist to hip ratio (WHR), visceral fat, insulin, insulin resistance, low density lipoprotein (LDL), atherogenic index, cholesterol and cortisol (P < 0.05). All variables remained unchanged in the control group (P > 0.05). Except for VAI, FBG, HDL, TG and AIP, the rest of the variables in the training and control groups show a significant difference (P < 0.05).

CONCLUSION

The results of the present study indicate that eight weeks of HIIT has beneficial effects on anthropometric, insulin sensitivity, fat profile, and inflammatory and cardiovascular indices in PCOS patients. It seems that the intensity of HIIT (100-110 MAV) is a determining factor in creating optimal adaptations in PCOS patients.

TRAIL REGISTRATION

IRCT20130812014333N143. Registration date: 22/03/2020. URL: https://en.irct.ir/trial/46295 .

Markers of insulin resistance in Polycystic ovary syndrome women: An update

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, affecting 5%-10% of women of reproductive age. The importance of this syndrome lies in the magnitude of associated comorbidities: infertility, metabolic dysfunction, cardiovascular disease (CVD), plus psychological and oncological complications. Insulin resistance (IR) is a prominent feature of PCOS with a prevalence of 35%-80%. Without adequate management, IR with compensatory hyperinsulinemia contributes directly to reproductive dysfunction in women with PCOS. Furthermore, epidemiological data shows compelling evidence that PCOS is associated with an increased risk of impaired glucose tolerance, gestational diabetes mellitus and type 2 diabetes. In addition, metabolic dysfunction leads to a risk for CVD that increases with aging in women with PCOS. Indeed, the severity of IR in women with PCOS is associated with the amount of abdominal obesity, even in lean women with PCOS. Given these drastic implications, it is important to diagnose and treat insulin resistance as early as possible. Many markers have been proposed. However, quantitative assessment of IR in clinical practice remains a major challenge. The gold standard method for assessing insulin sensitivity is the hyperinsulinemic euglycemic glucose clamp. However, it is not used routinely because of the complexity of its procedure. Consequently, there has been an urgent need for surrogate markers of IR that are more applicable in large population-based epidemiological investigations. Despite this, many of them are either difficult to apply in routine clinical practice or useless for women with PCOS. Considering this difficulty, there is still a need for an accurate marker for easy, early detection and assessment of IR in women with PCOS. This review highlights markers of IR already used in women with PCOS, including new markers recently reported in literature, and it establishes a new classification for these markers.

C-Reactive Protein, Fibrinogen, Leptin, and Adiponectin Levels in Women with Polycystic Ovary Syndrome

Background and Aim

We aimed to compare the levels of clinical, biochemical, hormonal, and metabolic parameters as well as serum CRP, fibrinogen, leptin, and adiponectin in cases with PCOS and control group to investigate whether they play a role in the etiology of the syndrome.

Materials and Methods

The present study included a total of 90 subjects, 45 subjects were diagnosed with PCOS (n = 45) and 45 subjects served as control group (n = 45). Serum CRP, fibrinogen, leptin, and adiponectin levels were analyzed for each subject.

Results

Serum CRP, fibrinogen, and leptin were found to be higher (statistically significant) in the group with PCOS as compared to the control group (p < 0.05). Serum Adiponectin was higher in the control group (statistically significantly) as compared with the patients in the PCOS group (p < 0.05).

Conclusion

CRP and fibrinogen (cardiac risk factor markers) increase in women with PCOS. The levels of leptin which affects metabolism increase, whereas the levels of adiponectin decrease.

Epidemiology, pathogenesis, genetics & management of polycystic ovary syndrome in India

Polycystic ovary syndrome (PCOS) is a common endocrine disorder predominantly affecting women of reproductive age. Clinical manifestations are diverse including hyperandrogenism, anovulation, infertility and increased risk of metabolic diseases besides psychosocial dysfunction. This review provides information on the problem of PCOS in India, its pathophysiology, genetics and an overview of current management options to instigate further research in this field. Prevalence of PCOS in India ranges from 3.7 to 22.5 per cent depending on the population studied and the criteria used for diagnosis. Abnormalities in leptin-adiponectin (adipocyte biology), oxidative stress and autoimmunity are among the mechanisms studied regarding pathogenesis of PCOS. Many candidate gene studies have shown associations with PCOS in various studies. Studies have consistently demonstrated the relationship between the well-known manifestation of hyperandrogenism among Indian PCOS women and the metabolic morbidities including insulin resistance, glucose intolerance and cardiovascular risk. Management of individual components of PCOS can be achieved by medications or surgical methods, though further clarification regarding pathogenesis of PCOS is needed to sharpen our therapeutic armamentarium.

Is there a relationship between PTSD and complicated obesity? A review of the literature

Recent research strongly supports the hypothesis that posttraumatic stress disorder (PTSD) can be accompanied by obesity and related metabolic disturbances. The mechanisms of these associations are however still not well defined, although disturbed functions in the sympathetic-adrenergic nervous system together with the disturbed release of hormones via the endocrine HPA (hypothalamic-pituitary-adrenal) axis apparently play a role. Leptin resistance and ghrelin excesses might contribute to a disturbed hypothalamic function, and also disturb other cerebral functions, leading to dysfunctional reward signaling and uncontrolled appetite combined with a tendency to alcohol abuse. Secondarily, cortisol stimulation will contribute to the development of central obesity which is known to facilitate the development of metabolic syndrome, including slightly increased levels of inflammatory biomarkers such as C-reactive protein and fibrinogen. While previous therapeutic strategies have focused on early psychotherapeutic interventions in PTSD, the present review emphasizes the importance of better therapeutic approaches regarding the somatic correlates of the syndrome. Strict regulation of dietary meals and food composition with minimal intake of sweets and saturated fat, as well as alcohol avoidance, can provide a basic therapeutic framework. A cognitive psychotherapeutic approach with graduated desensitization toward trigging factors, combined with pharmacotherapy, is discussed in the present review.

Associations of serum fetuin-A and oxidative stress parameters with polycystic ovary syndrome

Objective

The aim of this study was to compare serum fetuin-A levels and oxidative stress markers, as indicators of insulin resistance, in women with polycystic ovary syndrome (PCOS) and in healthy controls.

Methods

This prospective case-control study included 46 patients with PCOS and 48 age- and body mass index–matched control women. Levels of serum hormones, fetuin-A, and oxidative stress markers were measured in blood samples taken during the early follicular period from each participant.

Results

Follicle-stimulating hormone (FSH), luteinising hormone (LH), total testosterone levels, and the LH/FSH ratio were found to be significantly higher in women with PCOS than in controls. Serum total antioxidant status, total oxidant status, and oxidative stress index parameters all indicated significantly higher levels of oxidative stress in PCOS patients than in controls. Serum fetuin-A levels, which were analyzed as an indicator of insulin resistance, were higher in the PCOS group than in the control group (210.26±65.06 µg/mL and 182.68±51.20 µg/mL, respectively; p=0.024).

Conclusion

The data obtained from the present study suggest that higher levels of both serum fetuin-A and oxidative stress markers might be related with PCOS.

Serum Levels of Angiopoietin-Like Protein 2 and Obestatin in Iranian Women with Polycystic Ovary Syndrome and Normal Body Mass Index

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disease in women of reproduction age and a major cause of anovulatory infertility. Insulin resistance plays an important role in the development and durability of this disorder. ANGPTL2 is known as an inflammatory mediator derived from adipose tissue that links obesity to systemic insulin resistance, and obestatin has been identified as a hormone associated with insulin resistance that suppresses food reabsorption, inhibits gastric emptying and decreases weight gain. The aim of this study was to evaluate serum levels of ANGPTL2 and obestatin in PCOS women with normal body mass index (BMI). Methods: In this case-control study, 26 PCOS women based on the Rotterdam 2003 diagnostic criteria as the case group and 26 women with normal menstrual cycles as the control group were enrolled. Serum levels of ANGPTL2, obestatin, insulin and other hormone factors related with PCOS were measured by ELISA method and biochemical parameters were measured by an autoanalyzer. Data were analyzed by independent samples-T test, Chi Square, Correlation and a single sample Kolmogrov–Smirnov test using SPSS software, version 16. Results: There were no significant variations in the amount of ANGPTL2, obestatin, cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein, cholesterol, creatinine and dehydroepiandrosterone-sulfate between the two groups. There were significant increases in serum levels of fasting blood sugar (p = 0.01), insulin (p = 0.04), homeostasis model assessments of insulin resistance (p = 0.04), testosterone (p = 0.02), luteinizing hormone (p = 0.004), luteinizing hormone/follicle stimulating hormone (p = 0.006) and prolactin (p = 0.04) in case group compared to the control group. A significant positive correlation was observed between ANGPTL2 and insulin (p = 0.02), HOMA-IR (p = 0.01) and, on the other hand, a significant negative correlation was observed between obestatin and insulin (p = 0.01), HOMA-IR (p = 0.008) in PCOS group. Conclusions: In this study, no significant variations were observed in serum levels of ANGPTL2 and obestatin in PCOS women with normal BMI.

IGF-1R and Leptin Expression Profile and the Effects of Metformin Treatment on Metabolic and Endocrine Parameters in PCOS Mice

We aim to assess the effects of metformin treatment on metabolic and endocrine parameters and genes expression related to the insulin-responsive pathway in polycystic ovary syndrome (PCOS). This study comprises twenty-eight obese mice divided into three metformin-treated groups for seven and twenty days and eight nonobese and nontreated ones. We found a significant decrease in glycemia after metformin treatment at days seven and twenty. However, we did not observe differences in body weight measurement. Histologically, after twenty days we observed follicular development with regression of androgenic effects. Levels of IGF-1R protein expression were low after twenty days of treatment, but LEP proteins showed an overexpression in the ovarian stroma. We assessed the IGF-1R and LEP mRNAs levels; data showed a significant overexpression of LEP after seven days of treatment, while the IGF-1R was downregulated. Metformin therapy seems to exert a beneficial effect on histological and anovulatory features, reducing follicular number and pyknosis formation, possibly involved in the reversion of androgenic stimulus. Expression of IGF-1 and LEPR indicates a relevant role in androgenic features reversion present in PCOS, hormonal equilibrium, body weight regulation, and glucose metabolism, therefore, under phenotype obesity and infertility regulation in this model.

CXC Ligand 5 cytokine serum level in women with polycystic ovary syndrome and normal body mass index: A case-control study

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrine disease and associated with insulin resistance. CXC Ligand 5 (CXCL5) is a new cytokine which is secreted from white adipose tissue during obesity and by blocking insulin signaling pathway inhibits the activity of insulin and promotes insulin resistance.

OBJECTIVE

The aim of this study was to assess serum level of CXCL5 in PCOS women with normal body mass index.

MATERIALS AND METHODS

In this case-control study, 30 PCOS women with normal body mass index as the case group and 30 non-PCOS women as the controls were enrolled. Serum levels of CXCL5, insulin and other hormones factors related with PCOS were measured by ELISA method, also the biochemical parameters were measured by autoanalyzer.

RESULTS

Significant increases in serum insulin concentration, homeostasis model assessments of insulin resistance, luteinizing hormone, luteinizing hormone/follicle-stimulating hormone, fasting blood sugar, testosterone, and prolactin were observed in the case group compared to the controls. were in the serum level of CXCL5, cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol,dehydroepiandrosterone-sulfate, creatinine, and homeostasis model assessment of beta cell function between these two groups.

CONCLUSION

In this study, no significant change was observed in serum concentrations of CXCL5 in PCOS women with normal BMI.

Specific Metabolic Characteristics of Women With Former Gestational Diabetes: the Importance of Adipose Tissue

Women with a positive history of gestational diabetes mellitus (GDM) face a higher risk of developing type 2 diabetes mellitus (T2DM) and metabolic syndrome later in life. The higher risk of these metabolic complications is closely associated with adipose tissue. In this review, the importance of adipose tissue is discussed in relation to GDM, focusing on both the quantity of fat deposits and the metabolic activity of adipose tissue in particular periods of life: neonatal age, childhood, adolescence, and pregnancy followed by nursing. Preventive measures based on body composition and lifestyle habits with special attention to the beneficial effects of breastfeeding are also discussed.

Distinct Response of Fat and Gastrointestinal Tissue to Glucose in Gestational Diabetes Mellitus and Polycystic Ovary Syndrome

Gestational diabetes mellitus (GDM) and polycystic ovary syndrome (PCOS) are distinct pathologies with impaired insulin sensitivity as a common feature. The aim of this study was to evaluate the response of fat tissue adipokines and gastrointestinal incretins to glucose load in patients diagnosed with one of the two disorders and to compare it with healthy controls. Oral glucose tolerance test (oGTT) was performed in 77 lean young women: 22 had positive history of GDM, 19 were PCOS patients, and 36 were healthy controls. Hormones were evaluated in fasting and in 60 min intervals during the 3 h oGTT using Bio-Plex ProHuman Diabetes 10-Plex Assay for C-peptide, ghrelin, GIP, GLP1, glucagon, insulin, leptin, total PAI1, resistin, visfatin and Bio-Plex ProHuman Diabetes Adipsin and Adiponectin Assays (Bio-Rad). Despite lean body composition, both PCOS and GDM women were more insulin resistant than controls. Significant postchallenge differences between the GDM and PCOS groups were observed in secretion of adipsin, leptin, glucagon, visfatin, ghrelin, GIP, and also GLP1 with higher levels in GDM. Conversely, PCOS was associated with the highest resistin, C-peptide, and PAI1 levels. Our data suggest that decreased insulin sensitivity observed in lean women with GDM and PCOS is associated with distinct hormonal response of fat and gastrointestinal tissue to glucose load.

New markers of insulin resistance in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine-metabolic disorder in women of reproductive age. The diagnostic criteria include two out of three features: hyperandrogenism, polycystic ovaries on ultrasound and menstrual irregularities (Rotterdam Criteria 2003). PCOS patients are more vulnerable to develop diabetes, cardiovascular diseases and metabolic syndrome. Insulin resistance (IR) is prevalent in women with PCOS independently of obesity and is critically involved in reproductive and metabolic complications of the syndrome. Several tests have been developed to measure IR, some very reliable but complex like the hyperinsulinemic euglycemic glucose clamp and others less precise but easier and less invasive like HOMA-IR. New markers are needed to reach a more reliable assessment of insulin resistance. To date, several surrogate markers have been proposed in the literature to facilitate and improve the determination of IR. Many new proteins are strongly involved with PCOS physiopathology and IR, such as some adipocytokines (adiponectin, visfatin, vaspin and apelin), copeptin, irisin, PAI-1 and zonulin. Many other proteins have been proposed as potential new markers of IR in PCOS, such as resistin, leptin, RBP4, kisspetin and ghrelin, but their role is still controversial. In this review, we provide a short characterization of these new markers, recently studied as indicators of metabolic state.

Central leptin resistance and hypothalamic inflammation are involved in letrozole-induced polycystic ovary syndrome rats

Accumulating evidence indicates that leptin acts as an important mediator in energy homeostasis and reproduction. Since dysfunction of reproduction and metabolism are major characteristics of polycystic ovarian syndrome (PCOS), the role of leptin in pathogenesis of PCOS needs further research. Many studies have shown that central leptin resistance existed in obesity rats through leptin intracerebroventricular (icv) injection; however, central leptin resistance in PCOS rats has not been reported. This study aimed to investigate whether there was a state of central leptin resistance in PCOS rats, as well as explore the possible association of hypothalamic inflammation with central leptin resistance. First, letrozole was used to induce the PCOS model, 24 h food intake, 24 h body weight changes and the expression of p-STAT3 were determined following leptin or artificial cerebrospinal fluid (aCSF) icv injection in rats. Second, we further evaluated the expressions of IL-1β, IL-6, TNF-α, p-IKKβ, NF-κB, p-NF-κB, IκBα, p-IκBα and SOCS3 in hypothalamus. The results showed that 24 h food intake and body weight were decreased, while the expression of p-STAT3 was increased in control group rats following leptin icv injection compared with aCSF icv injection; however, both of them showed no significant difference in PCOS rats. Furthermore, inflammatory markers were upregulated in the hypothalami of PCOS rats. Taken together, our data indicated that there was a state of chronic low-grade inflammation in hypothalamus which might be the possible mechanism for central leptin resistance in PCOS rats.

Transcription factor‑microRNA synergistic regulatory network revealing the mechanism of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common type of endocrine disorder, affecting 5–11% of women of reproductive age worldwide. Transcription factors (TFs) and microRNAs are considered to have crucial roles in the developmental process of several diseases and have synergistic regulatory actions. However, the effects of TFs and microRNAs, and the patterns of their cooperation in the synergistic regulatory network of PCOS, remain to be elucidated. The present study aimed to determine the possible mechanism of PCOS, based on a TF-microRNA synergistic regulatory network. Initially, the differentially expressed genes (DEGs) in PCOS were identified using microarray data of the GSE34526 dataset. Subsequently, the TFs and microRNAs which regulated the DEGs of PCOS were identified, and a PCOS-associated TF-microRNA synergistic regulatory network was constructed. This network included 195 DEGs, 136 TFs and 283 microRNAs, and the DEGs were regulated by TFs and microRNAs. Based on topological and functional enrichment analyses, SP1, mir-355-5p and JUN were identified as potentially crucial regulators in the development of PCOS and in characterizing the regulatory mechanism. In conclusion, the TF-microRNA synergistic regulatory network constructed in the present study provides novel insight on the molecular mechanism of PCOS in the form of synergistic regulated model.