The incretin effect and secretion in obese and lean women with polycystic ovary syndrome: a pilot study

The microbial metabolite agmatine acts as an FXR agonist to promote polycystic ovary syndrome in female mice

Polycystic ovary syndrome (PCOS), an endocrine disorder afflicting 6-20% of women of reproductive age globally, has been linked to alterations in the gut microbiome. We previously showed that in PCOS, elevation of Bacteroides vulgatus in the gut microbiome was associated with altered bile acid metabolism. Here we show that B. vulgatus also induces a PCOS-like phenotype in female mice via an alternate mechanism independent of bile acids. We find that B. vulgatus contributes to PCOS-like symptoms through its metabolite agmatine, which is derived from arginine by arginine decarboxylase. Mechanistically, agmatine activates the farnesoid X receptor (FXR) pathway to subsequently inhibit glucagon-like peptide-1 (GLP-1) secretion by L cells, which leads to insulin resistance and ovarian dysfunction. Critically, the GLP-1 receptor agonist liraglutide and the arginine decarboxylase inhibitor difluoromethylarginine ameliorate ovarian dysfunction in a PCOS-like mouse model. These findings reveal that agmatine-FXR-GLP-1 signalling contributes to ovarian dysfunction, presenting a potential therapeutic target for PCOS management.

Therapeutic Potential of Glucagon-like Peptide-1 Agonists in Polycystic Ovary Syndrome: From Current Clinical Evidence to Future Perspectives

Despite the continuous effort to understand the pathophysiology and determine potential therapeutic targets, PCOS treatment largely depends on lifestyle intervention and symptomatic management of individual signs and symptoms. International guidelines recognize the importance of weight reduction as a cornerstone for the achievement of better metabolic, reproductive, and cardiovascular outcomes in PCOS women who are overweight or obese. With its profound weight loss potential in patients with or without diabetes, the administration of GLP-1 receptor agonists has been investigated in overweight/obese women with PCOS in several single-center randomized control trials with considerable variation in the dosing regimen, follow-up duration, and outcome measurements over recent years. Most trials reported superior weight loss effects of GLP-1 receptor agonists compared to lifestyle changes or metformin, with additional metabolic, reproductive, and cardiovascular benefits in this population. However, their use is currently not widely accepted by the clinical community that treats this population. The major concern is how to balance the reproductive and metabolic treatment strategies since the use of GLP-1 receptor agonists requires effective contraception while on therapy and a washout period before pregnancy. Both approaches are not mutually exclusive, yet the best choice requires a careful assessment of the clinical context. Knowing a patient’s individual circumstances, precise clinical sub-phenotyping, and regular monitoring are crucial components for the safe and effective use of these new tools. In the present narrative review, we explore the current clinical evidence and provide the future perspectives and challenges for their implementation in PCOS management.

Loss of the Incretin Effect in Type 2 Diabetes: A Systematic Review and Meta-analysis

CONTEXT

Loss of the incretin effect (IE) in type 2 diabetes (T2D) contributes to hyperglycemia and the mechanisms underlying this impairment are unclear.

OBJECTIVE

To quantify the IE impairment in T2D and to investigate the factors associated with it using a meta-analytic approach.

METHODS

PubMed, Scopus, and Web-of-Science were searched. Studies measuring IE by the gold-standard protocol employing an oral glucose tolerance test (OGTT) and an intravenous glucose infusion at matched glucose levels were selected. We extracted IE, sex, age, body mass index (BMI), and hemoglobin A1c, fasting values, and area under curve (AUC) of glucose, insulin, C-peptide, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1). In subjects with T2D, we also recorded T2D duration, age at diagnosis, and the percentage of subjects taking antidiabetic medications.

RESULTS

The IE weighted mean difference between subjects with T2D and those with normal glucose tolerance (NGT) was -27.3% (CI -36.5% to -18.1%; P < .001; I2 = 86.6%) and was affected by age (P < .005). By meta-regression of combined NGT and T2D data, IE was inversely associated with glucose tolerance (lower IE in T2D), BMI, and fasting GIP (P < .05). By meta-regression of T2D studies only, IE was associated with the OGTT glucose dose (P < .0001). IE from insulin was larger than IE from C-peptide (weighted mean difference 11.2%, CI 9.2-13.2%; P < .0001; I2 = 28.1%); the IE difference was inversely associated with glucose tolerance and fasting glucose.

CONCLUSION

The IE impairment in T2D vs NGT is consistent though considerably variable, age being a possible factor affecting the IE difference. Glucose tolerance, BMI, and fasting GIP are independently associated with IE; in subjects with T2D only, the OGTT dose is a significant covariate.

The Associations Between Serum Concentrations of Irisin and Glucose-dependent Insulinotropic Polypeptide with Body Mass Index Among Women with and Without Polycystic Ovary Syndrome

BACKGROUND

The actions of adipocytokines may be a connective factor between obesity and polycystic ovary syndrome (PCOS). It is suggested that irisin, as recently described cytokine secreted by skeletal muscles and glucose-dependent insulinotropic polypeptide (GIP) as an incretin hormone that induces cytokine expression, may play key roles in favoring obesity in these women.

OBJECTIVES

We aimed to evaluate the association between body mass index (BMI) and serum concentrations of irisin/GIP in women with and without PCOS in the linear and non-linear models.

METHODS

This cross-sectional study was conducted among 159 PCOS and 82 healthy eumenorrheic non-hirsute women aged 20 - 50 years. The fractional-polynomial model was used to develop a model of continuous risk factors, which evaluates non-linear associations between irisin/GIP and BMI among women with and without PCOS.

RESULTS

Women with PCOS were significantly younger (28.2 ± 5.8 vs. 33.0 ± 7.8 years, P < 0.001) and had a greater BMI (26.6 ± 5.2 vs. 25.2 ± 4.8 kg/m², P = 0.04) than the healthy counterparts. There were no significant linear and non-linear associations between serum concentration of irisin/GIP and BMI in both groups. The analysis of pair-wise age and BMI matching of women with PCOS and controls confirmed these findings.

CONCLUSIONS

This study showed that irisin and GIP have no association with BMI in women with or without PCOS. This finding could help to better understand the underlying pathophysiological status of PCOS, insulin resistance, and obesity-related disorders. Further large cohort studies are needed to confirm these findings.

RETRACTED: Whey protein preload enhances the active GLP-1 response and reduces circulating glucose in women with polycystic ovarian syndrome

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The article is a duplicate of a paper that has already been published in Nutrients: (Nutrients 2021, 13(7), 2451. https://doi.org/10.3390/nu13072451. Redundant publications overweigh the relative importance of published findings and distort the academic record of the authors. One of the conditions of submission of a paper for publication is therefore that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents a misuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Liraglutide: New Perspectives for the Treatment of Polycystic Ovary Syndrome

Polycystic ovary syndrome is a complex and heterogenous disorder involving multiple organ systems and different molecular pathways. It is tightly associated with obesity and especially abdominal obesity. As body weight reduction is the main modifiable risk factor for polycystic ovary syndrome, therapeutic approaches in overweight or obese women with polycystic ovary syndrome have been developed. Liraglutide is a glucagon-like peptide-1 receptor agonist that promotes sustained weight loss, as well as abdominal fat reduction, in individuals with obesity, prediabetes, and type 2 diabetes mellitus. The majority of current clinical studies have demonstrated that liraglutide therapy achieved significant reductions in body weight, body mass index, and abdominal circumference in overweight and obese women with polycystic ovary syndrome. Liraglutide therapy promoted significant improvements in free testosterone and sex hormone-binding globulin levels in some studies. Important metabolic and hormonal improvements were also reported after the combination of liraglutide with metformin. Increased menstrual frequency, as well as potential positive effects in reproduction, were described. However, the small number of participants, short duration, and low daily liraglutide dose are some of the main limitations of these studies. Larger and longer, multi-centred, double-blind, placebo-controlled trials of liraglutide monotherapy or combination therapy, with prolonged post-interventional monitoring, are crucially anticipated. Metabolic, hormonal, and reproductive primary outcomes should be uniformly addressed, to tailor future targeted treatment approaches, according to the patient phenotype and needs. This will improve long-term therapeutic outcomes in this population.

Updates on molecular and environmental determinants of luteal progesterone production

Progesterone, a critical hormone in reproduction, is a key sex steroid in the establishment and maintenance of early pregnancy and serves as an intermediary for synthesis of other steroid hormones. Progesterone production from the corpus luteum is a tightly regulated process which is stimulated and maintained by multiple factors, both systemic and local. Multiple regulatory systems, including classic mediators of gonadotropin stimulation such as the cAMP/PKA pathway and TGFβ-mediated signaling pathways, as well as local production of hormonal factors, exist to promote granulosa cell function and physiological fine-tuning of progesterone levels. In this manuscript, we provide an updated narrative review of the known mediators of human luteal progesterone and highlight new observations regarding this important process, focusing on studies published within the last five years. We will also review recent evidence suggesting that this complex system of progesterone production is sensitive to disruption by exogenous environmental chemicals that can mimic or interfere with the activities of endogenous hormones.

Evaluation of the incretin effect in humans using GIP and GLP-1 receptor antagonists

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) potentiate glucose-induced insulin secretion and are therefore thought to be responsible for the incretin effect. The magnitude of the incretin effect, defined as the fraction of postprandial insulin secretion stimulated by intestinal factors, has been reported to be up to ∼60% in healthy individuals. In several pathological conditions but especially in patients with type 2 diabetes, the incretin effect is severely reduced or even absent. In line with this, the insulinotropic effects of GIP and GLP-1 are impaired in patients with type 2 diabetes, even when administered in supraphysiological doses. In healthy individuals, GIP has been proposed to be the most important incretin hormone of the two, but the individual contribution of the two is difficult to determine. However, using incretin hormone receptor antagonists: the novel GIP receptor antagonist GIP(3-30)NH₂ and the widely used GLP-1 receptor antagonist exendin(9-39)NH₂, we can now distinguish between the effects of the two hormones. In this review, we present and discuss studies in which the individual contribution of GIP and GLP-1 to the incretin effect in healthy individuals have been estimated and discuss the limitations of using incretin hormone receptor antagonists.

A review of therapeutic options for managing the metabolic aspects of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. Metabolic sequelae associated with PCOS range from insulin resistance to type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Insulin resistance plays a significant role in the pathophysiology of PCOS and it is a reliable marker for cardiometabolic risk. Although insulin sensitising agents such as metformin have been traditionally used for managing metabolic aspects of PCOS, their efficacy is low in terms of weight reduction and cardiovascular risk reduction compared with newer agents such as incretin mimetics and SGLT2 inhibitors. With current pharmaceutical advances, potential therapeutic options have increased, giving patients and clinicians more choices. Incretin mimetics are a promising therapy with a unique metabolic target that could be used widely in the management of PCOS. Likewise, bariatric procedures have become less invasive and result in effective weight loss and the reversal of metabolic morbidities in some patients. Therefore, surgical treatment targeting weight loss becomes increasingly common in the management of obese women with PCOS. Newer emerging therapies, including twincretins, triple GLP-1 agonists, glucagon receptor antagonists and imeglemin, are promising therapeutic options for treating T2DM. Given the similarity of metabolic and pathological features between PCOS and T2DM and the variety of therapeutic options, there is the potential to widen our strategy for treating metabolic disorders in PCOS in parallel with current therapeutic advances. The review was conducted in line with the recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome 2018.

Neurotransmitter, neuropeptide and gut peptide profile in PCOS-pathways contributing to the pathophysiology, food intake and psychiatric manifestations of PCOS

Polycystic ovary syndrome (PCOS) is a major health problem with a heterogeneous hormone-imbalance and clinical presentation across the lifespan of women. Increased androgen production and abnormal gonadotropin-releasing hormone (GnRH) release and gonadotropin secretion, resulting in chronic anovulation are well-known features of the PCOS. The brain is both at the top of the neuroendocrine axis regulating ovarian function and a sensitive target of peripheral gonadal hormones and peptides. Current literature illustrates that neurotransmitters regulate various functions of the body, including reproduction, mood and body weight. Neurotransmitter alteration could be one of the reasons for disturbed GnRH release, consequently directing the ovarian dysfunction in PCOS, since there is plenty evidence for altered catecholamine metabolism and brain serotonin or opioid activity described in PCOS. Further, the dysregulated neurotransmitter and neuropeptide profile in PCOS could also be the reason for low self-esteem, anxiety, mood swings and depression or obesity, features closely associated with PCOS women. Can these altered central brain circuits, or the disrupted gut-brain axis be the tie that would both explain and link the pathogenesis of this disorder, the occurrence of depression, anxiety and other mood disorders as well as of obesity, insulin resistance and abnormal appetite in PCOS? This review intends to provide the reader with a comprehensive overview of what is known about the relatively understudied, but very complex role that neurotransmitters, neuropeptides and gut peptides play in PCOS. The answer to the above question may help the development of drugs to specifically target these central and peripheral circuits, thereby providing a valuable treatment for PCOS patients that present to the clinic with GnRH/LH hypersecretion, obesity or psychiatric manifestations.

An impaired glucagon-like peptide-1 response is associated with prediabetes in polycystic ovary syndrome with obesity

Objective

Impaired glucose homeostasis in polycystic ovary syndrome (PCOS) is associated with obesity, age, and disease phenotype. This study aimed to investigate the glucagon-like peptide-1 (GLP-1) response in patients with obesity and PCOS with normal glucose tolerance (NGT) or prediabetes.

Methods

Twenty-six women with obesity and PCOS were included. Thirteen women had NGT and 13 had prediabetes. Serum glucose, insulin, and GLP-1 levels were measured during an oral glucose tolerance test. Beta-cell function and insulin resistance were determined.

Results

Women with prediabetes had significantly lower GLP-1 levels than did those with NGT after a glucose load. GLP-1 levels <3.02 pM at 120 minutes were associated with prediabetes. Women with prediabetes had a lower oral glucose insulin sensitivity (OGIS) index and greater amount of visceral adipose tissue than did those with NGT. Plasma GLP-1 levels at 120 minutes were correlated with visceral adiposity and the OGIS index. A change in GLP-1 levels was correlated with a family history of type 2 diabetes.

Conclusion

The GLP-1 response is lower in patients with obesity, PCOS, and prediabetes than in those with obesity, PCOS, and NGT. Further investigation of the GLP-1 response as a potential separate risk factor for prediabetes in PCOS is required.

Neuroanatomical Framework of the Metabolic Control of Reproduction

A minimum amount of energy is required for basic physiological processes, such as protein biosynthesis, thermoregulation, locomotion, cardiovascular function, and digestion. However, for reproductive function and survival of the species, extra energy stores are necessary. Production of sex hormones and gametes, pubertal development, pregnancy, lactation, and parental care all require energy reserves. Thus the physiological systems that control energy homeostasis and reproductive function coevolved in mammals to support both individual health and species subsistence. In this review, we aim to gather scientific knowledge produced by laboratories around the world on the role of the brain in integrating metabolism and reproduction. We describe essential neuronal networks, highlighting key nodes and potential downstream targets. Novel animal models and genetic tools have produced substantial advances, but critical gaps remain. In times of soaring worldwide obesity and metabolic dysfunction, understanding the mechanisms by which metabolic stress alters reproductive physiology has become crucial for human health.

Incretins modulate progesterone biosynthesis by regulating bone morphogenetic protein activity in rat granulosa cells

The effects of incretins on ovarian steroidogenesis have not been clarified. In this study, we investigated the effects of incretins, including GIP and GLP-1, on ovarian steroidogenesis using rat primary granulosa cells. Treatment with incretins significantly suppressed progesterone synthesis in the presence of FSH, and the effect of GIP was more potent than that of GLP-1. In contrast, incretins had no significant effect on estrogen synthesis by rat granulosa cells. In accordance with the effects of incretins on steroidogenesis, GIP and GLP-1 suppressed the expression of progesterogenic factors and enzymes, including StAR, P450scc, 3βHSD, but not P450arom, and cellular cAMP synthesis induced by FSH. In addition, incretins moderately increased FSHR mRNA expression in granulosa cells. Of note, treatment with GIP, but not treatment with GLP-1, augmented Smad1/5/8 phosphorylation and transcription of the BMP target gene Id-1 induced by BMP-6 stimulation, suggesting that GIP upregulates BMP receptor signaling that can inhibit FSH-induced progesterone synthesis in rat granulosa cells. On the other hand, BMP-6 treatment suppressed the expression of GIP receptor but not that of GLP-1 receptor. Expression of the BMP type-I receptor ALK-3 was upregulated by treatment with GIP and GLP-1 and that of ALK-6 was also increased by GIP, while inhibitory Smad6 expression was impaired by GIP and GLP-1 in rat granulosa cells. Collectively, the results indicate that incretins, particularly GIP, impair FSH-induced progesterone production, at least in part, by upregulating BMP signaling in rat granulosa cells. The modulatory effects of incretins on endogenous BMP activity may be applicable to treatment of dysregulated steroidogenesis such as polycystic ovary syndrome.

Comparison of glycemic control and β-cell function in new onset T2DM patients with PCOS of metformin and saxagliptin monotherapy or combination treatment

BACKGROUND

Impaired insulin activity in women with polycystic ovary syndrome might differ from that seen in type 2 diabetes mellitus without polycystic ovary syndrome. This study was designed to compare the effects of treatment with metformin, saxagliptin, and their combination in newly diagnosed women with type 2 diabetes mellitus and polycystic ovary syndrome in China.

METHODS

A total of 75 newly diagnosed patients from Shanghai, China with type 2 diabetes mellitus and polycystic ovary syndrome were included in this randomized, parallel, open-label study. All patients received treatment for 24 weeks with metformin, saxagliptin, or their combination. Patients were allocated to one of three treatment groups by a computer-generated code that facilitated equal patient distribution of 25 patients per group. The primary outcome was a change in glycemic control and β-cell function.

RESULTS

A total of 63 patients completed the study (n = 21, for each group). The reduction in hemoglobin A1c was significant in the combination group, compared to the monotherapy groups (saxagliptin vs. combination treatment vs. metformin: - 1.1 vs. -1.3 vs. -1.1%, P = 0.016), whereas it was comparable between the metformin and saxagliptin groups (P > 0.05). Saxagliptin, metformin, and the combination treatment significantly reduced the homeostasis model assessment- insulin resistance index and increased the deposition index (P < 0.01 for all). However, no significant change was observed in the homeostasis model assessment- β-cell function among the metformin and combination groups, and no significant changes were observed in the insulinogenic index among all three groups (P > 0.05 for all). In addition, saxagliptin and metformin treatments significantly reduced body mass index and high-sensitivity C-reactive protein levels (P < 0.01 for both).

CONCLUSIONS

Saxagliptin and metformin were comparably effective in regulating weight loss, glycemic control, and β-cell function, improving lipid profiles, and reducing inflammation in newly diagnosed type 2 diabetes mellitus patients with polycystic ovary syndrome.

TRIAL REGISTRATION

ChiCTR-IPR-17011120 (retrospectively registered on 2017-04-12).

Effect of oral contraceptives and/or metformin on GLP-1 secretion and reactive hypoglycaemia in polycystic ovary syndrome

CONTEXT

Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS is undetermined.

SETTING

Outpatient clinic.

PATIENTS AND INTERVENTIONS

Randomized, controlled clinical trial. Ninety women with PCOS were randomized to 12-month treatment with OCP (150 mg desogestrel + 30 mg ethinylestradiol), metformin (2 g/day) or metformin + OCP. Five-hour oral glucose tolerance tests (5-h OGTT) measuring fasting and area under the curve (AUC) for GLP-1, glucose, insulin and C-peptide were performed before and after the intervention period. Sixty-five women completed the study and 34 weight-matched healthy women were included as controls.

MAIN OUTCOME MEASURES

Changes in GLP-1, glucose, insulin and C-peptide during 5-h OGTT.

RESULTS

Fasting GLP-1 levels increased during metformin + OCP vs OCP treatment, whereas AUC GLP-1 levels were unchanged during medical treatment. The prevalence of reactive hypoglycemia increased from 9/65 to 14/65 after intervention (P < 0.01) and was more common after treatment with metformin + OCP (increase from 3/23 to 6/23, P = 0.01). Reactive hypoglycaemia was associated with higher insulin and C-peptide levels during 5-h OGTT, but was unassociated with BMI and AUC GLP-1. GLP-1 levels were comparable in PCOS vs controls. AUC GLP-1 levels were significantly lower in obese vs lean patients and were inversely associated with BMI.

CONCLUSIONS

AUC GLP-1 levels were unchanged during treatment. Increased risk of hypoglycemia during metformin + OCP could be associated with increased insulin secretion.

GLP-1 Increases Preovulatory LH Source and the Number of Mature Follicles, As Well As Synchronizing the Onset of Puberty in Female Rats

Control of estrous cycle and reproductive capacity involves a large number of central and peripheral factors, integrating numerous nutritional and metabolic signals. Here we show that glucagon-like peptide-1 (GLP-1), a peptide with anorexigenic and insulinotropic actions, and the GLP-1 receptor agonist Exendin-4 (Ex4) exert a regulatory influence on the gonadal axis, in both adult and prepubertal female rats. In adult rats, Glp-1 receptor expression varies during the estrous cycle at the hypothalamus, pituitary, and ovary. Furthermore, acute treatment with GLP-1 in the morning proestrus doubled the amplitude of the preovulatory LH surge, as well as influencing estradiol and progesterone levels along the estrous cycle. These changes provoked an important increase in the number of Graafian follicles and corpora lutea, as well as in the litter size. Conversely, Ex4 diminished the levels of LH, later producing a partial blockade at the preovulatory surge, yet not affecting either the number of mature follicles or corpora lutea. Chronic administration of low doses of GLP-1 to prepubertal rats synchronized vaginal opening and increased LH levels on the 35th day of life, yet at these doses it did not modify their body weight, food intake, or ovarian and uterine weight. By contrast, chronic exposure to Ex4 produced a significant reduction in ovarian and uterine weight, and serum LH, and the animals treated chronically with Ex4 showed no vaginal opening in the period studied. Overall, our results demonstrate that GLP-1 and Ex4 act on the gonadal axis, involving the hypothalamic kisspeptin system, to influence reproductive efficiency in female rats.

Short-term intervention with liraglutide improved eating behavior in obese women with polycystic ovary syndrome

AIM

Glucagon-like peptide 1 receptor agonists (GLP-1 RA) stimulate satiety leading to reductions in food intake and body weight. The effects of long- acting GLP-1 RA liraglutide on eating behavior of women with PCOS have not been investigated yet.

METHODS

Thirty-six obese women with PCOS (mean ± SD, aged 31.2 ± 7.8 years, with BMI 38.7 ± 0.1 kg/m(2)), pretreated with metformin (1000 mg BID) were switched to liraglutide 1.2 mg QD sc for 12 weeks. Adiposity parameters and eating behavior as assessed by Three-Factor Eating Questionnaire (TFEQ-R18) were examined at baseline and after 12 weeks.

RESULTS

Subjects treated with liraglutide lost on average 3.8 ± 0.1 kg (p < 0.001). Significant reductions of waist circumference and visceral adipose tissue (VAT) mass, volume and area were demonstrated from liraglutide induction to the end of the study. TFEQ-R18 scores were significantly different pre- and post-liraglutide intervention. After treatment with liraglutide the uncontrolled eating (UE) score decreased from 36.8 ± 24.5 to 19.6 ± 18.4 (p < 0.001) and emotional eating (EE) score decreased from 49.9 ± 33.3 to 28.5 ± 26.9 (p < 0.001). Scores for cognitive restraint (CR) were not changed.

CONCLUSIONS

Short-term liraglutide treatment was associated with weight loss and significantly improved eating behavior in obese women with PCOS.

Gastrointestinal hormones and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disease of women in reproductive age. It is characterized by anovulation and hyperandrogenism. Most often patients with PCOS have metabolic abnormalities such as dyslipidemia, insulin resistance, and glucose intolerance. It is not surprising that obesity is high prevalent in PCOS. Over 60 % of PCOS women are obese or overweight. Modulation of appetite and energy intake is essential to maintain energy balance and body weight. The gastrointestinal tract, where nutrients are digested and absorbed, plays a central role in energy homeostasis. The signals from the gastrointestinal tract arise from the stomach (ghrelin release), proximal small intestine (CCK release), and distal small intestine (GLP-1 and PYY) in response to food. These hormones are recognized as "appetite regulatory hormones." Weight loss is the key in the treatments of obese/overweight patients with PCOS. However, current non-pharmacologic management of body weight is hard to achieve. This review highlighted the gastrointestinal hormones, and discussed the potential strategies aimed at modifying hormones for treatment in PCOS.

Multiple-dose pharmacokinetics and pharmacodynamics of evogliptin (DA-1229), a novel dipeptidyl peptidase IV inhibitor, in healthy volunteers

Purpose

Evogliptin (DA-1229) is a novel, potent, and selective dipeptidyl peptidase IV (DPP-IV) inhibitor in clinical development for the treatment of type 2 diabetes mellitus. This study aimed to investigate the pharmacokinetic and pharmacodynamic profiles and tolerability of evogliptin after repeated oral administration in healthy subjects.

Patients and methods

A block-randomized, double-blind, placebo-controlled, multiple-dose, dose-escalation study was performed in a total of 30 subjects. Repeated once-daily doses of 5, 10, or 20 mg evogliptin or the same doses of placebo were orally administered to ten subjects in each dosage group for 10 days. Subjects in each group were randomized to receive evogliptin or placebo with a ratio of 8:2. Pharmacokinetics of evogliptin were evaluated, with its concentrations in serial plasma and urine samples collected following the first and last administrations. DPP-IV activity and glucagon-like peptide-1, glucose, and insulin levels were quantified to evaluate evogliptin’s pharmacodynamics on the first and last dosing days.

Results

All participants completed the study without any serious or severe adverse event. The evogliptin plasma concentration reached its peak within 4–5 hours and decreased relatively slowly, with a terminal elimination half-life of 33–39 hours. Repeated administration resulted in a 1.4- to 1.5-fold accumulation. Evogliptin’s systemic exposure and inhibition of plasma DPP-IV activity increased in a dose-dependent manner. Inhibition of DPP-IV activity >80% was sustained over 24 hours in all evogliptin dose groups and provided an increase in postprandial active glucagon-like peptide-1 levels by 1.5- to 2.4-fold. Postprandial glucose levels in the evogliptin-treated groups were reduced 20%–35% compared to placebo, but were not accompanied by increased insulin levels.

Conclusion

Repeated administration of evogliptin in healthy subjects was well tolerated and exhibited linear pharmacokinetics within the 5–20 mg dose range. A once-daily regimen of 5–20 mg evogliptin effectively inhibited DPP-IV activity.

Fasting and post-prandial glucagon like peptide 1 and oral contraception in polycystic ovary syndrome

OBJECTIVE

We aimed to investigate whether fasting and meal regulated glucagon like peptide 1 (GLP-1) secretion are altered in patients with polycystic ovary syndrome (PCOS) compared to healty women and whether oral contraceptive use influence GLP-1 secretion dynamics in the syndrome.

DESIGN

Prospective observational study.

PATIENTS

Fourteen lean normal glucose tolerant patients with PCOS and 11 age- and body mass index (BMI)-matched healthy women.

MEASUREMENTS

Glucagon like peptide 1, glucose and insulin levels were measured during a standardized meal tolerance test and area under the curves (AUCs) were calculated. Whereas healthy controls were assessed at baseline, all tests were repeated in women with PCOS after treatment with ethinyl estradiol 30 μg/drospirenone 3 mg (EE/DRSP) for 3 months.

RESULTS

Both fasting and post-meal levels of GLP-1 were significantly reduced in women with PCOS compared to controls (P = 0·022 and P = 0·028, respectively). AUC for GLP-1 was also lower in PCOS (P = 0·012). Glucose and insulin measurements did not show a significant change between the groups. In the PCOS group, GLP-1, glucose and insulin levels did not show any change after 3 months of EE/DRSP use.

CONCLUSION

GLP-1 levels both at fasting and in response to a meal are blunted in lean women with PCOS compared to healthy women. Short term oral contraception do not alter GLP-1 secretion in PCOS. Disturbance in incretin secretion dynamics might contribute to the risk of impaired glucose tolerance and type 2 diabetes in PCOS.