Effects of Mixed of a Ketogenic Diet in Overweight and Obese Women with Polycystic Ovary Syndrome

A multiphase very-low calorie ketogenic diet improves serum redox balance by reducing oxidative status in obese patients

The very-low calorie ketogenic diet (VLCKD) is recommended as an effective dietary approach for the management of obesity. This study investigated changes in circulating biomarkers of redox homeostasis induced by a multiphase VLCKD in obese individuals. A total of 40 obese subjects were prescribed a multiphasic VLCKD for eleven weeks. Anthropometric measurements, body composition parameters, calorimetric measures, and standard laboratory markers of glucose and lipid metabolism were evaluated at baseline (T0) and at the end of the dietary intervention (T1). Additionally, circulating markers of oxidative damage and antioxidant status were analyzed in serum and erythrocytes. Compared to T0, at T1 the multiphase VLCKD induced significant weight loss and reduction of waist circumference, with beneficial effects on body composition parameters and the glucose/lipid biochemical profile. Moreover, a decrease in serum markers of oxidative damage was reported at T1, while no changes in serum markers of antioxidant status and in erythrocyte redox markers were observed. In addition, a significant association was found between variations in anthropometric measurements, body composition, glucose metabolism parameters, and changes in circulating markers of oxidative damage. Regression models showed that variation in lipofuscin was significant predictor of changes in body mass index, fat mass, visceral adiposity, and insulin sensitivity. In conclusion, this study demonstrated that the multiphase VLCKD improves serum redox balance by reducing markers of oxidative damage in obese individuals, highlighting the interplay between adiposity, glucose metabolism, and redox homeostasis in the pathogenesis of obesity. Furthermore, these data provide a rationale for future investigations aimed at testing serum lipofuscin as a reliable redox marker in obesity.

Hypogonadism and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), recently proposed to be renamed to metabolic dysfunction-associated steatotic liver disease (MASLD), is a major global public health concern, affecting approximately 25-30% of the adult population and possibly leading to cirrhosis, hepatocellular carcinoma, and liver transplantation. The liver is involved in the actions of sex steroids via their hepatic metabolism and production of the sex hormone-binding globulin (SHBG). Liver disease, including NAFLD, is associated with reproductive dysfunction in men and women, and the prevalence of NAFLD in patients with hypogonadism is considerable. A wide spectrum of possible pathophysiological mechanisms linking NAFLD and male/female hypogonadism has been investigated. As therapies targeting NAFLD may impact hypogonadism in men and women, and vice versa, treatments of the latter may affect NAFLD, and an insight into their pathophysiological pathways is imperative. This paper aims to elucidate the complex association between NAFLD and hypogonadism in men and women and discuss the therapeutic options and their impact on both conditions.

Ketogenic diet improves fertility in patients with polycystic ovary syndrome: a brief report

Introduction

Polycystic ovary syndrome (PCOS) affects up to 20 % of reproductive-age individuals and is strongly linked to obesity. The impacts of ketogenic diet on fertility in people with PCOS are unknown. This study aims to determine the effect of a ketogenic diet on restoration of regular menstrual cycles and fertility.

Methods

After approval from the Institutional Review Boards of Cleveland Clinic, a retrospective analysis was conducted using the electronic health record system. We analyzed data from thirty patients (n = 30) with polycystic ovary syndrome who followed a ketogenic diet for at least 3 months at the Cleveland Clinic, Cleveland, Ohio, USA. Main outcomes were percentage of women with restoration of regular menstrual cycles and pregnancy rate.

Results

All women (n = 30) had restoration of regular menstrual cycles. The overall pregnancy rate of women desiring pregnancy (n = 18) was 55.6% (n = 10). Pregnancy rate was 38.5% for women on metformin and 100% for those who were not (P = 0.036). Pregnancy rate was 62.5% for women using ovulation induction agents and 50.0% for those who did not (P = 0.66). Percent weight change between the pregnant and non-pregnant groups did not significantly differ [-8.1 ± 6.2, vs -6.4 ± 8.4, P = 0.64, respectively].

Conclusion

This study reports a higher rate of pregnancy with the ketogenic diet in women with PCOS compared to existing literature.

Problems and Opportunities in the use of Bioelectrical Impedance Analysis for Assessing Body Composition During Ketogenic Diets: A Scoping Review

PURPOSE OF THE REVIEW

The use of bioelectrical impedance analysis (BIA) for monitoring body composition during the ketogenic diet has experienced a rapid surge. This scoping review aimed to assess the validity of procedures applying BIA in the ketogenic diet and to suggest best practices for optimizing its utilization.

RECENT FINDINGS

We conducted a systematic scoping review of peer-reviewed literature involving BIA for assessing body composition in individuals adhering to a ketogenic diet. Searches of international databases yielded 1609 unique records, 72 of which met the inclusion criteria and were reviewed. Thirty-five studies used foot-to-hand technology, 34 used standing position technology, while 3 did not declare the technology used. Raw bioelectrical parameters were reported in 21 studies. A total of 196 body mass components were estimated, but predictive equations were reported in only four cases. Most research on BIA during ketogenic diets did not report the equations used for predicting body composition, making it impossible to assess the validity of BIA outputs. Furthermore, the exceedingly low percentage of studies reporting and analyzing raw data makes it challenging to replicate methodologies in future studies, highlighting that BIA is not being utilized to its full potential. There is a need for more precise technology and device characteristics descriptions, full report of raw bioelectrical data, and predictive equations utilized. Moreover, evaluating raw data through vectorial analysis is strongly recommended. Eventually, we suggest best practices to enhance BIA outcomes during ketogenic diets.

Self-reported menses physiology is positively modulated by a well-formulated, energy-controlled ketogenic diet vs. low fat diet in women of reproductive age with overweight/obesity

Weight loss can positively alter female physiology; however, whether dietary carbohydrate- or fat- restriction confer unique effects is less studied. Precisely designed, hypocaloric well-formulated ketogenic diets (KD; ~75% energy for weight maintenance) were compared to isocaloric/isonitrogenous low-fat diet (LFD) on self-reported menses in pre-menopausal overweight and obese women (mean ± SD: 34 ± 10 years, BMI: 32.3 ± 2.7 kg/m2). Women received a precisely-weighed and formulated KD with either twice-daily with ketone salts (KS; n = 6) or a flavor-matched placebo (PL; n = 7) daily for six-weeks. An age and BMI-matched cohort (n = 6) was later assigned to the LFD and underwent the same testing procedures as the KD. Self-reported menses fluctuations were assessed bi-weekly along with measures of body weight, body composition, and fasting serum clinical chemistries using repeated measures ANOVA with Bonferroni post-hoc corrections. Both diets elicited clinically-significant weight-loss (Δ: -7.0 ± 0.5 kg; p < 0.001), primarily from fat-mass (Δ: -4.6 ± 0.3 kg; p < 0.001), and improved insulin-sensitivity and serum lipids (all p < 0.05). Fasting plasma glucose and inflammatory markers were not different between diets. Fasting capillary beta-hydroxybutyrate (R-βHB) increased significantly during the KD, independent of supplementation (Δ: 1.2 ± 0.3 mM R-βHB; p < 0.001). Women randomized to the KD+KS (30%) and KD+PL (43%) reported subjective increases in menses frequency and intensity after 14 days, whereas another third reported a regain of menses (>1 year since the last period) after 28 days. No LFD participants reported menses changes. Nutrient-dense, whole-food KDs and LFD improved weight, BMI, body composition, and blood parameters in pre-menopausal women after six-weeks. Changes in self-reported menses were described by most of the KD participants, but none of the LFD women suggesting there may be unique effects of nutritional ketosis, independent of weight loss.

Do Popular Diets Impact Fertility?

Infertility affects 15% of the population in developed countries, and its prevalence is increasing. Fertility can be influenced by different factors. Although key factors like maternal age cannot be changed, there is growing evidence that other modifiable factors, such as diet, can have an impact on fertility. Diet has become increasingly important in recent years for a number of reasons: the new trend toward a healthy lifestyle, the higher prevalence of certain digestive disorders, a lack of time that leads people to consume more prepared and processed food, and personal choice to not eat meat, among others. To meet these needs, several diets have recently become popular, such as the Mediterranean diet, known as the gold standard of health; the DASH diet, known for preventing hypertension; the Western diet, characterized by processed food; the ketogenic diet, characterized by low carbohydrate intake; and the vegetarian diet, which is the choice for people who do not eat meat or animal by-products. Diets present a unique composition characterized by the presence or absence of specific nutrients, which have also been associated with male and female fertility individually. This review assesses the impact of these diets and of macro- and micronutrients on both female and male fertility.

High Fat Diet and Polycystic Ovary Syndrome (PCOS) in Adolescence: An Overview of Nutritional Strategies

Polycystic ovary syndrome (PCOS) is a multifaceted and heterogeneous disorder, linked with notable reproductive, metabolic, and psychological outcomes. During adolescence, key components of PCOS treatment involve weight loss achieved through lifestyle and dietary interventions, subsequently pursued by pharmacological or surgical therapies. Nutritional interventions represent the first-line therapeutic approach in adolescents affected by PCOS, but different kinds of dietary protocols exist, so it is necessary to clarify the effectiveness and benefits of the most well-known nutritional approaches. We provided a comprehensive review of the current literature concerning PCOS definition, pathophysiology, and treatment options, highlighting nutritional strategies, particularly those related to high-fat diets. The high-fat nutritional protocols proposed in the literature, such as the ketogenic diet (KD), appear to provide benefits to patients with PCOS in terms of weight loss and control of metabolic parameters. Among the different types of KD studies, very low-calorie ketogenic diets (VLCKD), can be considered an effective dietary intervention for the short-term treatment of patients with PCOS. It rapidly leads to weight loss alongside improvements in body composition and metabolic profile. Even though extremely advantageous, long-term adherence to the KD is a limiting factor. Indeed, this dietary regimen could become unsustainable due to the important restrictions required for ketosis development. Thus, a combination of high-fat diets with more nutrient-rich nutritional regimens, such as the Mediterranean diet, can amplify positive effects for individuals with PCOS.

Effects of ketogenic diet on weight loss parameters among obese or overweight patients with polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trails

Aim

To evaluate how effective a low carbohydrate ketogenic diet (KD) is for changing key physical measurements such as weight, waist circumference (WC), body mass index (BMI), and fat mass (FM) in women with polycystic ovary syndrome (PCOS) who were obese or overweight.

Methods

Several online databases, including PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science (WOS), were searched systematically to find relevant randomized controlled trials (RCTs) up until June 2023. The Q-test and I2 statistics were used to assess the level of heterogeneity among the included studies. The data were then combined using either a fixed or random effects model and presented as a weighted mean difference (WMD) along with a 95% confidence interval (CI).

Results

Of the 682 citations, 11 RCTs were included. The pooled results showed a significant decrease in the WMD of weight levels [WMD = -9.13 kg; 95% CI, -11.88, -6.39, P < 0.001; I2 = 87.23%] following KD. Moreover, KD significantly reduced BMI levels [WMD = -2.93 kg/m2; 95% CI, -3.65, -2.21, P < 0.001; I2 = 78.81%] compared to the controls. Patients with PCOS received KD demonstrated significant decrease in WC [WMD = -7.62 cm; 95% CI, -10.73, -4.50, P < 0.001; I2 = 89.17%] and FM [WMD = -5.32 kg; 95% CI, -7.29, -3.36, P < 0.001; I2 = 83.97%].

Conclusion

KD was associated with lower weight loss (WL) parameters, including weight, BMI, WC, and FM, in obese or overweight women with PCOS, highlighting the significance of physicians and nurses in taking care of the nutritional needs of overweight/obese patients with PCOS.

The impact of ketogenic diet on some metabolic and non-metabolic diseases: Evidence from human and animal model experiments

The ketogenic diet (KD) is recognized as minimum carbohydrate and maximum fat intakes, which leads to ketosis stimulation, a state that is thought to metabolize fat more than carbohydrates for energy supply. KD has gained more interest in recent years and is for many purposes, including weight loss and managing serious diseases like type 2 diabetes. On the other hand, many believe that KD has safety issues and are uncertain about the health drawbacks. Thus, the outcomes of the effect of KD on metabolic and non-metabolic disease remain disputable. The current narrative review aims to evaluate the effect of KD on several diseases concerning the human health. To our best knowledge, the first report aims to investigate the efficacy of KD on multiple human health issues including type 2 diabetes and weight loss, cardiovascular disease, kidney failure and hypertension, non-alcoholic fatty liver, mental problem, oral health, libido, and osteoporosis. The literature searches were performed in Databases, PubMed, Scopus, and web of Science looking for both animal and human model designs. The results heterogeneity seems to be explained by differences in diet composition and duration. Also, the available findings may show that proper control of carbohydrates, a significant reduction in glycemic control and glycated hemoglobin, and weight loss by KD can be an approach to improve diabetes and obesity, hypertension, non-alcoholic fatty liver, PCOS, libido, oral health, and mental problem if isocaloric is considered. However, for some other diseases like cardiovascular disease and osteoporosis, more robust data are needed. Therefore, there is robust data to support the notion that KD can be effective for some metabolic and non-metabolic diseases but not for all of them. So they have to be followed cautiously and under the supervision of health professionals.

Dietary Patterns and Fertility

Diet has a key role in the reproductive axis both in males and females. This review aims to analyze the impacts of different dietary patterns on fertility. It appears that the Mediterranean diet has a predominantly protective role against infertility, while the Western diet seems to be a risk factor for infertility. Moreover, we focus attention also on dietary patterns in different countries of the World (Middle Eastern diet, Asian diet). In particular, when analyzing single nutrients, a diet rich in saturated fatty acids, cholesterol, animal proteins, and carbohydrates with high glycemic index is highly associated with male and female infertility. Finally, we evaluate the effects of vegetarian, vegan, and ketogenic diets on fertility, which seem to be still unclear. We believe that comprehension of the molecular mechanisms involved in infertility will lead to more effective and targeted treatments for infertile couples.

New insights into the interaction between polycystic ovary syndrome and psychiatric disorders: A narrative review

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disease characterized by hyperandrogenism, ovulatory dysfunction, and ovarian polycystic changes, which combines with reproductive problems, metabolic disorders, and psychological disorders to exhibit a far-reaching impact on the physical and mental health of women. We reviewed previous research and discovered that psychiatric disorders are more common in PCOS patients and their children, potentially exacerbating the condition and creating a vicious loop. To understand the reasons, relevant articles were collected following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from PubMed, Web of Science, and Cochrane Library, through December 2022. Evidence suggested that PCOS-related clinical manifestations, hyperandrogenism, insulin resistance, obesity, gut dysbiosis, and other variables may increase the risk of psychiatric disorders in patients. In turn, psychiatric disorders may aggravate the pathologic process of PCOS and increase the difficulty of the treatment. We systematically reported the mechanisms underlying the psychiatric disorders-PCOS interactions, intending to provide potential ways to break the vicious cycle and lay the groundwork for future research. However, research on PCOS and psychiatric disorders were still in initial stages, which limited the scope of this review. More studies are needed to further verify our findings.

Effect of the ketogenic diet on gut microbiome composition and metabolomics in polycystic ovarian syndrome rats induced by letrozole and a high-fat diet

OBJECTIVES

The ketogenic diet (KD) is recommended to improve polycystic ovary syndrome (PCOS); however, its mechanisms of action are unclear. We aimed to study the effects and mechanisms of action of the KD on the gut microbiome and metabolites in PCOS rats and determine whether the sex hormone regulatory effects are related to modulations of the gut microbiota and metabolites.

METHODS

PCOS was induced with a high-fat diet and letrozole in the rats. A KD was fed to rats for 8 wk, serum samples were collected for biochemical analysis, and the rats' fecal samples were subjected to 16S ribosomal RNA sequencing and metabolomic analysis.

RESULTS

Feeding with a KD for 8 wk suppressed body weight gain, decreased luteinizing hormone and androgen levels, and improved insulin levels. Furthermore, the KD reversed the dysregulation of the gut microbiota in PCOS rats by adjusting the ratio of firmicutes and bacteroidetes. Also, the KD was involved in hormonal metabolic pathways by reducing the levels of some metabolites (such as testosterone and 7α-hydroxytestosterone) that are closely related to gut microbes.

CONCLUSIONS

The KD improved the clinical phenotype and insulin resistance in PCOS rats and altered the composition of the gut microbiome and metabolites, which were associated with androgen metabolism, representing a potential mechanism for mediating the effects of the KD on sex hormone metabolism in PCOS. However, our study found contradictory effects of KD on the gut microbiome in PCOS, which need further research.

Ketogenic Diet as a Possible Non-pharmacological Therapy in Main Endocrine Diseases of the Female Reproductive System: A Practical Guide for Nutritionists

PURPOSEOF REVIEW

This narrative review explored the role of ketogenic diets (KDs) in improving fertility outcomes, low-grade inflammation, body weight, visceral adipose tissue, and its potential use in certain types of cancer, through its favorable actions on mitochondrial function, reactive oxygen species generation, chronic inflammation, and tumor growth inhibition. RECENT FINDINGS  : Nutrition is crucial to maintain the female reproductive system's health. Evidence on the association between diet and female reproductive system has greatly expanded over the last decade, leading to the identification of specific diet therapy, particularly KDs. KDs has been proved to be an effective weight-loss tool. To date, KDs is being increasingly used in the treatment of many diseases, such as obesity, type 2 diabetes mellitus. KDs is a dietary intervention capable of ameliorating the inflammatory state and oxidative stress through several mechanisms. Due to the increasing use of KDs beyond obesity, this literature review will provide the latest scientific evidence of its possible use in common disorders of the female endocrine-reproductive tract, and a practical guide to its use in these patients.

Pathophysiology and Nutritional Approaches in Polycystic Ovary Syndrome (PCOS): A Comprehensive Review

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder in women of reproductive age worldwide. This disease causes menstrual, metabolic, and biochemical abnormalities such as hyperandrogenism, oligo-anovulatory menstrual cycles, polycystic ovary, hyperleptinemia, insulin resistance (IR), and cardiometabolic disorders, often associated with overweight or obesity and visceral adiposity.

RECENT FINDINGS

The etiology and pathophysiology of PCOS are not yet fully understood, but insulin seems to play a key role in this disease. PCOS shares an inflammatory state with other chronic diseases such as obesity, type II diabetes, and cardiovascular diseases; however, recent studies have shown that a healthy nutritional approach can improve IR and metabolic and reproductive functions, representing a valid therapeutic strategy to ameliorate PCOS symptomatology. This review aimed to summarize and collect evidence about different nutritional approaches such as the Mediterranean diet (MedDiet) and the ketogenic diet (KD), as well as bariatric surgery and nutraceutical supplementation as probiotics, prebiotics, and synbiotics, among the others, used in patients with PCOS.

Effects of Ketogenic Diet on Reproductive Hormones in Women With Polycystic Ovary Syndrome

Context

Ketogenic diet has recently made a comeback as a part of lifestyle and dietary modifications in patients with polycystic ovary syndrome (PCOS). Despite studies suggesting its beneficial effects in reversing hormonal imbalance in women with PCOS, evidence has been patchy and derived from small populations under varying conditions.

Objective

To pool evidence from clinical trials to study the effects of ketogenic diet on reproductive hormones (LH/FSH ratio, free testosterone, serum progesterone) and observe evidence of weight change.

Methods

PubMed, ScienceDirect, Scopus, and Web of Science core collection were searched for clinical trials evaluating the effects of ketogenic diet in established PCOS women consistent with the Rotterdam classification. Single- or double-arm studies that included an outcome of interest were included. Two investigators worked independently to screen potential articles and a designated investigator extracted data on study characteristics and evaluated the outcomes. Data were pooled using a random-effects model. The quality of selected studies was assessed using the Cochrane Risk of Bias Tool.

Results

Following ≥45 days of intervention with ketogenic diet among women with PCOS, significant improvement was observed in reproductive hormone levels, with reduced LH/FSH ratio (d -0.851; 95% CI -1.015, -0.686; P < .001), reduced serum free testosterone (d -0.223; 95% CI -0.328, -0.119; P  < .001), and an increased in serum sex hormone binding globulin (SHBG) (d 9.086; 95% CI 3.379, 14.792; P = .002). Significant weight loss was unanimously observed in all included studies (d -11.56; 95% CI -14.97, -8.15; P < .001).

Conclusion

Short-term ketogenic diet potentially improved hormonal imbalances commonly associated with PCOS.

Low-Calorie Ketogenic Diet: Potential Application in the Treatment of Polycystic Ovary Syndrome in Adolescents

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. Hyperandrogenism, hyperinsulinism and insulin resistance (IR) are the main drivers of clinical, metabolic and reproductive phenotypes of PCOS. In adolescence, the cornerstones of PCOS treatment are lifestyle and dietary interventions. In particular, the quality and quantity of carbohydrates introduced with the diet play a crucial role in the benefits of diet on PCOS. Recently, the ketogenic diet (KD) has attracted significant interest for the treatment of IR and for the control of carbohydrate metabolism, which has proven to be beneficial for several dysmetabolic conditions, including PCOS. The goal of the KD is to induce a fasting-like metabolism with production of chetonic bodies. Ketosis is a good regulator of calorie intake and mimics the starvation effect in the body, leading to body weight control and consequent metabolism. Additionally, during ketogenesis, insulin receptor sensitivity is also promoted. We proposed a broad overview of the available literature regarding KD indications and considered its metabolic benefits useful for improving PCOS management. The reported data support that a low-calorie ketogenic diet (LCKD) plays a positive role as a regulator of control weight, IR, glucose and lipid homeostasis and hormonal profile. Unfortunately, the evidence concerning the benefits of the very LCKD in adolescents with PCOS and excessive body weight is still numerically scarce. Further studies are necessary to understand whether these effects are due to weight loss or to the nutritional characteristics of this diet. Considering the long-term consequences of PCOS, it is crucial to detect the prospects of nutritional interventions to protect fertility, starting in adolescence.

A comparison of the portfolio low-carbohydrate diet and the ketogenic diet in overweight and obese women with polycystic ovary syndrome: study protocol for a randomized controlled trial

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most frequent endocrine disorders among women of fertile age. Women with PCOS manifest clinical symptoms like menstrual dysfunction, hirsutism, insulin resistance, and hyperinsulinemia. As excessive amounts of insulin levels directly increase ovarian production of androgens, hyperinsulinemia and insulin resistance are considered as the pathogenesis factors of PCOS. The portfolio low-carbohydrate diet (PLCD) is a plant-based diet with 40% carbohydrates combined with five cholesterol-lowering foods and nutrients. On the other hand, the ketogenic diet (KD) is a nutritional protocol with 10% carbohydrates. The purpose of this study is to determine whether PLCD or KD is more effective in alleviating PCOS symptoms.

METHODS

Forty-six overweight or obese women diagnosed with PCOS will be randomly stratified to receive either PLCD or KD for 8 weeks. Measures related to anthropometric and body composition, glucose, and insulin level, HOMA-IR, sex hormones, lipid profile, quality of life, dietary intake, physical activity, and Ferriman-Gallwey score of all participants will be accessed before and after the intervention.

DISCUSSION

Since the first line treatment of PCOS is lifestyle adjustment including diet control and exercise, there has not been determined the optimal diet for this population of women yet. Hence, the goal of conducting this study is to determine whether the PLCD or the KD could have more advantageous effects on attenuating PCOS manifestations. The result of this investigation will give us new insight into curing this disease and will provide evidence-based recommendations for prescribing an optimal diet for PCOS women.

TRIAL REGISTRATION

IRCT20200912048693N3, Trial registered 2022-12-14. https://www.irct.ir/trial/67548.

Adding a ketogenic dietary intervention to IVF treatment in patients with polycystic ovary syndrome improves implantation and pregnancy

Patients with polycystic ovary syndrome (PCOS) on a high-carbohydrate diet intrinsically suffer from exacerbated glucotoxicity, insulin resistance (IR), and infertility. Lowering the carbohydrate content has improved fertility in patients with IR and PCOS; however, the effects of a well-controlled ketogenic diet on IR and fertility in PCOS patients undergoing in vitro fertilization (IVF) have not been reported. Twelve PCOS patients with a previous failed IVF cycle and positive for IR (HOMA1-IR>1.96) were retrospectively evaluated. Patients followed a ketogenic diet (50 g of total carbohydrates/1800 calories/day). Ketosis was considered when urinary concentrations were > 40 mg/dL. Once ketosis was achieved, and IR diminished, patients underwent another IVF cycle. The nutritional intervention lasted for 14 ± 11 weeks. Carbohydrate consumption decreased from 208 ± 50.5 g/day to 41.71 ± 10.1 g/day, which resulted in significant weight loss (-7.9 ± 1.1 kg). Urine ketones appeared in most patients within 13.4 ± 8.1 days. In addition, there was a decrease in fasting glucose (-11.4 ± 3.5 mg/dl), triglycerides (-43.8 ± 11.6 mg/dl), fasting insulin (-11.6 ± 3.7 mIU/mL), and HOMA-IR (-3.28 ± 1.27). All patients underwent ovarian stimulation, and compared to the previous cycle, there was no difference in oocyte number, fertilization rate, and viable embryos produced. However, there was a significant improvement in the implantation (83.3 vs. 8.3 %), clinical pregnancy (66.7 vs. 0 %), and ongoing pregnancy/live birth rates (66.7 vs. 0 %). Here, restriction in carbohydrate consumption in PCOS patients induced ketosis, improved key metabolic parameters, and decreased IR. Even though this did not affect oocyte or embryo quality or quantity, the subsequent IVF cycle significantly improved embryo implantation and pregnancy rates.

The PCOS puzzle: putting the pieces together for optimal care

Polycystic ovary syndrome (PCOS) is a multifaceted hormonal disorder that has significant ramifications for both women's reproductive and metabolic well-being. This analysis aims to offer a thorough comprehension of PCOS by investigating the various contributing factors that are crucial for its effective management. We delve into the topic of hormonal imbalances, such as elevated androgens and disrupted estrogen-progesterone dynamics, and their effects on reproductive and metabolic health. Furthermore, we explore the intricate connection between insulin resistance, hyperinsulinemia, and PCOS, highlighting their pivotal role in metabolic dysfunction. Additionally, we examine fertility challenges, irregular menstrual patterns, and metabolic complications while also reviewing current treatment methodologies. Moreover, we address the latest research concerning genetic, environmental, and epigenetic influences on PCOS. By piecing together these essential elements, healthcare professionals can attain a comprehensive understanding of PCOS and deliver optimal care for those affected by the condition.

Correlation between Selected Clinical Symptoms and Severity of Aggression, Impulsiveness and Their Selected Behavioral Manifestations in Patients with Polycystic Ovary Syndrome Phenotype A

Previous studies on aggressiveness and impulsiveness in women with polycystic ovary syndrome (PCOS) are ambiguous. Furthermore, no biochemical or clinical factors related to these variables have been definitively confirmed. The aim of the study was to clarify whether, in women with phenotype A of PCOS, variables such as body mass index and clinical and biochemical hyperandrogenism have an impact on either the intensity of impulsivity or aggression or on other selected behavioral manifestations of these variables. The study included 95 patients diagnosed with PCOS phenotype A. The criterion for recruitment into the study group and the control group was body mass index. The study was conducted with the use of a closed-format questionnaire and calibrated clinical scales. Higher body mass index (BMI) values in women with PCOS phenotype A are associated with poor eating habits. The severity of impulsivity and aggression syndrome, as well as the tendency to engage in risky sexual behavior and patterns of alcohol consumption among patients diagnosed with PCOS phenotype A, are not dependent on BMI. The severity of impulsiveness and the syndrome of aggression in women with phenotype A PCOS are not associated with clinical symptoms of hyperandrogenism or with androgen levels.

Short-time effects of ketogenic diet or modestly hypocaloric Mediterranean diet on overweight and obese women with polycystic ovary syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women during reproductive age. It is characterized clinically by oligo-ovulation or anovulation, hyper-androgenism, and the presence of polycystic ovaries. Often comorbid with insulin resistance, dyslipidemia, and obesity, it also carries significant risk for the development of cardio-vascular and metabolic sequelae, including diabetes and metabolic syndrome. In light of these evidences, the most therapeutic option prescribed to PCOS women with obesity, regardless of the phenotype from the severity of clinical expression, is lifestyle correction by diet and physical activity.

PURPOSE

The aim of this study was to evaluate the association between PCOS with KD in overweight and/or obese women with PCOS, and evaluate the possible beneficial effects on metabolic and endocrine parameters, compared to a standard, balanced hypocaloric diet such as Mediterranean diet (MD).

METHODS

Participants were assigned to receive, in a 1:1 ratio, one of the two following dietary sequences: KD or MD. In all subjects anthropometric parameters, body composition and metabolic and endocrine parameters were obtained at baseline and after dietetic treatment.

RESULTS

Our results showed a significant change in the anthropometric and biochemical parameters in both groups after both diet therapies, with statistically significant differences (p < 0.001). Though, the reductions of all parameters were significantly greater in KD group than in MD group.

CONCLUSION

Our results suggest that a reduction of dietary intake of carbohydrates by KD may be considered as a valuable non-pharmacological treatment for PCOS.

Intake of Low Glycaemic Index Foods but Not Probiotics Is Associated with Atherosclerosis Risk in Women with Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS) are at high cardiometabolic risk. The atherogenic index of plasma (AIP) strongly predicts atherosclerosis. Some studies suggest that probiotic intake may lower AIP. This study analysed the relationship between the frequency of dietary intake of low glycaemic index (prebiotic) and probiotic foods and atherosclerosis risk in women with PCOS.

METHODS

A total of 127 women were divided into two groups: AIP over 0.11 (highAIP) and AIP ≤ 0.11 (lowAIP). The KomPAN® questionnaire was used to measure food frequency intake; pro-healthy, non-healthy, low glycaemic and probiotic dietary indexes were calculated based on daily food consumption. Body composition was measured by air displacement plethysmography (BodPod). AIP was calculated as a logarithm of triglycerides and high-density lipoproteins from plasma.

RESULTS

The highAIP group was 63% less likely to consume low glycaemic index foods three or more times a day than the lowAIP group. The HighAIP group was also 62% less likely to consume buckwheat, oats, whole-grain pasta or coarse-ground grains at least a few times a week. Pro-healthy foods tended to be less frequently consumed by the highAIP group, when adjusted for BMI and age.

CONCLUSION

Women with PCOS at high risk of atherosclerosis consumed less low glycaemic index foods than women with a low risk of atherosclerosis. Intake of high-fibre, low glycaemic index foods could prevent atherosclerosis in women with PCOS; however, the effect of probiotic food intake remains unclear.

Ketogenic Diet as Medical Prescription in Women with Polycystic Ovary Syndrome (PCOS)

PURPOSE OF REVIEW

The polycystic ovary syndrome (PCOS) is an endocrine dysfunction associated with a myriad of metabolic disorders and high rate of infertility. In order to aid its management, several lifestyle/dietary interventions have been evaluated. Very low-calorie ketogenic diet (VLCKD) is rapidly showing promising benefits not only in obesity but also in the treatment of other metabolic diseases. The main objective of this review is to assess the scientific evidence in support of this dietary pattern as an effective measure for treating PCOS and the metabolic disorders associated with it.

RECENT FINDINGS

Preliminary data suggested significant improvements in body weight and composition, metabolic profile (glucose, serum insulin, triglycerides, total and low-density lipoprotein cholesterol), and insulin resistance following VLCKD. However, the evidence is still scarce and needs to be more substantiated. Weight reduction in women with PCOS has been shown to improve metabolic derangements and body composition, but there is no consensus on the ideal dietary pattern or macronutrient composition. There is some evidence supporting the possible role of the Mediterranean diet in improving infertility (along with other well-known metabolic benefits) in women with PCOS. Of note, VLCKD might be considered a potential intervention for the short-term treatment of PCOS, but it must be prescribed and carefully guided by professionals.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Polycystic ovary syndrome and adipose tissue

Polycystic ovary syndrome (PCOS) is the most common endocrine metabolic disorder in women of reproductive age. Typically, it is associated with ovulatory dysfunction: dysovulation or anovulation, and symptoms of hyperandrogenism. It incurs risk of metabolic disorders such as diabetes, dyslipidemia and fatty liver. As a key endocrine organ in metabolic homeostasis, adipose tissue is often implicated in these complications. Studies of white adipose tissue (WAT) in PCOS have focused on the mechanism of insulin resistance in this tissue. Clinically, abnormalities in WAT distribution are seen, with decreased waist-to-hip ratio and increased ratio of adipose to lean mass. Such abnormalities are greater when total circulating androgens are elevated. At tissue level, white adipocyte hyperplasia occurs, along with infiltration of macrophages. Secretion of adipokines, cytokines and chemo-attractant proteins is increased in a pro-inflammatory manner, leading to reduced insulin sensitivity via alteration of glucose transporters, and hence decreased glucose uptake. The kinetics of non-esterified fatty acids (or free fatty acids) is also altered, leading to lipotoxicity. In recent years, brown adipose tissue (BAT) has been studied in women with PCOS. Although abundance is low in the body, BAT appears to play a significant role in energy expenditure and metabolic parameters. Both supra-clavicular skin temperature, which reflects BAT activity, and BAT mass are reduced in women with PCOS. Moreover, BAT mass and body mass index (BMI) are inversely correlated in patients. In the adipocyte, increased total circulating androgen levels reduce expression of uncoupling protein 1 (UCP1), a key protein in the brown adipocyte, leading to reduced biogenesis and mitochondrial respiration and hence a reduction in post-prandial thermogenesis. BAT is currently being investigated as a possible new therapeutic application.

Effects of intestinal flora on polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. Its clinical characteristics are mainly oligo-ovulation or anovulation, hyperandrogenemia (HA) and insulin resistance (IR). PCOS is considered to be one of the main causes of infertility in women of childbearing age, and its pathogenesis is still unclear. Intestinal flora, known as the "second genome" of human beings, is closely related to metabolic diseases, immune diseases and infectious diseases. At the same time, mounting evidence suggests that intestinal flora can regulate insulin synthesis and secretion, affect androgen metabolism and follicular development, and is involved in the occurrence of chronic inflammation and obesity. The imbalance of intestinal flora is caused by the abnormal interaction between intestinal flora and host cells caused by the change of intestinal microbial diversity, which is related to the occurrence and development of PCOS. The adjustment of intestinal flora may be a potential direction for the treatment of PCOS.

Revised Protein Sparing Diet in Obesity and Type 2 Diabetes Mellitus

Effective nutrition therapy is a pressing issue in obesity and type 2 diabetes mellitus (T2DM) management. As such, this research aimed to determine the performance of a revised dietary strategy built on the protein-sparing diet in obesity and type 2 diabetes mellitus with regard to obtaining a rapid and stable improvement in glucometabolic control, body weight, body composition, and energy metabolism when applying the strategy in just twenty-one days. The revised protein-sparing diet differs from the traditional protein-sparing modified fast (PSMF) because it does not include foods. The daily calorie intake of this diet is exclusively derived from Isolate whey protein in addition to a formulation of Isolate whey protein enriched with essential amino acids in free form, with the addition of lipids such as extra virgin olive oil and coconut oil as a source of medium chain fatty acids, where the latter is taken for only the first four days of the diet, together with the use, for the same duration, of extended-release metformin, as the only antihyperglycemic allowed. Anthropometric measurements, bioimpedance analysis, indirect calorimetry, and blood chemistry assessments were conducted at the beginning of the study, time 0 (T0), and at the end, time 1 (T1), i.e., on the 21st day. The main outcomes of the revised protein-sparing diet after only twenty-one days were a reduction in body weight with the predominant loss of visceral atherogenic abdominal fat and, therefore, a possible contextual reduction in ectopic fat deposits together with a simultaneous reduction in insulin resistance and normalization of insulin levels, maintenance of free fat mass and basal metabolism, restoration of metabolic flexibility, and improvement of the glucometabolic and lipidic parameters. These results demonstrate the promising potential of the revised protein-sparing diet as an "etiologic tool" in the integrated nutritional treatment of metabolic diseases such as obesity and type 2 diabetes mellitus.

Italian Ketogenic Mediterranean Diet in Overweight and Obese Patients with Prediabetes or Type 2 Diabetes

Obesity is a multifactorial disease strongly associated with insulin resistance and/or type 2 diabetes mellitus. Correct nutrition represents a valid strategy to fight these dysmetabolic pathologies responsible for numerous diseases, including inflammatory and cardiovascular ones. Medical nutrition therapy, including a Mediterranean diet (MD) and a very low-calorie ketogenic diet (VLKCD), is the first-line treatment for prediabetes/diabetes and overweight/obesity. Eighty patients (forty women and forty men) affected by overweight/obesity and type 2 diabetes mellitus or impaired glucose tolerance or impaired fasting glucose (51 (ys) ± 1.75; BMI (kg/m2) 33.08 ± 1.93; HA1c (%): 6.8% ± 0.25) were enrolled at the University Service of Diet Therapy, Diabetology and Metabolic Diseases, Policlinico Riuniti Hospital of Foggia, and subjected to a very-low-calorie Mediterranean diet and a very-low-calorie ketogenic Mediterranean diet for thirty days. Both diets result in a marked decrease in body weight (kg) and BMI (kg/m2). At the same time, only the very-low-calories ketogenic Mediterranean diet reduced waist and hip circumferences. Both diets helped reduce fat mass, but a major loss was achieved in a very low-calorie ketogenic Mediterranean diet. Among gluco-metabolic parameters, only the very-low-calorie ketogenic Mediterranean diet group showed a significant decrease in fasting blood glucose and HbA1c, insulin, C-peptide total cholesterol, LDL, and triglycerides. The results of our study seem to show that the very-low-calorie ketogenic Mediterranean diet is a good strategy to improve rapidly metabolic, anthropometric, and body composition parameters in patients with prediabetes or diabetes and overweight/obesity.

Usage of mobile health interventions among overweight/obese PCOS patients undergoing assisted reproductive technology treatment during the COVID-19 pandemic

Objective: In the context of the coronavirus disease 2019 (COVID-19) pandemic, telemedicine is a promising tool for providing clinical care for patients. Since the first-line treatment for infertile women with polycystic ovarian syndrome (PCOS) is lifestyle modification, a mobile-based service that provides lifestyle modification education would be helpful in the treatment of PCOS patients. In this observational study, the effect of a mobile Health (mHealth) application for lifestyle modification on PCOS patients undergoing assisted reproductive technology (ART) treatment was evaluated.Methods: A total of 79 overweight/obese patients (40 in the paper group and 39 in the WeChat application group) with PCOS from the First Affiliated Hospital of University of Science and Technology of China were enrolled in the study. The changes in the outcomes of BMI and ART treatment were analyzed between the two groups.Results: After three months of intervention, the BMIs in the control and mHealth groups were 24.5 ± 3.3 and 23.7 ± 3.1, respectively. The percentage of patients who lost weight was higher in the WeChat group than in the control group (87.2% vs. 67.5%). Furthermore, PCOS patients in the WeChat group were found to have a higher live birth rate than those in the control group (p = 0.005).Conclusion: Lifestyle modifications for PCOS patients undergoing ART treatment using the WeChat application improved weight loss and oocyte quality. Infertile patients with PCOS were more likely to make lifestyle modifications based on the usage of mobile applications during the COVID-19 pandemic.

Effects of the ketogenic diet in mice with hind limb ischemia

Background

The ketogenic diet (KD) has anti-tumor and anti-diabetic effects in addition to its anti-epileptic role. It could also improve cardiac function and attenuate neurological insult. However, the effect of KD on blood perfusion or tissue recovery after ischemia remains largely unknown. Thus, we observed blood flow and ischemic tissue recovery following hind limb ischemia (HLI) in mice.

Methods

C57 mice were fed with either a KD or normal diet (ND) for 2 weeks, before inducing hind limb ischemia, blood perfusion of ischemic limb tissue was observed at 0, 7, and 21 days post operation.

Results

KD not only decreased blood perfusion of ischemic limb tissue but also delayed muscle recovery after ischemia, induced muscle atrophy of non-ischemic tissue compared to mice fed with ND. Furthermore, KD delayed wound healing at the surgical site and aggravated inflammation of the ischemic tissue. At the cellular level, KD altered the metabolic status of limb tissue by decreasing glucose and ketone body utilization while increasing fatty acid oxidation. Following ischemia, glycolysis, ketolysis, and fatty acid utilization in limb tissue were all further reduced by KD, while ketogenesis was mildly increased post KD in this mice model.

Conclusion

The KD may cause impaired tissue recovery after ischemia and possible muscle atrophy under a prolonged diet. Our results hint that patients with limb ischemia should avoid ketogenic diet.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00695-z.

Ketogenic diet administration to mice after a high-fat-diet regimen promotes weight loss, glycemic normalization and induces adaptations of ketogenic pathways in liver and kidney

Objective

The ketogenic diet (KD), characterized by very limited dietary carbohydrate intake and used as nutritional treatment for GLUT1-deficiency syndromes and pharmacologically refractory epilepsy, may promote weight loss and improve metabolic fitness, potentially alleviating the symptoms of osteoarthritis. Here, we have studied the effects of administration of a ketogenic diet in mice previously rendered obese by feeding a high fat diet (HFD) and submitted to surgical destabilization of the medial meniscus to mimic osteoarthritis.

Methods

6-weeks old mice were fed an HFD for 10 weeks and then switched to a chow diet (CD), KD or maintained on a HFD for 8 weeks. Glycemia, β-hydroxybutyrate (BHB), body weight and fat mass were compared among groups. In liver and kidney, protein expression and histone post-translational modifications were assessed by Western blot, and gene expression by quantitative Real-Time PCR.

Results

After a 10 weeks HDF feeding, administration for 8 weeks of a KD or CD induced a comparable weight loss and decrease in fat mass, with better glycemic normalization in the KD group. Histone β-hydroxybutyrylation, but not histone acetylation, was increased in the liver and kidney of mice fed the KD and the rate-limiting ketogenic enzyme HMGCS2 was upregulated – at the gene and protein level – in liver and, to an even greater extent, in kidney. KD-induced HMGCS2 overexpression may be dependent on FGF21, whose gene expression was increased by KD in liver.

Conclusions

Over a period of 8 weeks, KD is more effective than a chow diet to induce metabolic normalization. Besides acting as a fuel molecule, BHB may exert its metabolic effects through modulation of the epigenome - via histone β-hydroxybutyrylation - and extensive transcriptional modulation in liver and kidney.

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In mice fed a high fat diet, the dietary switch to a ketogenic diet causes weight loss and loss of fat mass.

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Glycemic normalization is superior than observed in mice fed a chow diet.

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Ketogenic diet induces mild ketosis, and β-hydroxybutyrylation on histone H3 lysines.

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Upregulation of rate limiting ketogenic protein HMGCS2 is observed in kidney.

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Ketogenic diet may be a transitory nutritional intervention to favor weight loss.

Metabolic and Molecular Mechanisms of Diet and Physical Exercise in the Management of Polycystic Ovarian Syndrome

Polycystic ovary syndrome (PCOS) is an endocrine systemic disorder mainly characterized by a hormonal and metabolic disbalance that leads to oligo/anovulation, hyperandrogenism and the formation of ovarian cysts. Despite the progress that has been reached in its diagnosis and management, little is known about the molecular mechanisms and signaling pathways underlying the pathogenic mechanisms. In this sense, recent research has suggested that the influence of multiple factors, including age, environment, lifestyle and the disease state environment can change the clinical presentation of PCOS via epigenetic modifications. Variants in the genes encoding for proteins involved in steroidogenesis and glucose homeostasis play a crucial role in the development of the disease. Other genes involved in inflammation and cell proliferation seem to undergo an epigenetic control. Moreover, lifestyle factors influence the PCOS course and prognosis, including diet and physical activity, which are fundamental in reducing oxidative stress, inflammation and in improving metabolic and hormonal parameters. In the present review, literature evidence on molecular and epigenetic mechanisms related to PCOS etiology will be discussed, with a particular attention on the positive influence of diet and physical activity as nonpharmacological ways of intervention in the management of the disease.

Mediterranean Diet Combined With a Low-Carbohydrate Dietary Pattern in the Treatment of Overweight Polycystic Ovary Syndrome Patients

Objectives

To determine the therapeutic effect of a Mediterranean diet (MED) combined with a low-carbohydrate (LC) dietary model in overweight polycystic ovary syndrome (PCOS) patients.

Methods

In this 12-week randomized controlled clinical trial, 72 overweight patients with PCOS were randomly assigned to one of two energy-restricted dietary models: the MED/LC diet or the Low fat (LF) diet. After the intervention, the number of the two groups returned to normal menstruation was counted. Body weight, body mass index (BMI), waist circumference, waist-hip ratio (WHR), body fat percentage (BF%), serum fasting insulin(FINS), fasting plasma glucose(FPG), insulin resistance index (HOMA-IR), quantitative insulin sensitivity index (QUIKI), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride (TG), total testosterone (TT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) were compared between 2 groups before and after intervention.

Results

MED/LC group had more significant reduction trend in weight (−6.10 ± 1.52 kg vs −4.79 ± 0.97 kg, P < 0.05), BMI (−2.12 ± 0.57 kg/m² vs −1.78 ± 0.36 kg/m², P < 0.05), WC (−6.12 ± 5.95 cm vs −3.90 ± 1.58 cm, P < 0.05), WHR (−0.06 ± 0.02 vs −0.03 ± 0.02, P < 0.05), BF% (−2.97% ± 1.78% vs −1.19% ± 0.91%, P < 0.05), TT (−0.20 ± 0.24 ng/mL vs 0.08 ± 0.11 ng/Ml, P < 0.001), LH (−5.28 ± 3.31 mIU/mL vs −3.39 ± 3.64 mIU/mL, P < 0.05), and LH/FSH (−1.18 ± 0.75 vs -0.66 ± 1.05, P < 0.05) compared with the LF group. In addition, FPG (0.05 ± 0.38 mmol/mL vs -0.50 ± 1.01 mmol/mL, P < 0.001), FINS (−4.88 ± 6.11 μU/mL vs −8.53 ± 5.61 μU/mL, P < 0.01), HOMA-IR index (−1.11 ± 1.51 vs −2.23 ± 0.25, P < 0.05), and QUIKI index (0.014 ± 0.016 vs 0.028 ± 0.019, P < 0.05) decreased significantly in the MED/LC group compared with the LF group. Comparing the changes in lipid parameters between the two groups (LF vs MED/LC), significant differences in TG (−0.33 ± 0.32 mmol vs −0.76 ± 0.97 mmol, P < 0.05), TC (−0.40 ± 1.00 mmol vs −1.45 ± 2.00 mmol, P < 0.05), and LDL-C (−0.41 ± 1.05 mmol vs −0.73 ± 0.76 mmol, P < 0.05) were observed.

Conclusion

The results of this study suggest that the MED/LC diet model is a good treatment for overweight PCOS patients, significantly restoring their menstrual cycle, improving their anthropometric parameters and correcting their disturbed endocrine levels, and its overall effectiveness is significantly better than the LF diet model. Therefore, this study recommends that the MED/LC diet model can be used in the clinical treatment of patients with overweight PCOS.

A bibliometric and visual analysis of obesity and polycystic ovary syndrome from 2012 to 2022

BACKGROUND

Obesity is associated with polycystic ovary syndrome (PCOS). We aimed to elucidate the research status and explore research trends and future directions of research on obesity and PCOS.

METHODS

A bibliometric analysis of the published papers in the field of obesity and PCOS between 2012 and 2022 was conducted on the basis of the Web of Science Core Collection database. The collaboration networks, research trends, literature sources, citation analysis, co-citation analysis, and keywords analysis were statistically analyzed and visualized using the VOSviewer software.

RESULTS

We retrieved 2843 records from 681 journals by 12307 authors from 2942 institutes in 99 countries. The number of published papers and citations had a roughly increasing trend annually. The United States and China contributed the majority of the records. Monash University, Shanghai Jiaotong University, Aristotle University of Thessaloniki, Karolinska Institute, University of São Paulo, and Tehran University of Medical Sciences were the biggest nodes in their cluster of the collaboration network map, and Moran LJ, Teede HJ, Joham AE, Escobar-Morreale HF, and Macut D were prolific authors. Research trends and hotspots were identified and visualized in the field of obesity and PCOS. Research hotspots in this field focused on insulin resistance (IR), metabolic syndrome, metformin, and inflammation. Bariatric surgery, mitochondrial dysfunction, binding globulins, and comorbidities may be the frontiers of future research.

CONCLUSIONS

We concluded the research status and trends in the field of obesity and PCOS. A better understanding of collaboration patterns, research hotspots, and frontiers may be useful for researchers.

Activation of G protein-coupled receptors by ketone bodies: Clinical implication of the ketogenic diet in metabolic disorders

Ketogenesis takes place in hepatocyte mitochondria where acetyl-CoA derived from fatty acid catabolism is converted to ketone bodies (KB), namely β-hydroxybutyrate (β-OHB), acetoacetate and acetone. KB represent important alternative energy sources under metabolic stress conditions. Ketogenic diets (KDs) are low-carbohydrate, fat-rich eating strategies which have been widely proposed as valid nutritional interventions in several metabolic disorders due to its substantial efficacy in weight loss achievement. Carbohydrate restriction during KD forces the use of FFA, which are subsequently transformed into KB in hepatocytes to provide energy, leading to a significant increase in ketone levels known as "nutritional ketosis". The recent discovery of KB as ligands of G protein-coupled receptors (GPCR) - cellular transducers implicated in a wide range of body functions - has aroused a great interest in understanding whether some of the clinical effects associated to KD consumption might be mediated by the ketone/GPCR axis. Specifically, anti-inflammatory effects associated to KD regimen are presumably due to GPR109A-mediated inhibition of NLRP3 inflammasome by β-OHB, whilst lipid profile amelioration by KDs could be ascribed to the actions of acetoacetate via GPR43 and of β-OHB via GPR109A on lipolysis. Thus, this review will focus on the effects of KD-induced nutritional ketosis potentially mediated by specific GPCRs in metabolic and endocrinological disorders. To discriminate the effects of ketone bodies per se, independently of weight loss, only studies comparing ketogenic vs isocaloric non-ketogenic diets will be considered as well as short-term tolerability and safety of KDs.