The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility

Reproductive Adaptation of Astyanax mexicanus Under Nutrient Limitation

Reproduction is a fundamental biological process for the survival and continuity of species. Examining changes in reproductive strategies offers valuable insights into how animals have adapted their life histories to different environments. Since reproduction is one of the most energy-intensive processes in female animals, nutrient scarcity is expected to interfere with the ability to invest in gametes. Lately, a new model to study adaptation to nutrient limitation has emerged; the Mexican tetra Astyanax mexicanus. This fish species exists as two different morphs, a surface river morph and a cave-dwelling morph. The cave-dwelling morph has adapted to the dark, lower biodiversity, and nutrient-limited cave environment and consequently evolved an impressive starvation resistance. However, how reproductive strategies have adapted to nutrient limitations in this species remains poorly understood. Here, we compared breeding activities and maternal contributions between laboratory-raised surface fish and cavefish. We found that cavefish produce different clutch sizes of eggs with larger yolk compared to surface fish, indicating a greater maternal nutrient deposition in cavefish embryos. To systematically characterize yolk compositions, we used untargeted proteomics and lipidomics approaches to analyze protein and lipid profiles in 2-cell stage embryos and found an increased proportion of sphingolipids in cavefish compared to surface fish. Additionally, we generated transcriptomic profiles of surface fish and cavefish ovaries using a combination of single cell and bulk RNA sequencing to examine differences in maternal contribution. We found that genes essential for hormone regulation were upregulated in cavefish follicular somatic cells compared to surface fish. To evaluate whether these differences contribute to their reproductive abilities under natural-occurring stress, we induced breeding in starved female fish. Remarkably, cavefish maintained their ability to breed under starvation, whereas surface fish largely lost this ability. We identified insulin-like growth factor 1a receptor (igf1ra) as a potential candidate gene mediating the downregulation of ovarian development genes, potentially contributing to the starvation-resistant fertility of cavefish. Taken together, we investigated the female reproductive strategies in Astyanax mexicanus, which will provide fundamental insights into the adaptations of animals to environments with extreme nutrient deficit.

Impact of preconceptional intermittent fasting on reflex ontogenesis, physical and somatic development of the offspring of Wistar rats

BACKGROUND

Intermittent fasting (IF) has health benefits; however, little is known about its effects on the offspring when practiced by dams in the preconception period. The aim of the study was to evaluate the impact of IF during the preconception period on physical and somatic parameters, as well as on the reflex ontogenesis of Wistar rat offspring.

METHODS

The female rats were randomized into two groups: control (CG) and intermittent fasting group (IF) submitted to a feed restriction of 16 h for four weeks during the preconception period. Reproductive performance, body weight, and energy intake were evaluated in dams. Reflex ontogeny, physical and somatic development, brain fatty acids and the brain histology were evaluated in the offspring.

RESULTS

IF did not change the reproductive performance or weight of dams during the preconception period. An acceleration of vibrissae placing and negative geotaxis parameters of reflex ontogenesis was observed, as well as anticipation of the following physical development indicators: ear unfolding, an eruption of upper incisor teeth, and inferior teeth in the IF offspring. Although the nervous tissue did not present histological changes, the content of some brain fatty acids was found in greater amounts in the IF offspring such as dihomo-γ-linolenic acid (0.66 ± 0.01 %) and eicotrienoic acid (0.58 ± 0.03 %).

CONCLUSION

IF during preconception did not change the body weight or reproductive performance of the dams, and promoted beneficial effects on the neurodevelopment of the offspring in the early life.

Impact of maternal body mass index on pregnancy outcomes following frozen embryo transfer: A systematic review and meta-analysis

OBJECTIVE

There is still a significant gap in understanding how maternal body mass index (BMI) impacts outcomes of pregnancy after frozen embryo transfer (FET). This review aims to evaluate the effects of various BMI categories on clinical pregnancy and live birth rates in women undergoing FET.

METHODS

PubMed, Scopus, Embase, and Web of Science databases were searched for studies, published up to March, 2024, using the keywords "obesity", "overweight", "obese", "maternal body mass index," "pregnancy outcomes," "frozen embryo transfer,". Eligible studies were selected based on predefined inclusion criteria, statistical analysis was performed using a random-effects model, and ther results were presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

A total of 17 studies were included in the meta-analysis. Pooled findings indicate significantly reduced live birth rate in underweight (OR 0.93; 95% CI: 0.89, 0.98) and obese (OR 0.85; 95% CI: 0.77, 0.93) women but not in those who were overweight (OR 0.96; 95% CI: 0.92, 1.00), compared to those with normal BMI. Further, only those women who were underweight (OR 0.91; 95% CI: 0.85, 0.97) had reduced odds of clinical pregnancy rate but not those who were overweight (OR 0.99; 95% CI: 0.94, 1.05) or obese (OR 0.92; 95% CI: 0.82, 1.03).

CONCLUSION

Maternal BMI impacts pregnancy outcomes after frozen embryo transfer, with underweight and obese women having lower live birth rates and only underweight women showing reduced clinical pregnancy rates compared to those with normal BMI. These findings underscore the importance of addressing BMI in women undergoing FET to improve pregnancy outcomes.

Reproductive Adaptation of Astyanax mexicanus Under Nutrient Limitation

Reproduction is a fundamental biological process for the survival and continuity of species. Examining changes in reproductive strategies offers valuable insights into how animals have adapted their life histories to different environments. Since reproduction is one of the most energy-intensive processes in female animals, nutrient scarcity is expected to interfere with the ability to invest in gametes. Lately, a new model to study adaptation to nutrient limitation has emerged; the Mexican tetra Astyanax mexicanus . This fish species exists as two different morphs, a surface river morph and a cave-dwelling morph. The cave-dwelling morph has adapted to the dark, biodiversity, and nutrient-limited cave environment and consequently evolved an impressive starvation resistance. However, how reproductive strategies have adapted to nutrient limitations in this species remains poorly understood. Here, we compared breeding activities and maternal contributions between laboratory-raised surface fish and cavefish. We found that cavefish produce different clutch sizes of eggs with larger yolk compared to surface fish, indicating a greater maternal nutrient deposition in cavefish embryos. To systematically characterize yolk compositions, we used untargeted proteomics and lipidomics approaches to analyze protein and lipid profiles in 2-cell stage embryos and found an increased proportion of sphingolipids in cavefish compared to surface fish. Additionally, we generated transcriptomic profiles of surface fish and cavefish ovaries using a combination of single cell and bulk RNA sequencing to examine differences in maternal contribution. We found that genes essential for hormone regulation were upregulated in cavefish follicular somatic cells compared to surface fish. To evaluate whether these differences contribute to their reproductive abilities under natural-occurring stress, we induced breeding in starved female fish. Remarkably, cavefish maintained their ability to breed under starvation, whereas surface fish largely lost this ability. We identified insulin-like growth factor 1a receptor ( igf1ra ) as a potential candidate gene mediating the downregulation of ovarian development genes, potentially contributing to the starvation-resistant fertility of cavefish. Taken together, we investigated the female reproductive strategies in Astyanax mexicanus , which will provide fundamental insights into the adaptations of animals to environments with extreme nutrient deficit.

Serum metabolic profiles in quails: Effects of age, breed, and sex

Over the past decade, metabolomic research in livestock and poultry has gained considerable momentum; however, quail metabolomics still lags behind that of livestock species such as chickens, pigs, and cattle. Quails are important models due to their low-cost protein sources-both eggs and meat-and practical benefits such as minimal space requirements, high egg production, disease resistance, and rapid reproduction. Therefore, it is necessary to systematically understand the effects of various factors on quail metabolism to provide a theoretical basis for accurate feeding and breeding practices. In this study, liquid chromatography with tandem mass spectroscopy (LC-MS/MS)-based metabolomics was used to examine the effects of age, breed, and sex on the serum metabolic profile of quails. A total of 550 metabolites were identified. Relative to breed and sex, we found that age played a crucial role in influencing quail serum metabolites. At 20 days of age (D20), quails had high levels of serum thymidine and alpha-D-glucose, while at 70 days of age (D70), the lipids, including 3-isothujone, 15-deoxy-d-12,14-PGJ2, and 2-aminobut-2-enoate dominated the serum. Additionally, xanthine, hypoxanthine, diaminopimelic acid, and 2-deoxy-scyllo-inosose appeared to be specific metabolites of Japanese quail (JAPQ). Serum levels of N-acetylglutamic acid, hydroxypyruvic acid, carnosine, alloepipregnanolone, lumichrome, 6-hydroxynicotinate, and myristic acid were higher in D70 Hengyan white feather quails (HYWQ) than those in D70 JAPQ. Notably, this study also identified 2-hydroxy-2-ethylsuccinic acid and riboflavin as potential specific metabolites in female quails. Furthermore, integration analysis showed that amino acid biosynthesis and metabolism, as well as ABC transporters, were the key pathways distinguishing D20 from D70. Purine metabolism, pyrimidine metabolism, ABC transporters, and TCA cycle were the key pathways distinguishing HYWQ from JAPQ. Differences in energy metabolism and amino acid biosynthesis and metabolism were observed between males and females. These findings enhance our understanding of the dynamic changes in quail serum metabolites influenced by various factors and address the knowledge gap regarding serum metabolic changes at different stages in quails.

Nutritional Changes to Improve Female Fertility: Role of Obesity, Hormones, Dietary Patterns and Endocrine Disrupting Chemicals

Importance

Infertility affects around 180 million people in the world and can be influenced by a number of nutritional factors.

Objective

The idea of a pretreatment optimization including beneficial weight loss, adequate physical activity, and good lifestyle habits could enhance fertility for many couples who want to conceive a baby.

Results

There are different aspects related to nutrition, such as obesity (affecting 23%-30% of reproductive-aged women), dietary patterns (type of diet, good or bad habits, and physical activity), nutrients (vitamins or minerals), hormones (adipokines, among others), and endocrine-disrupting chemicals (phytoestrogens and bisphenol A, among others) that have a clear impact on women's fertility.

Evidence Acquisition

Findings have shown that a Mediterranean or balanced diet with an adequate weight loss in case of obesity and an appropriate serum concentration of different nutrients with low endocrine-disrupting exposure could improve female fertility. In addition, the context is quite important, as there are many differences between overweight and low-weight women, and both can encounter difficulties conceiving.

Conclusions and Relevance

The aim of this review is to elucidate the impact of obesity and hormones in women's fertility. In addition, how dietary patterns could help people to increase probability of conception and birth using less fertility treatments cycles will be also analyzed. Moreover, the role of endocrine-disrupting chemicals, pollutants, and contaminants will be discussed.

Unlocking Female Fertility with a Specific Reproductive Exercise Program: Protocol of a Randomized Controlled Clinical Trail

According to World Health Organization (WHO) data, 16% of people are affected by infertility across the globe. One underlying factor is the age-related decline of ovarian reserve (DOR), which can lead to a higher chance of infertility and has no widely accepted treatment currently. Specific supplements and moderate exercise have been shown to improve fertility; however, there is no consensus to date on the type of exercise providing the best results. Our goal is to develop a novel exercise program combined with natural supplements for the improvement of fertility. We also propose a single-centered, randomized, open-label clinical trial using our newly developed exercise in the intervention group, compared to walking and no exercise in the other groups, to investigate the benefits of this exercise program in the future. In this study, we developed a structured, novel combination of exercises focusing on the pelvic and ovarian regions, core strengthening and improvement of blood circulation in this region. The 70 min full body "reproductive gymnastics", includes strengthening, stretching, and relaxation exercises combined with yoga-inspired moves and diaphragmatic breathing with meditation elements to activate the parasympathetic pathway and stress relief. We believe we can improve fertility through the combination of natural supplements and our targeted, moderate physiotherapy program in women with DOR.

Study on the correlation between energy availability and subclinical menstrual disorders

Background

There are few studies on the correlation between energy availability (EA) and subclinical menstrual disorders (SMD) in female athletes. This study aims to explore the differences in EA between female athletes with eumenorrhea and those with SMD, and the correlation between EA and the occurrence of SMD.

Methods

Luteal phase defect (LPD) and anovulation were defined as SMD. Fifty-six adult female college athletes with regular menstrual cycles and no clinical symptoms of menstrual disorders (MD) were selected as subjects. The EA of the subjects was monitored, and SMD were identified. The EA was compared between the two groups, and the correlation between EA and the occurrence of SMD was analyzed.

Results

Nineteen subjects were identified as LPD, and 7 subjects were identified as anovulation. The occurrence of SMD was 46.4%. The EA of subjects with SMD was lower than that of subjects with eumenorrhea (t = 3.165, p = 0.003), and EA was negatively correlated with the occurrence of SMD (r = -0.396, p = 0.000).

Conclusion

There were differences in EA between female college athletes with eumenorrhea and SMD. EA was negatively correlated with the occurrence of SMD.

Genetically Determined Plasma Docosahexaenoic Acid Showed a Causal Association with Female Reproductive Longevity-Related Phenotype: A Mendelian Randomization Study

BACKGROUND

Female reproductive aging remains irreversible. More evidence is needed on how polyunsaturated fatty acids (PUFAs) affect the female reproductive lifespan.

OBJECTIVES

To identify and validate specific PUFAs that can influence the timing of menarche and menopause in women.

METHODS

We utilized a two-sample Mendelian randomization (MR) framework to evaluate the causal relationships between various PUFAs and female reproductive longevity, defined by age at menarche (AAM) and age at natural menopause (ANM). Our analyses leveraged summary statistics from four genome-wide association studies (GWASs) on the plasma concentrations of 10 plasma PUFAs, including 8866 to 121,633 European individuals and 1361 East Asian individuals. Large-scale GWASs for reproductive traits provided the genetic data of AAM and ANM from over 202,323 European females and 43,861 East Asian females. Causal effects were estimated by beta coefficients, representing, for each increase in the standard deviation (SD) of plasma PUFA concentration, the yearly increase in AAM or ANM. Replications, meta-analyses, and cross-ancestry effects were assessed to validate the inference.

CONCLUSIONS

Higher plasma DHA was identified to be associated with delayed natural menopause without affecting menarche, offering a potential intervention target for extending reproductive longevity.

Metabolic status is a key factor influencing proteomic changes in ewe granulosa cells induced by chronic BPS exposure

BACKGROUND

Bisphenol S (BPS) is the main substitute for bisphenol A (BPA), a well-known plasticiser and endocrine disruptor. BPS disrupts ovarian function in several species. Moreover, a few studies have reported that the effects of BPS might be modulated by the metabolic status, and none have characterised the granulosa cell (GC) proteome after chronic BPS exposure.

OBJECTIVES

This study aimed to decipher the mechanisms of action of chronic BPS exposure on the proteome of ewe GCs while considering the interaction between a deliberate contrasted metabolism and reproductive function.

METHODS

Forty ewes were split into two groups with contrasted diets: restricted (R, n = 20) and well-fed (WF, n = 20). The R and WF ewes were subdivided according to the dose of BPS administered through the diet (0-50 µg/kg/day), forming four groups: R0, R50, WF0 and WF50. After 3-month BPS daily exposure, GCs were recovered during the pre-ovulatory stage and proteins were analysed by nano-liquid chromatography coupled with tandem mass spectrometry.

RESULTS

Chronic exposure to BPS affected the GC proteome differently according to the ewe metabolic status. Fifty-nine out of 958 quantified proteins were differentially abundant between groups and are mainly involved in carbohydrate and lipid pathways. Unsupervised hierarchical clustering of differentially abundant proteins (DAPs) identified four clusters of 34, 6, 5 and 14 proteins according to the BPS exposure and diet interaction. Pairwise comparisons between groups also revealed a strong effect of BPS exposure and diet interaction. Functional analysis of DAPs highlighted that BPS upregulated β-glucuronidase (GUSB; p = 0.002), a protein especially able to deconjugate bisphenol glucuronides (BP-g). Moreover, among unexposed ewes, GUSB was detected only in well-fed ewes.

DISCUSSION

Conjugation of glucuronides inhibits the oestrogenic activity of bisphenols. Upregulation of GUSB in ewes dosed with BPS would prolong the oestrogenic effects of BPS by deconjugating BPS-g into free BPS. In addition, literature has reported an up-regulation of GUSB in people suffering from obesity. Therefore, people suffering from obesity could be subjected to prolonged and aggravated exposure to BPS. These data highlighted the deleterious effects of BPS and its interaction with metabolic status.

Probiotic Lactobacillus rhamnosus modulates MCLR-induced oogenesis disorders in zebrafish: Evidence from the transcriptome

Microcystin-LR (MCLR) produced by cyanobacterial blooms have received global attention. MCLR has been recognized as a reproductive toxin to fish and poses a threat to ecosystem stability. It has been proven that probiotic dietary management can improve reproductive performance of fish. It is worth paying attention to exploring whether probiotic management can alleviate the reproductive toxicity caused by MCLR. In this investigation, adult zebrafish were exposed to different doses of MCLR solution (0, 2.2, and 22 μg/L) with or without the Lactobacillus rhamnosus GG supplementation for a duration of 28 days. The results showed that female zebrafish spawning was reduced after exposure to MCLR, but this reduction was reversed when L. rhamnosus GG was added. To elucidate how L. rhamnosus GG mitigates reproductive toxicity caused by MCLR, we examined a series of indicators of MCLR accumulation, ovarian histology, hormones, and transcriptome levels. Our study showed that L. rhamnosus GG could alleviate oogenesis disorders and ultimately attenuate MCLR-induced reproductive toxicity by reducing MCLR accumulation in the gonads, modulating the expression of endocrine system and auto/paracrine factors. The transcriptome results revealed that single or combined exposure of MCLR and L. rhamnosus GG mainly affected the endocrine system, energy metabolism, and RNA degradation and translation. Overall, our results provide new insights for alleviating MCLR-induced reproductive toxicity and help promote healthy aquaculture.

Impact of high-fructose diet and metformin on histomorphological and molecular parameters of reproductive organs and vaginal microbiota of female rat

There are limited data on the effects of a high-fructose diet on the female reproductive system. Although metformin has some functional effects on female fertility, its reproductive outcome on high fructose diet-induced metabolic syndrome is unclear. The aim of the present study is to evaluate the impact of a high fructose diet on histomorphological and molecular parameters of the reproductive organs and vaginal microbiota as well as the treatment potential of metformin. Wistar albino rats were used in the study. The metabolic syndrome model was induced by a high-fructose diet in rats for 15 weeks. Metformin was orally administered once a day for the last 6 weeks. The high-fructose diet increased blood glucose, triglycerides, insulin, and ovarian testosterone levels; however, it reduced ovarian aromatase levels and follicle numbers and caused uterine inflammation. The high-fructose diet-induced molecular abnormalities on ovarian tissue were demonstrated by the downregulation of ovarian insulin signaling pathway proteins and dysregulation of ovarian mitogenic and apoptotic pathway proteins. A high-fructose diet caused vaginal dysbiosis, metformin increased probiotic bacteria in the vaginal microbiota. Our results revealed that metformin improves ovarian impairments by modulating hormonal balance, insulin level, mapk, and apoptotic signaling molecules, as well as regulating the vaginal microbiota.

Associations of periconception dietary glycemic index and load with fertility in women and men: a study among couples in the general population

BACKGROUND

The dietary glycemic index (GI) and load (GL) reflect carbohydrate quality and quantity, potentially impacting fertility through modulation of insulin sensitivity and generation of oxidative stress. While fertility is influenced by both women and men, reproductive research often emphasizes maternal factors. We first examined periconception dietary intake in both women and male partners, and subsequent associations of dietary GI and GL with fecundability and subfertility.

METHODS

Among 830 women and 651 male partners, participating in a population-based prospective cohort study from preconception onwards, we assessed periconception dietary intake and calculated GI and GL, using a food frequency questionnaire (FFQ) at median 12.4 weeks gestation (95% range 10.9, 18.4). Information on time to pregnancy was obtained through questionnaires, with subfertility defined as a time to pregnancy ≥ 12 months or use of assisted reproductive technology.

RESULTS

In the periconception period, mean energy intake in women was 1870 kcal (SD: 500; 46% carbohydrates, 16% protein, 33% fat; dietary GI 56.2 (SD: 3.5) and GL 141.4 (SD: 67.4)). Mean energy intake in men was 2350 kcal (SD: 591; 43% carbohydrates, 16% protein, 33% fat; dietary GI 56.8 (SD: 3.2) and GL 156.7 (SD: 75.4)). Median time to pregnancy was 4.8 months (IQR: 1.2, 16.4), with 30.6% of 830 women experiencing subfertility. Dietary GI and GL were not associated with fertility outcomes in women. In men, higher dietary GI and GL across the full range were associated with decreased fecundability, after adjusting for socio-demographic and lifestyle factors, as well as dietary GI or GL of female partners [FR: 0.91, 95% CI 0.83, 0.99; FR: 0.90, 95% CI 0.81, 0.99, per SDS increase in dietary GI and GL, respectively]. When assessing the combined influence of dietary GI clinical categories in women and men, both partners adhering to a low GI diet tended to be associated with increased fecundability, but not with subfertility risk.

CONCLUSIONS

Suboptimal periconception carbohydrate intake may be negatively associated with male fertility, but not with fertility outcomes in women. Further studies are needed to assess whether a lower GI and GL diet is a feasible lifestyle intervention to improve couples fertility.

Associations of nutritional status and dietary habits with the development of female infertility. A case-control study

Introduction

Female infertility is a multifactorial condition influenced by lifestyle and dietary factors. Understanding the relationship between nutritional status, dietary habits, and infertility could provide insights for targeted interventions.

Methods

A case-control study was conducted in health centers and hospitals in Alicante, Spain. The study included 60 infertile and 30 fertile women aged 18-40, selected through consecutive sampling. Data on body composition and dietary intake were collected and analyzed.

Results

Infertile women exhibited significantly lower muscle mass (p = 0.005) and larger hip circumference (p = 0.034) compared to fertile women. Additionally, a significant association was found between high red meat consumption and an increased risk of female infertility (p = 0.011).

Discussion

These results suggest that body composition and dietary habits, particularly muscle mass and red meat intake, play a key role in female fertility. Interventions aimed at improving muscle mass, reducing localized body fat, and limiting red meat consumption may enhance fertility outcomes. Further longitudinal research is needed to confirm these findings across diverse populations.

Novel Insights into Stereoselective Reproductive Toxicity Induced by Mefentrifluconazole in Earthworms (Eisenia fetida): First Report of Estrogenic Effects

Widespread use of the new chiral triazole fungicide mefentrifluconazole (MFZ) poses a threat to soil organisms. Although triazole fungicides have been reported to induce reproductive disorders in vertebrates, significant research gaps remain regarding their impact on the reproductive health of soil invertebrates. Here, reproduction-related toxicity end points were explored in earthworms (Eisenia fetida) after exposure for 28 d to soil containing 4 mg/kg racemic MFZ, R-(-)-MFZ, and S-(+)-MFZ. The S-(+)-MFZ treatment resulted in a more pronounced reduction in the number of cocoons and juveniles compared to R-(-)-MFZ treatment, and the expression of annetocin gene was significantly downregulated following exposure to both enantiomers. This reproductive toxicity has been attributed to the disruption of ovarian steroidogenesis at the transcriptional level. Further studies revealed that MFZ enantiomers were able to activate the estrogen receptor (ER). Indirect evidence for this estrogenic effect is provided by the introduction of 17β-estradiol, which also induces reproductive disorders through ER activation.

Contributions of white adipose tissue to energy requirements for female reproduction

Body composition impacts female fertility and there are established relationships between adipose tissue and the reproductive system. Maintaining functional adipose tissue is vital for meeting the energetic demands during the reproductive process, from ovulation to delivery and lactation. White adipose tissue (WAT) shows plastic responses to daily physiology and secretes diverse adipokines that affect the hypothalamic-pituitary-ovarian axis, but many other interorgan interactions remain to be determined. This review summarizes the current state of research on the dialogue between WAT and the female reproductive system, focusing on the impact of this crosstalk on ovarian and endometrial factors essential for fecundity.

The Role of the Mediterranean Diet in Assisted Reproduction: A Literature Review

The Mediterranean Diet, characterized by high consumption of plant-based foods, olive oil, moderate intake of fish and poultry, and low consumption of red meat and processed foods, has been suggested to improve assisted reproductive technology (ART) outcomes. This narrative review aimed to summarize and synthesize the evidence from observational studies on the associations between preconception adherence to the Mediterranean Diet and ART outcomes. PubMed/MEDLINE, Embase, ScienceDirect, Google Scholar, and Web of Science databases were searched to identify relevant studies. Seven observational studies (n = 2321 women undergoing ART) were included. Adherence to the Mediterranean Diet was assessed using food frequency questionnaires with 6-195 items. Three studies found that higher Mediterranean Diet scores were associated with improved clinical pregnancy rates (OR 1.4, 95% CI 1.0-1.9; RR 1.98, 95% CI 1.05-3.78) or live birth rates (RR 2.64, 95% CI 1.37-5.07). Two studies showed a positive effect on embryo yield (p = 0.028) and ovarian response. However, two studies reported no significant associations with ultimate ART success, and four studies found no effects on oocyte and embryo number or quality. The heterogeneity in study designs, Mediterranean Diet assessment methods, and ART protocols limited the strength of conclusions. Evidence for the effects of greater adherence to the Mediterranean Diet on ART outcomes is limited but promising. Future research should focus on conducting randomized controlled trials with standardized Mediterranean Diet assessment methods to establish causal relationships between Mediterranean Diet adherence and ART outcomes, and to elucidate potential mechanisms of action.

Determination of Fertility Hormones and Adipokines by LC-MRM/MS Analysis

Due to the increase in the rate of male and female infertility, assisted fertilization practices are currently adopted as valid support for couples unable to get pregnant. Analytical approaches for fertility hormone dosages are constantly being developed, following the technological progress of fertilization methods that have evolved for more than a century. Indeed, the analysis of fertility hormones in serum samples is a common clinical practice to check the fertility state, but absolute quantification of these hormones is a great challenge due to biological variability and low serum concentrations. Currently, ELISA (enzyme-linked immunosorbent assay) based methods are the most used analytical techniques to quantify hormones in blood in clinical settings. The current Article discusses the development of a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) to monitor multiple fertility hormones of a protein nature in a single chromatographic run, i.e., LH (luteinizing hormone), FSH (follicle-stimulating hormone), TSH (thyroid-stimulating hormone), AMH (anti-Müllerian hormone), adiponectin, ghrelin, leptin, glucagon, and obestatin. Particular attention has been paid to the AMH hormone, whose ELISA-based quantification is known to be controversial due to the poor reproducibility between the various kits used. For AMH, the internal standard method was used for the quantitative determination to compare mass spectrometry data to the ELISA assays performed by an accredited analysis laboratory on a cohort of samples from women aged between 18 and 60 years. The ability to monitor multiple transitions by LC-MRM/MS ensured both high specificity and high selectivity, which is necessary for the quantification of protein and steroid hormones, besides improvements in data reproducibility and reduced analysis times and costs.

Genome-wide variation study and inter-tissue communication analysis unveil regulatory mechanisms of egg-laying performance in chickens

Egg-laying performance is of great economic importance in poultry, but the underlying genetic mechanisms are still elusive. In this work, we conduct a multi-omics and multi-tissue integrative study in hens with distinct egg production, to detect the hub candidate genes and construct hub molecular networks contributing to egg-laying phenotypic differences. We identifiy three hub candidate genes as egg-laying facilitators: TFPI2, which promotes the GnRH secretion in hypothalamic neuron cells; CAMK2D, which promotes the FSHβ and LHβ secretion in pituitary cells; and OSTN, which promotes granulosa cell proliferation and the synthesis of sex steroid hormones. We reveal key endocrine factors involving egg production by inter-tissue crosstalk analysis, and demonstrate that both a hepatokine, APOA4, and an adipokine, ANGPTL2, could increase egg production by inter-tissue communication with hypothalamic-pituitary-ovarian axis. Together, These results reveal the molecular mechanisms of multi-tissue coordinative regulation of chicken egg-laying performance and provide key insights to avian reproductive regulation.

A metabolome-wide Mendelian randomization study prioritizes causal circulating metabolites for reproductive disorders including primary ovarian insufficiency, polycystic ovary syndrome, and abnormal spermatozoa

BACKGROUND

Accumulating studies have highlighted the significant role of circulating metabolomics in the etiology of reproductive system disorders. However, the causal effects between genetically determined metabolites (GDMs) and reproductive diseases, including primary ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), and abnormal spermatozoa (AS), still await thorough clarification.

METHODS

With the currently most comprehensive genome-wide association studies (GWAS) data of metabolomics, systematic two-sample Mendelian randomization (MR) analyses were conducted to disclose causal associations between 1,091 blood metabolites and 309 metabolite ratios with reproductive disorders. The inverse-variance weighted (IVW) method served as the primary analysis approach, and multiple effective MR methods were employed as complementary analyses including MR-Egger, weighted median, constrained maximum likelihood (cML-MA), contamination mixture method, robust adjusted profile score (MR-RAPS), and debiased inverse-variance weighted method. Heterogeneity and pleiotropy were assessed via MR-Egger intercept and Cochran's Q statistical analysis. Outliers were detected by Radial MR and MR-PRESSO methods. External replication and metabolic pathway analysis were also conducted.

RESULTS

Potential causal associations of 63 GDMs with POI were unearthed, and five metabolites with strong causal links to POI were emphasized. Two metabolic pathways related to the pathogenesis of POI were pinpointed. Suggestive causal effects of 70 GDMs on PCOS were detected, among which 7 metabolites stood out for strong causality with elevated PCOS risk. Four metabolic pathways associated with PCOS mechanisms were recognized. For AS, 64 GDMs as potential predictive biomarkers were identified, particularly highlighting two metabolites for their strong causal connections with AS. Three pathways underneath the AS mechanism were identified. Multiple assessments were conducted to further confirm the reliability and robustness of our causal inferences.

CONCLUSION

By extensively assessing the causal implications of circulating GDMs on reproductive system disorders, our study underscores the intricate and pivotal role of metabolomics in reproductive ill-health, laying a theoretical foundation for clinical strategies from metabolic insights.

RNAi-mediated glucose transporter 4 (Glut4) silencing inhibits ovarian development and enhances deltamethrin-treated energy depletion in Locusta migratoria

Energy metabolism is essential for insect development, reproduction and detoxification. Insects often reallocate energy and resources to manage external stress, balancing the demands of detoxification and reproduction. Glucose transport 4 (Glut4), a glucose transporter, is involved in glucose and lipid metabolism. However, the specific molecular mechanism of Glut4 in insect reproduction, and its role in the response to insecticide-induced oxidative stress remain unclear. In this study, LmGlut4 was identified and analyzed in Locusta migratoria. Silencing of LmGlut4 significantly reduced vitellogenin (Vg) biosynthesis in the fat body and Vg absorption by oocytes, ultimately hindering ovarian development and oocyte maturation. Knockdown of LmGlut4 also inhibited the biosynthesis of key insect hormones, such as juvenile hormone (JH), 20-hydroxyecdysone (20E) and insulin. Furthermore, LmGlut4 knockdown led to reduced triglyceride (TG) and glycogen content in the fat body and ovary, as well as decreased capacity for trehalose biosynthesis in adipocytes. Additionally, dsLmGlut4-treated locusts showed heightened sensitivity to deltamethrin, leading to increased triglyceride depletion during detoxification. This study sheds light on the biological function of LmGlut4 in the ovary and provides potential target genes for exploring biological pest management strategies.

Nutritional and exercise interventions to improve conception in women suffering from obesity and distinct nosological entities

Infertility among women, particularly those living with obesity, presents a multifaceted challenge with implications for reproductive health worldwide. Lifestyle interventions, mainly focusing on weight loss, have emerged as promising strategies to improve fertility outcomes in this population. This review aims to explore the effectiveness of various lifestyle interventions, encompassing dietary modifications and exercise regimens, in enhancing fertility outcomes among women with obesity and associated conditions such as polycystic ovary syndrome, congenital adrenal hyperplasia, type 2 diabetes mellitus, premenopause, hypothyroidism and eating disorders. Methodology of study search encompass a broad spectrum, ranging from interventions targeting weight management through slow or rapid weight loss to dietary approaches emphasizing whole food groups, specific nutrients, and dietary patterns like low-carbohydrate or ketogenic diets, as well as the Mediterranean diet. By synthesizing existing findings and recommendations, this review contributes to the understanding of lifestyle interventions in addressing infertility, with an emphasis on the population of women of reproductive age with excess weight and known or unknown infertility issues, while promoting their integration into clinical practice to optimize reproductive health and overall well-being.

Effects of Liquid Fructose Supplementation and Chronic Unpredictable Stress on Uterine Contractile Activity in Nonpregnant Rats

Increased fructose consumption and chronic stress, the major characteristics of modern lifestyle, impact human health; however, the consequences of their combination on the uterus remain understudied. In this study, we investigated contractile activity, morphology, and intracellular activity of antioxidant enzymes in uteri from virgin Wistar rats subjected to liquid fructose supplementation and/or unpredictable stress over 9 weeks. Contractile activity and uterine response to oxytocin or adrenaline were examined ex vivo using isolated bath chambers. Fructose supplementation, irrespective of stress, affected uterine morphology by increasing endometrium while decreasing myometrium volume density, attenuated uterine response to increasing doses of oxytocin, and increased glutathione peroxidase activity. Stress, irrespective of fructose, attenuated dose-dependent adrenaline-induced uterine relaxation. Stress, when applied solely, decreased mitochondrial superoxide dismutase activity. In the combined treatment, irregular estrous cycles and both reduced response to oxytocin and to adrenaline (as a consequence of fructose consumption and exposure to stress), along with fructose-related alteration of uterine morphology, were detected. In conclusion, fructose and stress affect uterine contractile activity, irrespective of each other, by inducing completely distinct responses in isolated uteri. In the combined treatment, the effects of both factors were evident, suggesting that the combination exerts more detrimental effects on the uterus than each factor individually.

High-fat diet-negative impact on female fertility: from mechanisms to protective actions of antioxidant matrices

Introduction

Excessive calorie intake poses a significant threat to female fertility, leading to hormonal imbalances and reproductive challenges. Overconsumption of unhealthy fats exacerbates ovarian dysfunction, with an overproduction of reactive oxygen species causing oxidative stress, impairing ovarian follicle development and leading to irregular ovulation and premature ovarian failure. Interest in biological matrices with high antioxidant properties to combat diet-related oxidative stress has grown, as they contain various bioactive factors crucial for neutralizing free radicals potentially preventing female reproductive health. This systematic review evaluates the female reproductive impact of biological matrices in mitigating oxidative damages induced by over calory habits and, in particular, high fat diets.

Methods

A comparative approach among mammalian models was utilized to interpret literature available data. This approach specifically investigates the antioxidant mechanisms of biological matrices on early and late ovarian folliculogenesis, under physiological and hormone-induced female reproductive cycle. Adhering to the PRISMA 2020 guidelines, only English-language publications from peer-reviewed international indexes were considered.

Results

The analysis of 121 publications meeting the inclusion criteria facilitated the identification of crucial components of biological matrices. These components, including carbocyclic sugars, phytonutrients, organosulfur compounds, and vitamins, were evaluated for their impact on ovarian follicle resilience, oocyte quality, and reproductive lifespan. The detrimental effects of oxidative stress on female fertility, particularly exacerbated by high saturated fat diets, are well-documented. In vivo studies across mammalian preclinical models have underscored the potential of antioxidants derived from biological matrices to mitigate diet-induced conditions. These antioxidants enhance steroidogenesis and ovarian follicle development, thereby improving oocyte quality. Additionally, discussions within these publications emphasized the clinical significance of these biological matrices, translating research findings into practical applications for female health.

Conclusion

Further research is essential to fully exploit the potential of these matrices in enhancing female reproduction and mitigating the effects of diets rich in fatty acids. This requires intensified in vitro studies and comprehensive collection of in vivo data before clinical trials. The promotion of ovarian resilience offers promising avenues for enhancing understanding and advancing female reproductive health world-wide.

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.

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

As a positional and geometrical isomer of linoleic acid, trans 10, cis 12 conjugated linoleic acid (t10c12-CLA) reduces white fat by reducing food intake, modulating lipid metabolism, and stimulating energy expenditure. However, the t10c12-CLA products are mostly mixtures, making it difficult to obtain accurate results. Studies are needed to investigate the effects of pure t10c12-CLA on animals and humans. In this study, we used the biallelic transgenic (tg) mice, which could produce t10c12-CLA itself, to investigate the effects of pure t10c12-CLA on female reproductive ability. The results showed that the body and relative ovary weights had no significant difference between tg and wild-type (wt) littermates at ages 3 or 10 weeks. While the fecundity test found that tg mice had a significantly longer first litter time (32.0 ± 4.70 days vs. 21.3 ± 2.31 days, P<0.05), and a significantly lower number of litters (4.75 ± 2.75 vs. 6.67 ± 0.57, P<0.05) when compared with wt mice during continuous mating within seven months. Hormone profiles showed that serum estradiol levels did not change in tg mice; however, significantly (P<0.05) decreased progesterone and increased prostaglandin E2 levels were observed in tg mice compared with those of wt mice. Hematoxylin-eosin staining showed no pathological characteristics in tg ovaries, except for the increased atresia follicles (P<0.05). Moreover, the tg mice had a significantly more extended diestrus period than the wt mice (48.4 ± 6.38% vs. 39.6 ± 3.81%, P<0.05). In summary, t10c12-CLA could affect serum progesterone and prostaglandin E2 levels, lead to a disordered estrus cycle, and impact the reproductive performance of female mice. This study provided theoretical and biosafety recommendations for applying t10c12-CLA in female mammals.

Genetic correlation and Mendelian randomization analyses support causal relationships between dietary habits and age at menarche

Dietary habits are essential in the mean age at menarche (AAM). However, the causal relationship between these factors remains unclear. Therefore, this study aimed to elucidate the genetic relationship between dietary habits and AAM. Genetic summary statistics for dietary habits were obtained from the UK Biobank. GWAS summary data for AAM was obtained from the ReproGen Consortium. Linkage disequilibrium score regression was used to test genetic correlations between dietary habits and AAM. The Mendelian randomization (MR) analyses used the inverse-variance weighted method. Genetic correlations with AAM were identified for 29 candi-date dietary habits, such as milk type (skimmed, semi-skimmed, full cream; coefficient = 0.2704, Pldsc = 1.13 × 10-14). MR evaluations revealed that 19 dietary habits were associated with AAM, including bread type (white vs. any other; OR 1.71, 95% CI 1.28-2.29, Pmr = 3.20 × 10-4), tablespoons of cooked vegetables (OR 0.437, 95% CI 0.29-0.67; Pmr = 1.30 × 10-4), and cups of coffee per day (OR 0.72, 95% CI 0.57-0.92, Pmr = 8.31 × 10-3). These results were observed to be stable under the sensitivity analysis. Our study provides potential insights into the genetic mechanisms underlying AAM and evidence that dietary habits are associated with AAM.

The kisspeptin system in and beyond reproduction: exploring intricate pathways and potential links between endometriosis and polycystic ovary syndrome

Endometriosis and polycystic ovary syndrome (PCOS) are two common female reproductive disorders with a significant impact on the health and quality of life of women affected. A novel hypothesis by evolutionary biologists suggested that these two diseases are inversely related to one another, representing a pair of diametrical diseases in terms of opposite alterations in reproductive physiological processes but also contrasting phenotypic traits. However, to fully explain the phenotypic features observed in women with these conditions, we need to establish a potential nexus system between the reproductive system and general biological functions. The recent discovery of kisspeptin as pivotal mediator of internal and external inputs on the hypothalamic-pituitary-gonadal axis has led to a new understanding of the neuroendocrine upstream regulation of the human reproductive system. In this review, we summarize the current knowledge on the physiological roles of kisspeptin in human reproduction, as well as its involvement in complex biological functions such as metabolism, inflammation and pain sensitivity. Importantly, these functions are known to be dysregulated in both PCOS and endometriosis. Within the evolving scientific field of "kisspeptinology", we critically discuss the clinical relevance of these discoveries and their potential translational applications in endometriosis and PCOS. By exploring the possibilities of manipulating this complex signaling system, we aim to pave the way for novel targeted therapies in these reproductive diseases.

[Influence of adherence to a mediterranean diet and nutritional status on ovarian reserve]

OBJECTIVE

Currently, esterility affects between 15% and 20% of couples of fertile age. Female reproductive success is mainly determined by age and ovarian reserve (OR). Recent studies highlight the influence of modifiable factors such as dietary habits and nutritional status on OR. In this regard, the Mediterranean Diet (MD) is postulated as a standard of healthy eating. Therefore, the objective of this paper was to analyze the influence of adherence to DM and nutritional status on the OR of infertile women.

METHODS

A descriptive cross-sectional study was carried out, lasting one year, between February 2022 and February 2023, in a sample of forty-five female patients who attended the Gynaecology-Esterility consultation at the Marina Salud Hospital in Denia (Spain) due to genital desire older than one year. An exploratory descriptive analysis based on univariate statistics was performed.

RESULTS

The mean age of the sample (n=45) was 31.84 (±3.99) years, with an average BMI of 26.27 (±6.08) kg/m2, with 44.4% (n=20) having excess body weight. The RO was measured based on AMH, with an average value of 2.32 (±1.59) ng/ml and RFA, with an average of 19.80 (±14.13) antral follicles. A statistically significant association was found between low adherence to DM and lower anti-Müllerian hormone (AMH; p=0.025) levels. In addition, an association was found between low consumption of vegetables (p=0.044), excessive consumption of red meat (p=0.027) and carbonated beverages (p=0.015) with insufficient AMH levels, indicative of low OR. Low fruit consumption was also found to be associated with low oestradiol levels (p=0.045). Statistically significant associations were also found reflecting the influence of nutritional status on OR.

CONCLUSIONS

One of the main factors conditioning the success of ART (assisted reproductive technology) is the woman's OR. The most widely used parameter to assess OR is AMH. Lifestyle and diet are modifiable factors that can influence OR. High adherence to DM and consumption of vegetables is associated with higher levels of AMH; however, high intake of red meat and carbonated beverages is associated with lower levels. Nutritional status, adherence to DM and dietary habits influence the status of OR, so it would be advisable to promote programmes to improve the population's diet in order to improve reproductive health.

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.

Association between oocyte donors' or recipients' body mass index and clinical outcomes after first single blastocyst transfers-the uterus is the most affected

OBJECTIVE

To assess whether high body mass index (BMI) in either oocyte donors or recipients is associated with poorer outcomes after the first single blastocyst transfer.

DESIGN

Retrospective study including 1,394 first blastocyst single embryo transfers (SETs) conducted by 1,394 recipients during oocyte donation cycles with the gametes retrieved from 1,394 women (January 2019-July 2021). Four BMI clusters were defined for both donors and recipients (underweight: <18.5 kg; normal weight: 18.5-24.9 kg; overweight: 25-29.9 kg; and obese: ≥30 kg).

SETTING

Network of private IVF centers.

PATIENTS

A total of 1,394 recipients aged 42.4 ± 4.0 and with a BMI of 23.2 ± 3.8 kg/m2, and 1,394 donors aged 26.1 ± 4.2 and with a BMI of 21.9 ± 2.5 kg/m2.

INTERVENTION

All oocytes were vitrified at 2 egg banks and warmed at 8 in vitro fertilization clinics that were part of the same network. Intracytoplasmic sperm injection, blastocyst culture, and either fresh or vitrified-warmed SETs were conducted. Putative confounders were investigated, and the data were adjusted through regression analyses.

MAIN OUTCOME MEASURES

The primary outcome was the live birth rate (LBR) per SET according to donors' and/or recipients' BMI. The main secondary outcome was the miscarriage rate (<22 gestational weeks) per clinical pregnancy.

RESULTS

The LBR per blastocyst SET showed no significant association with donors' BMI. Regarding recipients' BMI, instead, the multivariate odds ratio was significant in obese vs. normal-weight recipients (0.58, 95% confidence interval, 0.37-0.91). The miscarriage rate per clinical pregnancy was also significantly associated with recipients' obesity, with a multivariate odds ratio of 2.31 (95% confidence interval, 1.18-4.51) vs. normal-weight patients. A generalized additive model method was used to represent the relationship between predicted LBR or miscarriage rates and donors' or recipients' BMI; it pictured a scenario where the former outcome moderately but continuously decreases with increasing recipients' BMI to then sharply decline in the BMI range of 25-35 kg/m2. The miscarriage rate, instead, increases almost linearly with respect to both donors' and recipients' increasing BMI.

CONCLUSION

Obesity mostly affects the uterus, especially because of higher miscarriage rates. Yet, poorer outcomes can be appreciated already with a BMI of 25 kg/m2 in both oocyte donors and recipients. Finer markers of nutritional homeostasis are therefore desirable; recipients should be counseled about poorer expected outcomes in cases of overweight and obesity; and oocyte banks should avoid assigning oocytes from overweight donors to overweight and obese recipients.

Ovarian nesfatin-1 in Hemidactylus flaviviridis: Reproductive phase-dependent expression, role and hormonal regulation

Nesfatin-1 has recently emerged as a modulator of ovarian functions in mammals. Studies in non-mammalian vertebrates, though limited and majorly restricted to fishes, have evidenced a role of this peptide in the regulation of ovarian steroidogenesis and oocyte maturation. Interestingly, nesfatin-1 remains completely unexplored in reptiles. Therefore, the present study aimed to identify nesfatin-1 and elucidate its role and regulation in the ovary of Hemidactylus flaviviridis. Ovarian expression of nucb2/nesfatin-1 was highest during late recrudescence and breeding while it was lowest during regression. Follicular stage-dependent expression analysis showed significantly high expression of nucb2/nesfatin-1 in previtellogenic follicles. Further, in vitro treatment of recrudescent wall lizard ovaries with nesfatin-1 resulted in increased expression of anti-apoptotic gene, bcl-2, along with a concomitant decline in the pro-apoptotic gene, caspase-3. In addition, proliferation/differentiation markers like scf, c-kit, pcna, and bmp-15 were stimulated in ovaries incubated with the peptide. Ovarian steroidogenesis was also positively influenced by nesfatin-1 as treatment with the peptide resulted in heightened star expression as well as increased estradiol and progesterone production. Also, all concentrations of nesfatin-1 stimulated glucose uptake and metabolism in wall lizard ovary. Our observations provide the first evidence of ovarian functions of nesfatin-1 in a reptile. Further, ovarian nucb2/nesfatin-1 was differentially regulated by gonadotropin and sex steroids wherein its expression was stimulated by dihydrotestosterone (DHT) and 17β-estradiol (E2) but inhibited by follicle-stimulating hormone (FSH). In summary, this is the first report of the presence, reproductive stage-dependent expression, role, and regulation of ovarian nucb2/nesfatin-1 in H. flaviviridis.

Methylation of the leptin gene promoter is associated with a negative correlation between leptin concentration and body fat in Tupaia belangeri

AIMS

Leptin is a signaling protein secreted by white adipose tissue encoded by the obesity gene, and its main function is to regulate the food intake and energy metabolism in mammals. Previous studies had found that animal leptin concentration was positively correlated with its body fat, but the leptin concentration of Tupaia belangeri was negatively correlated with its body fat mass. The present study attempted to investigate the mechanisms of leptin concentration negatively correlated with its body fat mass in T. belangeri.

MATERIAL AND METHODS

We measured the leptin concentration of the two groups of animals by enzyme linked immunosorbent assay (ELISA) and quantified the leptin mRNA expression by qPCR. Then, the histological, transcriptomic, and bisulfite sequencing of the two groups of animals were studied. Moreover, to investigate the energy metabolism under the negative correlation, we also analyzed the metabolomics and metabolic rate in T. belangeri.

KEY FINDINGS

We revealed the negative correlation was mediated by leptin gene methylation of subcutaneous adipose tissue. Further, we also found that T. belangeri increased energy metabolism with leptin decreased.

SIGNIFICANCE

We challenge the traditional view that leptin concentration was positively correlated with body fat mass, and further revealed its molecular mechanism and energy metabolism strategy. This special leptin secretion mechanism and energy metabolism strategy enriched our understanding of energy metabolism of animals, which provided an opportunity for the clinical transformation of metabolic diseases.

The association between weight-adjusted-waist index and self-reported infertility among women of reproductive age in the United States

AIM

This study aimed to determine whether the weight-adjusted-waist index (WWI) affected infertility in women of childbearing age in the United States.

METHODS

In this study, a database from the 2013 to 2018 National Health and Nutrition Examination Survey (NHANES) was used. We analyzed 3374 participants' data cross-sectionally. The survey used WWI and fertility status as independent and dependent variables. To determine the effect of WWI, an analysis of the independent relationship between WWI and infertility was conducted using weighted multivariable logistic regression and a generalized additive mode (GAM). A smooth curve fitting test was used to calculate whether there was a linear association between WWI and the incidence rate of infertility, as well as subgroup analyses and interaction tests.

RESULTS

The prevalence of infertility was 10.19% among 3374 participants. Higher WWI quartiles were associated with higher infertility rates. Based on a fully adjusted model, the effects of WWI on fertility were positive (odds ratio = 1.39, 95% confidence interval: 1.17-1.66). As a result of smooth curve fitting, the association was linear across the entire WWI. Different characteristics were associated with different risks of infertility in subgroup analysis.

CONCLUSION

Among women of reproductive age in the United States, WWI levels were positively associated with infertility. This relationship needs to be confirmed by further studies.

Effect of hyperlipidemia on the outcome of in vitro fertilization in non-obese patients with polycystic ovary syndrome

Introduction

It is little known whether hyperlipidemia alone has adverse effects on the outcome of in vitro fertilization (IVF) in patients with polycystic ovarian syndrome (PCOS).

Methods

The PCOS patients with body mass index (BMI) < 30 kg/m2 were performed IVF or intracytoplasmic sperm injection treatment, including 208 fresh cycles and 127 frozen embryo transfer (FET) cycles. All the patients were divided into hyperlipidemia and control groups, and embryo quality and pregnancy outcomes between the two groups were compared.

Results

In the fresh cycles, total gonadotropin dosage in the control group was significantly lower than that in the hyperlipidemia group, and serum estradiol levels on trigger day were reversed (P < 0.05). The embryo fragment score was positively correlated with serum low-density lipoprotein level (r = 0.06, P < 0.05) and negatively with serum high-density lipoprotein (HDL) and lipoprotein A levels (r = -0.489 and -0.085, P < 0.01). Logistic regression analysis found that HDL was beneficial for clinical pregnancy (OR = 0.355, 95% CI: 0.135-0.938, P < 0.05). In the FET cycles, there were no differences in pulse index, systolic/diastolic ratio and serum estradiol and progesterone levels between the two groups, but resistance index in the hyperlipidemia group was significantly higher than that in the control group (P < 0.05).

Conclusion

Hyperlipidemia may increase the dosage of gonadotropin and have adverse effect on the embryo quality, endometrial receptivity, and clinical outcomes of lean PCOS patients. It is recommended that the non-obese patients with hyperlipidemia and PCOS perform lipid-lowering treatment before undergoing embryo transfer.

Feeding neurons integrate metabolic and reproductive states in mice

Balance between metabolic and reproductive processes is important for survival, particularly in mammals that gestate their young. How the nervous system coordinates this balance is an active area of study. Herein, we demonstrate that somatostatin (SST) neurons of the tuberal hypothalamus alter feeding in a manner sensitive to metabolic and reproductive states in mice. Whereas chemogenetic activation of SST neurons increased food intake across sexes, ablation decreased food intake only in female mice during proestrus. This ablation effect was only apparent in animals with low body mass. Fat transplantation and bioinformatics analysis of SST neuronal transcriptomes revealed white adipose as a key modulator of these effects. These studies indicate that SST hypothalamic neurons integrate metabolic and reproductive cues by responding to varying levels of circulating estrogens to modulate feeding differentially based on energy stores. Thus, gonadal steroid modulation of neuronal circuits can be context dependent and gated by metabolic status.

Beneficial effects of metformin on mice female fertility after a high-fat diet intake

Female fertility is highly dependent on energy balance. High fat diet (HFD) intake entails a risk of infertility and ovulatory disorders. Considering the increase in the prevalence of overweight and obesity over the last decades, it is crucial to understand the mechanisms involved in overweight-associated infertility. In this study, we evaluated the reproductive performance of female mice fed with a HFD and the effects of metformin administration on ovarian function in these mice. We hypothesized that one of the mechanisms involved in subfertility due to a HFD intake is the alteration of ovarian blood vessel formation. We found that mice fed with HFD had altered estrous cycles and steroidogenesis, increased ovarian fibrosis, fewer pups per litter and require more time to achieve pregnancy. HFD-fed mice also presented dysregulated ovarian angiogenesis and an increase in nuclear DNA damage in ovarian cells. Ovulation rates were lower in these animals, as evidenced both in natural mating and after ovulation induction with gonadotropins. Metformin ameliorated ovarian angiogenesis, improved steroidogenesis, fibrosis, and ovulation, decreased the time to pregnancy and increased litter sizes in HFD-fed mice. We conclude that ovarian angiogenesis is one of the mechanisms detrimentally affected by HFD intake. Since metformin could improve ovarian microvasculature, it may be an interesting strategy to study in women to shed light on new targets for patients with metabolic disturbances.

The interactive effects of psychosocial stress and diet composition on health in primates

Social disadvantage and diet composition independently impact myriad dimensions of health. They are closely entwined, as social disadvantage often yields poor diet quality, and may interact to fuel differential health outcomes. This paper reviews effects of psychosocial stress and diet composition on health in nonhuman primates and their implications for aging and human health. We examined the effects of social subordination stress and Mediterranean versus Western diet on multiple systems. We report that psychosocial stress and Western diet have independent and additive adverse effects on hypothalamic-pituitary-adrenal and autonomic nervous system reactivity to psychological stressors, brain structure, and ovarian function. Compared to the Mediterranean diet, the Western diet resulted in accelerated aging, nonalcoholic fatty liver disease, insulin resistance, gut microbial changes associated with increased disease risk, neuroinflammation, neuroanatomical perturbations, anxiety, and social isolation. This comprehensive, multisystem investigation lays the foundation for future investigations of the mechanistic underpinnings of psychosocial stress and diet effects on health, and advances the promise of the Mediterranean diet as a therapeutic intervention on psychosocial stress.

Dietary Protein Regulates Female Estrous Cyclicity Partially via Fibroblast Growth Factor 21

Fibroblast growth factor 21 (FGF21), a hormone predominantly released in the liver, has emerged as a critical endocrine signal of dietary protein intake, but its role in the control of estrous cyclicity by dietary protein remains uncertain. To investigated the role of FGF21 and hypothalamic changes in the regulation of estrous cyclicity by dietary protein intake, female adult Sprague-Dawley rats with normal estrous cycles were fed diets with protein contents of 4% (P4), 8% (P8), 13% (P13), 18% (P18), and 23% (P23). FGF21 liver-specific knockout or wild-type mice were fed P18 or P4 diets to examine the role of liver FGF21 in the control of estrous cyclicity. Dietary protein restriction resulted in no negative effects on estrous cyclicity or ovarian follicular development when the protein content was greater than 8%. Protein restriction at 4% resulted in decreased bodyweight, compromised Kiss-1 expression in the hypothalamus, disturbed estrous cyclicity, and inhibited uterine and ovarian follicular development. The disturbed estrous cyclicity in rats that received the P4 diet was reversed after feeding with the P18 diet. Liver Fgf21 mRNA expressions and serum FGF21 levels were significantly increased as dietary protein content decreased, and loss of hepatic FGF21 delayed the onset of cyclicity disruption in rats fed with the P4 diet, possibly due to the regulation of insulin-like growth factor-1. Collectively, severe dietary protein restriction results in the cessation of estrous cyclicity and ovarian follicle development, and hepatic FGF21 and hypothalamic Kiss-1 were partially required for this process.

Differential effects of western versus mediterranean diets and psychosocial stress on ovarian function in female monkeys (Macaca fascicularis)

Ovarian dysfunction increases risk for chronic diseases of aging including cardiovascular disease, depression, cognitive impairment, as well as bone and muscle loss which promote frailty. Psychosocial stress can disrupt ovarian function, and recent observations suggest that consumption of a Western Diet may also. Determination of causal relationships among diet, psychosocial stress, and ovarian physiology is difficult in humans. Long-tailed (a.k.a. cynomolgus) macaques (Macaca fascicularis) are an excellent translational model for the study of diet and psychosocial effects on ovarian physiology and aging-related processes. They have 28-day menstrual cycles with hormonal fluctuations like those of women, and similar physiologic responses to alterations and/or cessation of cyclicity. We examined ovarian function in 38 middle-aged socially housed females fed either a Western or Mediterranean diet for 31 months (≈ a 9-year period for humans). During the last year, we examined cycle length and peak progesterone per cycle using blood sampling (3/week) and vaginal swabbing for menses (6/week). Repeated measures analysis revealed a circannual pattern consistent with increased menstrual cycle disturbance during the late Summer and early Fall (F(11,348)= 4.05 p < 0.001). In addition, both Western diet (F(1,34)= 3.99; p = 0.05) and the stress of low social status (F(1,34)= 3.99; p = 0.04) reduced mean progesterone levels. Thus, on average, subordinates in the Western group had the lowest average progesterone levels (10.02 ng/pl). Compared to Western diets, Mediterranean diets exhibited protective effects via menstrual cycle regularity. For dominant monkeys, consuming Mediterranean diets resulted in significantly greater likelihood of having regular menstrual cycles. Mediterranean diets also protected individuals from shorter than normal menstrual cycles. The relationships between diet and menstrual regularity were partially mediated by both adrenal reactivity and social isolation. This study demonstrates the additive negative effects of poor diet and psychosocial stress on ovarian physiology in mid-life and lays the groundwork for future investigations to uncover their impact on metabolic signatures of accelerated aging. The results also suggest that - compared to Western-style diets - a Mediterranean diet may exert a protective influence against ovarian dysfunction and its pathologic sequelae.

Effects of dietary coenzyme Q10 supplementation during gestation on the embryonic survival and reproductive performance of high-parity sows

BACKGROUND

Fertility declines in high-parity sows. This study investigated whether parity-dependent declines in embryonic survival and reproductive performance could be restored by dietary coenzyme Q10 (CoQ10) supplementation.

METHODS

Two experiments were performed. In Exp. 1, 30 young sows that had completed their 2^nd parity and 30 high-parity sows that had completed their 10^th parity, were fed either a control diet (CON) or a CON diet supplemented with 1 g/kg CoQ10 (+ CoQ10) from mating until slaughter at day 28 of gestation. In Exp. 2, a total of 314 post-weaning sows with two to nine parities were fed the CON or + CoQ10 diets from mating throughout gestation.

RESULTS

In Exp. 1, both young and high-parity sows had a similar number of corpora lutea, but high-parity sows had lower plasma CoQ10 concentrations, down-regulated genes involved with de novo CoQ10 synthesis in the endometrium tissues, and greater levels of oxidative stress markers in plasma and endometrium tissues. High-parity sows had fewer total embryos and alive embryos, lower embryonic survival, and greater embryo mortality than young sows. Dietary CoQ10 supplementation increased the number of live embryos and the embryonic survival rate to levels similar to those of young sows, as well as lowering the levels of oxidative stress markers. In Exp. 2, sows showed a parity-dependent decline in plasma CoQ10 levels, and sows with more than four parities showed a progressive decline in the number of total births, live births, and piglets born effective. Dietary supplementation with CoQ10 increased the number of total births, live births, and born effective, and decreased the intra-litter covariation coefficients and the percentage of sows requiring farrowing assistance during parturition.

CONCLUSIONS

Dietary CoQ10 supplementation can improve the embryonic survival and reproductive performance of gestating sows with high parity, probably by improving the development of uterine function.

Time-to-conception and clinical pregnancy rate with a myo-inositol, probiotics, and micronutrient supplement: secondary outcomes of the NiPPeR randomized trial

OBJECTIVE

To determine whether a combined myo-inositol, probiotics and micronutrient nutritional supplement impacts time-to-natural-conception and clinical pregnancy rates.

DESIGN

Secondary outcomes of a double-blind randomized controlled trial.

SETTING

Community recruitment.

PATIENTS

Women aged 18 to 38 years planning to conceive in the United Kingdom, Singapore, and New Zealand, excluding those with diabetes mellitus or receiving fertility treatment.

INTERVENTION

A standard (control) supplement (folic acid, iron, calcium, iodine, β-carotene), compared with an intervention additionally containing myo-inositol, probiotics, and other micronutrients (vitamins B2, B6, B12, D, zinc).

MAIN OUTCOME MEASURES

Number of days between randomization and estimated date of natural conception of a clinical pregnancy, as well as cumulative pregnancy rates at 3, 6, and 12 months.

RESULTS

Of 1729 women randomized, 1437 (83%; intervention, n=736; control, n=701) provided data. Kaplan-Meier curves of conception were similar between intervention and control groups; the time at which 20% achieved natural conception was 90.5 days (95% confidence interval: 80.7, 103.5) in the intervention group compared with 92.0 days (76.0, 105.1) in the control group. Cox's proportional hazard ratios (HRs) comparing intervention against control for cumulative achievement of pregnancy (adjusted for site, ethnicity, age, body mass index, and gravidity) were similar at 3, 6, and 12 months. Among both study groups combined, overall time-to-conception lengthened with higher preconception body mass index, and was longer in non-White than in White women. Among women who were overweight the intervention shortened time-to-conception compared with control regardless of ethnicity (12-month HR=1.47 [1.07, 2.02], P=.016; 20% conceived by 84.5 vs. 117.0 days) and improved it to that comparable to nonoverweight/nonobese women (20% conceived by 82.1 days). In contrast, among women with obesity, time-to-conception was lengthened with intervention compared with control (12-month HR=0.69 [0.47, 1.00]; P=.053; 20% conceived by 132.7 vs. 108.5 days); an effect predominantly observed in non-White women with obesity.

CONCLUSIONS

Time-to-natural-conception and clinical pregnancy rates within a year were overall similar in women receiving the intervention supplement compared with control. Overweight women had a longer time-to-conception but there was suggestion that the supplement may shorten their time-to-conception to that comparable to the nonoverweight/nonobese women. Further studies are required to confirm this.

CLINICAL TRIAL REGISTRATION NUMBER

clinicaltrials.gov (NCT02509988).

Socioeconomic disparities in fertility treatments and associated likelihood of livebirth following in vitro fertilization

OBJECTIVE

To determine whether neighborhood-level socioeconomic characteristics are associated with the likelihood of livebirth (LB) following in vitro fertilization (IVF). Specifically, we evaluated neighborhood-level household income, unemployment rate, and educational attainment.

DESIGN

A retrospective cross-sectional study was conducted for patients undergoing autologous IVF cycles.

SETTING

Large academic health system.

INTERVENTIONS

For each patient, ZIP code of residence was used as a proxy for neighborhood. Neighborhood characteristics were compared between patients with and without LB. Generalized estimating model was used to adjust the association between SES factors and likelihood of a live birth with respect to relevant clinical factors.

RESULTS

A total of 4942 autologous IVF cycles from 2768 patients were included: 1717 (62.0%) had at least one associated LB. Patients who achieved LB from IVF were younger, had higher anti-Mullerian hormone (AMH) levels, lower body mass index (BMI), and differed by ethnic background, primary language, and neighborhood socioeconomic characteristics. In a multivariable model, language, age, AMH, and BMI were associated with a live birth from IVF. None of the neighborhood-level socioeconomic variables were associated with the total number of IVF cycles or cycles required to achieve first LB.

CONCLUSION

Patients living in neighborhoods with lower annual household income have lower odds of livebirth after IVF compared to those living in more affluent areas, despite undergoing the same number of IVF stimulation cycles.

Percentages of serum, liver and adipose tissue fatty acids and body weight are affected in female rats by long-term Central kisspeptin treatments

This study was conducted to determine the possible effects of long-term exogenous kisspeptin and its antagonist P234 on serum, liver and adipose tissue fatty acids (FA) profiles, as well as body weight, in female rats. Kisspeptin (50 pmol) and P234 (1 nmol) were administrated to the weaned Sprague-Dawley female rats by an intracerebroventricular injection from the 26th postnatal day to the 60th postnatal day. Percentages of the serum total saturated FA (∑SFA) and total monounsaturated FA (∑MUFA) were lower in the kisspeptin group. In the adipose tissue, ∑SFA was lower and total unsaturated FA higher in the P234 group. Moreover, long-term central kisspeptin injection caused a decrease in the body weight. When compared to the kisspeptin group, the final body weights were higher in the P234 and kisspeptin + P234 groups. According to our results, we suggest that kisspeptin has a regulatory role in FA metabolism and regulation of body weight.

Differential effects of continuous and intermittent daytime food deprivation periods on metabolism and reproductive performance in diurnal zebra finches

We investigated whether food availability effects on metabolism and reproduction are the result of the sum effect of daily feeding (food availability) and starvation (food deprivation) periods. Adult zebra finches were paired and subjected to a time-restricted feeding (TRF) regimen consisting of continuous and intermittent daytime food deprivation periods. Birds were given food during the 12-h day for a total of 4-h in the evening (1 *4-h, hour 8-12), or in 2 splits of 2 h each (2 * 2-h) or 4 splits 1 h each (4 * 1-h), with controls on food ad libitum, until they had the first egg clutch. TRF caused significant changes in hepatic expression of metabolism-associated sirt1, egr1, pparα and foxo1 genes despite no difference in the food intake, body mass and blood glucose levels. Importantly, TRF resulted in a significant reduction in plasma testosterone and estradiol levels, delayed nest-building and egg laying, and reduced clutch size. Concurrently, under TRF regimes, we found a significantly lower expression of th and mtr genes linked with motivation and affiliation (but not of dio2, dio3, gnrh1 and gnih genes linked with gonadal maturation) in the hypothalamus, and of star and hook 1 genes in the testes and star, cyp19 and erα genes in the ovary. These results demonstrate the importance of daily food deprivation times on the metabolism and reproduction, and suggest a possible provisioning of energy available from daily feeding for the maintenance of body condition at the expense of reproduction performance in diurnal animals.

Diet and Fertility Status: Relevance in Health and Disease

The prevalence of obesity and other metabolic disorders is increasing worldwide [...].

The Influence of Metabolic Factors and Diet on Fertility

Infertility is a disease globally affecting 20-30% of the reproductive age female population. However, in up to 50% on recorded cases, problems with infertility are ascribed to men; therefore, it is important to popularize healthy eating also in this group. During the last decade, it has been observed that society's lifestyle changed drastically: reduced energy expenditure in physical activity per day, increased consumption of hypercaloric and high-glycemic-index foods with high content of trans fats, and reduced consumption of dietary fiber, which negatively affects fertility. Increasing evidence points to a link between diet and fertility. It is becoming clear that well-planned nutrition can also contribute to the effectiveness of ART. The low-GI plant-based diet appears to have a positive effect, especially when it is based on Mediterranean dietary patterns: rich in antioxidants, vegetable protein, fiber, MUFA fatty acids, omega-3, vitamins, and minerals. Importantly, this diet has been shown to protect against chronic diseases associated with oxidative stress, which also translates into pregnancy success. As lifestyle and nutrition seem to be important factors affecting fertility, it is worth expanding knowledge in this regard among couples trying to conceive a child.

Chrononutrition behavior during the COVID-19 pandemic and its relationship with body weight among college students

Introduction

Students in colleges are exposed to unhealthy lifestyles and poor dietary choices. They are at risk of being overweight, skipping meals, and developing eating disorders. However, there is a paucity of information on their chrononutrition behavior, which is very important, especially concerning the timing of food consumption across the day. Therefore, the present study aimed to investigate chrononutrition behavior and its potential association with body weight status among college students in Malaysia.

Methods

This cross-sectional study was conducted on 409 college students aged above 18 in Malaysia. The chrononutrition behavior was assessed using the validated Chrononutrition Profile Questionnaire (CP-Q). The questionnaire was distributed using an online platform. Participants self-reported their body weight and height, and the Body Mass Index (BMI) was computed. Data were analyzed using the SPSS software.

Results

A total of 409 participants were recruited, with a mean age of 21.5 ± 2.2 years. The prevalence of underweight, normal, and overweight was 24.7, 49.4, and 25.9%, respectively. The chrononutrition behavior revealed that participants ate breakfast about four times/week (mean 4.27 ± 2.43 days), and only 135 (33.0%) consumed breakfast daily. The largest meal consumed was during lunch (75.8%), and the mean of snacking after the last meal was 3.23 ± 2.01 days. The prevalence of night eating was low, and most participants (70.9) did not wake up at night to eat. The frequency, however, was significantly higher in the underweight group compared to the normal weight group (p < 0.05). We observed a significant association between BMI and eating window, evening latency, evening eating, and night eating. It was found that the underweight had a poor eating window (p < 0.01), poor evening latency (p < 0.01), poor evening eating (p < 0.01), and poor night eating (p < 0.05) compared to those with normal and overweight BMI groups. In contrast to predictions, poor chrononutrition behavior was more likely to predict being underweight compared to normal (p < 0.05).

Conclusion

Underweight young adults are more likely to have poor chrononutrition behavior. The results of the present study suggest that future nutrition education should also focus on the chrononutrition behavior of college students.

The effects of weight loss-related amenorrhea on women's health and the therapeutic approaches: a narrative review

Background and Objective

Weight loss-related amenorrhea is defined as the reversible functional inhibition of the hypothalamic-pituitary-ovarian (HPO) axis associated with weight loss or low body weight, which occurs mostly in adolescents and women of reproductive age. The specific pathological mechanisms of this disease have not yet been elucidated, and the optimal evidence-based guidelines for its clinical assessment and management are limited. This review summarizes its adverse effects on female health, and the individualized, emerging, and multidisciplinary therapeutic approaches used to treat it.

Methods

We searched the PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) databases for Chinese and English literature on functional hypothalamic amenorrhea (FHA), and retrieved original articles (on basic and clinical research) and reviews published up to December 2022.

Key Content and Findings

We reviewed the findings on the unfavorable effects of weight loss-related amenorrhea with a focus on reproduction, the skeletal and cardiovascular system, other endocrine effects, and mental health. Lifestyle changes and hormonal replacement have been shown to alleviate the underlying causes and lead to the recovery of menstruation. However, the efficacy of treatments is affected by many factors, such as psychological stress and heterogeneity.

Conclusions

Weight loss-related amenorrhea, which is an important type of FHA, is manifested by anovulation and hypoestrogenism, and has both short- and long-term adverse effects on women's overall health. It is difficult to alleviate its underlying causes. Individualized treatments need to be optimized and emerging or multidisciplinary therapeutic approaches need to be explored that aim to recover normal menstruation and ovulation, eliminate the undesirable effects of prolonged hypoestrogenism and alleviate psychological disorders.

Feeding Neurons Integrate Metabolic and Reproductive States in Mice

Trade-offs between metabolic and reproductive processes are important for survival, particularly in mammals that gestate their young. Puberty and reproduction, as energetically taxing life stages, are often gated by metabolic availability in animals with ovaries. How the nervous system coordinates these trade-offs is an active area of study. We identify somatostatin neurons of the tuberal nucleus (TNSST) as a node of the feeding circuit that alters feeding in a manner sensitive to metabolic and reproductive states in mice. Whereas chemogenetic activation of TNSST neurons increased food intake across sexes, selective ablation decreased food intake only in female mice during proestrus. Interestingly, this ablation effect was only apparent in animals with a low body mass. Fat transplantation and bioinformatics analysis of TNSST neuronal transcriptomes revealed white adipose as a key modulator of the effects of TNSST neurons on food intake. Together, these studies point to a mechanism whereby TNSST hypothalamic neurons modulate feeding by responding to varying levels of circulating estrogens differentially based on energy stores. This research provides insight into how neural circuits integrate reproductive and metabolic signals, and illustrates how gonadal steroid modulation of neuronal circuits can be context-dependent and gated by metabolic status.