Sustained obesity reduces litter size by decreasing proteins regulating folliculogenesis and ovulation in rats - A cafeteria diet model

Cafeteria Diet-Induced Obesity Alters Uterine Function by Disrupting Insulin and Sex Steroid Actions in Rats

BACKGROUND

The cafeteria diet (CAFD) model leads to obesity in rats, disrupting glucose metabolism, hormonal balance, and ovarian function, which results in macrosomic offspring. Insulin and ovarian hormones are essential for uterine growth, but there is limited research on how CAFD-induced obesity affects uterine function by modulating hormonal concentrations.

OBJECTIVE

This study aimed to assess how CAFD-induced obesity impacts uterine function in adult female rats by analyzing concentration of ovarian steroids and insulin,along with uterine responses.

METHODS

Postweaning female Sprague-Dawley rats (22 d), were divided into a control group fed pelleted rat chow and an obese group fed energy-dense snacks (CAFD) and pelleted rat chow for 32 wk. Body weight, food intake, energy intake, and estrous cycles were monitored during the experiment. After the experimental period, the uterine tissues were evaluated histologically, and protein expression was analyzed using western blotting and immunofluorescence. Serum hormone concentrations were assessed by ELISA, and uterine oxidative stress markers (superoxide dismutase, catalase, reduced glutathione, lipid peroxidase, and vitamin C) were measured using spectrophotometric methods.

RESULTS

CAFD-fed rats exhibited increased body weight, BMI, and abdominal girth, along with hyperglycemia, extended estrous cycles averaging 8.9 d and 40% reduction in uterine weight (P < 0.0001). The expression of proliferating cell nuclear antigen was elevated (P < 0.0001), with a significant increase in uterine cell proliferation. Obese rats showed lower concentrations of superoxide dismutase, reduced glutathione, and vitamin C, whereas concentrations of lipid peroxidase and catalase were higher in uteri (P < 0.0001). Exposure to CAFD significantly reduced serum concentrations of prolactin, progesterone, and estradiol. Moreover, progesterone receptor and its target molecules (Indian hedgehog homolog, peroxisome proliferator-activated receptor γ, and prolactin receptor) were upregulated, whereas estrogen receptor-α (P < 0.0001) and its responsive molecules (vascular endothelial growth factor and homeobox A11) were downregulated (P < 0.0001).

CONCLUSION

Consumption of CAFD causes obesity, which reduces ovarian steroid and insulin secretion and increases oxidative stress in the rat uterus, altering the expression of key molecules vital for uterine function.

Pre-gestational restraint stress affects reproductive outcomes in adult rats by modulating ovarian and uterine function

The impact of gestational stress on reproductive outcomes is well-established, but the effects of pre-gestational stress remain inconclusive. Using female Wistar rats, we demonstrated that pre-gestational stress negatively affects fertility and pregnancy outcomes. The rats were subjected to restraint stress (RS) for 15 days, with 3 h of stress each day, before mating. The RS group exhibited higher levels of corticosterone and prolactin, along with lower levels of adrenocorticotropic hormone (ACTH), indicating a successful stress model. Stressed rats showed reduced fertility and fecundity indices, longer conception times, and decreased levels of ovarian steroids, such as progesterone, testosterone, and estradiol. Additionally, the ovaries of the RS group had fewer antral follicles and more ovarian cysts. Elevated protein levels of cytochrome P450 side-chain cleavage enzyme (CYP11A1) and aromatase (CYP19A1), along with decreased levels of 17β-hydroxysteroid dehydrogenase (17β-HSD), indicating impaired ovarian steroidogenesis in stress exposed rats. In the RS group, there was a significant increase in proteins associated with folliculogenesis, specifically octamer-binding transcription factor 4 (OCT 4) and growth differentiation factor 9 (GDF 9). Additionally, proteins linked to ovulation, such as the prolactin receptor (PRLR), peroxisome proliferator-activated receptor-γ (PPAR-γ), and cyclooxygenase 2 (COX 2), were elevated. The increased levels of PRLR, progesterone receptor (PR), androgen receptor (AR), and estrogen receptor (ER) combined with heightened oxidative stress in the uteri of the RS group, suggest a potential disruption in uterine function. Overall, this research indicates that pre-gestational stress can significantly impact reproductive health by altering gonadotrophin and ovarian steroid dynamics in the female reproductive tract.

Dietary and lifestyle-related factors behind delayed conception in females

Delayed conceiving is a failure of a female to attain clinical pregnancy within a year without the use of contraception or any precautionary measure. The females of reproductive age (20-49 years) are the sufferers, that is, about 1.5 million or 10% of couples globally are facing this issue. Delayed conception can be caused by several reasons including diet, lifestyle, and genetic and clinical problems. Deficiencies or overconsumption of any nutrient may also cause delayed conception in females. Dietary deficits such as iron, iodine, zinc, folate, and vitamin D reduce the ovarian reserve. Heavy metals such as copper, manganese, lead, and cadmium also have an impact on fertility. Overconsumption of fast foods and nonhome-made foods increases the likelihood of infertility by 2-3. Smoking, physical activity, age, polycystic ovary syndrome (PCOS), obesity, and depression have all been considered lifestyle and clinical factors. If women have a sedentary lifestyle, too much exercise or obesity both contribute to infertility. In clinical factors, type 1 diabetes, insulin resistance, and hypertension mainly cause infertility. Our focus in this review is on the studies probe that how these variables contributed to delayed conception and how it can be controlled to help combat infertility. Prevention from delayed conception involves consuming a healthy and balanced diet that contains essential nutrients engaging in physical activity and abstaining from smoking, PCOS, and medical issues.

Establishment and validation of a nomogram model for predicting ovulation in the PCOS women

BACKGROUND

The mechanisms underlying ovulatory dysfunction in PCOS remain debatable. This study aimed to identify the factors affecting ovulation among PCOS patients based on a large sample-sized randomized control trial.

METHODS

Data were obtained from a multi-centered randomized clinical trial, the PCOSAct, which was conducted between 2011 and 2015. Univariate and multivariate analysis using binary logistic regression were used to construct a prediction model and nomogram. The accuracy of the model was assessed using receiver operating characteristic (ROC) curves and calibration curves.

RESULTS

The predictive variables included in the training dataset model were luteinizing hormone (LH), free testosterone, body mass index (BMI), period times per year, and clomiphene treatment. The ROC curve for the model in the training dataset was 0.81 (95% CI [0.77, 0.85]), while in the validation dataset, it was 0.7801 (95% CI [0.72, 0.84]). The model showed good discrimination in both the training and validation datasets. Decision curve analysis demonstrated that the nomogram designed for ovulation had clinical utility and superior discriminative ability for predicting ovulation.

CONCLUSIONS

The nomogram composed of LH, free testosterone, BMI, period times per year and the application of clomiphene may predict the ovulation among PCOS patients.

Associations of fertility parameters with fatty acids and DNA methylation in Mexican women undergoing in vitro fertilization

BACKGROUND

Fatty acids (FA) likely affect human fertility at multiple levels, as deviations from physiological FA profiles are obesogenic, and FA can modify DNA methylation (DNAm). Yet, the interplay of follicular fluid (FF) and serum FA with BMI and percentage body fat (PBF) in human fertility is not completely understood. Also, associations of DNAm with fertility are largely unexplored.

METHODS

Reproductive parameters ranging from retrieved oocyte number to infant birth weight, were recorded in Mexican women undergoing in vitro fertilization (n = 88). Multiple regression analysis sought BMI-adjusted and age-adjusted associations. Receiver operating characteristic analysis tested for discrimination between outcomes.

RESULTS

Associations of FF and serum FA were markedly distinct. While various FF FA (C16:1, C18:0, C20:2, C20:3, arachidonic acid) were significantly and inversely associated only with retrieved oocyte number, selected serum FA were associated with a broad range of pre-fertilization and post-fertilization parameters. Associations of BMI and FF FA were complex, as arachidonic acid was inversely associated with both BMI and retrieved oocyte number, while oleic acid (OA) was directly associated with BMI and PBF. Ultrasound-assessed clinical pregnancy outcome (CP) was directly associated with serum OA but inversely with its trans isomer elaidic acid (EA) and with BMI. Compounded BMI, serum EA and OA discriminated CP well (AUC = 0.74). Whole blood DNA methylation was significantly associated with and a moderate predictor (AUC = 0.66) of percent fertilized oocytes.

CONCLUSIONS

Overall FF FA pool composition rather than FA identity may impact oocyte production and cellular memory of FF FA is lost as the oocyte exits the follicular environment. The contrasting associations of BMI, FF OA and arachidonic acid suggest that the control of oocyte homeostasis by FF FA is uncoupled from BMI. Further studies are warranted to assess the potential of compounding BMI with serum EA and OA to predict CP.

Bisphenol A exposure modulates reproductive and endocrine system, mitochondrial function and cellular senescence in female adult rats: A hallmarks of polycystic ovarian syndrome phenotype

Bisphenol A (BPA) mimics estrogen and consequently suspected to be detrimental to female reproductive system. Biomonitoring confirms the BPA burden in body leading to a complex condition called polycystic ovarian syndrome (PCOS) which is frequently attributed to female infertility. Due to unclear precise molecular pathomechanisms of BPA in PCOS, we intend to examine the molecular mechanisms of the reproductive, endocrine, mitochondrial features, and cellular senescence in BPA-treated rats. We analyzed vaginal smears and ovarian follicles using microscope, assessed sex hormones by ELISA, analyzed BPA target gene expression by semi-quantitative RT-PCR, assessed senescence induction by β-galactosidase staining and immunofluorescence in BPA-treated rats. Our data showed hormonal imbalance, impaired folliculogenesis, abnormal expression patterns of target genes, CDKN2A overexpression and enhanced ROS levels in BPA-treated rats. This study provides insights on the effects of BPA exposure on ovulatory, hormonal, mitochondrial dysfunction, and senescence that benefit in better understanding of PCOS induced by BPA.

Prevalence and associated factors of infertility among 20-49 year old women in Henan Province, China

Background

Infertility is a reproductive health problem which affects not only individuals, families and social populations. Recently, the infertility rate in China has a trend of increase year by year, and few studies have reported the infertility rate in Henan Province, China. The aim of this study was to investigate the current prevalence and associated factors of infertility among women of childbearing age in Henan Province, China.

Methods

This cross-sectional study was conducted from March 2019 to October 2019. We sampled 765 women who were 20–49 years old in eight hospitals of four cities in Henan Province, China. This survey included a questionnaire, physical examination, vaginal ultrasound examinations, and serum anti-Mullerian hormone (AMH) assessment, all of which were conducted under uniform standards by trained personnel. According to the data collected from questionnaire, participants were divided into infertile and fertile groups and analyzed associated factors.

Results

Among all the 765 participants in this study, the prevalence of infertility was 24.58%. The prevalence of primary infertility was 6.54%, and the prevalence of secondary infertility was 18.04%. In logistic multivariate regression analyses, infertility was associated with age (p < 0.001), history of gynecological surgery (p < 0.001), sweet food (p = 0.003) and decreased ovarian reserve (DOR) (p < 0.001). After further analyses, factors associated with primary infertility were age of marriage (p = 0.006), age of first sexual intercourse (p = 0.003), long-term air-conditioning environment (p < 0.001), decreased ovarian reserve (p = 0.005) and age (p = 0.002). And factors associated with secondary infertility were history of gynecological surgery (p < 0.001), decreased ovarian reserve (p = 0.002), waist-to-hip ratio (WHR) above 0.85 (p = 0.043), delivery times (p = 0.001) and ages (p < 0.001).

Conclusion

The prevalence of infertility among women aged 20–49 was 24.58% and only 61.17% infertile women sought medical help in Henan Province, China. Age, history of gynecological surgeries and DOR may increase the risk of infertility. Local public health departments and medical professionals need to discharge their duty of reducing the high incidence of infertility and protecting women’s reproductive health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-021-01298-2.

Infertility prevalence rate has increased in the past 30 years. Infertility plagues thousands of women of childbearing age. Although not life-threatening, the detrimental influence of infertility to patients, their families, and society should not be underestimated, especially in China. In order to investigate the prevalence of infertility, determine the associated factors, and promote disease prevention and treatment, we conducted a cross-sectional study among 20–49 year old women in Henan, one of the central provinces of China.

This study distributed 920 questionnaires and collected 803 completed questionnaires. Interviews, questionnaires, and physical and ultrasound examinations were done.

Among all the 765 participants in this study, the prevalence of infertility was 24.58%. The prevalence of primary infertility was 6.54%, and the secondary infertility was 18.04%. Age, history of gynecological surgeries and DOR may increase the risk of infertility.

In conclusion, among women aged 20–49 years in Henan Province, China, the prevalence of infertility in 2019 was 24.58% and 61.17% of infertile women sought medical help.

High-fat diet and fructose drink introduced after weaning rats, induces a better human obesity model than very high-fat diet

In the present study, we associated a high-fat diet (HF group: 45% kcal from lipids) or very high-fat (VHF group: 60% kcal from lipids) diet with a fructose drink (10% fructose) for hydration. Normal rat chow that received the control diet (content 16.3% kcal from lipid-AIN93G) and water. The treatments were introduced soon after weaning and were administered for 70 days. We aimed to compare HF and VHF groups and find which acts as a better model mimicking human obesity. Body mass gain, final body weight, adipocyte area in inguinal depots, visceral and subcutaneous adipose depots, serum triacylglycerol, and VLDL-c were all higher in the HF group, followed by the VHF group, compared to the C group. Only the HF group showed hyperinsulinemia and hyperleptinemia and higher total caloric intake, Lee index, HOMA2-IR, and total cholesterol. Serum TNF-α and IL-6 levels were lower in the HF and VHF groups than in the C group at the end for 70 days. In Summary, the HF (45%) diet administered with fructose induced a higher similarity of metabolic and hormonal alterations associated with human obesity. PRACTICAL APPLICATIONS: High intake of lipids with sugary drinks has been associated with obesity and its comorbidities. Although a diet with 45% or 60% of lipids is considered hyperlipidic, they are different in their effects on eating behavior and also probably from a metabolic point of view. Common sense is that the reduction in intake of lipids is favorable to health. Our study shows that this is not wholly true, and this information contributes to the guidelines for the treatment of obesity. In addition, the scientific literature on the subject has shown the most diverse results and also the use of experimental models with few similarities with human obesity. Our findings can contribute as a good model of obesity initiated during childhood to investigate possible using nutritional strategies, or the adoption of ergogenic nutritional resources in future studies, for example.

Effect of Myristica fragrans extract on total body composition in cafeteria diet induced obese rats

It is of interest to evaluate the effect of Myristica fragrans on body composition of cafeteria diet induced obese rats. Thirty rats (150-160g) grouped into 5 and each group contains 6 rats. Group-1 was normal control and 2-5 groups were fed with cafeteria diet for 15 weeks to induce obesity. From 16th week to 25th week test drugs were given as mentioned in the experimental protocol. Body weight, BMI, changes in body composition was measured by TOBEC, adipose tissue weights, organ weights, abdominal circumference were measured according to standard methods. After 70days of treatment with MFE 200mg/kg, 400mg/kg Body weight reduced by 9.29%, 12.87% respectively. BMI was also decreased. Abdominal circumference, total fat percentage, organ weights, was substantially reduced. At 400mg/kg of MFE has shown maximum potentiality when compared with 200mg/kg. Orlistat 50mg was used as standard drug. Tetrahydrofuran, flavonoids, saponins, present in Myristica fragrans has shown anti obesity activity. Our findings explain the potentiality of phytochemicals as a potent anti obesity agent, provide scientific evidence for its traditional use and suggest the possible mechanism of action.