The Thyroid Hormone Axis and Female Reproduction

Impact of Laboratory-Measured Euthyroid Hashimoto's Thyroiditis on Reproductive Hormone Profile in Women with Obesity

Introduction: Hashimoto's thyroiditis is a common endocrinological disorder that often coexists with obesity. Thyroid hormones interact with the regulation of sex steroids, and thyroid autoimmunity has a negative impact on female fertility. There are studies showing when euthyroid state is achieved with hormone replacement therapy (HRT), the reproductive hormone profile is improved but they usually compare the reproductive hormones before and after HRT in the same individuals. Studies comparing patients with Hashimoto's thyroiditis in an euthyroid state receiving HRT with individuals having normal thyroid function are limited. Here, it was aimed to search the impact of euthyroid Hashimoto's thyroiditis on reproductive hormone profile in women living with obesity. Materials and Methods: Sixty-one randomly selected female patients with Hashimoto's thyroiditis were included as the case group and 60 patients without Hashimoto's thyroiditis were included as the control group, from our obesity center. The case group included patients who had menstrual cycles and were euthyroid under l-thyroxine treatment for at least 6 months. Data on weight, height, body mass index (BMI), waist circumference (WC), free thyroxine (fT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), cortisol, insulin, prolactin (PRL), follicular stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), progesterone (prog), testosterone (T), and dehydroepiandrosterone sulfate (DHEAS) levels, l-thyroxine treatment dosage (for case group), and accompanying diseases were recorded. The results were evaluated using SPSS. Results: A total of 121 patients were included in the study. Mean age was 41.8 ± 8.5 years in case and 38.6 ± 8.9 years in control group. There was no significant difference in weight, height, BMI, WC, or accompanying diseases between Hashimoto's thyroiditis and control group. fT4, anti-TPO, cortisol levels were higher in Hashimoto's thyroiditis group when compared with control group, but there was no significant difference for TSH, insulin, FSH, LH, E2, prog, T, DHEAS, or PRL. Conclusion: In women living with obesity, it is important to screen for Hashimoto's thyroiditis and achieve euthyroidism through effective LT4 treatment to promote a healthy reproductive system and improve fertility rates.

Perfluorooctanoic acid disrupts thyroid hormone biosynthesis by altering glycosylation of Na+/I- symporter in larval zebrafish

Perfluorooctanoic acid (PFOA) is a well-known thyroid disruptor that has been found to induce hypothyroidism. However, the exact molecular mechanism by which PFOA reduces thyroid hormone levels remains unclear. In this study, we have discovered that PFOA disrupts the glycosylation process of the sodium/iodide symporter (NIS), which inhibits the translocation of NIS onto the plasma membrane of thyroid follicular cells. Our results also demonstrate that PFOA disrupts thyroid stimulating hormone (TSH)-dependent signaling pathways involved in cellular glycosylation, impairing NIS glycosylation and reducing the ability of iodine uptake. This leads to an insufficiency of iodine for thyroid hormone production inside the follicular cells of the thyroid, resulting in lower-than-normal thyroxine levels detected in zebrafish larvae. These findings are consistent with our previously published data, which showed that PFOA induces neural behavior changes during the early stages of neuronal development in zebrafish. This new discovery provides valuable insights into the molecular characteristics of endocrine-disrupting chemicals (EDCs) that are known to affect the thyroid. It may also contribute to a better understanding of how altered glycosylation could be a potential risk factor for the association between exposure to specific per- and polyfluoroalkyl substances (PFAS) and various health effects in humans.

Organochlorine pesticides and epigenetic alternations in unexplained female infertility

Epigenetic alterations could potentially have a significant impact on the adverse reproductive consequences in connection with exposure to environmental contaminants. In this study, the changes in Thyroid Stimulating Hormone Receptor (TSHR) and Ataxia Telangiectasia Mutated (ATM) genes methylation related to exposure to certain Organochlorine Pesticides (OCLs) in women with unexplained female infertility (UFI) were investigated. Promoter methylation of TSHR and ATM genes was conducted using methylation specific PCR in blood from 113 UFI and 103 controls. The methylation percentage of the TSHR was 48 % in UFI and 50 % in controls and the difference was statistically insignificant. But, promoter methylation of ATM was significantly higher in UFI than controls (67.9 % and 43.3 % respectively, p = 0.042). Logistic regression analysis also revealed that some OCLs (2,4-DDE, γ-HCH, 2,4-DDT, β-HCH, 4,4-DDT, and 4,4-DDE) affected methylation of ATM promoter. Among total OCLs, there were significant correlations between the ATM promoter methylation and Ʃ3 HCH, Σ2 DDE, and Ʃ7 OCLs in an adjusted model. The study posits that OCLs could modify epigenetic markers, thereby impacting gene function. Hypermethylation of the ATM gene in UFI cases, and its association with selected and total OCLs, underscores the detrimental effects of the accumulation of environmental stressors on female reproductive health, potentially leading to UFI. Furthermore, the role of ATM-mediated DNA Double-Strand Break repair in reproductive health was highlighted. Additionally, this research underscores the need for further investigation into the relationship between ATM gene promoter methylation, pesticide exposure, and UFI across various populations.

Phthalates and Non-Phthalate Plasticizers and Thyroid Dysfunction: Current Evidence and Novel Strategies to Reduce Their Spread in Food Industry and Environment

Thyroid hormones (THs) play a crucial role in various biological functions, including metabolism, cell growth, and nervous system development, and any alteration involving the structure of the thyroid gland and TH secretion may result in thyroid disease. Growing evidence suggests that phthalate plasticizers, which are commonly used in a wide range of products (e.g., food packaging materials, children's toys, cosmetics, medical devices), can impact thyroid function, primarily affecting serum levels of THs and TH-related gene expression. Like phthalate compounds, recently introduced alternative plasticizers can leach from their source material into the environment, particularly into foods, although so far only a very limited number of studies have investigated their thyroid toxicity. This review aimed at summarizing the current knowledge on the role of phthalate and non-phthalate plasticizers in thyroid dysfunction and disease, describing the major biological mechanisms underlying this relationship. We will also focus on the food industry as one of the main players for the massive spread of such compounds in the human body, in turn conveyed by edible compounds. Given the increasing worldwide use of plasticizers and the essential role of THs in humans, novel strategies should be envisaged to reduce this burden on the thyroid and, in general, on human health.

Early-life exposure to PCBs and PFAS exerts negative effects on the developing central nervous system

Persistent organic pollutants (POPs) are ubiquitous in the environment and display the capacity to bioaccumulate in living organisms, constituting a hazard to both wildlife and humans. Although restrictions have been applied to prohibit the production of several POPs since the 1960s, high levels of these compounds can still be detected in many environmental and biological matrices, due to their chemical properties and significantly long half-lives. Some POPs can be passed from mother to the fetus and can gain entry to the central nervous system (CNS), by crossing the blood-brain barrier (BBB), resulting in significant deleterious effects, including neurocognitive and psychiatric abnormalities, which may lead to long-term socio-economic burdens. A growing body of evidence obtained from clinical and experimental studies has increasingly indicated that these POPs may influence neurodevelopment through several cellular and molecular mechanisms. However, studies assessing their mechanisms of action are still incipient, requiring further research. Polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) are two of the main classes of POPs associated with disturbances in different human systems, mainly the nervous and endocrine systems. This narrative review discusses the main PCB and PFAS effects on the CNS, focusing on neuroinflammation and oxidative stress and their consequences for neural development and BBB integrity. Moreover, we propose which mechanisms could be involved in POP-induced neurodevelopmental defects. In this sense, we highlight potential cellular and molecular pathways by which these POPs can affect neurodevelopment and could be further explored to propose preventive therapies and formulate public health policies.

Roles of thyroid and leptin hormones and their crosstalk in male reproductive functions: an updated review

PURPOSE

This review aims to provide updated information regarding the role of thyroid and leptin hormones and their crosstalk in affecting the male reproductive function in hypothyroid and obesity conditions.

METHOD

A wide literature search was made using online search engines on published articles using keywords including thyroid hormone, hypothyroidism, leptin hormone, hyperleptinemia, obesity, the relationship between thyroid and leptin hormones and male reproduction, and hypothyroidism, obesity, and male reproduction.

RESULTS

All information pertaining thyroid and leptin hormone effects on male reproduction, hypothyroidism, hyperleptinemia, and obesity effect on male fertility as well as the related molecular mechanisms are obtained.

CONCLUSION

Thyroid and leptin hormones individually play a significant role in male reproduction. Alterations of these hormones' levels could adversely affect the male reproductive functions. PI3K/AKT signaling was found to be the major signaling pathway involved in mediating the effect of both hormones on male reproduction. Impaired crosstalk between the two hormones may occur in hypothyroidism with obesity which would contribute towards male reproductive dysfunction.

Recent Advances in Individualized Clinical Strategies for Polycystic Ovary Syndrome: Evidence From Clinical Trials and Emerging Pharmacotherapies

PURPOSE

Clinical trials are advancing the treatment of polycystic ovary syndrome (PCOS), an endocrine disorder affecting 8-13% of women. Lifestyle interventions, including nutritional plans, physical activity, and stress management, can improve reproductive hormones and metabolic health. Novel pharmacotherapies targeting hormonal, metabolic, and reproductive abnormalities are being explored for individualized treatment. Combination therapies and lifestyle interventions like acupuncture, high-intensity interval training, and vitamin D3 supplementation are also being explored.

METHODS

We conducted a narrative review by searching English-language studies across electronic databases such as PubMed, Science direct, and Google Scholar for articles related to the topics of PCOS and novel drug therapies such as metformin, LIK-066, elagolix, saxenda, exenatide, clomiphene, letrozole, and other diagnostic interventions. Our review excluded preclinical studies and articles not in english.

FINDINGS

In addition to pharmacological treatments, lifestyle interventions such as Tung's acupuncture, high-intensity interval training (HIIT), and vitamin D3 supplementation have proven effective in managing symptoms of PCOS and enhancing overall health outcomes. These interventions offer a complementary approach to traditional medical therapies, emphasizing the importance of integrating lifestyle modifications into the treatment plan for women with PCOS.

IMPLICATIONS

This comprehensive approach underscores the importance of tailored treatments in optimizing clinical outcomes and quality of life for women with PCOS. The aim of this review is to highlight recent advancements in the treatment of PCOS through clinical trials and emerging pharmacotherapies, emphasizing the need for individualized and multifaceted treatment approaches.

TRα1 mutant suppresses KLF9 to cause endometrial metaplasia with ectopic IL-33 expression leading to uterine fibrosis and infertility

Thyroid hormone receptors (TRs) mediate the genomic actions of thyroid hormone. Mutations of THRA gene cause a human disease known as resistance to thyroid hormone (RTHα). We created a mouse model expressing a dominant negative mutated TRα1 (Thra1PV/+ mice) that exhibits growth retardation, bone abnormalities, constipation, and anemia, as found in RTHα patients. In addition, female Thra1PV/+ mice exhibit decreased fertility. In the present study, we aimed to characterize the molecular events leading to infertility. Histologically, there was progressive uterine atrophy in Thra1PV/+ mutant mice, characterized by squamous metaplasia of the endometrial mucosa and endometrial fibrosis. RNA-seq analysis of laser-captured micro-dissected endometrium and spatial transcriptomics revealed a key role for Krüppel-like factor (Klf9), a directly-regulated TR target gene, in normal endometrial differentiation. Klf9 was suppressed in the endometrium of mice harboring mutated TRα1 and pathway analysis revealed that deficient Klf9 signaling was associated with squamous differentiation, consistent with the endometrial metaplasia observed histologically. Further, we showed that this metaplastic endometrial mucosa was the source of ectopic IL-33, which was associated with increased T-cell infiltrates, destruction of glands, and endometrial fibrosis. Our studies provide new insights to understand uterine epithelial morphogenesis and how thyroid dysfunction could lead to female infertility.

Methimazole-Induced Hypothyroidism Increases the Content of Glycogen and Changes the Expression of LDH, GLUT4, and Aromatase in the Pregnant Uterus of Rabbits

Objective: To determine the impact of hypothyroidism on uterine glycogen accumulation during pregnancy. Methods: Non-pregnant and pregnant (days 5, 10, and 20) rabbits were grouped into control and methimazole (MMI) groups. In rabbits, serum concentrations of thyroxine (T4), triiodothyronine, glucose, insulin, progesterone, and estradiol were quantified. In uterine inter- and implantation sites, the glycogen content and expression of lactate dehydrogenase (LDH), GLUT4, and aromatase were quantified via Western blot. Fetuses' characteristics at 20 days of pregnancy were analyzed. Two-way ANOVA was used to compare variables between groups. Results: Pregnancy reduced T4 concentrations but not T3. In virgin groups, MMI treatment significantly reduced the concentrations of T4 and T3 and increased the expression of GLUT4 and aromatase in the uterus compared to the control group. In pregnant groups, T4, T3, glucose, insulin, progesterone, and estradiol levels were similar between control and MMI-treated rabbits. Compared to controls, MMI treatment in pregnant rabbits (a) reduced GLUT4 expression on inter-implantation sites on day 5; (b) increased glycogen content on implantation sites but reduced GLUT4 expression on inter-and implantation sites on day 10; (c) increased glycogen content and LDH and aromatase expression but reduced GLUT4 on inter-implantation sites; and (d) increased glycogen content and the expression of LDH, GLUT4, and aromatase on day 20 on implantation sites. Moreover, the fetus characteristics were similar between groups. Conclusions: MMI-induced hypothyroidism is associated with changes in the uterine content of glycogen and the expression of LDH, GLUT4, and aromatase during pregnancy.

The Perinatal Microbiota-Gut-Brain Axis: Implications for Postpartum Depression

BACKGROUND

Pregnancy and childbirth are accompanied by widespread maternal physiological adaptations and hormonal shifts that have been suggested to result in a period of vulnerability for the development of mood disorders such as postpartum depression (PPD). There is also evidence of peripartum changes in the composition of the gut microbiota, but the potential contribution of intestinal microbes to the adaptations, or subsequent vulnerabilities, during this period are unknown.

SUMMARY

Here, we outline key pathways involved in peripartum adaptations including GABAergic signaling, oxytocin, and immunomodulation that are also associated with susceptibility to mood disorders and present evidence that these pathways are modulated by gut microbes. We also discuss the therapeutic potential of the microbiota-gut-brain axis in PPD and identify future directions for research to help realize this potential.

KEY MESSAGES

Peripartum adaptations are associated with shifts in gut microbial composition. Disruption of GABAergic, oxytocin, and immunomodulatory pathways may contribute to vulnerability of mood disorders including PPD. These key adaptive pathways are modulated by intestinal microbes suggesting a role for the gut microbiota in determining susceptibility to PPD. More research is needed to confirm relationship between gut microbes and PPD and to gain the mechanistic understanding required to realize the therapeutic potential of microbiota-gut-brain axis in this mood disorder.

Exploring How Adipose Tissue, Obesity, and Gender Influence the Immune Response to Vaccines: A Comprehensive Narrative Review

Vaccines represent an essential tool for the prevention of infectious diseases. Upon administration, a complex interaction occurs between the vaccine formulation and the recipient's immune system, ultimately resulting in protection against disease. Significant variability exists in individual and population responses to vaccination, and these differences remain the focus of the ongoing research. Notably, well-documented factors, such as age, gender, and genetic predisposition, influence immune responses. In contrast, the effects of overweight and obesity have not been as thoroughly investigated. The evidence indicates that a high body mass index (BMI) constitutes a significant risk factor for infections in general, with adipose tissue playing a crucial role in modulating the immune response. Furthermore, suboptimal levels of vaccine seroconversion have been observed among individuals with obesity. This review provides a plausible examination of the immunity and protection conferred by various vaccines in individuals with an overweight status, offering a comprehensive analysis of the mechanisms to enhance vaccination efficiency.

QRFP43 modulates the activity of the hypothalamic-pituitary-thyroid axis in female sheep

Since the early discovery of QRFP43, intensive research has been primarily focused on its role in the modulation of food intake. As is widely recognised, the regulation of the body's energy status is a highly complex process involving numerous systems, hormones and neurotransmitters. Among the most important regulators of energy status, alongside the satiety and hunger centre located in the hypothalamus, is the HPT axis, which directly and indirectly affects the regulation of metabolism in all cells of the body. Therefore, it seems highly important to conduct studies aimed at elucidating how QRFP43 may impact the secretory activity of the HPT axis. The objective of this work was to investigate the role of QRFP43 in modulating HPT axis activity in sheep. The study examined mRNA and peptide expression of TRH and TSH in the hypothalamus and pituitary, as well as plasma concentrations of TSH, free T4 (FT4) and free T3 (FT3). Moreover, the relationship between QRFP34 and mRNA expression of the Dio1, Dio2, and Dio3 genes was explored in selected tissues of the HPT axis. The animals (n = 48) were randomly divided into three experimental groups: a control group receiving an ICV infusion of Ringer-Locke solution, and two experimental groups receiving ICV infusions of QRFP43 at doses of 10 and 50 µg per day. Four 50-minute ICV infusions were administered to all sheep at 30 min intervals each of three consecutive days. Hypothalamic, pituitary and thyroid glands were collected and preserved for further immunohistochemical and molecular biological analyses. Additionally, blood samples were collected during the experiment for subsequent RIA determinations. In summary, the results of the experiment have indicated that QRFP43 modulates the secretory activity of the HPT axis at all organisational levels. Moreover, QRFP43 can alter the mRNA expression profiles of DIO1, DIO2 and DIO3 in HPT tissues, leading to discrete changes in the metabolism of the cells studied and their response to signals transmitted by T4 and T3.

Possible association between subclinical hypothyroidism and age at menopause in Colombian women

OBJECTIVE

To evaluate the association between subclinical hypothyroidism with early menopause, premature menopause, and last menstrual bleeding before the natural age of menopause.

METHODS

This was a cross-sectional study conducted in 643 postmenopausal women aged 40-69 years. Groups were formed according to last menstrual episode: ≥45 [Natural age at menopause], 40-44 and [Early menopause], <40 [Premature menopause], and <45 [last menstrual episode before the natural age of menopause]. The Zulewski scale was applied to identify manifestations related to hypothyroidism and subclinical hypothyroidism, diagnosed with a serum TSH > 4.5 µIU/mL plus T4-free between 0.7 and 1.9 ng/dL.

RESULTS

It was found that 24.4% had the last menstrual episode before the natural age of menopause, 18.6% had early menopause, and 5.7% had premature menopause. Subclinical hypothyroidism was diagnosed in 4.5% of patients. Among women with subclinical hypothyroidism, there was a higher frequency of early menopause, premature menopause, and last menstrual episode before the natural age of menopause, than in women without subclinical hypothyroidism (p < 0.05). Paresthesia (50%) and dry skin (40.7%) were the most reported hypothyroidism-related manifestations. Early menopause, premature menopause, and last menstrual episode before the natural age of menopause were associated with subclinical hypothyroidism, OR: 3.37 [95% CI: 1.40-8.10], OR: 4.31 [95% CI: 1.24-14.97], and OR: 3.57 [95% CI: 1.57-8.10], respectively.

CONCLUSIONS

The last menstrual episode before the natural age of menopause, early menopause, and premature menopause were significantly associated with a higher chance of subclinical hypothyroidism.

Prenatal exposure to nitrate alters uterine morphology and gene expression in adult female F1 generation rats

Objective

Nitrate is ubiquitously found in the environment and is one of the main components of nitrogen fertilizers. Previous studies have shown that nitrate disrupts the reproductive system in aquatic animals, but no study has evaluated the impact of nitrate exposure on the uterus in mammals. This study aimed to evaluate the impact of maternal exposure to nitrate during the prenatal period on uterine morphology and gene expression in adult female F1 rats.

Materials and methods

Pregnant Wistar rats were either treated with sodium nitrate 20 mg/L or 50 mg/L dissolved in drinking water from the first day of pregnancy until the birth of the offspring or were left untreated. On postnatal day 90, the uteri of female offspring rats were collected for histological and gene expression analyses. Morphometric analyses of the uterine photomicrographs were performed to determine the thickness of the layers of the uterine wall (endometrium, myometrium, and perimetrium) and the number of endometrial glands.

Results

The highest nitrate dose increased the myometrial thickness of the exposed female rats. Treatment with both nitrate doses reduced the number of endometrial glands compared with no treatment. Additionally, nitrate treatment significantly increased the expression of estrogen receptors and reduced the expression of progesterone receptors in the uterus.

Conclusion

Our results strongly suggest that prenatal exposure to nitrate programs gene expression and alters the uterine morphology in female F1 rats, potentially increasing their susceptibility to developing uterine diseases during adulthood.

Application of Human Plasma Targeted Lipidomics and Analysis of Toxic Elements to Capture the Metabolic Complexities of Hypothyroidism

BACKGROUND

Hypothyroidism (HT) affects millions worldwide and can lead to various lipid disorders. The metabolic complexity and the influence of toxic elements in autoimmune and non-autoimmune HT subtypes are not fully understood. This study aimed to investigate the relationships between plasma lipidome, toxic elements, and clinical classifications of HT in unexposed individuals.

METHODS

Samples were collected from 120 adults assigned to a study group with Hashimoto's disease and non-autoimmune HT, and a healthy control group. Quantification of 145 pre-defined lipids was performed by using triple quadrupole tandem mass spectrometry (TQ MS/MS) in multiple reactions monitoring (MRM) mode via positive electrospray ionization (ESI). Levels of toxic elements were determined using inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

Significant associations between altered levels of several components of the plasma lipidome and Al, Cd, Ni, As, and Pb with HT were found. We show metabolic differences in lysophosphatidylcholines (LPC) and phosphatidylcholines (PC) between HT and controls, with distinct predicted activation patterns for lysolecithin acyltransferase and phospholipase A2.

CONCLUSIONS

There are significant changes in the lipidome profiles of healthy subjects compared to euthyroid HT patients treated with L-thyroxine, which are related to the type of hypothyroidism and non-occupational exposure to toxic elements.

Beyond the Thyroid: A Narrative Review of Extra-thyroidal Manifestations in Hashimoto's Disease

Hashimoto's disease, the most common cause of hypothyroidism in iodine-sufficient regions, is traditionally viewed as a thyroid-specific autoimmune disorder. However, emerging evidence indicates that Hashimoto's disease has far-reaching systemic effects, manifesting in multiple organ systems beyond the thyroid gland. This comprehensive review aims to elucidate the extra-thyroidal manifestations of Hashimoto's disease, highlighting their pathophysiology, clinical presentation, and management strategies. The review explores neurological, cardiovascular, dermatological, gastrointestinal, musculoskeletal, and hematological manifestations, which can significantly impact the quality of life and complicate the clinical course of the disease. Neurological symptoms such as cognitive impairment, depression, and peripheral neuropathy, as well as cardiovascular complications like dyslipidemia and atherosclerosis, are increasingly recognized as significant concerns in patients with Hashimoto's disease. Additionally, autoimmune skin disorders, gastrointestinal motility issues, and musculoskeletal pain are discussed in the context of their connection to thyroid dysfunction. The review emphasizes the importance of recognizing these systemic manifestations for comprehensive patient management and suggests that a holistic approach, rather than focusing solely on thyroid hormone replacement, is essential. This review aims to improve diagnostic accuracy, treatment outcomes, and overall patient care by broadening the understanding of Hashimoto's disease to include its extra-thyroidal effects. Further research is encouraged to explore novel therapeutic approaches targeting the autoimmune mechanisms underlying these systemic manifestations.

A Review of Autoimmune Thyroid Diseases and Their Complex Interplay with Female Fertility

Hashimoto thyroiditis and Graves' disease are autoimmune thyroid disorders that are common in women of reproductive age and have a complex relationship with female fertility and health of the maternal-fetal dyad. Both hyperthyroidism and hypothyroidism, whether subclinical or overt in severity, directly or indirectly affect nearly every level of the hypothalamic-pituitary-ovary axis, uterine and ovarian function, as well as fetal development from implantation through delivery. Autoimmunity itself also appears to negatively impact both spontaneous and assisted fertility, as well as miscarriage risk, although the mechanism remains unclear, and the presence and magnitude of risk is variable in published literature. While treatment of overt hyperthyroidism and hypothyroidism is unequivocally recommended by professional societies, the impact of treatment on fertility outcomes, and the role of treatment in subclinical thyroid disease is more controversial. Unfortunately, levothyroxine has not been shown to abrogate the risk of subfertility and miscarriage observed in euthyroid thyroid autoantibody positive women.

Oncosexology - selected issues taking into account the problem of sexological care of patients with cancer

As can be seen from research, 44% of oncological problems disclose problems in relationships with a partner. About 80% of oncological patients report deterioration of the quality of their sexual life. Although the situation improves, a significant majority of ill persons do not obtain assistance in the scope of sexuality during oncological treatment. Intimacy is an important sphere of life and can support the process of recovery. Intimacy plays special role in the difficult period of the fight against disease. Independently of the applied method of oncological treatment, side effects of therapy can influence one's sexual life. This means that an increasing number of persons who are healed from cancerous disease are exposed to the long-term undesirable influence of treatment. The process of oncological treatment has an essential impact on the intimate life of those who suffer from oncological diseases. To a great extent, this process and the disease itself contribute to a decrease of the quality of life due to the appearance of symptoms caused by earlier menopause, they negatively influence the feeling desire and sexual performance. Unfortunately, despite the development of oncosexology, sexual problems of oncologically ill persons are not noticed, and sometimes they are played down or overlooked due to everyday problems.

Factors predicting menstrual irregularity among university students in Ho Chi Minh City, Vietnam: A cross-sectional study

Background

University students often face menstrual irregularities, particularly among healthcare students, due to rigorous study environments, such as night duties resembling professional staff responsibilities.

Objective

This study aimed to examine the prevalence of and factors predicting menstrual irregularities among female students in Ho Chi Minh City, Vietnam.

Methods

A cross-sectional study was conducted from April to July 2023 at the University of Medicine and Pharmacy at Ho Chi Minh City (UMP). Data were collected using self-administered questionnaires comprising sections on personal background, menstrual cycles, sleep duration, and academic stress. Descriptive statistics and multiple logistic regression were employed for data analysis.

Results

Approximately 48.3% of participants experienced menstrual irregularities. Overweight or obese students were more likely to experience irregularities compared to those of normal weight (AOR = 7.56, 95% CI = 1.34, 80.8). Nursing majors (including nursing, midwifery, and anesthesia resuscitation nursing) showed a higher likelihood of irregularities compared to other majors (AOR = 2.5, 95% CI = 1.35, 4.13).

Conclusion

This study highlights a significant prevalence of menstrual irregularities among female students. Interventions in nursing education should focus on promoting healthy lifestyles and regular physical activity to manage weight and mitigate menstrual irregularities.

Omega 3 fatty acids preserve testicular function by ameliorating BPF-induced dysthyroidism: role of p53/Bcl-2 signaling and proton pump activities

OBJECTIVE

Bisphenol F (BPF) is an endocrinedisrupting chemical, but information about its effect on thyroid hormones has not been fully explored. Omega 3 fatty acids (O3FA), on the other hand, are antioxidant and antiapoptotic agents. Therefore, this study explored the role and associated molecular mechanism of O3FA in BPF-induced hypothyroidism-mediated testicular dysfunction in male Wistar rats.

METHODS

Twenty (20) male Wistar rats were randomized into four groups (n=5/group), namely: the control group; the BPF treated group (30 mg/kg of BPF); and the intervention groups (30mg/kg BPF + 100mg/kg O3FA (BPF+O3FA-L) and 30mg/kg BPF + 300mg/kg of O3FA for 28 days).

RESULTS

Low and high doses of O3FA ameliorated BPF-induced hypothyroidism-mediated reduction in sperm quality, testosterone, luteinizing hormone, follicle-stimulating hormone, catalase, superoxide dismutase, total antioxidant capacity, and nuclear factor erythroid 2-related factor 2 and increases in estrogen, malondialdehyde, c-reactive protein, interleukin 1 beta, caspase 3. Furthermore, O3FA prevented BPF-induced Na+/K+-ATPase and Ca2+-ATPase dysfunction, estrogen receptor beta overexpression, and tumor protein P53 (p53)/ b-cell lymphoma 2 (Bcl-2) imbalance.

CONCLUSIONS

This study showed that O3FA ameliorated BPF-induced dysthyroidism-mediated testicular dysfunction by preventing proton pump dysfunction and p53/BCl-2 imbalance.

Effect of thyroid disruption on ovarian development following maternal exposure to Bisphenol S

Thyroid hormones play a crucial role in numerous physiological processes, including reproduction. Bisphenol S (BPS) is a structural analog of Bisphenol A known for its toxic effects. Interference of this substitute with normal thyroid function has been described. To investigate the effect of thyroid disruption on ovarian development following maternal exposure to BPS, female rats were exposed, daily, to either AT 1-850 (a thyroid hormone receptor antagonist) (10 nmol/rat) or BPS (0.2 mg/kg) during gestation and lactation. The effects on reproductive outcome, offspring development, histological structures, hormone levels, oxidative status, cytoskeleton proteins expression, and oocyte development gene expression were examined. Our results are in favor of offspring ovarian development disruption due to thyroid disturbance in adult pregnant females. During both fetal and postnatal stages, BPS considerably altered the histological structure of the thyroid tissue as well as oocyte and follicular development, which led to premature ovarian failure and stimulation of oocyte atresia, being accompanied with oxidative stress, hypothalamic-pituitary-ovarian axis disorders, and cytoskeletal dynamic disturbance. Crucially, our study underscores that BPS may induce reproductive toxicity by blocking nuclear thyroid hormone receptors, evidenced by the parallelism and the perfect meshing between the data obtained following exposure to AT 1-850 and those after the treatment by this substitute.

Thyroid diseases and female sexual dysfunctions

INTRODUCTION

Female sexual dysfunctions (FSDs) have received little attention in the context of thyroid diseases, despite the high prevalence of both conditions.

OBJECTIVES

This review aims to update and summarize the state of knowledge on the association between thyroid diseases and FSDs and to investigate the complex mechanisms through which thyroid hormone imbalance can impact female sexual health in the context of the biopsychosocial model.

METHODS

A comprehensive literature search was performed through the PubMed, MEDLINE, and Scopus databases, using the following keywords: "female sexual function," "sexual dysfunction," "hypoactive sexual desire disorder," "thyroid disease," "thyroiditis," "hypothyroidism," and "hyperthyroidism."

RESULTS

To date, well-designed studies that describe the relationship between FSDs and thyroid disorders are lacking. However, despite the limitations on available studies, current data indicate that sexual alterations are frequently associated with thyroid diseases in women. A complex interplay of direct and indirect hormonal and nonhormonal mechanisms has been hypothesized, including hormonal changes, neurotransmitter imbalance, reduced nitric oxide release, mood disorders, and other systemic consequences of both hypothyroidism and hyperthyroidism. Thyroid hormone receptors have also been identified in the genitourinary system.

CONCLUSIONS

In a clinical setting, physicians should investigate the sexuality of patients consulting for thyroid disease. At the same time, an evaluation of thyroid function should be performed in patients presenting with FSD, especially after menopause, when the risk of thyroid diseases and FSDs increases strongly.

Autoimmune thyroid disease and ovarian hypofunction: a review of literature

Thyroid hormones(THs) are essential for the proper functioning of the ovaries, and multiple studies have shown that thyroid abnormalities, especially during adolescence and reproductive age, can lead to lifelong ovarian dysfunction. Autoimmune thyroid disease (AITD), one of the most common organ specific autoimmune diseases, is mainly mediated by cellular autoimmune reactions, and has strong inflammatory infiltration and immune active cells, including chemokines and cytokines, which are important components of ovarian aging. This suggests that autoimmune and inflammatory molecular processes may play a role in the emergence of ovarian dysfunction. The purpose of this review is to summarize recent in vivo and in vitro evidence of a complex relationship between AITD and ovarian dysfunction. AITD is closely related to the decline of ovarian function from the perspective of antibody, cytokine, oxidative stress, and genetic factors. Finally, some of the currently known treatments for AITD and hypo ovarian disease are summarized.

Menstrual Cycle Characteristics in Women With and Without Thyroid Disease

INTRODUCTION

This study was designed to evaluate the frequency and type of menstrual disorders in thyroid dysfunction. The relationship between thyroid dysfunction and menstrual disorders has been known for a long time. The menstrual cycle should be checked in women with thyroid dysfunction. On the contrary, women with menstrual irregularities should be investigated for thyroid dysfunction.

METHODS

Women who presented to our hospital's internal medicine and endocrinology clinics that recently diagnosed thyroid dysfunction were included. The patients were divided into five groups (subclinical hypothyroidism, overt hypothyroidism, subclinical hyperthyroidism, overt hyperthyroidism, and euthyroid) according to thyroid functions. They were questioned regarding the amount, frequency, and duration of menstrual bleeding. The prevalence of menstrual disturbances, including secondary amenorrhea, hypomenorrhea, oligomenorrhea, hypermenorrhea, polymenorrhea, menorrhagia, metrorrhagia, and menometrorrhagia, was examined in 485 patients and 108 healthy controls.

RESULTS

Hypermenorrhea was significantly more common in patients with overt hypothyroidism (33%) than in controls (6%) (p<0.05). The types and frequencies of menstrual disorders in patients with hyperthyroidism and those with normal thyroid function were not significantly different from those in controls.

CONCLUSION

Menstrual abnormalities frequently occur in women with thyroid dysfunction. Therefore, menstrual dysfunction should be considered when treating patients with thyroid abnormalities.

Hypothyroidism and Its Impact on Menstrual Irregularities in Reproductive-Age Women: A Comprehensive Analysis at a Tertiary Care Center

BACKGROUND

Hypothyroidism is known to affect a wide range of physiological systems, including menstrual function, in women of reproductive age. This study aims to comprehensively analyze the association between hypothyroidism and menstrual irregularities in women attending a tertiary care center.

METHODS

The study included 120 women aged 18-45 who presented with menstrual abnormalities. Convenience sampling was used to select participants from the outpatient department of obstetrics and gynecology. Thyroid function tests were conducted in the hospital's biochemistry laboratory, including assessments of thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid peroxidase antibodies (TPOAb). The study aimed to determine the prevalence of hypothyroidism and its association with various menstrual irregularities, such as oligomenorrhea, polymenorrhea, menorrhagia, and amenorrhea. Data analysis was performed using SPSS software, applying descriptive statistics, Pearson correlation for continuous variables, and Chi-square tests for categorical variables. A significance level of p<0.05 was set for the analyses.

RESULTS

The mean age of the participants was 33.1 years (SD ± 7.2). The distribution of menstrual irregularities was 60 (50%) oligomenorrhea, 24 (20%) polymenorrhea, 24 (20%) menorrhagia, and 12 (10%) amenorrhea. Elevated TSH levels (>4.0 mIU/L) were observed in 42 (35%) of the participants, low FT4 levels (<0.8 ng/dL) in 18 (15%), low FT3 levels (<2.5 pg/mL) in 12 (10%), and elevated TPOAb levels (>55 IU/mL) in 24 (20%). A significant association was found between elevated TSH levels and oligomenorrhea (66 (55%), p<0.05) and between reduced FT4 levels and menorrhagia (78 (65%), p<0.05). Additionally, elevated TPOAb levels were significantly associated with amenorrhea (60 (50%), p<0.05). The correlation analysis showed a moderately positive correlation between TSH levels and the severity of menstrual irregularities (r=0.35, p<0.01). Subclinical hypothyroidism was detected in 25% of the participants, while 15% had clinical hypothyroidism.

CONCLUSION

This study underscores a notable link between hypothyroidism and menstrual irregularities in women of reproductive age. The results highlight the necessity of routine thyroid function screenings for women experiencing menstrual abnormalities, facilitating precise diagnosis and suitable treatment.

Urinary haloacetic acid concentrations and thyroid function among women: Results from the TREE study

BACKGROUND

Disinfection byproducts (DBPs) have been shown to impair thyroid function in experimental models. However, epidemiological evidence is scarce.

METHODS

This study included 1190 women undergoing assisted reproductive technology (ART) treatment from the Tongji Reproductive and Environmental (TREE) cohort from December 2018 to August 2021. Serum thyrotropin (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were measured as indicators of thyroid function. FT4/FT3 and TSH/FT4 ratios were calculated as markers of thyroid hormone homeostasis. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), the two most abundant HAAs, in urine were detected to assess individual DBP exposures.

RESULTS

After adjusting for relevant covariates, positive associations were observed between urinary TCAA concentrations and serum TSH and TSH/FT4 levels (e.g., percent change = 5.82 %, 95 % CI: 0.70 %, 11.21 % for TSH), whereas inverse associations were found for serum FT3 and FT4 (e.g., percent change = -1.29 %, 95 % CI: -2.49 %, -0.07 % for FT3). There also was a negative association between urinary DCAA concentration and serum FT4/FT3 (percent change = -2.49 %, 95 % CI: -4.71 %, -0.23 %). These associations were further confirmed in the restricted cubic spline and generalized additive models with linear or U-shaped dose-response relationships.

CONCLUSION

Urinary HAAs were associated with altered thyroid hormone homeostasis among women undergoing ART treatment.

Effects of crosstalk between steroid hormones mediated thyroid hormone in zebrafish exposed to 4-tert-octylphenol: Estrogenic and anti-androgenic effects

Alkylphenols, such as nonylphenol and 4-tert-octylphenol (OP), are byproducts of the biodegradation of alkylphenol ethoxylates and present substantial ecological and health risks in aquatic environments and higher life forms. In this context, our study aimed to explore the effect of OP on reproductive endocrine function in both female and male zebrafish. Over a period of 21 days, the zebrafish were subjected to varying concentrations of OP (0, 0.02, 0.1, and 0.5 μg/L), based on the lowest effective concentration (EC10 = 0.48 μg/L) identified for zebrafish embryos. OP exposure led to a pronounced increase in hepatic vitellogenin (vtg) mRNA expression and 17β-estradiol biosynthesis in both sexes. Conversely, OP exhibits anti-androgenic properties, significantly diminishes gonadal androgen receptor (ar) mRNA expression, and reduces endogenous androgen (testosterone and 11-ketotestosterone) levels in male zebrafish. Notably, cortisol and thyroid hormone (TH) levels demonstrated concentration-dependent elevations in zebrafish, influencing the regulation of gonadal steroid hormones (GSHs). These findings suggest that prolonged OP exposure may result in sustained reproductive dysfunction in adult zebrafish, which is largely attributable to the intricate reciprocal relationship between hormone levels and the associated gene expression. Our comprehensive biological response analysis of adult zebrafish offers vital insights into the reproductive toxicological effects of OP, thereby enriching future ecological studies on aquatic systems.

Mineral patterns in hair: A decisive factor between reproducible and repeat breeder dairy cows

Reproduction, especially impregnation, is a critical aspect of dairy cow management that directly influences herd milk productivity. We conducted a noninvasive hair mineral assay to compare the mineral profiles of two dairy cow groups: reproducible and repeat breeder, by investigating the levels of 11 essential minerals (Ca, Mg, Na, K, Fe, Cu, Mn, Zn, Cr, Se, and P) and 6 toxic elements (Hg, Pb, Cd, Al, As, and Ni) in both groups. We also conducted principal component and correlation matrix analyses to compare hair mineral patterns between the groups. Compared to their reproducible counterparts, repeat breeder cows had lower levels of Na, K, and Se. However, Fe, Cd, Al, and As levels were higher in repeat breeders than in their reproducible counterparts. The correlation matrix showed notable correlation patterns for each group. Ca, K, and Na levels were positively correlated in reproducible cows, whereas repeat breeder cows showed positive correlations only between Ca and K levels. Se showed positive correlations with Zn only in the reproducible cow group. Negative correlations were not found in the reproducible group, whereas the repeat breeder group exhibited 7 negative correlations. Despite the limitations of hair mineral analysis, this study provided useful insights into the reproductive potential of dairy cows. These findings aid in easing the prediction of repeat breeder occurrences in herds and are expected to facilitate timely mineral supplementation and other interventions to improve overall herd reproduction in dairy farms.

Impact of mildly evaluated thyroid-stimulating hormone levels on in vitro fertilization or intracytoplasmic sperm injection outcomes in women with the first fresh embryo transfer: a large study from China

PURPOSE

This study aimed to investigate the association between mild elevation of thyroid-stimulating hormone (TSH) levels and pregnancy outcomes of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments in women with the first fresh embryo transfer.

METHODS

Large single-center retrospective cohort study of 15,728 patients from January 2018 to December 2022 were enrolled in the analyses. Clinical pregnancy rates, live birth rates, miscarriage rates, and ectopic pregnancy rates were compared between the TSH levels < 2.5 mIU/L group (N = 10,932) and TSH levels ≥ 2.5 mIU/L group (N = 4796). Subgroup analysis was performed for patients with TSH levels ≥ 2.5 mIU/L, dividing them into the thyroid peroxidase antibody (TPO)-negative group (N = 4524) and the TPO-positive group (N = 272).

RESULTS

There were no significant differences in the aforementioned pregnancy outcomes between the TSH levels < 2.5 mIU/L group and TSH levels ≥ 2.5 mIU/L group. Similarly, no significant differences were observed in the pregnancy outcomes between the TPO-negative group and the TPO-positive group.

CONCLUSION

Mildly elevated pre-conception TSH levels in thyroid-normal infertile patients did not have an impact on pregnancy outcomes of IVF/ICSI treatments.

Risk assessment of transgender people: implementation of a demasculinizing-feminizing rodent model including the evaluation of thyroid homeostasis

BACKGROUND

Individuals whose gender identity differs from the biological sex and the social norms are defined as transgender. Sometimes transgender undergo gender affirming hormone therapy, which lasts for the entire life making essential to evaluate its potential long-term effects. Moreover, transgender can represent a susceptible sub-group of population and specific attention is needed in risk assessment, including the development of targeted animal models. Aim of the study is the implementation of a rodent demasculinizing-feminizing model through the setting of appropriate dose of hormone therapy and the selection of specific biomarkers to evaluate the sex transition. Specific attention is paid to thyroid homeostasis due to the close link with reproductive functions. Four male adult rats/group were subcutaneously exposed to three doses plus control of β-estradiol valerate plus cyproterone acetate at: 0.045 + 0.2 (low), 0.09 + 0.2 (medium) and 0.18 + 0.2 (high) mg/dose, five times/week. The doses were selected considering the most recent recommendations for transgender woman. Sperm count, histopathological analysis (testis, liver, thyroid), testosterone, estradiol, triiodothyronine and thyroid-stimulating hormone serum levels and gene expression of sex dimorphic CYP450 were evaluated.

RESULTS

The doses induced feminizing-demasculinizing effects: decreased testosterone serum levels at the corresponding cisgender, increased estradiol, impairment of male reproductive function and reversal of sex-specific CYP liver expression. However, the medium and high doses induced marked liver toxicity and the low dose is considered the best choice, also for long-term studies in risk assessment. The alterations of thyroid indicated follicular cell hypertrophy supported by increased thyroid-stimulating hormone serum levels at the higher doses.

CONCLUSIONS

The implementation of animal models that mimic the effects of gender affirming hormone therapy is essential for supporting clinical studies in transgender people and filling data gap in order to ensure an appropriate risk assessment and a more accurate, personalized care for transgender people.

The causal association between thyroid disease and gout: A Mendelian randomization study

Observational studies have reported some associations between thyroid disease and gout, but the causal relationship between the 2 is not clear. We used Mendelian randomization (MR) Analysis to investigate the causal association between some thyroid diseases (autoimmune hypothyroidism, autoimmune hyperthyroidism, thyroid nodules, and thyroid cancer) and gout. GWAS data were used for analysis. The exposure factors were autoimmune hypothyroidism, autoimmune hyperthyroidism, thyroid nodules and thyroid cancer, and the outcome variables were gout. IVW, MR-Egger, Weighted median and Weighted mode were used for MR analysis. Cochran Q test MR-PRESSO and MR-Egger intercept analysis were used to detect heterogeneity and multi directivity. Autoimmune hypothyroidism has a causal effect on gout, IVW results show (OR = 1.13, 95% CI = 1.03-1.21, PFDR = 0.0336); Autoimmune hyperthyroidism has a causal effect on gout, IVW results show (OR = 1.07, 95% CI = 1.01-1.12, PFDR = 0.0314); Thyroid cancer has no causal effect on gout, IVW results show (OR = 1.03, 95% CI = 0.98-1.09, PFDR = 0.297); Thyroid nodules has no causal effect on gout, IVW results show (OR = 1.03, 95% CI = 0.98-1.08, PFDR = 0.225); Reverse MR Studies show that gout have no causal effect on the above thyroid diseases. Autoimmune hypothyroidism and autoimmune hyperthyroidism increase the risk of gout.