Association between leptin, obesity, hormonal interplay and male infertility

Where do obesity and male infertility collide?

The parallel rise in obesity and male infertility in modern societies necessitates the identification of susceptibility genes underlying these interconnected health issues. In our study, we conducted a comprehensive search in the OMIM database to identify genes commonly associated with male infertility and obesity. Subsequently, we performed an insilico analysis using the REVEL algorithm to detect pathogenic single nucleotide polymorphisms (SNPs) in the coding region of these candidate genes. To validate our findings in vivo, we conducted a comprehensive analysis of SNPs and gene expression of candidate genes in 200 obese infertile subjects and 240 obese fertile individuals using ARMS-PCR. Additionally, we analyzed 20 fertile and 22 infertile obese individuals using Realtime-qPCR. By removing duplicated queries, we obtained 197 obesity-related genes and 102 male infertility-related genes from the OMIM database. Interestingly, the APOB gene was found in common between the two datasets. REVEL identified the rs13306194 variant as potentially pathogenic with a calculated score of 0.524. The study identified a significant association between the AA (P value = 0.001) genotype and A allele (P value = 0.003) of the APOB rs13306194 variant and infertility in obese men. APOB expression levels were significantly lower in obese infertile men compared to obese fertile controls (p < 0.01). Moreover, the AA genotype of rs13306194 APOB was associated with a significant decrease in APOB gene expression in obese infertile men (p = 0.05). There is a significant association between the Waist-to-Hip Ratio (WHR) and LH with infertility in the obese infertile group. These results are likely to contribute to a better understanding of the causes of male infertility and its association with obesity.

Expression Patterns of Leptin, Leptin Receptor, Kiss1, and HOTAIR Genes in Blood and Semen of Infertile Males with Oligospermia

Background

Infertility affects about 15% of couples during reproductive age and male factor infertility accounts for half of these cases. This study aimed to evaluate the expression of leptin, KISS1, leptin receptor, and HOTAIR genes in blood and semen samples of individuals diagnosed with oligospermia in comparison to healthy controls.

Methods

In the current investigation, we studied 36 semen and 30 blood samples from fertile oligospermic men as well as the same number of healthy controls. RNA was extracted and cDNA was synthesized. Real-time polymerase chain reaction (PCR) was conducted to assess the gene expression levels. Statistical analysis was performed using Graph Pad Prism software. The results were reported as mean±SEM and any P< 0.05 were considered statistically significant.

Results

A significant increase in the expression of the leptin gene in infertile males, particularly in semen samples (P< 0.001) was found when compared to the healthy controls. On the other hand, significant decrease in the expression of the KISS1 (P< 0.0001) and HOTAIR (P< 0.001) genes, particularly in semen samples were found when compared to the controls. As it was shown, the expression of leptin receptor had no significant effects on male infertility. Additionally, there may be a potential correlation between the expression of HOTAIR and the leptin and KISS1 genes, with a negative correlation observed between HOTAIR and leptin, and a positive correlation between HOTAIR and KISS1 in both blood and semen samples. However, further investigations are necessary to establish the statistical significance of these correlations.

Conclusions

According to the results, leptin, KISS1, and HOTAIR genes seem to be affected in oligospermia, however, further studies with higher sample sizes are necessary.

A ripple effect? The impact of obesity on sperm quality and function

Infertility affects approximately 15% of couples trying to conceive. Male-related causes account for roughly 50% of cases, with obesity emerging as a possible significant factor. Obesity, defined as a body mass index of 30.0 or higher, has become a widespread epidemic associated with numerous health issues, including a decrease of fertility. This review discusses the relationship between obesity and male infertility, particularly focusing on sperm quality and function. An overview of the literature suggests that obesity may influence the male reproductive system via disruptions in hormonal profiles, oxidative stress, and inflammation, leading to changes in sperm parameters. Several studies have discussed if obesity causes a decrease in sperm concentration, motility, and normal morphology, so far without a consensus being reached. However, available evidence suggests an impairment of sperm function in obese men, due to an increase in DNA damage and oxidative stress, impaired mitochondrial function and acrosome reaction in response to progesterone. Finally, the relationship between obesity and assisted reproductive technologies outcomes remains debatable, with conflicting evidence regarding the influence on fertilisation, pregnancy, and live birth rates. Therefore, the actual impact of obesity on human spermatozoa still needs to be clarified, due to the multiple factors potentially in play.

Bezafibrate alleviates diabetes-induced spermatogenesis dysfunction by inhibiting inflammation and oxidative stress

The metabolic disorders caused by diabetes can lead to various complications, including male spermatogenesis dysfunction. Exploring effective therapeutics that attenuate diabetes mellitus (DM)-induced male subfertility is of great importance. Pharmaceuticals targeting PPARα activation such as bezafibrate have been regarded as an important strategy for patients with diabetes. In this study, we use streptozocin (STZ) injection to establish a type 1 DM mice model and use bezafibrate to treat DM mice and evaluate the effects of bezafibrate on the spermatogenic function of the DM male mice. Bezafibrate treatment exhibited protective effects on DM-induced spermatogenesis deficiency, as reflected by increased testis weight, improved histological morphology of testis, elevated sperm parameters, increased serum testosterone concentration as well as increased mRNA levels of steroidogenesis enzymes. Meanwhile, testicular cell apoptosis, inflammation accumulation and oxidative stress status were also shown to be alleviated by bezafibrate compared with the DM group. In vivo and in vitro studies, PPARα specific inhibitor and PPARα knockout mice were further used to investigate the role of PPARα in the protective effects of bezafibrate on DM-induced spermatogenesis dysfunction. Our results indicated that the protection of bezafibrate on DM-induced spermatogenesis deficiency was abrogated by PPARα inhibition or deletion. Our study suggested that bezafibrate administration could ameliorate DM-induced spermatogenesis dysfunction and may represent a novel practical strategy for male infertility.

Association between per- and polyfluoroalkyl substances and sex hormone levels in males based on human studies

BACKGROUND

Per- and poly-fluoroalkyl substances (PFAS) are ubiquitous chemicals in the environment and our daily lives. Several epidemiological studies have revealed that PFAS exposure is linked to male sex hormone levels; however, the conclusions are inconsistent across studies. Consequently, we performed a meta-analysis to systematically evaluate the association between PFAS exposure and male sex hormones.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards were followed during the meta-analysis. PubMed, Wed of Science, Embase, Cochrane Library, and Ovid databases were used to identify suitable articles before June 2023. The 95% CI and β values were calculated to assess the association between male sex hormone levels and PFAS exposure. Heterogeneity among the included studies was tested using inconsistency statistics (I2).

RESULTS

The literature search identified 12 published articles that met our search criteria, involving 7506 participants. Our results revealed that perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA) exposures were negatively correlated with testosterone (β = -0.05; 95% CI: -0.09, -0.02, P = 0.003) and (β = -0.04; 95% CI: -0.08, 0.00, P = 0.049), respectively.

CONCLUSION

Exposure to PFNA and PFOA is negatively correlated with changes in male testosterone levels. This correlation suggests that we need to pay attention in the future to whether they are potential risk factors for male reproductive health.

Sperm DNA damage: The possible link between obesity and male infertility, an update of the current literature

Obesity prevalence worldwide is increasing significantly. Whilst maternal obesity has clear detrimental impacts on fertility, pregnancy and foetal outcomes, more recently there has been an increasing focus on the role of paternal obesity in human fertility. Recent meta-analyses have indicated that obesity in men negatively affects basic sperm parameters such as sperm count, concentration and motility, increases the incidence of infertility and reduces the chances of conception. Sperm DNA damage, typically characterised by DNA strand breaks and oxidation of DNA nucleotides, is a specialised marker of sperm quality that has been independently associated with recurrent miscarriage, reduced assisted reproduction success and increased mutational loads in subsequent offspring. Whilst, there are still conflicting data in humans as to the association of obesity in men with sperm DNA damage, evidence from rodent models is clear, indicating that male obesity increases sperm DNA damage. Human data are often conflicting because of the large heterogeneity amongst studies, the use of body mass index as the indicator of obesity and the methods used for detection of sperm DNA damage. Furthermore, comorbidities of obesity (i.e., heat stress, adipokines, insulin resistance, changes in lipids, hypogonadism and obstructive sleep apnoea) are also independently associated with increased sperm DNA damage that is not always modified in men with obesity, and as such may provide a causative link to the discrepancies amongst human studies. In this review, we provide an update on the literature regarding the associations between obesity in men and fertility, basic sperm parameters and sperm DNA damage. We further discuss potential reasons for the discrepancies in the literature and outline possible direct and indirect mechanisms of increased sperm DNA damage resulting from obesity. Finally, we summarise intergenerational obesity through the paternal linage and how sperm DNA damage may contribute to the transmission.

Exploring the underlying mechanisms of obesity and diabetes and the potential of Traditional Chinese Medicine: an overview of the literature

Obesity and diabetes are closely related metabolic disorders that have become major public health concerns worldwide. Over the past few decades, numerous studies have explored the underlying mechanisms of these disorders and identified various risk factors, including genetics, lifestyle, and dietary habits. Traditional Chinese Medicine (TCM) has been increasingly recognized for its potential to manage obesity and diabetes. Weight loss is difficult to sustain, and several diabetic therapies, such as sulfonylureas, thiazolidinediones, and insulin, might make it harder to lose weight. While lifestyle changes should be the primary approach for people interested in lowering weight, drugs are also worth investigating. Since some of the newer glucose-lowering medications that cause weight loss, such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2i), are additionally utilized or are under consideration for use as anti-obesity drugs, the frontier between glucose-lowering medication and weight loss drugs appears to be shifting. This review provides an overview of the literature on the underlying mechanisms of obesity and diabetes and the prospect of TCM in their management. We discuss the various TCM interventions, including acupuncture, herbal medicine, and dietary therapy, and their effects on metabolic health. We also highlight the potential of TCM in regulating gut microbiota, reducing inflammation, and improving insulin sensitivity. The findings suggest that TCM may provide a promising approach to preventing and managing obesity and diabetes. However, further well-designed studies are needed to confirm the efficacy and safety of TCM interventions and to elucidate their underlying mechanisms of action.

Obesity prevalence, physical activity, and dietary practices among adults in Saudi Arabia

Introduction

The current study evaluated obesity prevalence, physical activity, and dietary practices among Saudi adults in the Makkah region of the Kingdom of Saudi Arabia (KSA). The current survey was accomplished between November 2021 and March 2022.

Method

A validated questionnaire, Arab Teens Lifestyle Study (ATLS), was used to evaluate all participants' physical activities, sedentary behaviors, and nutritional habits in addition to demographic data.

Result

A total of 2,115 people [1,238 (58.5%) women and 877 (41.5%) men] participated in this survey. Being overweight was prevalent in 32.8% of the population (41% of men and 28.9% of women), obesity was prevalent in 23% of the population (males 23.1% and females 24.2%). Obese people consumed more soft drinks, and overweight people did not consume enough vegetables (fresh/cooked). Obese people consumed fast food (e.g., burgers, sausage, pizza, or Arabic shawarma) over three times each week. The mean (SD) number of days of practice walking was 2.51 (2.05) vs. 1.3 (1.87) (p < 0.001) for lean and obese individuals, respectively. In addition, individuals with normal BMI had more days of jogging, moderate and high-intensity exercise, dancing, and strength training than those with obesity. The odds of being obese increased with age (OR: 1.07; p < 0.001), in males (OR: 2.16; p < 0.001), in participants earning <5,000 SR/month (1.3 thousand $) and 10-15 thousand SR/month (1.34-2.66 thousand $) (OR: 2.36; P = 0.01). Obesity was inversely associated with moderate-intensity exercise (OR: 0.802; p = 0.009), and regular walking (OR: 0.685; CI: 0.624-0.752; p < 0.001).

Discussion

Overweight and obesity were prevalent in 32.8% and 23% of the population, respectively. Sociodemographic factors associated with obesity. Focused intervention strategies are needed to overcome the obesity issue.

CHANGES IN THE SERUM LEVEL OF LEPTIN AND TRANSFORMING GROWTH FACTOR-Β1 IN PATIENTS WITH ARTERIAL HYPERTENSION ON A BACKGROUND OF ABDOMINAL OBESITY

OBJECTIVE

The aim: Study of the levels of leptin and the growth modulator TGF-β1 in the blood serum of patients with hypertension, which occurs on the background of AO and without it.

PATIENTS AND METHODS

Materials and methods: Carbohydrate metabolism was studied by the enzymatic method, the level of insulin in the blood (by the enzyme immunoassay method), the oral glucose tolerance test and the calculation of the NOMA index.

RESULTS

Results: The data obtained in the work indicate a significant role of leptin in the formation of hypertension itself and the development of obesity, carbohydrate and lipid metabolism disorders. The increased level of transforming growth factor-β1 in the blood of such patients can be used as a fairly informative marker of the unfavorable prognosis of these diseases.

CONCLUSION

Conclusions: 1. In the control group, there was a significant increase in the initial values of heart rate, average levels of SBP and DBP, the frequency of hy-percholesterolemia and insulin resistance was established. 2. Significant disorders of lipid and carbohydrate metabolism and leptin synthesis were found in patients with hypertension, which occurs against the background of AO. 3. When analyzing the level of leptin depending on gender, a statistically significant increase in the level of blood leptin was found in the group of women with AH with AO compared to women with AH without AO and the control group. 4. A significant increase in the level of transforming growth factor-β1 in blood serum of patients with hypertension was established.

An association between adropin hormone and total testosterone in obese men: a case-control study

BACKGROUND

Obesity is associated with low testosterone levels that could be caused by many mechanisms. Adropin, a peptide hormone, its levels are decreased in obesity and its receptors are expressed in the hypothalamus, the pituitary gland, and the testis. Adropin association to total testosterone in obese men is not detected yet. This study tries to find out possible associations between serum levels of adropin, adiponectin, total testosterone, and lipid profile in obese men.

METHODS

Serum levels of adropin, adiponectin, total testosterone, and lipid profile parameters were measured in 43 obese men and 40 age-matched normal-weight men.

RESULTS

Adropin, adiponectin, and testosterone levels were significantly lower in obese men versus normal-weight men. In all participants, positive correlations between adropin, adiponectin, and total testosterone were detected. Adropin is considered a predictor risk factor for testosterone.

CONCLUSIONS

This study suggests a possible causal relationship between adropin and total testosterone which needs further investigation.

TRIAL REGISTRATION

Clincialtrials.gov NCT03724825 , registered October 30th, 2018.

Evaluation of selected semen parameters and biomarkers of male infertility - preliminary study

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (<12 mL) or with a normal volume of testes and 2) with abnormal levels of at least one of the reproductive hormones (FSH, LH, PRL, TSH, total T - electrochemiluminescence method) or with normal hormonal profiles and 3) with high level of SDF (>30%), moderate (>15-30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann-Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal-Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage.

Biomarkers Predictive of Metabolic Syndrome and Cardiovascular Disease in Childhood Cancer Survivors

The improvement in childhood cancer treatments resulted in a marked improvement in the survival of pediatric cancer patients. However, as survival increased, it was also possible to observe the long-term side effects of cancer therapies. Among these, metabolic syndrome is one of the most frequent long-term side effects, and causes high mortality and morbidity. Consequently, it is necessary to identify strategies that allow for early diagnosis. In this review, the pathogenetic mechanisms of metabolic syndrome and the potential new biomarkers that can facilitate its diagnosis in survivors of pediatric tumors are analyzed.

Association between hypertriglyceridemic waist phenotype and hypogonadism in Taiwanese adult men

Background

Aging-related hypogonadism in men is related to the deterioration of overall health. Those with this disease rarely receive treatment. The hypertriglyceridemic waist (HTGW) phenotype is a tool for predicting abnormalities of cardiovascular metabolism. However, the relationship between the HTGW phenotype and hypogonadism remains undetermined. This study aimed to determine the association between HTGW phenotype and hypogonadism in different age groups.

Methods

Data of this cross-sectional study were obtained from MJ Health Screening Center in Taiwan from 2007 to 2016. The HTGW phenotype was divided into four categories based on whether the waist circumference (WC) and triglyceride levels were normal. WC of <90 cm and triglyceride level of <150 mg/dL were defined as normal. Hypogonadism was defined as a testosterone level of <300 ng/dL.

Results

Overall, 6442 male participants were divided into three age groups: <50, 50–64, and ≥65 years (n = 4135, 1958, and 349; age groups 1, 2, and 3, respectively). The overall prevalence of hypogonadism was 10.6%. In group 1, participants with HTGW (odds ratio, 1.98; 95% confidence interval (CI), 1.354–2.896) had a higher risk of hypogonadism than those with normal WC and normal triglyceride levels after adjustment for body mass index and fasting blood glucose level. In group 2, participants with HTGW (odds ratio, 1.873; 95% CI, 1.099–3.193) had an increased risk of hypogonadism after adjustment for body mass index, fasting blood glucose level, Cholesterol levels, high-density lipoprotein (HDL) levels, low-density lipoprptein (LDL) levels and smoking status. However, no relationship was observed between HTGW phenotype and hypogonadism in group 3.

Conclusion

HTGW phenotype was highly associated with hypogonadism in Taiwanese adult men. More attention should be paid to men aged <50 years with HTGW.

Systematic Review of Literature Documenting the Link Between BMI, Sperm Parameters, and Leptin

Background: Leptin administration to rats causes adverse effects on sperm that resemble those reported in obese males. The purpose of this review is, therefore, to examine whether human and animal studies have taken this information on board and have attempted to link the poor sperm quality in obese or overweight individuals to leptin in their methodology, data analysis, and discussion. The review also documents the link between low sperm quality in the obese and leptin.

Method: A search was made for articles reporting body mass index (BMI), sperm parameters, and leptin, published until September 2020 in PubMed, Science Direct, Google Scholar, and Springer Link using a number of search terms.

Results: Forty-four of the 53 human and animal studies on BMI and sperm parameters reported abnormal sperm parameters in the obese but only 9 of those had measured serum leptin. None, however, attempted to link sperm abnormalities to leptin. Nine animal studies report of adverse effects of leptin on sperm in normal weight rats that were found to be similar to those reported in obese males.

Conclusion: Although none of the human studies had actually linked the raised leptin to sperm abnormalities in the obese, there is nevertheless, convincing evidence linking leptin to obesity-related poor sperm quality and male infertility. There is a need, therefore, to include measures that will help reduce the impact of raised leptin levels on male reproductive function, particularly, in obese infertile or subfertile males.

Improving Gander Reproductive Efficacy in the Context of Globally Sustainable Goose Production

The goose is a popular poultry species, and in the past two decades the goose industry has become highly profitable across the globe. Ganders low reproductive performance remains a barrier to achieving high fertility and hatchability in subsequent flocks. To address the global demand for cheaper animal protein, various methodologies for improving avian (re)production should be explored. A large amount of literature is available on reproduction traits and techniques for commercial chicken breeder flocks, while research on improved reproduction in ganders has been carried out to a lesser extent. The present review aims to provide a comprehensive literature overview focusing on recent advancements/techniques used in improving gander reproductive efficacy in the context of ensuring a globally sustainable goose industry.

Replicability of leptin associations with testosterone, estradiol, follicle-stimulating hormone, and luteinizing hormone in healthy Ache men of Paraguay: A multiple daily assessment

OBJECTIVE

Associations between leptin and male reproductive hormone levels have been reported in men. However, few of these investigations have focused on associations in healthy men without obesity or overweight or nonindustrial societies.

METHODS

We test hypotheses that leptin is associated with testosterone, estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) within healthy Ache men, an indigenous nonindustrialized South American community using archived data.

RESULTS

Archived data of serum FSH, LH, leptin, and salivary testosterone and estradiol levels collected from healthy Ache men (n = 17, mean age = 37.1 ± 14.2) on two separate days revealed leptin was correlated with FSH (D1 p = .07, D2 p = .009) and PM testosterone (TsalPM, D1 p = .05, D2 p = .05). However, controlling for age, associations with FSH were not significant. Mean comparisons and linear regression of values over 2 days resulted in leptin (t = 0.08, p = .94, r²  = .58, p = .0009), LH (t = 1.16, p = .26, r²  = .11, p = .27), FSH (U = 131.5, p = .88, r²  = .63, p = .0002), AM testosterone (TsalAM, t = 4.0, p = .001, r²  = .02, p = 0.75), and TsalPM (t = 2.99, p = .01, r²  = .56, p = .01).

CONCLUSION

We conclude (a) FSH, TsalPM, and leptin levels within individual men are relatively invariant over a span of days; (b) despite small sample sizes, results suggest ecological and lifestyle variation can contribute to variation in leptin associations with male reproductive hormones.

Environmental and occupational exposures associated with male infertility

The upsurge in male infertility over the last two decades, possibly due to environmental exposure, has raised significant interest, particularly boosted by reports from fertility clinics, which showed that chronic diseases and hereditary or other medical conditions might only partially explain current incidence of male infertility. Both environmental and occupational settings may have a significant role in exposure to complex mixtures of endocrine disruptors (ED), which play a major role in fertility disorders. The aim of this review is to give an insight into the current knowledge on exposure settings which may be associated with male infertility. Our study relied on a systematic search of PubMed, Scopus, and Web of Science for articles published between January 2000 and September 2020. It showed that some well documented factors associated with male infertility include smoking, and physiological disturbances or chronic diseases such as obesity and diabetes, which in turn, may also reflect lifestyle choices and environmental exposures, especially to EDs such as phthalates, bisphenols, pesticides, and flame retardants. However, the number of studies on the aetiology of male infertility is still too low in comparison with the size of affected population. Occupational health follow-ups and medical surveillance do not collect any data on male infertility, even though ED chemicals are part of many technological processes.

Impairment of testes development in Yangzhou ganders by augmentation of leptin receptor signaling

The aim of this study was to determine the cellular and molecular mechanisms of leptin (LEP) and the leptin receptor (LEPR) in testicular development of prepubertal ganders. In an in vivo animal experiment, active immunization against LEPR severely depressed prepubertal testicular development by significantly reducing testicular weights at 200 and 227 days of age. The number of elongated spermatids in the seminiferous tubules was also significantly decreased by immunization with LEPR at ages of 200 and 227 days. Inhibition of testicular development by LEPR immunization was associated with decreases in LHR, StAR, 3β-HSD, CYP11A1, CYP17A1, and PRLR mRNA expression levels in testicular tissue, which resulted in a significant decrease in testosterone synthesis. In the in vitro experiments, the addition of LEP combined with anti-LEPR antibodies strengthened LEPR signal transduction, and inhibited significantly testosterone production in cultured Leydig cells isolated from prepubertal gander testes. The mRNA expression of LHR, StAR, 3β-HSD, CYP11A1, CYP17A1 also decreased significantly after treatment with LEP combined with anti-LEPR antibodies in cultured Leydig cells. These results suggest that anti-LEPR antibodies strengthen LEPR signaling transduction in the presence of LEP, and immunization against LEPR inhibited testes development and testosterone secretion in prepubertal ganders.

Effect of seminal redox status on lipid peroxidation, apoptosis and DNA fragmentation in spermatozoa of infertile Saudi males

Objectives:

To assess the effect of seminal redox status on lipid peroxidation (LPO), apoptosis and integrity of sperm DNA in infertile males.

Methods:

In this case-control study, the total antioxidant status (TAS) and reactive oxygen species (ROS) levels were analyzed within the seminal plasma of fertile normozoospermic, n=40 and infertile (asthenozoospermic, n=30; oligoasthenoteratozoospermic, n=30) males. Additionally, the level of 4-hydroxynonenal (4-HNE), DNA fragmentation, and caspase-3 activity were estimated in the spermatozoa.

Results:

Significantly (p<0.001) increased seminal ROS level with decreased TAS scores was observed in the infertile groups compared to normozoospermics. The infertile males showed marked elevated (p<0.001) levels of 4-HNE, DNA fragmentation and caspase-3 activity compared to normozoospermics, which was positively correlated to increased seminal ROS levels and negatively to the TAS score in the studied groups. Seminal ROS level was significantly inverse correlated to the semen parameters. Additionally, a strong negative correlation between DNA fragmentation, LPO, caspase-3activity and seminal parameters were observed.

Conclusion:

Seminal oxidative stress is a potential risk factor for LPO, DNA damage, and apoptosis in spermatozoa, which can affect semen quality and male fertility. Thus, in addition to conventional seminological parameters, measurement of seminal oxidative stress and sperm DNA integrity may also be employed to investigate the functional integrity of spermatozoa at the molecular level.

Male adiposity, sperm parameters and reproductive hormones: An updated systematic review and collaborative meta-analysis

The present updated systematic review and meta-analysis aims to summarize the evidence from published studies with low risk for any important bias (based on methodological quality assessment) investigating the potential associations of adiposity with sperm quality and reproductive hormones. We conducted a systematic search of the literature published in MEDLINE-PubMed and EMBASE through June 2019. Based on the criteria in our review, 169 eligible publications were used for data abstraction. Finally, 60 articles were included in the qualitative analysis and 28 in the quantitative analysis. Our systematic review results indicated that overweight and/or obesity were associated with low semen quality parameters (i.e., semen volume, sperm count and concentration, sperm vitality and normal morphology) and some specific reproductive hormones (e.g., inhibin B, total testosterone and sex hormone-binding globulin). Overweight and/or obesity were also positively associated with high estradiol concentrations. Meta-analysis indicated that overweight and/or obesity categories were associated with lower sperm quality (i.e., semen volume, sperm count and concentration, sperm vitality, total motility and normal morphology), and underweight category was likewise associated with low sperm normal morphology. In conclusion, our results suggest that maintaining a healthy body weight is important for increasing sperm quality parameters and potentially male fertility.

The role of leptin and obesity on male infertility

PURPOSE OF REVIEW

Several studies suggest a strong association between leptin, obesity, and infertility with respect to the hypothalamic-pituitary-gonadal (HPG) axis, androgen regulation, and sperm production, but the direct mechanistic association between these is still largely unexplored. This review focuses on understanding the association between leptin, obesity, and male infertility.

RECENT FINDINGS

Obesity is linked to fertility dysfunction in both genders. Obesity in men may affect their fertility by impaired spermatogenesis, reduced testosterone levels, erectile dysfunction, and poor libido by putatively targeting the HPG and hypothalamic-pituitary-adrenal axes. Leptin plays key roles in many metabolic functions, including reproduction. High concentrations of leptin have been found in infertile men with disorders affecting the testicular parenchyma, including nonobstructive azoospermia, oligozoospermia, and oligo-astheno-teratozoospermia. Additionally, serum leptin levels have negative associations with serum testosterone levels and sperm parameters and positive associations with serum follicle-stimulating hormone and luteinizing hormone levels and abnormal sperm morphology.

SUMMARY

Excessive leptin production may be a significant contributor to the development of androgen insufficiency and reduced reproductive function in obese men. Understanding the relation between leptin, obesity, and reproduction may shed light on future targeted treatments for male infertility.

Lifestyle, metabolic disorders and male hypogonadism - A one-way ticket?

Hypogonadism is more frequent among men with common metabolic diseases, notably obesity and type 2 diabetes. Indeed, endocrine disruption caused by metabolic diseases can trigger the onset of hypogonadism, although the underlying molecular mechanisms are not entirely understood. Metabolic diseases are closely related to unhealthy lifestyle choices, such as dietary habits and sedentarism. Therefore, hypogonadism is part of a pathological triad gathering unhealthy lifestyle, metabolic disease and genetic background. Additionally, hypogonadism harbors the potential to aggravate underlying metabolic disorders, further sustaining the mechanisms leading to disease. To what extent does lifestyle intervention in men suffering from these metabolic disorders can prevent, improve or reverse hypogonadism, is still controversial. Moreover, recent evidence suggests that the metabolic status of the father is related to the risk of inter and transgenerational inheritance of hypogonadism. In this review, we will address the proposed mechanisms of disease, as well as currently available interventions for hypogonadism.

Altered sperm parameters and subclinical hypothyroidism; A cross sectional study in Karachi, Pakistan

OBJECTIVE

The purpose of this study is to compare the thyroid hormone (TH) profile in male infertile subjects with normal and altered sperm parameters and assess its relationship with spermogram and reproductive hormones.

DESIGN

This cross-sectional study was conducted in Karachi from August 2017 till September 2018 on 376 male subjects between 25 and 55 years of age. The reference values for the "Normal Sperm Parameters" group was; sperm count (TC) >39 million per ejaculate, total sperm motility (Progressive and Non-progressive) >40% and normal morphology of ≥4%. Male subjects, having any one of the sperm parameters below the reference values comprised the group of "Altered Sperm Parameters". The thyroid profile; Thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone, Thyroid Peroxidase antibodies (Anti-TPO) was estimated in addition to reproductive hormones Testosterone and Sex hormone binding globulin (SHBG). Independent sample T test and Analysis of Variance was applied for comparison of groups. Linear regression was performed and unadjusted and adjusted beta coefficient with 95% CI was reported. A P-value of <.05 was considered significant.

RESULTS

Two hundred and sixteen subjects had normal, whereas 160 had "Abnormal Sperm Parameters." In "Normal Sperm Parameter" group; 206 (95.3%) were euthyroid while 10 (4.6%) were having subclinical hypothyroidism (SCH). Among the "Abnormal Sperm Parameters" group; eighty-seven (54%) subjects were euthyroid, sixty-two (38.75%) had SCH and eleven (6.8%) were having overt hypothyroidism. Testosterone and SHBG were significantly lower in "Altered Sperm Parameters" group as compared with "Normal Sperm Parameters" (P < .001 for both).

CONCLUSION

A higher frequency of SCH, decreased levels of testosterone and SHBG was observed in the "Altered Sperm Parameters" group. The results establish relationship of disturbance in TH with alteration of sperm parameters and reproductive hormones thus contributing to male infertility.

Oxidized-LDL inhibits testosterone biosynthesis by affecting mitochondrial function and the p38 MAPK/COX-2 signaling pathway in Leydig cells

Abnormal lipid/lipoprotein metabolism induced by obesity may affect spermatogenesis by inhibiting testosterone synthesis in Leydig cells. It is crucial to determine which components of lipoproteins inhibit testosterone synthesis. Circulating oxidized low-density lipoprotein (oxLDL), the oxidized form of LDL, has been reported to be an independent risk factor for decreased serum testosterone levels. However, whether oxLDL has a damaging effect on Leydig cell function and the detailed mechanisms have been rarely studied. This study first showed the specific localization of oxLDL and mitochondrial structural damage in testicular Leydig cells of high-fat diet-fed mice in vivo. We also found that oxLDL reduced the mitochondrial membrane potential (MMP) by disrupting electron transport chain and inhibited testosterone synthesis-related proteins and enzymes (StAR, P450scc, and 3β‑HSD), which ultimately led to mitochondrial dysfunction and decreased testosterone synthesis in Leydig cells. Further experiments demonstrated that oxLDL promoted lipid uptake and mitochondrial dysfunction by inducing CD36 transcription. Meanwhile, oxLDL facilitated COX2 expression through the p38 MAPK signaling pathway in Leydig cells. Blockade of COX-2 attenuated the oxLDL-induced decrease in StAR and P450scc. Our clinical results clarified that the increased serum oxLDL level was associated with a decline in circulating testosterone levels. Our findings amplify the damaging effects of oxLDL and provide the first evidence that oxLDL is a novel metabolic biomarker of male-acquired hypogonadism caused by abnormal lipid metabolism.

Reasons for worldwide decline in male fertility

PURPOSE OF REVIEW

To review the evidence regarding a decrease in worldwide sperm parameters and discuss potential causative factors.

RECENT FINDINGS

The topic of worldwide decline in sperm parameters is contentious; however, recent high-quality studies have demonstrated that there is indeed a decline in sperm parameters. Several retrospective and basic science studies have shown possible links for this decline in sperm parameters such as obesity, diet, and environmental toxins.

SUMMARY

There exist substantial data to suggest a decline in sperm counts over time. Although causative factors have yet to be fully elucidated, potential causes include, increased rates of obesity, poor diet, and exposure to environmental toxins. How this decline in sperm counts reflects fertility has yet to be determined. As such, further studies are necessary to evaluate whether this decline in sperm count correlates with decreased fecundity and how to identify and mitigate potential causative factors.

Lipid accumulation product and late-onset hypogonadism in middle-aged and elderly men: results from a cross-sectional study in China

OBJECTIVES

Hypogonadism in men is related to the deterioration of general health. However, the association between lipid overaccumulation and ageing-related hypogonadism remains an undetermined concept. We aimed to provide an insight into the possible links between the lipid accumulation product (LAP) and late-onset hypogonadism (LOH).

SETTING

Sun Yat-sen Memorial Hospital of Sun Yat-sen University.

PARTICIPANTS

We included a population sample of 997 subjects aged 40 years or older.

PRIMARY AND SECONDARY OUTCOME MEASURES

The LAP was calculated by gender-specific equations using waist circumference (WC) and triglyceride (TG). LOH was defined by the presence of androgen deficiency symptoms and low serum total testosterone levels.

RESULTS

The prevalence of LOH was 9.4% in this population and gradually increased according to increasing LAP quartiles. Compared with subjects without LOH, ageing men with LOH had higher body mass index, WC, systolic blood pressure, percentage of subjects currently smoking, TG and follicle stimulating hormone and lower low-density lipoprotein cholesterol and sex hormone binding globulin. In multivariate logistic regression analysis, the adjusted ORs of LOH for increasing LAP quartiles 1-4 were 1.00 (reference), 1.10 (95% CI 0.45-2.69), 2.15 (95% CI 0.93-4.94) and 3.83 (95% CI 1.73-8.45), respectively.

CONCLUSION

Body lipid accumulation evaluated by the LAP is independently associated with the prevalence of LOH in middle-aged and elderly Chinese men.