Physical activity and television watching in relation to semen quality in young men

Investigating male factors and their relationships with reproductive health outcomes: a case-control study protocol for Towards Optimal Fertility, Fathering, and Fatherhood studY (TOFFFY) in Singapore

INTRODUCTION

Despite the global prevalence of low fertility rates, male contributions to fertility and reproductive health outcomes have been understudied. This study aims to investigate the male contribution to fertility and explore the underlying biological mechanisms. Specifically, we aim to (1) identify male factors associated with successful pregnancy, (2) develop a fertility index incorporating modifiable factors for both males and females to predict pregnancy rate and (3) explore the relationship of male modifiable factors with semen parameters and molecular characteristics.

METHODS AND ANALYSIS

We will conduct an unmatched case-control study involving 240 couples with impaired male fertility (cases) and 240 couples with normal male fertility (controls). Between July 2024 and June 2026, we will recruit 480 eligible couples from KK Women's and Children's Hospital, Singapore. Male and female participants will complete questionnaires on sociodemographics, general health and lifestyle factors, and their anthropometry and body fat composition will be measured. Blood and semen samples from the male participants will be collected for biochemical, molecular and semen analyses. Predictive male factors will be identified using the least absolute shrinkage and selection operator method, accounting for female factors. We will construct a logistic regression model incorporating both male and female factors to derive a fertility index, which will be evaluated using cross-validation on subsets of the study population. Multivariable linear regression will be used to explore relationships between male modifiable exposures and semen parameters.

ETHICS AND DISSEMINATION

The study protocol has received approval from the Centralised Institutional Review Board of SingHealth (2024/2120), Singapore. Participants will provide written informed consent. Study results will be disseminated through conferences and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT06293235.

Intensity and type of physical activity and semen quality in healthy young men

OBJECTIVE

To study the relationship between intensity of physical activity (PA) and semen quality in healthy young men.

DESIGN

A prospective cohort study with repeated measures for each subject.

PATIENT(S)

Healthy high school and university students who did not regularly smoke tobacco, drink alcohol, or take drugs or medicine, with normal body mass index and abdominal circumference.

EXPOSURE

The participants underwent urologic visit, fasting blood and semen sampling, and anthropometric measurements, and filled in the International Physical Activity Questionnaire, at enrollment and after 4 and 8 months. Duration and frequency of walking, moderate-intensity, and vigorous-intensity activities in the last week were assessed, and a score was computed for total PA.

MAIN OUTCOME MEASURE(S)

Semen specimens were taken at each visit through masturbation, after 3-5 days of abstinence, and analyzed by an expert urologist. Sperm concentration, total and progressive motility, and proportion of spermatozoa with normal morphology were measured. Linear and generalized linear mixed models with the Poisson family were fitted to assess the relationships between PA variables and sperm parameters, after adjusting for season, time, and study arm. The shape of the relationship was modeled through restricted cubic spline regression.

RESULT(S)

A total of 143 male subjects, aged 18-23 years (median, 20 years), were enrolled. They had a median PA of 1,960 (95% confidence interval, 1,055-3,182) Metabolic Equivalent of Tasks in min/wk. Statistically significant differences were found for total, progressive motility, and percent of cell with normal morphology across categories of total PA; the highest medians of total (47%) and progressive motility (34%) and of the percentage of normal morphology cells (7%) were found for medium PA. Positive associations of sperm total motility and normal morphology with medium levels of PA, and negative associations with walking and vigorous-intensity activity emerged. Spline regression analysis confirmed these findings, showing an inverse U-shape relationship, with the highest value of total motility and normal morphology for medium PA, and the lowest values for lower and higher activity.

CONCLUSION(S)

These findings support the present recommendations to practice moderate PA for health improvement, including semen quality.

Do Exercise and Magnesium Sulfate Improve Infertility Caused by Lithium Carbonate in Male Rats?

Background

Lithium (Li) is widely used in the treatment of bipolar disorder, but it may lead to toxicity in the reproductive system. Considering the harmful effect of Li consumption on fertility and the positive effect of magnesium sulfate (MgSo4) and moderate-intensity training (MIT) on improving the quality of men's sperm, the current research was conducted to determine the impact of MIT and MgSo4 on infertility caused by Li.

Materials and Methods

Seventy-two male rats were divided into 12 groups, control, Li10 mg/kg/day/ip, MgSo4 80 mg/kg/day/ip; MIT; Li40 mg/kg/day/ip; Li10+MgSo4; Li10+MIT; Li10+MgSo4+MIT; Li40+MgSo4; Li40+MIT; Li40+MgSo4+MIT. All animals received the drugs every day. The groups under the exercise protocol followed this program for 42 days (6 weeks). Total sperm count, sperm concentration, total motility, and progressive motility were analyzed. A blood sample was taken from the heart to quantify testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH).

Results

Li40 mg/kg decreased the progressive motility and quantity of sperms together with nonprogressive motility and immobile sperms increased significantly. Administration of MgSo4 and MIT alone and simultaneously led to a significant improvement in the above mentioned parameters. Li40 mg/kg reduced the serum level of testosterone and LH compared to the control group. On the other hand, the administration of MgSo4 and MIT together with Li40 (Li40+MgSo4+MIT) did not have any effect on serum testosterone levels.

Conclusions

Li probably causes damage to reproductive functions by affecting the antioxidant system. However, MgSo4 and MIT reduce the impacts of Li on the reproductive system and improved its performance.

Correlation of mediterranean diet pattern and lifestyle factors with semen quality of men attending fertility clinics: A cross-sectional study

BACKGROUND

While numerous studies have examined the impact of individual or combined nutrients on semen quality, research on the correlation between overall dietary patterns and semen quality remains limited. This cross-sectional study investigates the relationship between adherence to the alternative Mediterranean diet (aMED) and semen quality.

METHODS

A total of 274 men, presenting with both normal and abnormal semen parameters, participated in this study. Dietary data were collected using a 147-item semi-quantitative food frequency questionnaire (FFQ). Participants were divided into three groups based on their adherence to the Mediterranean diet (T1, T2, and T3). Statistical analyses, including ANOVA for numerical data and Chi-square tests for categorical data, were conducted. Multivariable logistic regression models were employed to estimate the association between aMED scores and abnormal semen parameters.

RESULTS

Participants in the highest adherence group (T3) were younger and had lower BMI compared to those in the other tertiles. Significant differences in sperm parameters were observed across the tertiles. T3 recorded the highest levels of sperm concentration, total sperm count, motility, progressive motility, and normal morphology (57.53 ± 36.16, 213.8 ± 158.9, 73.4 ± 25.9, 61.2 ± 24.6, and 6.42 ± 1.51, respectively), whereas T1 had the lowest values (11.92 ± 22.29, 43.3 ± 73.8, 36.7 ± 33.8, 4.6 ± 5.7, respectively). No significant differences were found in semen volume and viscosity. The regression analysis revealed a significant positive correlation between aMED scores and sperm concentration (B = 1.32, P = 0.001), total sperm count (B = 1.12, P = 0.001), and total motility (B = 0.71, P = 0.001).

CONCLUSION

Adherence to a high-quality Mediterranean diet is positively associated with improved semen quality and increased male fertility potential. Promoting healthy dietary patterns may be an effective strategy to enhance sperm motility and overall male reproductive health.

Longitudinal trends and correlation between autism spectrum disorder prevalence and sperm quality parameters (2000-2024): a comprehensive statistical analysis

Introduction

Over the past few decades, there has been growing concern about the concurrent trends of increasing Autism Spectrum Disorder (ASD) prevalence and declining sperm quality. These trends represent significant public health challenges that warrant thorough investigation of their underlying causes and implications.

Objectives

The primary objectives of this study are to analyze trends in ASD prevalence and sperm quality parameters from 2000 to 2024, assess the statistical significance and effect size of these trends, explore potential correlations between ASD prevalence and sperm quality parameters, and identify significant predictors among sperm quality parameters that influence ASD prevalence.

Methods

This study employed a longitudinal approach using multiple regression, time series analysis, ANOVA, Principal Component Analysis (PCA), hierarchical clustering, logistic regression, and cross-correlation analysis. Data on ASD prevalence were sourced from the CDC Autism and Developmental Disabilities Monitoring Network, while sperm quality data were collected from various published studies.

Results

The findings reveal significant negative associations between ASD prevalence and sperm quality parameters such as sperm concentration and motility, suggesting that better sperm quality is linked to lower ASD rates. Conversely, parameters like sperm DNA fragmentation (SDF), volume of ejaculate, pH level, and semen viscosity show positive associations with ASD prevalence, indicating higher values in these parameters correlate with higher ASD rates.

Conclusion

The study highlights the importance of maintaining reproductive health to potentially mitigate ASD risk and calls for further research to elucidate the underlying mechanisms driving these trends. These findings support the hypothesis that reproductive health factors play a crucial role in ASD etiology and suggest potential biological markers for assessing ASD risk.

The influence of lifestyle and biological factors on semen variability

PURPOSE

Semen parameters are subjected to within-individual variability over time. The driving factors for this variability are likely multi-factorial, with healthier lifestyle associated with better semen quality. The extent in which variations in individual's lifestyle contributes to within-individual semen variability is unknown.

METHODS

A total of 116 repeat semen samples from 29 men aged 19-37 over 6 months were collected. Basic semen analysis as per 5th WHO manual and extended semen parameters (sperm DNA fragmentation, redox potential and lipid peroxidation, sperm binding to hyaluronan and hyperactive motility) were assessed. An additional 39 lifestyle/biological factors (weight, blood pressure, etc.) were collected at each sample including validated health questionnaires SF36 Health Status, Australian Recommend Food Score, and International Physical Activity Questionnaire.

RESULTS

Only 10 out of the 39 lifestyle factors varied within men across samples including age (P = 0.0024), systolic blood pressure (P = 0.0080), social functioning (P = 0.0340), energy (P = 0.0069), non-alcoholic caffeinated beverages (P = 0.0010), and nutrition (P < 0.0001). The only semen parameter that varied between collections was sperm morphology (coefficient of variation 23.8 (6.1-72.0), P < 0.05). We only observed weak (r < 0.3) to moderate (r > 0.3- < 0.6) correlations between lifestyle factors, including body mass index, waist circumference, nutrition, exercise, blood pressure and semen parameters including sperm count, progressive motility, and sperm DNA fragmentation (P < 0.05).

CONCLUSION

In healthy men from the general population, semen quality and associated lifestyle factors do not significantly vary over 6 months, indicating that one semen sample is likely sufficient for determining male fertility in this population.

The impact of obesity and metabolic health on male fertility: a systematic review

The impact of paternal obesity and metabolic disease on semen quality and fertility outcomes is not fully appreciated. With increasing obesity rates, researchers have studied the intricate relationship between paternal body mass index, metabolic health, and male fertility. This systematic review identified 112 articles in the MEDLINE database between 2013 and 2023 that investigated the effects of body mass index, diabetes, metabolic syndrome, exercise, weight loss medication, or bariatric surgery on semen parameters, sperm quality, or fertility outcomes. This review suggests that obesity, diabetes, and metabolic syndrome have a negative impact on various parameters of male fertility, from semen quality to sperm deoxyribonucleic acid integrity. There is also mounting evidence that male obesity is correlated negatively with live births via both natural conception and assisted reproductive technologies. Lifestyle interventions, such as physical exercise, generally appear to improve male fertility markers; however, the type and intensity of exercise may play a crucial role. Pharmacologic treatments for weight loss, such as metformin and glucagon-like peptide 1 agonists, present a more complex picture, with studies suggesting both beneficial and detrimental effects on male reproductive health. Similarly, surgical interventions, such as gastric bypass surgery, show promise in improving hormonal imbalances but have mixed effects on semen parameters. Future research is needed to clarify these associations and inform clinical guidelines. In the interim, health practitioners should incorporate these insights into clinical practices, encouraging proactive lifestyle changes and providing targeted treatments to improve male reproductive health.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Reproduction as a window for health in men

Male factor infertility is widely considered a harbinger for a man's general health. Failure of reproduction often accompanies other underlying processes, with growing evidence suggesting that a diagnosis of infertility increases the likelihood of developing future cardiac, metabolic, and oncologic diseases. The goal of this review is to provide a comprehensive overview of the research on male fertility as a marker for current and future health. A multidisciplinary approach is essential, and there is growing consensus that the male fertility evaluation offers an opportunity to better men's wellness beyond their immediate reproductive ambitions.

Decrease of air pollution during lockdown in Tuscany (Italy): An effect on sperm DNA fragmentation?

In March 2020, the Italian government imposed a national lockdown which was almost completely removed in June 2020. Due to the abrupt stop of human activities, emissions of air pollutants decreased. Air pollution is an environmental risk factor for noncommunicable disease and mortality. Emerging evidence also suggests a role in male infertility. In this study, we compared sperm DNA fragmentation (sDF) levels and conventional semen parameters between subjects undergoing sDF determination and routine semen analysis in a single Italian centre, during about 6 months before (N = 119) and after lockdown (N = 105). After lockdown, we found an improvement of sperm progressive motility (48.00[38.50-58.00]% vs. 42.00[33.00-53.00]%) and sDF levels (as total: 24.79[18.33-33.97]% vs. 35.02[25.04-45.73]%, p < .001; brighter: 14.02[10.69-17.93]% vs 18.54[13.58-25.82]%, p < .001 and dimmer sDF: 9.24[5.64-15.78]% vs. 12.24[8.08-19.10]%, p < .01), mirrored by a decrease of leukocyte semen concentration (p < .01). The improvement of sperm motility and DNA quality was maintained after adjusting for leukocyte concentration and several conditions known to affect sperm motility and/or sDF levels. With a significant decrease in air pollution observed in Tuscany during and after lockdown, associated improvement in sperm motility and DNA quality in patients referred to the infertility clinic is suggestive of the potential role of air pollution in male infertility.

The role of physical agents' exposure in male infertility: A critical review

BACKGROUND

A decrease in semen quality is an increasingly widespread pathological condition worldwide. Jobs and lifestyles have changed a lot with the advancement of technology in the last few decades, and a new series of risk factors for male infertility have spread.

OBJECTIVE

This review aims to summarize the current literature on this relationship, evaluating alterations in semen parameters and hormonal profile.

METHODS

A deep research was performed through MEDLINE via PubMed, Scopus, and Web of Science on articles regarding the relationship between physical agents and male fertility over the last twenty years. Some physical agents already associated with male infertility, such as heat and radiation, while emerging ones, such as physical exertion, psychological stress and sedentary activities, were newly considered.

RESULTS

Most studies described sperm quality after exposure. Overall sperm impairment was shown after radiation and alteration of specific parameters, such as sperm concentration, were observed after psychological stress and sedentary work. In addition, an association was also reported between physical exertion and hormonal profile, especially pituitary hormones and testosterone.

CONCLUSIONS

Although the associations between physical agents and male infertility are suggestive, the level of evidence of the studies is not adequate to define their influence, except for physical exertion. Therefore, new prospective studies are necessary for the validation of the correlation and the possible safeguarding of the exposed working classes.

The future of sperm: a biovariability framework for understanding global sperm count trends

The past 50 years have seen heated debate in the reproductive sciences about global trends in human sperm count. In 2017, Levine and colleagues published the largest and most methodologically rigorous meta-regression analysis to date and reported that average total sperm concentration among men from 'Western' countries has decreased by 59.3% since 1973, with no sign of halting. These results reverberated in the scientific community and in public discussions about men and masculinity in the modern world, in part because of scientists' public-facing claims about the societal implications of the decline of male fertility. We find that existing research follows a set of implicit and explicit assumptions about how to measure and interpret sperm counts, which collectively form what we term the Sperm Count Decline hypothesis (SCD). Using the study by Levine and colleagues, we identify weaknesses and inconsistencies in the SCD, and propose an alternative framework to guide research on sperm count trends: the Sperm Count Biovariability hypothesis (SCB). SCB asserts that sperm count varies within a wide range, much of which can be considered non-pathological and species-typical. Knowledge about the relationship between individual and population sperm count and life-historical and ecological factors is critical to interpreting trends in average sperm counts and their relationships to health and fertility.

Recreational Drug Misuse and Its Potential Contribution to Male Fertility Levels' Decline: A Narrative Review

Recreational drug intake may be associated with a range of medical untoward consequences, including male infertility. However, as the related evidence is still limited, the main outcome of this review is to provide a better understanding of the existence of any association between recreational drug misuse and male fertility levels' decline. Whilst searching the MEDLINE/PubMed, a comprehensive overview of the literature regarding male infertility and substances of abuse (e.g., phytocannabinoids, opiates/opioids, stimulants, 'herbal highs', psychedelics, and 'novel psychoactive substances) was here undertaken. Due to the paucity of robust, high-quality, empirical, human studies, a narrative strategy was here preferred over a systematic approach. Relevant data are qualitatively analyzed and presented in a table. Although most available evidence is in support of a detrimental role of cannabis on human spermatogenesis, a few remaining studies failed to document any effect of this drug on seminal quality, and it is not clear to which extent this drug impacts fertility rates/time to pregnancy. The current understanding of the impact of opiate-, cocaine- and amphetamine/stimulant-misuse on human reproduction is widely unknown, and most studies dealing with this matter represent only an extrapolation of data derived from specific clinical circumstances. Although the message of 'no smoking, no alcohol and no street drugs' should always be offered as good health advice to all patients seeking medical help for fertility issues, robust scientific clinical evidence in support of a direct detrimental impact of recreational drugs on spermatogenesis is scant to date.

[Impact of lifestyle and environmental factors on male reproductive health]

The identification of potential environmental hazards is of clinical relevance for the diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders. Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproduction. Reproductive toxicity may evolve at the hypothalamic-pituitary, testicular, or posttesticular level; endpoints comprise deterioration of spermatogenesis and sperm function as well as endocrine disorders and sexual dysfunction. However, due to the complex regulation of the male reproductive system, information regarding single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal or in vitro studies remains difficult. Nevertheless, the assessment of relevant exposures to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.

Preliminary prediction of semen quality based on modifiable lifestyle factors by using the XGBoost algorithm

Introduction

Semen quality has decreased gradually in recent years, and lifestyle changes are among the primary causes for this issue. Thus far, the specific lifestyle factors affecting semen quality remain to be elucidated.

Materials and methods

In this study, data on the following factors were collected from 5,109 men examined at our reproductive medicine center: 10 lifestyle factors that potentially affect semen quality (smoking status, alcohol consumption, staying up late, sleeplessness, consumption of pungent food, intensity of sports activity, sedentary lifestyle, working in hot conditions, sauna use in the last 3 months, and exposure to radioactivity); general factors including age, abstinence period, and season of semen examination; and comprehensive semen parameters [semen volume, sperm concentration, progressive and total sperm motility, sperm morphology, and DNA fragmentation index (DFI)]. Then, machine learning with the XGBoost algorithm was applied to establish a primary prediction model by using the collected data. Furthermore, the accuracy of the model was verified via multiple logistic regression following k-fold cross-validation analyses.

Results

The results indicated that for semen volume, sperm concentration, progressive and total sperm motility, and DFI, the area under the curve (AUC) values ranged from 0.648 to 0.697, while the AUC for sperm morphology was only 0.506. Among the 13 factors, smoking status was the major factor affecting semen volume, sperm concentration, and progressive and total sperm motility. Age was the most important factor affecting DFI. Logistic combined with cross-validation analysis revealed similar results. Furthermore, it showed that heavy smoking (>20 cigarettes/day) had an overall negative effect on semen volume and sperm concentration and progressive and total sperm motility (OR = 4.69, 6.97, 11.16, and 10.35, respectively), while age of >35 years was associated with increased DFI (OR = 5.47).

Conclusion

The preliminary lifestyle-based model developed for semen quality prediction by using the XGBoost algorithm showed potential for clinical application and further optimization with larger training datasets.

Effect of Stress and Caffeine on Male Infertility

Caffeine is a natural psychoactive chemical found in beverages made from coffee. In addition, it is added by the manufacturers of a large number of sodas and energy drinks. It does this by stimulating both the brain and the central nervous system, enabling you to avoid being sleepy while still keeping you attentive. A state of emotional or physical tension is defined as stress. It can be induced through the experience of something or thinking of something that causes you to feel uncomfortable, irritated, or nervous. Your body's response to adversity or demand is what we call stress. Among couples, male infertility is common. A failure in spermatogenesis is accountable for nearly half of all occurrences of infertility in marriage. Ageing, psychological stress, diet, physical exercise, coffee, hot water, hot scrotum, and cell phone usage are some of the few modifiable lifestyle variables that have a role in the development of infertility. Many hypotheses have been proposed to establish the link between stress in the workplace, life events (war, earthquake, etc.), and inability to conceive have been linked to inferior or degraded semen quality. In this review, we will discuss the effect on male fertility of elements including quality of life (such as exercise, diet, and other alterations to one's daily routine) and psychological stress. In addition, the effects on male fertility of elevated scrotal temperature, improper dietary habits, and physical inactivity will be discussed. The loss in male fertility, mainly due to ageing, inappropriate lifestyles, and environmental factors, is a significant public health concern in this century. Couples can enhance their quality of life and increase their chances of naturally conceiving a child by altering their way of life and supplementing it with nutraceutical antioxidants and an organised educational, environmental, dietary, and physical exercise program.

Association of occupations with decreased semen quality in eastern China: a cross-sectional study of 12 301 semen donors

OBJECTIVES

This study aims to examine the association between occupational factors and semen quality in semen donors in eastern China.

METHODS

We recruited 12 301 semen donors from 2006 to 2020 as the studying population. A self-designed questionnaire was applied for collecting lifestyle and work style information. Semen samples were analysed according to WHO guidelines. A crude and adjusted linear regression model was used to analyse the association between occupational factors and semen quality.

RESULTS

College students accounted for 36.2% of all semen donors. The majority (81.3%) of semen donors were between 18 year and 30 years. Soldiers or the police had the highest semen volume (the median value=3.8 mL), however, they had the lowest sperm concentration (53.6×10⁶/ml) and sperm motility (45.5%). Workers in finance or insurance had an elevated risk of low semen volume, sperm concentration and total sperm count (OR=1.43, 1.57 and 1.98, respectively). Unemployed men had a high risk of low sperm concentration and low total sperm count (OR=1.84 and 1.58, respectively). Working in the information technology industry had a deleterious effect on the progressive motility of sperm (OR=1.27, 95% CI 1.03 to 1.57).

CONCLUSION

Our study indicated that sedentary work style and intensive sports in certain professions might be associated with decreased semen quality. We reported evidence of becoming unemployed on the damage to semen quality. Hence, we advocate a healthy work style to improve semen quality in eastern China.

Running exercise training-induced impact on oxidative stress and mitochondria-related apoptosis in rat's testicles

The current study has been designed to explore the effects of running exercise training protocols (ETPs), with different intensities, on testicular redox and antioxidant capacities. Moreover, the crosstalk between oxidative stress (OS) and mitochondria-related apoptosis was analysed. To this end, 24 Wistar rats were subdivided into sedentary control, low- (LICT), moderate- (MICT), and high (HICT)-intensity continuous running ETP groups. Following 8 weeks, the Johnsen score, sperm count, testicular malondialdehyde (MDA) content, total oxidant status (TOS), and redox biomarkers, including glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) levels were evaluated. Additionally, the expression levels of Bcl-2, Bax, caspase-3, proteins involving in the mitochondria-related apoptosis, and the apoptotic index were analysed. The LICT and MICT running ETPs did not affect the spermatogenesis development, sperm count, and antioxidant and redox capacities. Accordingly, no significant changes were revealed in Bcl-2, Bax, and caspase-3 expression levels and apoptosis index compared to sedentary rats. In contrast, the HICT-induced rats showed a significant (p < 0.05) reduction in spermatogenesis development, sperm count, antioxidant and redox capacities versus control, LICT, and MICT groups. Moreover, the expression of Bcl-2 was decreased, while the Bax and caspase-3 expression levels were increased in the HICT-induced group. Finally, the apoptosis index was increased in the HICT group. In conclusion, the suppressed redox system after HICT can trigger the mitochondria-mediated ROS overload, result in OS condition in the testicular tissue, and reversely target the mitochondrial membrane permeability. All of these molecular alterations are suspected to initiate progressive mitochondria-related apoptosis after HICT.

Women's and men's intake of omega-3 fatty acids and their food sources and assisted reproductive technology outcomes

BACKGROUND

Long-chain omega-3 fatty acids and their food sources have garnered interest as a potential nutrient with wide-range health benefits, including fertility.

OBJECTIVE

This study aimed to investigate the association of women's and men's intake of omega-3 fatty acids and omega-3 rich-foods with semen quality and outcomes of infertility treatment with assisted reproductive technologies.

STUDY DESIGN

Couples presenting to the Massachusetts General Hospital were invited to enroll in a prospective cohort study (2007-2020). Male and female diets were assessed using a validated 131-item food frequency questionnaire. The primary outcomes were implantation, clinical pregnancy, and live birth probabilities. The secondary outcomes included total and clinical pregnancy loss and conventional semen parameters, for males only. We estimated the relationship between intakes of omega-3 fatty acids, nuts, and fish and the probability (95% confidence interval) of study outcomes using generalized linear mixed models to account for repeated treatment cycles per participant while simultaneously adjusting for age, body mass index, smoking status, education, dietary patterns, total energy intake, and male partner diet.

RESULTS

A total of 229 couples and 410 assisted reproductive technology cycles were analyzed for primary and secondary outcomes. Of note, 343 men contributing 896 semen samples were included in analyses for semen quality measures. Women's docosahexaenoic acid + eicosapentaenoic acid intake was positively associated with live birth. The multivariable-adjusted probabilities of live birth for women in the bottom and top quartiles of eicosapentaenoic acid + docosahexaenoic acid intake were 0.36 (95% confidence interval, 0.26-0.48) and 0.54 (95% confidence interval, 0.42-0.66) (P trend=.02). Eicosapentaenoic acid + docosahexaenoic acid intake was inversely related to the risk of pregnancy loss, which was 0.53 among women in the lowest quartile of eicosapentaenoic acid + docosahexaenoic acid intake and 0.05 among women in the highest quartile (P trend=.01). Men's intake of total omega-3 fatty acids was positively related to sperm count, concentration, and motility, but unrelated to any assisted reproductive technology outcomes. Similar associations were observed when evaluating the intake of primary food sources of these fatty acids.

CONCLUSION

Women's consumption of omega-3 fatty acids and omega-3-rich foods may improve the probability of conception by decreasing the risk of pregnancy loss. In addition, men's intake of omega-3 fatty acids may influence semen quality.

Environmental factors in declining human fertility

A severe decline in child births has occurred over the past half century, which will lead to considerable population declines, particularly in industrialized regions. A crucial question is whether this decline can be explained by economic and behavioural factors alone, as suggested by demographic reports, or to what degree biological factors are also involved. Here, we discuss data suggesting that human reproductive health is deteriorating in industrialized regions. Widespread infertility and the need for assisted reproduction due to poor semen quality and/or oocyte failure are now major health issues. Other indicators of declining reproductive health include a worldwide increasing incidence in testicular cancer among young men and alterations in twinning frequency. There is also evidence of a parallel decline in rates of legal abortions, revealing a deterioration in total conception rates. Subtle alterations in fertility rates were already visible around 1900, and most industrialized regions now have rates below levels required to sustain their populations. We hypothesize that these reproductive health problems are partially linked to increasing human exposures to chemicals originating directly or indirectly from fossil fuels. If the current infertility epidemic is indeed linked to such exposures, decisive regulatory action underpinned by unconventional, interdisciplinary research collaborations will be needed to reverse the trends.

Irisin Improves High-Fat Diet-Induced Sexual Dysfunction in Obese Male Rats

INTRODUCTION

Obesity is known to cause sexual dysfunction including erectile dysfunction and poor semen quality. Lifestyle modifications such as exercise have increasingly been more recognized to lower the likelihood of having sexual dysfunction or infertility in obese men. In this context, as an exercise-mimetic hormone, irisin has a potential to improve obesity-related reproductive dysfunctions. We aimed to elucidate possible effects of irisin on high-fat diet (HFD)-induced reproductive dysfunction in obese male rats.

METHODS

Rats were divided into four groups: vehicle, irisin, obese, and obese + irisin. The rats in obese and obese+irisin groups were fed with HFD (60% kcal fat) pellets for 12 weeks to induce obesity, and then obesity-induced sexual dysfunction was confirmed by the sexual behavior test (SBT). Irisin and obese+irisin groups received irisin (100 ng/kg/day) infusion by an s.c. osmotic minipump for 4 weeks after HFD-induced obesity was formed.

RESULTS

Irisin did improve a number of measures of copulation, including penile erection, ejaculation, and sexual performance, and also improved sperm morphology and motility and decreased fat-induced testicular damage. It decreased serum leptin levels. On the other hand, irisin did not affect serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone. It also increased gene expression of tyrosine hydroxylase (TH) and adrenoceptor alpha 1A (ADRA1A) in the medial preoptic area (mPOA) and nucleus accumbens (NAc).

CONCLUSION

Irisin provided a marked enhancement of HFD-induced decrease in libido, potency, sexual performance, and erection in SBT. Taken together, our results emphasize that irisin has a restorative and improver role in HFD-induced reproductive dysfunctions in obese male rats.

The combined effect of lifestyle intervention and antioxidant therapy on sperm DNA fragmentation and seminal oxidative stress in IVF patients: a pilot study

PURPOSE

Sperm DNA fragmentation (SDF) and seminal oxidative stress are emerging measurable factors in male factor infertility, which interventions could potentially reduce. We evaluated (i) the impact of lifestyle changes combined with oral antioxidant intake on sperm DNA fragmentation index (DFI) and static oxidation-reduction potential (sORP), and (ii) the correlation between DFI and sORP.

MATERIALS AND METHODS

We conducted a prospective study involving 93 infertile males with a history of failed IVF/ICSI. Ten healthy male volunteers served as controls. Semen analysis was carried out according to 2010 WHO manual, whereas seminal sORP was measured using the MiOXSYS platform. SDF was assessed by sperm chromatin structure assay. Participants with DFI >15% underwent a three-month lifestyle intervention program, primarily based on diet and exercise, combined with oral antioxidant therapy using multivitamins, coenzyme Q10, omega-3, and oligo-elements. We assessed changes in semen parameters, DFI, and sORP, and compared DFI results to those of volunteers obtained two weeks apart. Spearman rank correlation tests were computed for sORP and DFI results.

RESULTS

Thirty-eight (40.8%) patients had DFI >15%, of whom 31 participated in the intervention program. A significant decrease in median DFI from 25.8% to 18.0% was seen after the intervention (P <0.0001). The mean DFI decrease was 7.2% (95% CI: 4.8-9.5%; P <0.0001), whereas it was 0.42% (95%CI; -4.8 to 5.6%) in volunteers (P <0.00001). No differences were observed in sperm parameters and sORP. Based on paired sORP and DFI data from 86 patients, no correlation was observed between sORP and DFI values (rho=0.03).

CONCLUSION

A 3-month lifestyle intervention program combined with antioxidant therapy reduced DFI in infertile men with elevated SDF and a history of failed IVF/ICSI. A personalized lifestyle and antioxidant intervention could improve fertility of subfertile couples through a reduction in DFI, albeit controlled trials evaluating reproductive outcomes are needed before firm conclusions can be made. Trial registration number and date: clinicaltrials.gov NCT03898752, April 2, 2019.

The combined effect of lifestyle intervention and antioxidant therapy on sperm DNA fragmentation and seminal oxidative stress in IVF patients: a pilot study

PURPOSE

Sperm DNA fragmentation (SDF) and seminal oxidative stress are emerging measurable factors in male factor infertility, which interventions could potentially reduce. We evaluated (i) the impact of lifestyle changes combined with oral antioxidant intake on sperm DNA fragmentation index (DFI) and static oxidation-reduction potential (sORP), and (ii) the correlation between DFI and sORP.

MATERIALS AND METHODS

We conducted a prospective study involving 93 infertile males with a history of failed IVF/ICSI. Ten healthy male volunteers served as controls. Semen analysis was carried out according to 2010 WHO manual, whereas seminal sORP was measured using the MiOXSYS platform. SDF was assessed by sperm chromatin structure assay. Participants with DFI >15% underwent a three-month lifestyle intervention program, primarily based on diet and exercise, combined with oral antioxidant therapy using multivitamins, coenzyme Q10, omega-3, and oligo-elements. We assessed changes in semen parameters, DFI, and sORP, and compared DFI results to those of volunteers obtained two weeks apart. Spearman rank correlation tests were computed for sORP and DFI results.

RESULTS

Thirty-eight (40.8%) patients had DFI >15%, of whom 31 participated in the intervention program. A significant decrease in median DFI from 25.8% to 18.0% was seen after the intervention (P <0.0001). The mean DFI decrease was 7.2% (95% CI: 4.8-9.5%; P <0.0001), whereas it was 0.42% (95%CI; -4.8 to 5.6%) in volunteers (P <0.00001). No differences were observed in sperm parameters and sORP. Based on paired sORP and DFI data from 86 patients, no correlation was observed between sORP and DFI values (rho=0.03).

CONCLUSION

A 3-month lifestyle intervention program combined with antioxidant therapy reduced DFI in infertile men with elevated SDF and a history of failed IVF/ICSI. A personalized lifestyle and antioxidant intervention could improve fertility of subfertile couples through a reduction in DFI, albeit controlled trials evaluating reproductive outcomes are needed before firm conclusions can be made. Trial registration number and date: clinicaltrials.gov NCT03898752, April 2, 2019.

Effects of treadmill exercise on sexual behavior and reproductive parameters in chronically stressed-male rats

Exposure to chronic stress stimulates the hypothalamic-pituitary-adrenal (HPA) axis and then simultaneously inhibits hypothalamic-pituitary-gonadal axis (HPG) axis activity. The inhibition formed by the HPA axis is the main mechanism of action of stress on reproductive function. HPG axis activity is known to be changed by various factors, including exercise. Exercise has been found to have a number of positive effects on sexual behavior, reproductive hormones, and sperm parameters in studies with animal models for many years. The main aim of this study is to investigate the effects of chronic treadmill exercise on chronically stressed-male rats' sexual behavior, reproductive hormones, and sperm parameters. A total of 40 sexually adult male rats were randomly and equally divided into four groups as control, stress, exercise, and stress+exercise. Animals in the exercise group were subjected to the chronic treadmill exercise (moderate intensity) for 33 days with a periodic increase in speed and duration. Animals in the stress group were exposed to restraint stress for 1 h, 2 h, and 3 h during the first, second and third 15 days respectively. Sexual behavior parameters, hormone measurements, and sperm parameters were evaluated. The main effects of chronic exercise on sexual behavior were centered on a significant increase in the ejaculation frequency (EF) in the stress+exercise group. Also, sperm concentration and motility in the stress group significantly decreased, and then sperm motility was improved by exercise in the stress+exercise group. In sum, our results show that chronic treadmill exercise may improve the adverse effects of chronic stress on sexual behavior and sperm parameters in male rats in terms of some parameters.

Association between intake of soft drinks and testicular function in young men

STUDY QUESTION

Is intake of sugar-sweetened beverages (SSB) or artificially sweetened beverages (ASB) associated with testicular function in young men?

SUMMARY ANSWER

Among young men unaware of their semen quality and reproductive hormone levels, intake of SSBs was associated with lower sperm concentration, lower total sperm count, and a lower ratio of serum inhibin-B/FSH.

WHAT IS KNOWN ALREADY

SSBs may adversely impact testicular function, but results are not consistent across studies. Moreover, the associations of ASB, energy-drinks or fruit juices with testicular function are unclear.

STUDY DESIGN, SIZE, DURATION

Young healthy men and unselected for fertility status men enrolled in a cross-sectional study between 2008 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2935 young (median age: 19 years) men enrolled in the study. Intake of SSBs, ASBs, fruit juices, and energy-drinks was assessed with a validated food frequency questionnaire. Testicular function was assessed through conventional semen quality parameters (semen volume, sperm concentration, total count, motility and morphology), testicular volume assessed with ultrasound, and serum reproductive hormone concentrations (total testosterone, free testosterone, E2, inhibin-B, LH, FSH, sex hormone-binding globulin) were measured.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable-adjusted analyses, men in the highest category of SSB intake (median: 1.1 servings (∼220 ml)/day) had a 13.2 million/ml lower median sperm concentration (95% CI: -21.0, -5.5) than non-consumers. A similar pattern was observed with total sperm count (-28 million (95% CI: -48, -9)), serum inhibin-B (-12 pg/ml (95% CI: -21, -4)), and inhibin-B/FSH ratio (-9 (95% CI: -18, 0)). The adjusted median difference in sperm concentration and inhibin-B associated with increasing SSB intake by 1 serving (∼200ml)/day at the expense of water was -3.4 million sperm/ml (95% CI: -5.8, -1.0) and -7 pg/ml (95% CI: -11, -3), respectively.

LIMITATIONS, REASONS FOR CAUTION

Inferring causality is limited owing to the cross-sectional design. We adjusted for a number of potential confounders but cannot exclude that unmeasured lifestyle and behavior associated with soft drink intake is associated with testicular function in these young men.

WIDER IMPLICATIONS OF THE FINDINGS

In the largest study to date, intake of SSBs was associated with lower sperm concentration, total sperm count, and serum inhibin-B/FSH ratio, consistent with a direct suppressive effect of SSB intake on testicular function among otherwise healthy men, potentially affecting fertility. However, the observed association between higher SSB intake and lower semen quality does not necessarily imply a decrease in fertility.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by research from the Danish Council for Strategic Research (2101-08-0058), Independent Research Fund Denmark (8020-00218B), European Union (212844), the Kirsten and Freddy Johansen's Foundation (95-103-72087), the Research Fund of the Capital Region of Denmark (A6176), and the NIH (P30DK046200). The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Moderate-Intensity Exercise Training in Association with Insulin Promotes Heat Shock Proteins 70 and 90 Expressions in Testicular Tissue of Experimental Type 1 Diabetes

Objective

The current research was designed to analyze the effect of moderate-intensity exercise training (MEXT), solely and simultaneous with insulin, on the network between oxidative stress and Hsp70 and Hsp90 chaperones after experimental type I diabetes (DM) induction in rats.

Materials and Methods

In the experimental study, 36 mature Wistar rats were assigned into control and experimental type I DM-induced groups, and then the diabetic animals were categorized to sedentary type I DM-induced (SDM), exercise training-sole without DM (E), exercise training DM-induced (EDM), insulin-treated sedentary DM-induced (ISDM), and exercise training insulin-treated DM-induced (EIDM) groups. After 6 weeks, Johnson’s score was evaluated to analyze the spermatogenesis ratio.

Results

The Hsp70 and Hsp90 expression levels, testicular total antioxidant capacity (TAC), protein peroxidation ratio, testicular DNA fragmentation ratio, and mRNA damage were investigated. The animals in EDM and EIDM groups (solely and simultaneously) represented a significant (P<0.05) improvement in Johnson’s score, spermatogenesis, and TAC ratios versus SDM animals. Moreover, the DM-induced DNA and mRNA damage and protein peroxidation ratio were significantly (P<0.05) recovered in EDM and ISDM groups, which was more remarkable in the EIDM group. The EDM and EIDM groups exhibited significant (P<0.05) increment in Hsp70 and Hsp90 expression levels versus the control and SEDT1 animals. However, the EIDM group exhibited no significant changes compared to the control animals.

Conclusion

The EX could ameliorate the EDT1-induced detrimental impact by up-regulating Hsp70 and Hsp90 expressions. Meanwhile, it exerts potentially more effective impact, when it is considered simultaneously with insulin therapy.

Male subfertility and oxidative stress

To date 15% of couples are suffering from infertility with 45-50% of males being responsible. With an increase in paternal age as well as various environmental and lifestyle factors worsening these figures are expected to increase. As the so-called free radical theory of infertility suggests, free radicals or reactive oxygen species (ROS) play an essential role in this process. However, ROS also fulfill important functions for instance in sperm maturation. The aim of this review article is to discuss the role reactive oxygen species play in male fertility and how these are influenced by lifestyle, age or disease. We will further discuss how these ROS are measured and how they can be avoided during in-vitro fertilization.

Interactive Effects of Unhealthy Lifestyle Behaviors on Testicular Function among Healthy Adult Men: A Cross-Sectional Study in Taiwan

Recently, the role of lifestyle factors in testicular function has developed into a growing area of interest. Based on cross-sectional data on 3283 Taiwanese men, we investigated whether interactive effects of unhealthy lifestyle behaviors were associated with testicular function. The men were recruited from a private screening institute between 2009 and 2015. Lifestyle behaviors (smoking, alcohol drinking, physical activity (PA), sleeping habits, and diet) were obtained by a validated self-reported questionnaire. The men provided a semen sample and had blood drawn for sex hormone measurement. Men who smoked and drank had higher testosterone (T) levels (β = 0.81, p < 0.001) than those who neither smoked nor drank. Men who smoked and had high Western dietary pattern scores had higher T levels-by 0.38 ng/mL (p = 0.03). Those who drank and did not get enough sleep or had high Western dietary pattern scores had elevated T levels-by 0.60 ng/mL (p = 0.005) or 0.45 ng/mL (p = 0.02), respectively. Light PA and insomnia were associated with decreased T levels-by 0.64 ng/mL (p < 0.001). Those who smoked and drank or had light PA or had high Western dietary pattern scores had lower normal sperm morphologies (NSMs)-by 2.08%, 1.77%, and 2.29%, respectively. Moreover, drinkers who had high Western dietary pattern scores had higher sperm concentrations-by 4.63 M/mL (p = 0.04). Awareness and recognition of the long-term impact of lifestyle behaviors and better lifestyle choices may help to optimize the chance of conception amongst couples.

ROS and metabolomics-mediated autophagy in rat's testicular tissue alter after exercise training; Evidence for exercise intensity and outcomes

AIMS

Oxidative damage and altered metabolic reactions are suspected to initiate the autophagy. The exercise training significantly impacts testicular antioxidant and metabolic potentials. However, the underlying mechanism(s) that the exercise-induced alterations can affect the autophagy markers remained unknown. This study explored the effect of exercise training on antioxidant and metabolic statuses of testicular tissue and uncovered the possible cross-link between these statuses and autophagy-inducers expression.

MAIN METHODS

Wistar rats were divided into sedentary control, low (LICT), moderate (MICT), and high (HICT) intensity continuous training groups. Following 8 weeks of training, the testicular total antioxidant capacity (TAC), total oxidant status (TOS), glutathione (GSH), and NADP⁺/NADPH as oxidative biomarkers along with intracytoplasmic carbohydrate and lipid droplet patterns, lactate dehydrogenase (LDH) activity, and lactate as metabolic elements were assessed. Finally, the autophagy-inducers expression and sperm count were examined.

KEY FINDINGS

With no significant impact on the oxidative biomarkers and metabolic elements, the LICT and MICT groups exhibited statistically unremarkable (p < 0.05) impacts on spermatogenesis differentiation, spermiogenesis ratio, and sperm count while increased the autophagy-inducers expression. Reversely, the HICT group, simultaneous with suppressing the antioxidant biomarkers (TAC↓, GSH↓, TOS↑, NADP⁺/NADPH↑), significantly (p < 0.05) reduced the testicular LDH activity and lactate level, changed the intracytoplasmic carbohydrate and lipid droplet's pattern, and amplified the classical autophagy-inducers p62, Beclin-1, autophagy-related gene (ATG)-7, and light chain 3 (LC3)-II/I expression.

SIGNIFICANCE

The autophagy-inducers overexpression has occurred after HICT induction, most probably to eliminate the oxidative damage cargoes, while increased to maintain the metabolic homeostasis in the LICT and MICT groups.

Chronic exercise training attenuates prostate cancer-induced molecular remodelling in the testis

PURPOSE

Prostate cancer is a major cause of cancer-related death in males worldwide and, in addition to impairing prostate function, also causes testicular adaptations. In this study, we aim to investigate the preventive effect of exercise training on PCa-induced testicular dysfunction.

METHODS

As a model, we used fifty Wistar Unilever male rats, randomly divided in four experimental groups. Prostate cancer was chemically and hormonally induced in two groups of animals (PCa groups). One control group and one PCa group was submitted to moderate intensity treadmill exercise training. Fifty weeks after the start of the training the animals were sacrificed and sperm, prostate, testis and serum were collected and analyzed. Sperm concentration and morphology, and testosterone serum levels were determined. In addition, histological analyses of the testes were performed, and testis proteomes and metabolomes were characterized.

RESULTS

We found that prostate cancer negatively affected testicular function, manifested as an arrest of spermatogenesis. Oxidative stress-induced DNA damage, arising from reduced testis blood flow, may also contribute to apoptosis of germ cells and consequential spermatogenic impairment. Decreased utilization of the glycolytic pathway, increased metabolism of ketone bodies and the accumulation of branched chain amino acids were also evident in the PCa animals. Conversely, we found that the treadmill training regimen activated DNA repair mechanisms and counteracted several metabolic alterations caused by PCa without impact on oxidative stress.

CONCLUSIONS

These findings confirm a negative impact of prostate cancer on testis function and suggest a beneficial role for exercise training in the prevention of prostate cancer-induced testis dysfunction.

Physical Activity and Male Reproductive Function: A New Role for Gamete Mitochondria

Several studies demonstrated that some types of physical exercise might affect male reproductive potential, even though the potential mechanisms involved in the modulation of sperm quality remain poorly understood. Therefore, we propose a new role for gamete mitochondria as a key hub that coordinates molecular events related to the effects induced by physical exercise.

Physical and Sedentary Activities in Association with Reproductive Outcomes among Couples Seeking Infertility Treatment: A Prospective Cohort Study

BACKGROUND

The aim of this study was to investigate the association of physical activity (PA) with assisted reproductive technology (ART) treatment and pregnancy outcomes among couples seeking infertility treatment.

METHODS

This prospective cohort study was carried out among 128 infertile individuals (64 couples), entering the infertility clinic for ART procedures. Baseline PA (before entering any treatment) was assessed using accelerometry for both women and men. For every couple the infertility treatment outcomes were recorded.

RESULTS

The couples that required invasive ART procedures such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) spent less time in vigorous PA (-73 min/week per couple, woman + man) than those couples who became spontaneously pregnant after entering the study (p = 0.001). We observed no significant associations between the time spent in physical activities and positive pregnancy test or live birth.

CONCLUSIONS

Our results do not support a positive nor negative relation between the time the couples spent in physical activities and the chances of getting pregnant or having a baby among patients seeking infertility treatment. However, couples undergoing invasive ART procedures did less vigorous PA than couples that became spontaneously pregnant, suggesting that PA may interfere with their reproductive health.

Lifestyle in urology: Benign diseases

Modifiable lifestyle-related risk factors are the object of increasing attention, with a view to primary and tertiary prevention, to limit the onset and development of diseases.Also in the urological field there is accumulating evidence of the relationship between urological diseases and lifestyle-related risk factors that can influence their incidence and prognosis. Risk factors such as nutrition, physical activity, sexual habits, tobacco smoking, or alcohol consumption can be modified to limit morbidity and reduce the social impact and the burdensome costs associated with diagnosis and treatment.This review synthesizes the current clinical evidence available on this topic, trying to satisfy the need for a summary on the relationships between the most important lifestyle factors and the main benign urological diseases, focusing on benign prostatic hyperplasia (BPH), infections urinary tract (UTI), urinary incontinence (UI), stones, erectile dysfunction, and male infertility.

Endogenous transient doping: physical exercise acutely increases testosterone levels-results from a meta-analysis

PURPOSE

Although endogenous testosterone levels are demonstrated to be affected by both acute exercise and resistance training, the dynamic regulation of androgen production after physical activity is still a matter of debate. This meta-analysis was designed to assess whether physical exercise acutely affects testosterone levels in men.

METHODS

The literature search was conducted to identify longitudinal trials evaluating the acute change of both total testosterone (TT) and free testosterone (fT) after physical activity in adult men. Sensitivity analyses were performed considering the sample collected (blood or saliva), the intensity of the physical exercise and the interval between the end of the exercise and the sample collection.

RESULTS

Forty-eight studies were included in the analysis, accounting for 126 trials. A total of 569 patients were enrolled (mean age 29.7 ± 13.1 years). The physical activity increased acutely TT (standardized mean difference 0.74, 95%CI: 0.56, 0.91 nmol/L), considering both serum and saliva samples (p < 0.001). Testosterone increased after moderate (p < 0.001) and high-intensity (p < 0.001) exercises, but not after mild physical activity (p = 0.19). Moreover, the testosterone increase was evident when measured immediately at the end of the exercise and within 30 min (p < 0.001), but not after 30 min (p = 0.930). Similar significant results were obtained considering fT, while SHBG did not change after physical activity (p = 0.090).

CONCLUSION

The comprehensive evaluation of the acute physical activity effect on testosterone levels identified a clear increase after exercise, irrespective of the sample collected. The main determinant of this fluctuation was the exercise intensity, with a mechanism that seems to be mostly SHBG independent. In particular, moderate/intense physical activity resulted able to increase endogenous androgenic production, albeit acutely and transitory.

TRIAL REGISTRATION NUMBER

PROSPERO registration ID: 157348.

Physical activity and sedentary time in relation to semen quality in healthy men screened as potential sperm donors

STUDY QUESTION

Is physical activity or sedentary time associated with semen quality parameters?

SUMMARY ANSWER

Among healthy men screened as potential sperm donors, higher self-reported physical activity was associated with increased progressive and total sperm motility.

WHAT IS KNOWN ALREADY

Despite the claimed beneficial effect of moderate physical activity on semen quality, results from epidemiological studies have been inconclusive. Previous studies were mostly conducted among endurance athletes or male partners of couples who sought infertility treatment.

STUDY DESIGN, SIZE, DURATION

Healthy men screened as potential sperm donors were recruited at the Hubei Province Human Sperm Bank of China. Between April 2017 and July 2018; 746 men completed the long-form International Physical Activity Questionnaire (IPAQ) and provided repeated semen samples (n = 5252) during an approximately 6-month period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Total metabolic equivalents (METs), moderate-to-vigorous METs and sedentary time were abstracted from the IPAQ. Sperm concentration, total sperm count, progressive motility and total motility in repeated specimens were determined by trained clinical technicians. Mixed-effect models were applied to investigate the relationships between physical activity and sedentary time and repeated measures of semen quality parameters.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for multiple confounders, total METs and moderate-to-vigorous METs were both positively associated with progressive and total sperm motility. Compared with men in the lowest quartiles, those in the highest quartiles of total and moderate-to-vigorous METs had increased progressive motility of 16.1% (95% CI: 6.4, 26.8%) and 17.3% (95% CI: 7.5, 27.9%), respectively, and had increased total motility of 15.2% (95% CI: 6.2, 24.9%) and 16.4% (95% CI: 7.4, 26.1%), respectively. Sedentary time was not associated with semen quality parameters.

LIMITATIONS, REASONS FOR CAUTION

The IPAQ was reported only once from study participants; measurement errors were inevitable and may have biased our results. Furthermore, although we have adjusted for various potential confounders, the possibility of unmeasured confounding cannot be fully ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that maintaining regular exercise may improve semen quality parameters among healthy, non-infertile men. Specifically, we found that higher self-reported total and moderate-to-vigorous METs were associated with improved sperm motility, which reinforces the existing evidence that physical activity may improve male reproductive health.

STUDY FUNDING/COMPETING INTEREST(S)

Y.-X.W was supported by the Initiative Postdocs Supporting Program (No. BX201700087). A.P. was supported by the National Key Research and Development Program of China (2017YFC0907504). C.-L.X. was supported by the National Key Research and Development Program of China (2016YFC1000206). The authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Fetal Programming of Semen Quality (FEPOS) Cohort - A DNBC Male-Offspring Cohort

BACKGROUND

Prenatal exposures may contribute to male infertility in adult life, but large-scale epidemiological evidence is still lacking. The Fetal Programming of Semen quality (FEPOS) cohort was founded to provide means to examine if fetal exposures can interfere with fetal reproductive development and ultimately lead to reduced semen quality and reproductive hormone imbalances in young adult men.

METHODS

Young adult men at least 18 years and 9 months of age born to women in the Danish National Birth Cohort living in relative proximity to Copenhagen or Aarhus and for whom a maternal blood sample and two maternal interviews during pregnancy were available were invited to FEPOS. Recruitment began in March 2017 and ended in December 2019. The participants answered a comprehensive questionnaire and underwent a physical examination where they delivered a semen, urine, and hair sample, measured their own testicular volume, and had blood drawn.

RESULTS

In total 21,623 sons fulfilled eligibility criteria of whom 5697 were invited and 1058 participated making the response rate 19%. Semen characteristics did not differ between sons from the Copenhagen and Aarhus clinics. When comparing the FEPOS semen parameters to similar cohorts, the median across all semen characteristics was slightly lower for FEPOS participants, although with smaller variation.

CONCLUSION

With its 1058 young adult men, the FEPOS cohort is the largest population-based male-offspring cohort worldwide specifically designed to investigate prenatal determinants of semen quality. Wide-ranging information on maternal health, lifestyle, socioeconomic status, occupation, and serum concentrations of potential reproductive toxicants during pregnancy combined with biological markers of fertility in their sons collected after puberty allow for in-depth investigations of the 'fetal origins of adult disease hypothesis'.

Maternal physical activity and sedentary behaviour before and during in vitro fertilization treatment: a longitudinal study exploring the associations with controlled ovarian stimulation and pregnancy outcomes

PURPOSE

To evaluate the association of objectively measured physical activity (PA) and sedentary behaviour before and during in vitro fertilization (IVF) with controlled ovarian stimulation (COS) and pregnancy outcomes.

METHODS

This longitudinal study involved 107 infertile women undergoing IVF treatment. PA and sedentary behaviour were measured for 14 consecutive days using accelerometry as follows: (1) before IVF treatment, (2) during IVF at the implantation time, immediately after embryo transfer, and (3) after positive pregnancy test. Total screen time was assessed by questionnaires. COS results were measured as the number of oocytes and embryos obtained, and the study outcomes included positive hCG, clinical pregnancy, and live birth.

RESULTS

Compared with baseline activity levels, women significantly reduced their PA and increased sedentary behaviour during IVF (p ≤ 0.001). Higher average PA, light PA, and ratio between breaks in every ≥ 30-min blocks of sedentary time showed positive associations, while sedentary time, number, and time accumulated in blocks of ≥ 30 min of sedentary time associated negatively with oocyte and embryo counts (all p < 0.05). Women with high total screen time during non-work days (≥ 7 h) obtained 4.7 oocytes (p = 0.005) and 2.8 embryos (p = 0.008) less in COS. PA and sedentary behaviour before and during IVF did not affect the positive hCG, clinical pregnancy, and live birth outcomes.

CONCLUSION

Our study results suggest that higher time spent in PA and lower time spent in sedentary behaviour before entering assisted reproduction is associated with better COS outcomes, while activity levels before and during IVF do not affect the implantation, pregnancy, and live birth outcomes.

Effectiveness of a therapeutic multiple-lifestyle intervention taking into account the periconceptional environment in the management of infertile couples: study design of a randomized controlled trial - the PEPCI study

BACKGROUND

Infertility is defined as the inability to conceive after 12 months of unprotected intercourse. It affects approximately one in six couples seeking pregnancy in France or western countries. Many lifestyle factors of the couples' pre and peri-conceptional environment (weight, diet, alcohol, tobacco, coffee, drugs, physical activity, stress, sleep…) have been identified as risk factors for infertility in both males and females. The high prevalence rates of unhealthy diets and lifestyles in the reproductive population of industrialized countries are worrisome. Nevertheless, adoption of a healthy lifestyle may improve fertility but lifestyle changes are difficult to achieve and to maintain due notably to behavioral factors.

METHODS

Consequently, we decided to propose an interventional study aimed at improving the quality of life of infertile couples before the start of assisted reproductive technology treatment. It is a randomized controlled multicentre trial. Both members of the couples are involved in an integrated global care program (PEPCI for "Parcours Environnement PériConceptionnel en Infertilité") vs. usual care. This global intervention not only considers diet and/or physical activity but follows a holistic approach, including a multidisciplinary assessment to address complete physical, psychological and social well-being. According to patient needs, this includes interventions on weight, exercise, diet, alcohol and drugs, mental and social health.

DISCUSSION

The main objective of trial is to demonstrate that periconceptional multidisciplinary care has a positive impact on reproductive functions. We will also focus on feasibility, acceptance, compliance and conditions of success of a multifaceted lifestyle intervention.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov, Identifier: NCT02961907 on November 11, 2016.

Oxidative Stress in Male Infertility: Causes, Effects in Assisted Reproductive Techniques, and Protective Support of Antioxidants

The spermatozoon is a highly specialized cell, whose main function is the transport of the intact male genetic material into the oocyte. During its formation and transit throughout male and female reproductive tracts, sperm cells are internally and externally surrounded by reactive oxygen species (ROS), which are produced from both endogenous and exogenous sources. While low amounts of ROS are known to be necessary for crucial physiological sperm processes, such as acrosome reaction and sperm-oocyte interaction, high levels of those species underlie misbalanced antioxidant-oxidant molecules, generating oxidative stress (OS), which is one of the most damaging factors that affect sperm function and lower male fertility potential. The present work starts by reviewing the different sources of oxidative stress that affect sperm cells, continues by summarizing the detrimental effects of OS on the male germline, and discusses previous studies addressing the consequences of these detrimental effects on natural pregnancy and assisted reproductive techniques effectiveness. The last section is focused on how antioxidants can counteract the effects of ROS and how sperm fertilizing ability may benefit from these agents.

Association of the Dietary Approaches to Stop Hypertension, Physical Activity, and Their Combination with Semen Quality: A Cross-Sectional Study

The influence of individual lifestyle factors is widely described in studies on semen quality. However, their synergistic effect is often neglected. The aim of the study was to examine the association between semen quality and dietary approaches to stop hypertension (DASH) diet, physical activity (PA), and the two separately and in combination. A cross-sectional study was carried out among 207 men aged 20–55. Dietary data were collected by a food frequency questionnaire (FFQ) and analysed according to the DASH scoring index. Physical activity was evaluated by the International Physical Activity Questionnaire. Semen parameters were assessed via the computer-aided semen analysis (CASA). Adherence to the DASH diet was associated with higher sperm count (Δ_T3-T1 = 82.1 mln/ej) and concentration (Δ_T3-T1 = 24.6 mln/mL). Higher PA was related to higher sperm count (Δ_T3-T1 = 69.4 mln/ej), total (Δ_T3-T1 = 11.9%), and progressive motility (Δ_T3-T1 = 8.5%) and morphology (Δ_T3-T1 = 2.8%) in the crude model and remained significant after adjustment. The combination of the DASH diet and PA, was significantly positively associated with sperm count (Δ_T3-T1 = 98.1 mln/ej), sperm concentration (Δ_T3-T1 = 17.5 mln/mL), total (Δ_T3-T1 = 11.8%), and progressive motility (Δ_T3-T1 = 10.0%) and morphology (Δ_T3-T1 = 3.3%) in both models. Adherence to the DASH diet was related to higher sperm count and concentration, whereas after its combination with physical activity it was also positively correlated with sperm motility and morphology.

Vitamin D status is not associated with reproductive parameters in young Spanish men

BACKGROUND

Relatively low sperm count was reported among young Spanish men in 2013. Several potential culprits have been suggested as explanations for reported trends in sperm counts in Western men, including lifestyles. Although controversial, some studies suggest that semen parameters, such as low sperm motility or abnormal morphology, may be associated with low serum vitamin D levels.

OBJECTIVES

To evaluate associations between semen parameters and reproductive hormones and serum 25-hydroxyvitamin D (25OHD) status in young Spanish men and to examine these associations in relation to dietary intake of vitamin D.

MATERIALS AND METHODS

This cross-sectional study includes 198 university students recruited in 2010-2011 in southern Spain, who provided samples of blood and semen and food frequencies. Semen quality was evaluated by measuring volume, concentration, sperm counts, motility, and morphology, according to the WHO guidelines. Serum samples were analyzed for total 25OHD and reproductive hormones, including FSH, LH, testosterone, inhibin B, and estradiol. Dietary vitamin D intake was assessed using a validated food frequency questionnaire. Associations with semen quality and reproductive hormones were examined using linear regression, adjusting for potential confounders.

RESULTS

Almost all men had adequate levels of serum vitamin D - only three men (1.5%) were vitamin D deficient (<30 nmol/L) and 17% were insufficient (<50 nmol/L). However, dietary vitamin D intakes were relatively low (below recommended 600 IU/day in 99% of men). Neither dietary intake nor serum vitamin D levels were associated with any sperm parameter or any reproductive hormone (all p ≥ 0.09).

DISCUSSION

We did not observe an association between vitamin D status and any reproductive parameter in our study population.

CONCLUSIONS

Our results suggest that serum vitamin D levels are sustained in Spanish men despite low dietary intake and therefore low vitamin D does not explain the poor semen quality previously observed in these young Spanish men.

[Impact of lifestyle and environmental factors on male reproductive health]

The identification of potential environmental hazards may be clinically relevant in the diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders. Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproductive function. Reproductive toxicity may evolve at the hypothalamic-pituitary, testicular, or post-testicular level; endpoints comprise deterioration of spermatogenesis and sperm function as well as endocrine disorders and sexual dysfunction. With regard to the complex regulation of the male reproductive system, the available information concerning single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal or in vitro studies remains difficult. Nevertheless, the assessment of relevant exposure to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.

Variance in Stallion Semen Quality among Equestrian Sporting Disciplines and Competition Levels

Simple Summary

Despite the increased demand for breeding stallions to be performing at elite levels of competition, little research has been conducted into how equestrian disciplines and competition level affect seminal quality. Using statistical analysis, we found that competing stallions have lower quality semen than non-competing stallions and competitive activity may have a greater negative impact on spermatogenesis than age. In addition, dressage stallions recorded improved semen characteristics when compared to show jumping and eventing stallions. Stallions at elite levels of competition recorded higher total sperm count and progressive motility compared to those competing at lower levels of competition. We suggest that appropriate management of the competition stallion may reduce the negative impacts which exercise can induce on semen quality.

Abstract

Most stallions within breeding programmes are expected to breed and compete concurrently. The exercising of stallions with regards to training regimes during the breeding season is a controversial subject. Daily exercise at low intensities is important for the mental and reproductive well-being of the stallion, however higher intensities of exercise, as seen in competing stallions, may have detrimental effects on seminal quality. To calculate if competition does affect semen quality, this study investigated the effect that equestrian discipline and timing of competition had on a range of stallion semen characteristics. This was a retrospective study that evaluated the seminal data of 1130 stallion semen collections from two UK based stud farms between 2009 and 2016. Competing stallion semen quality was significantly lower with regards to concentration (p < 0.05) and progressive motility (p < 0.05) than non-competing stallions. Semen volume was higher in competing stallions (p < 0.05) than non-competing stallions. There was a significant difference in seminal attributes among disciplines and competition levels (p < 0.05). The difference in semen quality among competing and non-competing stallions, as well as the difference among disciplines suggests endocrinological and physiological changes occur in relation to training intensity and competition.

Semen Quality in Chinese College Students: Associations With Depression and Physical Activity in a Cross-Sectional Study

OBJECTIVE

Behavioral and psychosocial factors have been associated with a decline of the quality of semen. However, the relationship of depression and physical activity (PA) with semen quality remains unclear.

METHODS

Data were obtained from 587 young male Chinese college students in June 2013. Participants completed a questionnaire assessing life-style factors, the Zung self-rated depression scale, and three items related to PA. They underwent a physical examination and provided a semen sample and a blood sample for reproductive hormones (testosterone, estrogen, progesterone, follicle-stimulating hormone, luteinizing hormone, and prolactin).

RESULTS

Men with high depression scores (n = 63, 10.7%) had lower sperm concentration (M (SD) = 66.9 (74.5) versus 72.6 (56.9) [10/ml], p = .043) and total sperm count (M (SD) = 241.6 (299.7) versus 257.0 (204.0) [10], p = .024) than nondepressed men. Participants with low PA levels (n = 99, 16.9%) had lower total sperm count (M (SD) = 204.4 (153.7) versus 265.8 (225.8) [10/ml], p = .017) than participants with higher activity levels. After adjusting for potential confounders, depressed men had 18.90% (95% confidence interval [CI] = 1.14%-33.47%) lower sperm concentration and 21.84% (95% CI = 3.39%-36.90%) lower total sperm count than nondepressed men. Men with low PA levels had 23.03% (95% CI = 2.80%-46.89%) lower total sperm count than physically active participants. An interaction effect between depression and PA on sperm concentration was detected (p = .033). There were no significant associations of depression and PA with reproductive hormones (p > .05).

CONCLUSIONS

Depression and low levels of PA are associated with lower levels of semen quality, which may have implications for reproductive health.

The in vitro effects of gibberellin on human sperm motility

Gibberellin, a plant growth regulator, is widely used to increase the shelf life and quality of fruits and vegetables. In this study, human semen samples were exposed to different concentrations of gibberellin, which reduced spermatozoa motility in vitro. Gibberellin exposure also increased levels of reactive oxygen species and the protein levels of apoptosis markers in human sperm. Gibberellin inhibited the activity of Na+/K+-adenosine triphosphatase (ATPase) and Ca2+-ATPase, which maintain the stability of ions inside and outside the membranes of spermatozoa. Moreover, gibberellin exposure suppressed adenosine triphosphate production and reduced the protein levels of adenosine triphosphate synthases, which may have induced the protein expression of adenosine 5'-monophosphate-activated protein kinase (AMPK) and its phosphorylated form. These results suggest that gibberellin reduces human sperm motility in vitro by increasing reactive oxygen species levels and reducing ATPase activity, which may upregulate AMPK and consequently reduce the fertilization potential of spermatozoa.