Cigarette smoking and male infertility

Influence of BMI, Cigarette Smoking and Cryopreservation on Tyrosine Phosphorylation during Sperm Capacitation

Capacitation involves tyrosine phosphorylation (TP) as a key marker. Lifestyle-related factors, such as obesity and smoking, are recognized for their adverse effects on semen quality and male fertility, yet the underlying mechanisms, including their potential impact on TP, remain unclear. Moreover, the effect of sperm cryopreservation on TP at the human sperm population level is unexplored. Flow cytometry analysis of global TP was performed on pre-capacitated, post-capacitated and 1- and 3-hours' incubated fresh and frozen-thawed samples from sperm donors (n = 40). Neither being overweight nor smoking (or both) significantly affected the percentage of sperm showing TP. However, elevated BMI and smoking intensity correlated with heightened basal TP levels (r = 0.226, p = 0.003) and heightened increase in TP after 3 h of incubation (r = 0.185, p = 0.017), respectively. Cryopreservation resulted in increased global TP levels after capacitation but not immediately after thawing. Nonetheless, most donors' thawed samples showed increased TP levels before and after capacitation as well as after incubation. Additionally, phosphorylation patterns in fresh and frozen-thawed samples were similar, indicating consistent sample response to capacitation stimuli despite differences in TP levels. Overall, this study sheds light on the potential impacts of lifestyle factors and cryopreservation on the dynamics of global TP levels during capacitation.

The effects of tobacco and cannabis use on semen and endocrine parameters in infertile males

Substances such as tobacco and cannabis can negatively modulate seminal parameters and sex hormones and lead to fertility problems in males. The present study aimed to determine the effect of cigarettes, dipping tobacco, and cannabis on semen parameters and sex hormones in infertile males. A total of 160 infertile healthy participants (cigarette smokers n = 40, dipping tobacco users n = 40, cannabis users n = 40 and infertile controls n = 40) were included in the study. Fasting blood samples were collected from all the participants using the aseptic technique, and semen samples were collected by masturbation following sexual abstinence of 2-7 days. The levels of serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined using ELISA. The serum level of FSH was significantly higher in cannabis users relative to the control group (p = 0.043). A mild non-significant decrease in sperm count, serum LH and testosterone levels were observed in all drug users compared to controls. In conclusion, chronic use of tobacco and cannabis mildly modulates semen and hormonal parameters in infertile males.

Self-reported Male Infertility and Metabolic Disturbance: A Cross-Sectional Study

Background

Male infertility is a growing health problem. It is proposed that infertility is associated with some metabolic abnormalities.

Objectives

This study aimed to examine the prevalence of self-reported male infertility and related metabolic disturbances.

Methods

This is a cross-sectional analysis of the Tehran Lipid and Glucose Study (TLGS). A total of 1526 males participated in the study. Logistic regression was used to examine metabolic factors associated with self-reported male infertility.

Results

The total prevalence of self-reported male infertility was 6.42%. The mean (SD) body mass index (BMI) of participants among fertile and infertile males was 26.80 (3.93) and 26.92 (4.36), respectively. The majority of participants in both groups were in the age group of 40-50 years old. In the fully adjusted model, the odds of infertility were significantly increased by each unit increase in total cholesterol [TC; odds ratio (OR), 1.01; 95% CI, 1.01 - 1.01; P = 0.03] and hip circumference (HC; OR, 1.06; 95% CI, 1.00 - 1.12; P = 0.02), respectively.

Conclusions

The prevalence of self-reported male infertility was 6.42%. Male infertility was positively associated with TC and HC, indicating that knowledge about these risks might assist health care professionals and governments in developing and executing measures to change the status quo.

Impact of heavy alcohol consumption and cigarette smoking on sperm DNA integrity

The purposes of the presents study were to investigate the impact of alcohol consumption and cigarette smoking on semen parameters and sperm DNA quality, as well as to determine whether tobacco smoking, or alcohol consumption causes more deterioration of sperm quality. Two hundred and eleven semen samples of men were included in this study. Four groups were studied: heavy smokers (N = 48), heavy drinkers (N = 52), non-smokers (n = 70), and non-drinkers (n = 41). Semen parameters were determined according to WHO guidelines, protamine deficiency assessed by chromomycin (CMA3) staining, and sperm DNA fragmentation (sDF) evaluated by TUNEL assay. Sperm parameters were significantly higher in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.005). However, protamine deficiency and sDF were significantly lower in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.0001). No significant difference in the semen analysis parameters was observed between heavy smokers and heavy drinkers (semen volume: 3.20 ± 1.43 vs. 2.81 ± 1.56 ml, semen count: 65.75 ± 31.32 vs. 53.51 ± 32.67 mill/ml, total motility: 24.27 ± 8.18 vs. 23.75 ± 1.75%, sperm vitality: 36.15 ± 18.57 vs. 34.62 ± 16.65%, functional integrity: 41.56 ± 18.57 vs. 45.96 ± 17.98% and the morphologically normal spermatozoa: 28.77 ± 11.82 vs. 27.06 ± 13.13%, respectively). However, protamine deficiency was significantly higher among drinkers than smokers (37.03 ± 9.75 vs. 33.27 ± 8.56%, p = 0.020). The sDF was also significantly higher among drinkers than smokers (22.37 ± 7.60 vs. 15.55 ± 3.33%, p < 0.0001). Thus, cigarette smoking, and heavy alcohol intake can deteriorate sperm quality. However, alcohol consumption deteriorates sperm maturity and damages DNA integrity at significantly higher rates than cigarette smoking.

Causes and Risk Factors for Male Infertility: A Scoping Review of Published Studies

Background

Despite the evidence of declining sperm counts worldwide and the increasing prevalence of male infertility, there has been limited documentation of the potential causes and risk factors for male infertility. With limited methods of primary treatment of male infertility, understanding the causes and risk factors will pinpoint specific lines of prevention.

Objective

We reviewed published studies on causes and risk factors for male infertility and identify gaps in the literature enabling more focused research and innovations.

Design/Setting

The study was a scoping review. The review included studies on the causes and risk factors of male infertility published in scientific/academic publications. It was not limited to any region or date. The following databases were searched: Cumulative Index to Nursing and Allied Health Literature, Wiley online, HINARI, Science Direct, PubMed/Medline, Google Scholar, African Journals Online, and the WHO Repository. In total, 1295 articles were identified. After removing 357 duplicates, 938 articles were screened, and 71 articles were identified for inclusion, while 60 articles met the inclusion criteria.

Results

Four broad causes and risk factors of male infertility identified were 1) biological/physiological/genetic causes, 2) behavioral/lifestyle risk factors, 3) environmental factors, and 4) socio-demographic risk factors. However, no substantive results on actual causes under each category were identified, leaving gaps for further research and experimentation.

Conclusion

The results indicate limited knowledge of the actual causes of male infertility in published studies. The gaps in knowledge that need to be bridged to enable a fuller understanding of the actual causes of male infertility were highlighted.

Addiction and human male fertility: A systematic review and a critical appraisal

BACKGROUND

Addiction is a global problem that has many negative consequences on human health as well as the quality of life.

OBJECTIVES

This review aimed to assess the effect of addiction on human male fertility.

METHODS

A systematic review was conducted on various electronic sites.

RESULTS

The initial literature search identified a total of 5239 articles in all searched databases. After removing duplicates and application of inclusion/exclusion criteria,177 were potential articles, 112 were omitted because no direct relevance was encountered. Finally, 65 studies were retained for review. They were classified according to the type of addiction into; opioids and cannabinoids (18 articles), alcohol (7 articles), cocaine (2 articles), Androgenic Anabolic steroids AAS (15 articles), tobacco (10 articles) and caffeine (13 articles). Most of these recruited articles demonstrated a negative impact of the addressed substance on male fertility with variable levels of evidence.

CONCLUSIONS

It was concluded that addiction harms human male fertility that should be put into consideration. More future studies are needed after a proper methodological and statistical approach, including logistic regression analysis, to predict the effect of a specific substance on human male fertility. This article is protected by copyright. All rights reserved.

Genome-wide evaluation of transcriptomic responses of human tissues to smoke: A systems biology study

The harmful compounds in various sources of smoke threaten human health. So far, many studies have investigated the effects of compounds of smoke on transcriptome changes in different human tissues. However, no study has been conducted on the effects of these compounds on transcriptome changes in different human tissues simultaneously. Hence, the present study was conducted to identify smoke-related genes (SRGs) and their response mechanisms to smoke in various human cells and tissues using systems biology based methods. A total of 6,484 SRGs were identified in the studied tissues, among which 4,095 SRGs were up-regulated and 2,389 SRGs were down-regulated. Totally, 459 SRGs were smoke-related transcription factors (SRTFs). Gene regulatory network analysis showed that the studied cells and tissues have different gene regulation and responses to compounds of smoke. The comparison of different tissues revealed no common SRG among the all studied tissues. However, the CYP1B1 gene was common among seven cells and tissues, and had the same expression trend. Network analysis showed that the CYP1B1 is a hub gene among SRGs in various cells and tissues. To the best of our knowledge, for the first time, our results showed that compounds of smoke induce and increase the expression of CYP1B1 key gene in all target and non-target tissues of human. Moreover, despite the specific characteristics of CYP1B1 gene and its identical expression trend in target and non-target tissues, it can be used as a biomarker for diagnosis and prognosis.

Influence of tobacco cigarette heavy smoking on DNA methylation patterns and transcription levels of MAPK8IP3, GAA, ANXA2, PRRC2A, and PDE11A genes in human spermatozoa

Background

Tobacco smoking is considered as one of the lifestyles factors that influence the sperm DNA methylation and global sperm DNA methylation and that may affect the sperm phenotype. This study was performed to investigate whether tobacco cigarette heavy smoking influences sperm DNA methylation patterns and semen parameters and to determine whether there is an alteration in the transcription level of MAPK8IP3, GAA, ANXA2, PRRC2A, and PDE11A genes in heavy smokers compared to non-smokers. Thirty samples were subjected to 450K arrays as a screening study to assess the variation in sperm DNA methylation levels between heavy smokers and non-smokers. Five CpG sites have the highest difference in methylation levels (cg07869343, cg05813498, cg09785377, cg06833981, and cg02745784), which are located in the MAPK8IP3, GAA, ANXA2, PRRC2A, and PDE11A genes, respectively, and were selected for further analysis using deep bisulfite sequencing in 280 independent samples (120 proven non-smokers and 160 heavy smokers) with a mean age of 33.8 ± 8.4 years. The global sperm DNA methylation, sperm DNA fragmentation, and chromatin non-condensation were evaluated also.

Results

A significant increase was found in the methylation level at seven, three, and seventeen CpGs within the GAA, ANXA2, and MAPK8IP3 genes amplicon, respectively (P< 0.01) in heavy smokers compared to non-smokers. Additionally, a significant increase was found in the methylation levels at all CpGs within PRRC2A and PDE11A gene amplicon (P< 0.01). A significant increase was found in the level of sperm chromatin non-condensation, DNA fragmentation, and global DNA methylation (P < 0.001) in heavy smokers compared to non-smokers.

Conclusion

These results indicate that tobacco cigarette smoking can alter the DNA methylation level at several CpGs, the status of global DNA methylation, and transcription level of the following genes “MAPK8IP3, GAA, ANXA2, PRRC2A, and PDE11A” in human spermatozoa. These findings may affect negatively semen parameters and men’s fertility.

Young-Onset Carcinogenesis - The Potential Impact of Perinatal and Early Life Metabolic Influences on the Epigenome

The last decade has witnessed a significant rise in cancers in young adults. This spectrum of solid organ cancers occurring in individuals under the age of 40 years (some reports extending the age-group to <50 years) in whom aetiology of cancer cannot be traced back to pre-existing familial cancer syndromes, is referred to as termed young-, or early- onset cancers. The underlying causes for young-onset carcinogenesis have remained speculative. We recently proposed a hypothesis to explain the causation of this entity. We propose that the risk for young-onset cancer begins in the perinatal period as a result of the exposure of the foetus to stressors, including maternal malnutrition, smoking or alcohol, with the consequent epigenomic events triggered to help the foetus cope/adapt. Exposure to the same stressors, early in the life of that individual, facilitates a re-activation of these ‘responses designed to be protective’ but ultimately resulting in a loss of regulation at a metabolic and/or genetic level culminating in the evolution of the neoplastic process. In this manuscript, we will provide a rationale for this hypothesis and present evidence to further support it by clarifying the pathways involved, including elucidating a role for Acetyl-CoA and its effect on the epigenome. We present strategies and experimental models that can be used to test the hypothesis. We believe that a concerted effort by experts in different, but complementary fields, such as epidemiology, genetics, and epigenetics united towards the common goal of deciphering the underlying cause for young-onset cancers is the urgent need. Such efforts might serve to prove, or disprove, the presented hypothesis. However, the more important aim is to develop strategies to reverse the disturbing trend of the rise in young-onset cancers.

Changes in seminal parameters among Brazilian men between 1995 and 2018

Aiming to investigate trends in seminal parameter values among Brazilian men between 1995 and 2018, we performed a retrospective analysis of spermograms of couples admitted for infertility testing at UNICAMP/Brazil. For the present study, only the first sample produced by each man was analyzed (9,267 samples). Total motile sperm count (TMSC), percentage of spermatozoa with normal morphology (NM), and sperm concentration after seminal processing (SCA) were considered dependent variables. Statistical analysis was carried out through linear regression for the median values both in the general population and in the population categorized by age group (<30, 30–39, and ≥40 years). During the study period, the mean age of men was 32.46 (± 6.48) years, with a median of 32 (18–67) years. We found a significant decrease in the median values of TMSC (reduction of 2.84 million/year), NM (reduction of 0.52% each year) and SCA (reduction of 0.24 million/mL each year). In conclusion, we observed that Brazilian men undergoing infertility investigation had a decline in seminal parameters in the past 23 years. Surveillance should be maintained in the coming years, and further studies are needed to elucidate possible causes for seminal deterioration and to devise strategies to reverse this trend.

The effects of lycopene supplement on the spermatogram and seminal oxidative stress in infertile men: A randomized, double-blind, placebo-controlled clinical trial

Infertility is a major, worldwide problem that is affected, and mediated, by several factors, in particular, oxidative stress. Thus, the aim of this study was to evaluate the effect of lycopene supplementation on spermatogram and seminal oxidative stress. In this randomized, double-blind, placebo-controlled trial study, 44 infertile men with oligozoospermia were randomly divided into two groups: The experimental group was supplemented with 25 mg of lycopene, and the control group received placebo for 12 weeks. Anthropometric, physical activity and dietary assessment, semen analysis, total antioxidant capacity (TAC), malondialdehyde, and glutathione peroxidase were measured pre- and post-intervention. At the end of the study, there was a significant increase in total sperm count and concentration in the lycopene group, and the latter total count remained significant after adjustment (p < .05). Intragroup analysis showed a significant increase in ejaculate volume, total sperm count, concentration total motility, nonprogressive, and nonmotility in lycopene group (p < .05). The TAC changes, in both groups, remained significant after adjustment (p < .05). Also, within-group analysis showed a significant increase in TAC levels (p < .05). Lycopene supplement can improve sperm parameters and oxidative stress biomarkers in oligozoospermia infertile men; however, further studies with larger sample size and duration are required.

Deterioration of semen quality and sperm-DNA integrity as influenced by cigarette smoking in fertile and infertile human male smokers-A prospective study

In modernized lifestyle smoking is one of the trendy, psychological, and socioeconomic scenarios of young adolescents mainly in the age of the reproductive stage. Based on a number of cigarettes smoked, age, and duration of the smoke, the study aims to search for the profound effects of smoking and its impact on semen parameters, sperm-DNA integrity, and fragmentation of sperm DNA with cotinine and apoptotic caspase-3 marker in the seminal plasma of fertile and infertile smokers. To determine oxidative damage by 8-hydroxy deoxyguanosine (8-OHdG) from isolated sperm DNA (steps: reactive oxygen species washing by nitro blue tetrazolium (NBT), sperm lysis, salt digestion, ethanol washing, and finally with high-performance liquid chromatography analysis). Level of DNA fragmentation (percentage) in native and intact DNA, the activity of caspase-3 in infertile smokers will be compared with the control group of nonsmokers. Also, the sperm viability was visualized by eosin-nigrosin and aniline blue staining. Cotinine is one of the best markers of smoking. The cotinine level (2224.24 ± 1.19 *** ng/mL), when abundant it negative correlates with morphology and rapid motility in infertile smokers than nonsmokers. Gel preprogram measured the sperm integrity and was found to be less in smokers than nonsmokers. The spermatic oxidative marker 8-OHdG was high and gave an R ² value of 0.9104 with morphology and 0.9007 for rapid motility of infertile sperm, respectively. Infertile smoking subjects (<10 cigarettes/day) had significant changes increase in sperm fragmentation, caspase-3, and cotinine while negative impact with motility, morphology, and pH of semen compared with fertile, infertile nonsmoking subjects.

Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo

Male exposure to cigarette smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to cigarette smoke condensate (CSC) causes molecular defects in germ cells and phenotypic effects in their offspring. Here we used an ex vivo testicular explant model and in vivo exposure to determine the concentration at which CSC impairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P)5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specific markers revealed that the explant system maintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 µg/ml) of CSC and confirmed that nicotine in the CSC was metabolized to cotinine. We assessed various growth and differentiation parameters, as well as testosterone production, and observed that many spermatogenesis features were impaired at 160 µg/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo Finally, females mated to males that were exposed to 160 µg/ml CSC neonatally had increased rates of pup resorption. We conclude that male exposure to CSC impairs offspring development and that the concentration at which CSC impairs spermatogenesis is similar in vivo and ex vivo. Given that the concentrations of CSC we used contained similar doses of nicotine as human smokers are exposed to, we argue that our model mimics human male reproductive effects of smoking.-Esakky, P., Hansen, D. A., Drury, A. M., Felder, P., Cusumano, A., Moley, K. H. Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo.

Human sperm DNA damage inhibition and antioxidant activity of T. arjuna bark: an in vitro study

Complimentary or natural antioxidant type of alternative medicine is developed worldwide to treat male infertility. The aim of this study is to the extraction of T. arjuna bark and activity against human sperm DNA damage in asthenoteratospermic smoker's subjects-an in vitro study. All preliminary and antioxidant assays (DPPH, H₂O₂, and total antioxidant, reducing power activity) were done. T. arjuna bark metal analysis was done with AAS. On the other hand, patients were asked to fill a direct questionnaire about smoking history; 25 infertile smokers were identified as asthenoteratospermic; 34 fertile non-smokers (control) were assessed for semen parameters by CASA, seminal plasma Zinc analysis by AAS, DNA fragmentation by colorimetric method and semen genomic DNA damage inhibition by modified non-enzymatic salting out extraction method. Most of the antioxidants are highly present in the aqueous extract; meanwhile, the major content in this extract is zinc 16 µg/g (Ca = 0.5 µg/g; Se = 2.2 µg/g and Mg = 1.6 µg/g) along with FT-IR peaks which also confirmed the metal presence. The semen parameters in smokers that were noticed are low sperm count and morphological changes. Meanwhile, in the seminal plasma of smokers, zinc and DNA fragmentation results were positively correlated with sperm morphology (p < 0.001). Repaired DNA bands were noticed in the in vitro study of aqueous T. arjuna bark, in smokers' semen. T. arjuna bark will act as cryo protector as well as great zinc supplementary to maintain sperm motility and morphology in smokers.

From sperm to offspring: Assessing the heritable genetic consequences of paternal smoking and potential public health impacts

Individuals who smoke generally do so with the knowledge of potential consequences to their own health. What is rarely considered are the effects of smoking on their future children. The objective of this work was to review the scientific literature on the effects of paternal smoking on sperm and assess the consequences to offspring. A literature search identified over 200 studies with relevant data in humans and animal models. The available data were reviewed to assess the weight of evidence that tobacco smoke is a human germ cell mutagen and estimate effect sizes. These results were used to model the potential increase in genetic disease burden in offspring caused by paternal smoking, with specific focus on aneuploid syndromes and intellectual disability, and the socioeconomic impacts of such an effect. The review revealed strong evidence that tobacco smoking is associated with impaired male fertility, and increases in DNA damage, aneuploidies, and mutations in sperm. Studies support that these effects are heritable and adversely impact the offspring. Our model estimates that, with even a modest 25% increase in sperm mutation frequency caused by smoke-exposure, for each generation across the global population there will be millions of smoking-induced de novo mutations transmitted from fathers to offspring. Furthermore, paternal smoking is estimated to contribute to 1.3 million extra cases of aneuploid pregnancies per generation. Thus, the available evidence makes a compelling case that tobacco smoke is a human germ cell mutagen with serious public health and socio-economic implications. Increased public education should be encouraged to promote abstinence from smoking, well in advance of reproduction, to minimize the transmission of harmful mutations to the next-generation.

Relationship of DNA integrity to HRG C633T SNP and ART outcome in infertile couples

The status of sperm DNA fragmentation, protamine deficiency, free thiols and disulphide bonds in colloid-selected samples and its relationship to ART outcome or HRG C633T SNP is not known. The objective of this study was to determine these relationships in spermatozoa from men with male factor or unknown factor infertility (n = 118) undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Sperm DNA integrity was analysed by flow cytometry using three fluorescent probes (acridine orange, monobromobimane and chromomycin A3). Principal component analysis (PCA) was used to identify the parameters that most influenced fertility. The relationships of sperm DNA integrity with seminal parameters, HRG C633T SNP and ART outcome were established using ANOVA and t-test. Sperm concentration and yield after preparation accounted for 27% of the total variance; sperm DNA integrity (%DFI and disulphide bonds) accounted for 16% of the variance in men from infertile couples. Sperm %DFI was significantly higher (P < 0.05) in older men than in younger men. A significant difference (P < 0.01) was observed in %DFI between smokers and non-smokers. Sperm %DFI was significantly higher (P < 0.01) in male factor infertility compared to either female factor or unknown factor infertility while free thiols were significantly higher (P < 0.01) in unknown infertility factor. No significant difference was observed between IVF success/failure in any of the seminal parameters studied. There was a tendency for protamine deficiency to be higher and disulphide concentration to be lower in men with HRG 633T. Such assessments may provide additional useful information about the prognosis for ART outcome, although more research is needed before clinical guidelines can be provided.

Paternal smoking and germ cell death: A mechanistic link to the effects of cigarette smoke on spermatogenesis and possible long-term sequelae in offspring

Paternal exposure to constituents of cigarette smoke (CS) is reportedly associated with infertility, birth defects and childhood cancers even though the mechanism behind this relationship is still unclear. Chronic cigarette smoking by men leads to poor sperm quality and quantity mainly through oxidative stress and also direct assault by CS metabolites. Among several carcinogenic and teratogenic components of cigarette smoke condensate (CSC), polycyclic aromatic hydrocarbons (PAHs) display a preeminent role in accelerating germ cell death via the cytoplasmic transcription factor, aryl hydrocarbon receptor (AHR) that is present across all stages of spermatogenesis. Activation of AHR by growth factors though benefits normal cellular functions, its mediation by CSC in a spermatocyte cell line [Gc2(spd)ts] adversely affects the expression of a battery of genes associated with antioxidant mechanisms, cell proliferation and apoptosis, and cell cycle progress. Besides, the CSC-mediated cross talk either between AHR and NRF2 or AHR-NRF2 and MAPKs pathways inhibits normal proliferation of the spermatogenic GC-2spd(ts) cells in vitro and cell death of spermatocytes in vivo. Pharmacological inactivation of CSC-induced AHR but not its genetic manipulation seems preventing DNA and cell membrane damage in Gc2(spd)ts. Data from recent reports suggest that the cigarette smoke affects both the genomic and epigenomic components of the sperm and attributes any associated changes to developmental defects in the offspring. Thus, the studies discussed here in this review shed light on possible mechanistic factors that could probably be responsible for the paternally mediated birth defects in the offspring following exposure to the toxic constituents of cigarette smoke.

Does being overweight affect seminal variables in fertile men?

The effect of being overweight on seminal variables was assesed in 165 fertile men. Participants were divided into three groups: fertile men with normal body mass index (BMI) (18.5-24.9 kg/m²), fertile overweight men (BMI 25-29.9 kg/m²) and fertile obese men (BMI >30 kg/m²). Medical history was taken, a clinical examination conducted. Semen analysis was undertaken and BMI measured. Seminal reactive oxygen species (ROS) was estimated by chemiluminescent assay, sperm vitality by the hypo-osmotic swelling test and sperm DNA fragmentation by propidium iodide staining with flowcytometry. Fertile obese men had significantly lower sperm concentration, progressive sperm motility and sperm normal morphology, with significantly higher seminal ROS and sperm DNA fragmentation compared with fertile normal-weight men and overweight men (all P < 0.05). BMI was negatively correlated with sperm concentration (r = -0.091; P = 0.014), progressive sperm motility (r = -0.697; P = 0.001), normal sperm morphology (r = -0.510; P = 0.001), sperm vitality (r = -0.586; P = 0.001), but positively correlated with sperm DNA fragmentation percentage (r = 0.799; P = 0.001) and seminal ROS (r = 0.673; P = 0.001). Increased BMI was found to affect semen parameters negatively even in fertile men.

Paternal exposure to cigarette smoke condensate leads to reproductive sequelae and developmental abnormalities in the offspring of mice

Paternal smoking is associated with infertility, birth defects and childhood cancers. Our earlier studies using cigarette smoke condensate (CSC) demonstrated several deleterious changes in male germ cells. Here, we hypothesize that chronic paternal exposure to CSC causes molecular and phenotypic changes in the sire and the offspring, respectively. In this mouse study, CSC caused DNA damage and cytotoxicity in testes via accumulation of benzo(a)pyrene (B[a]P) and cotinine. Decreased expression of growth arrest and DNA damage inducible alpha (Gadd45a), aryl hydrocarbon receptor (Ahr), and cyclin-dependent kinase inhibitor 1A (P21) was seen in CSC exposed testes. Apoptotic germ cell death was detected by induction of Fas, FasL, and activated caspase-3. The CSC-exposed males displayed reduction in sperm motility and fertilizing ability and sired pups with reduced body weight and crown-rump length, and smaller litter size with higher numbers of resorption. This model of CSC exposure demonstrates testicular toxicity and developmental defects in the offspring.

Association between air pollution and sperm quality: A systematic review and meta-analysis

Exposure to ambient air pollution has been clearly linked to adverse reproductive outcome and fecundation index, but its effects on male semen quality are still uncertain. In this study, we reviewed information from ten studies to get the qualitative evidence of the influence of the ambient air pollution on sperm quality and collected data from six of the ten studies to conduct meta-analysis. The original studies classified participants into different exposure levels and the highest and lowest expose levels were chosen as high expose and low expose groups, respectively. The random-effect model was used in the meta-analysis with the weight mean difference (WMD) as the measure indicator. The WMDs (95% confidence intervals, CIs) of sperm volume, sperm count, semen concentration, sperm progressive motility, total motility, and normal morphology were 0.09 (-0.04, 0.23), 0.46 (-4.47, 5.39), -8.21 (-20.38, 3.96), -7.76 (-16.26, 0.74), -7.61 (-16.97, 1.74) and -3.40 (-7.42, 0.62), respectively. In conclusion, although the differences are not statistically significant between the two groups, the overall trends and evidence from this review indicate the chronic exposure to ambient pollutants at high level may alter men sperm quality.

The prevalence of positive urinary cotinine tests in Korean infertile couples and the effect of smoking on assisted conception outcomes

OBJECTIVE

Smoking has been reported to harm nearly every organ of the body, but conflicting results have been reported regarding the effects of smoking on assisted conception. In this prospective cohort study, we aimed to investigate the prevalence of positive urinary cotinine tests in infertile couples and whether cotinine positivity was associated with infertility treatment outcomes.

METHODS

A qualitative urinary cotinine test was administered to 127 couples who underwent in vitro fertilization (IVF, n=92) or intrauterine insemination (IUI, n=35).

RESULTS

The overall prevalence of positive urinary cotinine test was 43.3% (55/127) in the male partners and 10.2% (13/127) in the female partners with similar prevalence rates in both genders in the IUI and IVF groups. Semen characteristics, serum markers of ovarian reserve, and number of retrieved oocytes were comparable among cotinine-positive and cotinine-negative men or women (with the exception of sperm count, which was higher among cotinine-positive men). The results of urinary cotinine tests in infertile couples were not associated with IVF and IUI outcomes.

CONCLUSION

The presence of cotinine in the system, as indicated by a positive urinary cotinine test, was not associated with poorer outcomes of infertility treatment.

Cigarette smoke-induced cell death of a spermatocyte cell line can be prevented by inactivating the Aryl hydrocarbon receptor

Cigarette smoke exposure causes germ cell death during spermatogenesis. Our earlier studies demonstrated that cigarette smoke condensate (CSC) causes spermatocyte cell death in vivo and growth arrest of the mouse spermatocyte cell line (GC-2spd(ts)) in vitro via the aryl hydrocarbon receptor (AHR). We hypothesize here that inactivation of AHR could prevent the CSC-induced cell death in spermatocytes. We demonstrate that CSC exposure generates oxidative stress, which differentially regulates mitochondrial apoptosis in GC-2spd(ts) and wild type (WT) and AHR knockout (AHR-KO) mouse embryonic fibroblasts (MEFs). SiRNA-mediated silencing of Ahr augments the extent of CSC-mediated cellular damage while complementing the AHR-knockout condition. Pharmacological inhibition using the AHR-antagonist (CH223191) modulates the CSC-altered expression of apoptotic proteins and significantly abrogates DNA fragmentation though the cleavage of PARP appears AHR independent. Pretreatment with CH223191 at concentrations above 50 μM significantly prevents the CSC-induced activation of caspase-3/7 and externalization of phosphatidylserine in the plasma membrane. However, MAPK inhibitors alone or together with CH223191 could not prevent the membrane damage upon CSC addition and the caspase-3/7 activation and membrane damage in AHR-deficient MEF indicates the interplay of multiple cell signaling and cytoprotective ability of AHR. Thus the data obtained on one hand signifies the protective role of AHR in maintaining normal cellular homeostasis and the other, could be a potential prophylactic therapeutic target to promote cell survival and growth under cigarette smoke exposed environment by receptor antagonism via CH223191-like mechanism. Antagonist-mediated inactivation of the aryl hydrocarbon receptor blocks downstream events leading to cigarette smoke-induced cell death of a spermatocyte cell line.

Home smoking restrictions before, during and after pregnancy-a qualitative study in rural China

Worldwide, many nonsmokers (often women and children) are exposed to second-hand smoke (SHS) in home settings, as men retain their traditional power and control within their family and women and children have limited agency to intervene. This study, set up to explore home smoking management in rural China, found that some women were able to positively intervene to restrict men's smoking at three key stages: prior to conception, during their pregnancy and at the early years of their children's lives. By utilizing dominant social, health and political narratives about the importance of raising a healthy child supported by the One-Child Policy in China, combined with the fear of health risks of SHS to young children, the women were able to use their elevated status as bearer and carers of the only children to subvert the pre-eminence of men in domestic environments, enabling them to positively influence home smoking. While this study highlights the possibility for future smoking cessation initiatives in China by incorporating family carers' elevated awareness of protection of children's health in key stages of childhood, there is also a need for further health education, as family members were unsure why they needed to keep children smoke-free, which may partially explain why few households were smoke-free.

Smoking influence on sperm vitality, DNA fragmentation, reactive oxygen species and zinc in oligoasthenoteratozoospermic men with varicocele

This study aimed to assess the influence of smoking duration and intensity on sperm vitality, sperm DNA fragmentation, reactive oxygen species (ROS) and zinc (Zn) levels in oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). A total of 246 men were investigated who were divided into OAT nonsmokers, OAT smokers, OAT nonsmokers and OAT smokers with Vx. They were subjected to history taking, clinical examination and semen analysis. In their semen, sperm hypo-osmotic swelling (HOS) test, sperm DNA fragmentation test, seminal ROS and seminal Zn were assessed. The results demonstrated significantly decreased HOS test, seminal Zn level and significantly increased sperm DNA fragmentation, seminal ROS levels in OAT smokers with Vx more than OAT smokers compared with OAT nonsmokers. Smoking intensity, smoking duration and Vx grade demonstrated significant negative correlations with sperm motility, HOS test percentage and significant positive correlations with sperm DNA fragmentation, seminal ROS level. It is concluded that smoking has a negative impact on sperm progressive motility, HOS test, seminal Zn and positive impact on sperm DNA fragmentation, semen ROS level that are exaggerated if Vx is associated being correlated with smoking intensity, smoking duration and Vx grade.

Effect of smoking on sperm vitality, DNA integrity, seminal oxidative stress, zinc in fertile men

OBJECTIVE

To assess the effect of smoking on sperm vitality, sperm DNA integrity, semen reactive oxygen species, and zinc levels in fertile men.

METHODS

One-hundred sixty men were investigated. They were divided into 2 equal groups: healthy fertile nonsmokers and healthy fertile smokers. They were subjected to history taking, clinical examination, and semen analysis. In their semen, sperm hypo-osmotic swelling test, sperm DNA fragmentation test, seminal reactive oxygen species, and zinc were assessed.

RESULTS

Compared with fertile nonsmokers, fertile smokers were significantly associated with lower hypo-osmotic swelling test and seminal zinc levels and significantly associated with higher sperm DNA fragmentation percent and seminal reactive oxygen species levels.

CONCLUSION

Smoking (cigarettes/day and duration) has detrimental effects on sperm motility, viability, DNA fragmentation, seminal zinc levels, and semen reactive oxygen species levels, even in fertile men, and it is directly correlated with cigarette quantity and smoking duration.

Sperm DNA and RNA abnormalities in fertile and oligoasthenoteratozoospermic smokers

This study aimed to assess sperm DNA and RNA abnormalities in fertile and oligoasthenoteratozoospermic (OAT) smokers. In all, 140 subjects were included and classified into fertile nonsmokers, fertile smokers, OAT nonsmokers and OAT smokers. They were subjected to history taking, clinical examination, semen analysis, assessment of sperm DNA and RNA abnormalities. The results showed that an increased percentage of abnormal sperm DNA and RNA was demonstrated in fertile smokers compared with fertile nonsmokers and in OAT smokers compared with OAT nonsmokers. Increased percentage of severe, moderate sperm DNA and RNA damage was demonstrated in fertile heavy smokers compared with fertile light smokers and in OAT heavy smokers compared with OAT light smokers. It is concluded that smoking has a negative impact on sperm DNA and RNA abnormalities that is accentuated in heavy smokers compared with light smokers.

Effect of smoking status on seminal parameters and apoptotic markers in infertile men

PURPOSE

We assessed semen parameters, sperm apoptotic markers and seminal plasma cotinine in infertile smokers.

MATERIALS AND METHODS

A total of 160 men were divided into 4 equal groups, including fertile smokers, fertile nonsmokers, infertile smokers and infertile nonsmokers. Smoking was classified as mild--fewer than 10, moderate--10 to 20 or heavy--more than 20 cigarettes daily. All men underwent semen analysis, and assessment of sperm caspase-9, Smac/DIABLO, DNA fragmentation and seminal plasma cotinine.

RESULTS

Infertile men, particularly smokers, have significantly lower semen variables and significantly higher sperm Smac/DIABLO, caspase-9 activity, the percent of DNA fragmentation and seminal plasma cotinine. The mean number of cigarettes smoked daily and smoking duration significantly correlated positively with sperm Smac/DIABLO, caspase-9 activity, the percent of DNA fragmentation and seminal plasma cotinine, and significantly correlated negatively with tested semen variables. Heavy smoking was associated with a significant increase in sperm Smac/DIABLO, caspase-9 activity and seminal plasma cotinine, and with a significant decrease in tested semen variables compared with those in moderate or mild smokers.

CONCLUSIONS

Smoking has a negative impact on semen variables. It is associated with increased sperm caspase-9, Smac/DIABLO and the percent of DNA fragmentation, especially in infertile heavy smokers.