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

Unveiling the hidden risk: paternal smoking and alcohol exposure prior to conception as independent factors for allergic rhinitis in children

Introduction

Limited knowledge exists regarding the impact of paternal smoking and alcohol exposure on the development of allergic rhinitis in offspring. Our study aimed to investigate the potential association between preconception paternal smoking and alcohol exposure and the likelihood of children allergic rhinitis.

Methods

A retrospective case-control study of 556 prepubertal children aged 3-12 years was performed. The participants were 278 children with allergic rhinitis and 278 healthy controls matched for age and gender. Self-administered questionnaires were distributed and collected on-site, focusing on various factors related to the children's fathers, mothers, and the children themselves during the first year of life and the past 12 months, from March to October 2022.

Results

Multivariate analysis demonstrated that paternal smoking, paternal alcohol consumption prior to conception, paternal allergic diseases, children with a family history of allergies, maternal allergic diseases and pregnancy complications were identified as independent risk factors for allergic rhinitis in their offspring. Moreover, after considering confounding factors, it was observed that paternal smoking exceeding 5 cigarettes per day in the year preceding pregnancy and exceeding 11 years significantly elevated the likelihood of allergic rhinitis in children (OR = 2.009 and 2.479, respectively). Furthermore, the consumption of alcohol by the father at intervals of less than one month in the year prior to pregnancy and a duration of alcohol consumption exceeding 11 years prior to pregnancy are both associated with a significantly increased risk of allergic rhinitis in children (OR = 2.005 and 3.149, respectively).

Conclusions

Paternal smoking and alcohol consumption prior to conception contribute to an increased risk of allergic rhinitis in children, with the risk being dependent on the dosage and duration of exposure. Therefore, it is important to not only focus on personal and maternal environmental exposures when considering the occurrence risk of allergic rhinitis in children, but also to consider paternal detrimental exposures prior to conception.

Effects of Reactive Oxygen and Nitrogen Species on Male Fertility

Significance: In recent decades, male fertility has been severely reduced worldwide. The causes underlying this decline are multifactorial, and include, among others, genetic alterations, changes in the microbiome, and the impact of environmental pollutants. Such factors can dysregulate the physiological levels of reactive species of oxygen (ROS) and nitrogen (RNS) in the patient, generating oxidative and nitrosative stress that impairs fertility. Recent Advances: Recent studies have delved into other factors involved in the dysregulation of ROS and RNS levels, such as diet, obesity, persistent infections, environmental pollutants, and gut microbiota, thus leading to new strategies to solve male fertility problems, such as consuming prebiotics to regulate gut flora or treating psychological conditions. Critical Issues: The pathways where ROS or RNS may be involved as modulators are still under investigation. Moreover, the extent to which treatments can rescue male infertility as well as whether they may have side effects remains, in most cases, to be elucidated. For example, it is known that prescription of antioxidants to treat nitrosative stress can alter sperm chromatin condensation, which makes DNA more exposed to ROS and RNS, and may thus affect fertilization and early embryo development. Future Directions: The involvement of extracellular vesicles, which might play a crucial role in cell communication during spermatogenesis and epididymal maturation, and the relevance of other factors such as sperm epigenetic signatures should be envisaged in the future.

Resolving Secondary Infertility: A Case Report of the Successful Treatment of Sperm DNA Fragmentation Through the Physiological Intracytoplasmic Sperm Injection Method

This case report presents an illustrative account of a couple experiencing secondary infertility attributed to the fragmentation of DNA in sperm. Secondary infertility, the inability to conceive after having previously successfully conceived a child, can be due to various factors, including male infertility issues. Sperm DNA fragmentation (SDF) has emerged as a major factor influencing male fertility, resulting in poor embryo development and lower pregnancy rates. This case is about the use of advanced assisted reproductive technologies, specifically physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic sperm injection (ICSI), to treat secondary infertility caused by fragmentation of sperm DNA. PICSI enables the identification and selection of spermatozoa with optimal functional integrity using hyaluronan, a natural binding substance. Preparing a PICSI dish requires skill and precision. Sperm exhibiting a high DNA fragmentation index were excluded from the selection process to enhance embryo development potential. The couple underwent controlled ovarian stimulation, egg retrieval, and ICSI with PICSI. The treatment resulted in the successful conception of a singleton pregnancy. Subsequent prenatal monitoring indicated a healthy pregnancy progression, ultimately culminating in the delivery of a healthy baby girl at term. This case report highlights the efficacy of integrating PICSI as a sperm selection method preceding ICSI, specifically in cases of secondary infertility related to SDF. Further research and larger-scale studies are warranted to approve the findings of this case report and establish the broader applicability of this treatment approach.

Diet and recreational drug use in relation to male reproductive health

Diet and lifestyle interventions present promising avenues for the improvement of male fertility. Our objective was to review and synthesize the existing observational and experimental studies among humans on the associations of diet and recreational drug use with semen quality and fertility outcomes. The available data on this topic are limited and, at times, conflicting. Nevertheless, on the basis of this review, dietary patterns that are composed of higher intakes of fruits, vegetables, whole grains, nuts, low-fat dairy, and seafood, as well as lower intakes of red and processed meats, sweets, and sugar-sweetened beverages were identified as having the strongest evidence for associations with better sperm quality. However, whether these dietary patterns translate into positive associations with clinical fertility endpoints such as assisted reproductive technology success rates or time-to-pregnancy among couples trying to conceive without medical assistance remains unclear. Male caffeine and alcohol intake, within low-to-moderate ranges of intake, do not appear to be detrimental to semen quality. Yet high-quality research on this topic, focused on clinical fertility endpoints, should continue given the conflicting evidence, particularly in populations undergoing infertility treatment with assisted reproductive technology. Recreational drug use, including marijuana, electronic cigarettes, and other illicit drugs, does not appear to be beneficial for male reproductive health and should be avoided or ceased. In conclusion, men should be encouraged to consume a healthy diet rich in fruits, vegetables, whole grains, nuts, low-fat dairy, and seafood, as well as lacking in red and processed meats, sweets, and sugar-sweetened beverages, and to avoid recreational drug use for improved male reproductive health.

Global, regional and national burden of male infertility in 204 countries and territories between 1990 and 2019: an analysis of global burden of disease study

BACKGROUND

Many countries and regions have experienced male fertility problems due to various influencing factors, especially in less developed countries. Unlike female infertility, male infertility receives insufficient attention. Understanding the changing patterns of male infertility in the world, different regions and different countries is crucial for assessing the global male fertility and reproductive health.

METHODS

We obtained data on prevalence, years of life lived with disability (YLD), age-standardized rates of prevalence (ASPR) and age-standardized YLD rate (ASYR) from the Global Burden of Disease Study 2019. We analyzed the burden of male infertility at all levels, including global, regional, national, age stratification and Socio-demographic Index (SDI).

RESULTS

In 2019, the global prevalence of male infertility was estimated to be 56,530.4 thousand (95% UI: 31,861.5-90,211.7), reflecting a substantial 76.9% increase since 1990. Furthermore, the global ASPR stood at 1,402.98 (95% UI: 792.24-2,242.45) per 100,000 population in 2019, representing a 19% increase compared to 1990. The regions with the highest ASPR and ASYR for male infertility in 2019 were Western Sub-Saharan Africa, Eastern Europe, and East Asia. Notably, the prevalence and YLD related to male infertility peaked in the 30-34 year age group worldwide. Additionally, the burden of male infertility in the High-middle SDI and Middle SDI regions exceeded the global average in terms of both ASPR and ASYR.

CONCLUSION

The global burden of male infertility has exhibited a steady increase from 1990 to 2019, as evidenced by the rising trends in ASPR and ASYR, particularly in the High-middle and Middle SDI regions. Notably, the burden of male infertility in these regions far exceeds the global average. Additionally, since 2010, there has been a notable upward trend in the burden of male infertility in Low and Middle-low SDI regions. Given these findings, it is imperative to prioritize efforts aimed at improving male fertility and reproductive health.

Effects of cigarette smoking on semen quality, reproductive hormone levels, metabolic profile, zinc and sperm DNA fragmentation in men: results from a population-based study

Background

Cigarette smoking seems to have a negative impact on men's reproductive health, but our knowledge of its effects on the reproductive function of Russian men is still very limited. The purpose of this study was to evaluate the effect of cigarette smoking on semen quality, including sperm DNA fragmentation, hormonal, zinc and metabolic status in young men from the general multi-ethnic Russian population (n=1,222, median age 23 years) and to find out the ethno-specific effects of smoking by comparing male groups of different ethnicity.

Methods

Each participant filled out a standardized questionnaire, provided one blood and semen sample. Semen parameters, serum reproductive hormones, lipids, glucose, uric acid and seminal zinc were analyzed. Participants were classified as smokers (n=450) and non-smokers (n=772), and smokers were stratified into moderate (≤10 cigarettes/day) and heavy (>10 cigarettes/day) smokers.

Results

In the entire study population, heavy smokers were characterized by a decrease in semen volume, total sperm count, sperm concentration and motility, and an increase in sperm DNA fragmentation and teratozoospermia compared with non-smokers (p<0.05). There was also a reduction in the serum and seminal zinc level as well as an impairment in metabolic health in smokers compared with non-smokers (p<0.05). No significant differences between smokers and non-smokers were found for serum levels of LH, FSH, inhibin B, testosterone and estradiol. In the second part of our study, the most numerous ethnic groups of Slavs (n=654), Buryats (n=191), and Yakuts (n=125) were selected from the entire study population. Among three ethnic groups, the smoking intensity was higher in Slavs than in Buryats or Yakuts suggesting a greater tobacco addiction in Slavs than in Asians. A decrease in semen parameters and seminal zinc levels, and an increase in sperm DNA fragmentation and teratozoospermia was observed only in smoking Slavs (p<0.05); moderate decrease in testosterone and increase in triglyceride levels were revealed in smoking Yakuts (p<0.05), but no significant changes were detected in smoking Buryats.

Conclusion

We concluded that cigarette smoking has an ethno-specific effect on male reproductive function, probably due to the different activity of the seminal antioxidant system, which is yet to be elucidated.

Smoking Induces a Decline in Semen Quality and the Activation of Stress Response Pathways in Sperm

Male infertility is a prevalent concern affecting couples worldwide. While genetic factors, hormonal imbalances, and reproductive system defects play significant roles, emerging evidence suggests that lifestyle choices also profoundly impact male fertility. This study aimed to explore the effects of several lifestyle factors, including tobacco and alcohol consumption, physical activity, and dietary habits, on semen quality parameters and molecular biomarkers. Thirty healthy male volunteers were recruited in the Urology service at Hospital Infante D. Pedro, Aveiro, Portugal. Participants completed lifestyle questionnaires and provided semen samples, which were analyzed according to the World Health Organization criteria by experienced technicians. We also analyzed the expression levels of antioxidant enzymes and heat-shock response-related proteins to explore the activation of signaling pathways involved in stress response within sperm cells. Our results revealed that tobacco consumption reduced semen volume and total sperm count. Although the changes in the percentage of total motility and normal morphology in the smokers' group did not reach statistical significance, a slight decrease was observed. Moreover, we identified for the first time a significant association between tobacco consumption and increased levels of heat shock protein 27 (HSP27) and phosphorylated HSP27 (p-HSP27) in sperm cells, indicating the potential detrimental effects of tobacco on the reproductive system. This study highlights that lifestyle factors reduce semen quality, possibly by inducing stress in sperm, raising awareness about the effects of these risk factors among populations at risk of male infertility.

Association of living environmental and occupational factors with semen quality in chinese men: a cross-sectional study

Sperm quality can be easily influenced by living environmental and occupational factors. This study aimed to discover potential semen quality related living environmental and occupational factors, expand knowledge of risk factors for semen quality, strengthen men's awareness of protecting their own fertility and assist the clinicians to judge the patient's fertility. 465 men without obese or underweight (18.5 < BMI < 28.5 kg/m2), long-term medical history and history of drug use, were recruited between June 2020 to July 2021, they are in reproductive age (25 < age < 45 years). We have collected their semen analysis results and clinical information. Logistic regression was applied to evaluate the association of semen quality with different factors. We found that living environment close to high voltage line (283.4 × 106/ml vs 219.8 × 106/ml, Cohen d = 0.116, P = 0.030) and substation (309.1 × 106/ml vs 222.4 × 106/ml, Cohen d = 0.085, P = 0.015) will influence sperm count. Experienced decoration in the past 6 months was a significant factor to sperm count (194.2 × 106/ml vs 261.0 × 106/ml, Cohen d = 0.120, P = 0.025). Living close to chemical plant will affect semen PH (7.5 vs 7.2, Cohen d = 0.181, P = 0.001). Domicile close to a power distribution room will affect progressive sperm motility (37.0% vs 34.0%, F = 4.773, Cohen d = 0.033, P = 0.030). Using computers will affect both progressive motility sperm (36.0% vs 28.1%, t = 2.762, Cohen d = 0.033, P = 0.006) and sperm total motility (57.0% vs 41.0%, Cohen d = 0.178, P = 0.009). After adjust for potential confounding factors (age and BMI), our regression model reveals that living close to high voltage line is a risk factor for sperm concentration (Adjusted OR 4.03, 95% CI 1.15-14.18, R2 = 0.048, P = 0.030), living close to Chemical plants is a protective factor for sperm concentration (Adjusted OR 0.15, 95% CI 0.05-0.46, R2 = 0.048, P = 0.001) and total sperm count (Adjusted OR 0.36, 95% CI 0.13-0.99, R2 = 0.026, P = 0.049). Time spends on computer will affect sperm total motility (Adjusted OR 2.29, 95% CI 1.11-4.73, R2 = 0.041, P = 0.025). Sum up, our results suggested that computer using, living and working surroundings (voltage line, substation and chemical plants, transformer room), and housing decoration may association with low semen quality. Suggesting that some easily ignored factors may affect male reproductive ability. Couples trying to become pregnant should try to avoid exposure to associated risk factors. The specific mechanism of risk factors affecting male reproductive ability remains to be elucidated.

The Impact of Heavy Smoking on Male Infertility and Its Correlation with the Expression Levels of the PTPRN2 and PGAM5 Genes

Smoking has been linked to male infertility by affecting the sperm epigenome and genome. In this study, we aimed to determine possible changes in the transcript levels of PGAM5 (the phosphoglycerate mutase family member 5), PTPRN2 (protein tyrosine phosphatase, N2-type receptor), and TYRO3 (tyrosine protein kinase receptor) in heavy smokers compared to non-smokers, and to investigate their association with the fundamental sperm parameters. In total, 118 sperm samples (63 heavy-smokers (G1) and 55 non-smokers (G2)) were included in this study. A semen analysis was performed according to the WHO guidelines. After a total RNA extraction, RT-PCR was used to quantify the transcript levels of the studied genes. In G1, a significant decrease in the standard semen parameters in comparison to the non-smokers was shown (p < 0.05). Moreover, PGAM5 and PTPRN2 were differentially expressed (p ≤ 0.03 and p ≤ 0.01, respectively) and downregulated in the spermatozoa of G1 compared to G2. In contrast, no difference was observed for TYRO3 (p ≤ 0.3). In G1, the mRNA expression level of the studied genes was correlated negatively with motility, sperm count, normal form, vitality, and sperm membrane integrity (p < 0.05). Therefore, smoking may affect gene expression and male fertility by altering the DNA methylation patterns in the genes associated with fertility and sperm quality, including PGAM5, PTPRN2, and TYRO3.

Effects of alcohol use on sperm chromatin structure, a retrospective analysis

BACKGROUND

The evaluation of the infertile couple is often complex as multiple factors in both the male and female can contribute, including social history. Previous studies have displayed that male ethanol consumption can disturb sperm motility, nuclear maturity, and deoxyribonucleic acid (DNA) integrity. The main purpose of this study is to evaluate the effects of male alcohol use on sperm chromatin structure analysis (SCSA®). This study was a retrospective chart review of 209 couples that presented to a midsize infertility clinic in the Midwest and had a semen analysis and SCSA® performed. Data extracted from the electronic medical record included demographics, tobacco use, alcohol use, occupational exposures, semen analysis results, and SCSA® results (DNA Fragmentation index (DFI) and High DNA stainability (HDS)). Statistical analysis was performed on this data set to determine significance with a p-level of 0.05, with the primary input being level of alcohol use and primary outcome being the SCSA® parameters.

RESULTS

Overall, 11% of the cohort had heavy alcohol use (> 10 drinks/week), 27% moderate (3-10/week), 34% rare (0.5- < 3/week), and 28% none. 36% of the cohort had HDS > 10% (a marker of immature sperm chromatin). Level of alcohol use was not significantly associated with HDS > 10% or DFI. Heavier alcohol use was significantly associated with lower sperm count (p = 0.042). Increasing age was significantly associated with increasing DNA Fragmentation Index (p = 0.006), increased sperm count (p = 0.002), and lower semen volume (p = 0.022). Exposure to heat at work was significantly associated with lower semen volume (p = 0.042). Tobacco use was associated with lower sperm motility (p < 0.0001) and lower sperm count (p = 0.002).

CONCLUSIONS

There was not a significant association between the level of alcohol use and the High DNA Stainability or DNA Fragmentation Index of sperm. Increasing age was associated with semen parameters as expected, heat exposure was associated with lower semen volume, and tobacco use was associated with lower sperm motility and density. Further studies could investigate alcohol use and reactive oxidative species in sperm.