The effect of cigarette smoking on the semen parameters of infertile men

Abstract

Introduction

36.9% of men worldwide use tobacco. Previous studies suggest a negative effect of cigarette smoking on semen quality, but the results are contradictory. We have studied the effects of smoking on the semen characteristics such as sperm concentration, semen volume, sperm motility, sperm vitality and sperm morphology in a large group of infertile men.

Methods

This retrospective study was conducted on a total of 5146 infertile men with at least one year of idiopathic infertility, who admitted to the Centre for Reproductive medicine (CRG) at the Brussels University Hospital, Belgium between 2010 and 2017. The smokers were classified as mild (1-10 cigarettes/d), moderate (11-20 cigarettes/d) or heavy smokers (> 20 cigarettes/d). Semen analysis was performed for all patients. Statistical analysis was performed using the R software package and t-test or Mann-Whitney U tests were used, group comparisons were performed using ANOVA, ANCOVA or Kruskal-Wallis tests as appropriate. A p-value <0.05 was considered as statistically significant.

Results

Comparing the semen parameters in the two global groups showed that smoking had a significant decrease in semen volume (p=0.04074) and sperm concentration (p=0.029). ANOVA testing on the different smoking groups versus non-smoking group showed a significant decrease in sperm concentration (p=0.0364). After adjusting for the confounders, age and testosterone, ANCOVA testing showed significant effect on the sperm concentration (p=0.03871) in smokers versus non-smokers. No significant correlation was detected between the other semen characteristics.

Conclusion

We concluded that smoking had a significant and independent effect on the sperm concentration in a semen analysis. Other parameters, like semen volume, sperm motility, sperm vitality and sperm morphology were not influenced by smoking.

摘要

前言 全世界有36.9%的男性吸烟。研究表明吸烟对精液质量有不良影响, 但研究结果意见尚不一致。在大样本的不育男性中, 我们研究了吸烟对精子密度、精液量、精子活动率、精子活力和精子形态等精液特性的影响。

方法 本研究对2010年至2017年间在比利时布鲁塞尔大学医院生殖医学中心(CRG)就诊的5146名特发性不育症男性进行了回顾性研究。吸烟者分为轻度吸烟者(1∼10支/d)、中度吸烟者(11∼20支/d)和重度吸烟者(>20支/d)。对所有患者进行精液分析。应用R语言进行统计分析, t检验或Mann-Whitney U检验, 组间比较应用ANOVA、ANCOVA或KruskalWallis检验。P值<0.05被认为具有统计学意义。

结果 比较两个组的精液参数显示, 吸烟显著降低精液体积(p=0.04074)和精子浓度(p= 0.029)。方差分析显示, 不同的吸烟组较非吸烟组的精子浓度显著降低(p=0.0364)。在调整混杂因素年龄和睾酮后, ANCOVA分析显示, 吸烟者与非吸烟者比较精子的浓度有显著影响(p=0.03871)。在其他精液特征之间没有检测到显著的相关性。

结论 在精液分析中, 我们得出结论：吸烟是精子密度的显著且独立的影响因素。其他参数, 如精液量、精子活动率、精子活力和精子形态都不受到吸烟的影响。

Keywords:

• Sperm analysis
• semen analysis
• smoking
• tobacco
• male infertility

Disclosure statement

No potential conflict of interest was reported by the authors.