Synergistic effects of cigarette smoking and varicocele on semen parameters in 715 patients

Objective To evaluate whether there is a synergistic effect of varicocele and smoking status on semen parameters. Methods A retrospective evaluation of 715 men attending an infertility clinic between 2001 and 2009 was carried out. The presence of a varicocele was determined by clinical examination and cigarette smoking habits were documented allowing patients to be divided into 4 groups: non-smokers (n = 369), mild smokers (n = 186, 1-10 cigarettes/day), moderate smokers (n = 129, 10-20 cigarettes/ day) and heavy smokers (n = 31, over 20 cigarettes/ day). Semen samples were harvested according to the World Health Organization (WHO) guidelines. Additionally, serum luteinizing hormone (LH), free testosterone and follicle stimulating hormone (FSH) levels were measured in all patients. Multivariate analysis of variance (MANOVA) was carried out and further corroborated with the non-parametric Kruskal-Wallis and Mann-Whitney U-tests. A p-value of <0.05 was considered statistically significant. Results The median patient age was 30.2 years. Overall there was a statistically significant negative effect of higher varicocele grade on sperm motility and concentration (p < 0.05) and a significant negative effect of smoking status on sperm morphology and motility (very progressive, p < 0.01) as well as a significant synergistic effect of varicocele and smoking status on motility (p = 0.03). In the group of patients smoking less than 10 cigarettes per day no significant synergistic effect on semen parameters could be proven compared to patients with varicocele who did not smoke. Conclusions We could show a significant synergistic effect of smoking status (> 10 cigarettes) in patients with varicocele on sperm morphology and motility. These findings could play an important role in counselling infertile patients presenting with varicocele and severe smoking to improve their semen quality parameters if they stop smoking. Past smoking history was not investigated.