Effect of cigarette smoking on levels of seminal oxidative stress in infertile men: a prospective study.

OBJECTIVE To investigate levels of seminal oxidative stress (OS) and sperm quality in a group of infertile men with a history of cigarette smoking. DESIGN A prospective clinical study. SETTING Male infertility clinic, Urological Institute, the Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S) Infertile men who smoked cigarettes (n = 20), infertile men who were nonsmokers (n = 32), and healthy nonsmoking donors (n = 13). INTERVENTION(S) Genital examination, standard semen analysis, sperm DNA damage. MAIN OUTCOME MEASURE(S) Levels of seminal reactive oxygen species (ROS) and total antioxidant capacity (TAC) measured by a chemiluminescence assay and seminal OS assessed by calculating a ROS-TAC score. Sperm DNA damage was measured by sperm chromatin structure assay. RESULT(S) Smoking was associated with a 48% increase in seminal leukocyte concentrations (P<.0001), a 107% increase in ROS levels (P=.001), and a 10-point decrease in ROS-TAC scores (P=.003). Differences in standard sperm variables and DNA damage indices between the infertile smokers and infertile nonsmokers were not statistically significant. CONCLUSION(S) Infertile men who smoke cigarettes have higher levels of seminal OS than infertile nonsmokers. Given the potential adverse effects of seminal OS on fertility, physicians should advise infertile men who smoke cigarettes to quit.