[Impact of cigarette smoking on sperm quality and seminal plasma ROS in preconception males]

To investigate the influence of cigarette smoking on sperm quality and ROS in the seminal plasma of preconception males in Chongqing so as to provide some guidance for preconception couples.

Totally, 368 preconception males were enrolled in this study, including 196 smokers and 172 non-smokers, and the former divided into mild smokers (n = 88, ≤9 cigarettes per day for ≤5 years) and moderate to heavy smokers (n = 108, ≥10 cigarettes per day for ≥5 years or ≤9 cigarettes per day for ≥10 years). All the subjects underwent physical examination, medical history interview, health questionnaire investigation, and determination of semen parameters, ROS in the seminal plasma and sperm DNA fragmentation index (DFI).

Among the 368 preconception males, 53.26% had a history of cigarette smoking, of whom 29.35% were moderate to heavy smokers. Only 55.4% of the subjects were found with normal sperm morphology and 52.6% with normal sperm progressive motility. Compared with the non-smokers, the moderate to heavy smokers showed significantly decreased semen volume (［3.33 ± 1.20］ vs ［2.78 ± 1.08］ ml, P < 0.05), sperm concentration (［88.19 ± 70.33］ vs ［75.16 ± 60.13］ × 10⁶/ml, P < 0.05), and percentages of progressively motile sperm (PMS, ［36.58 ± 13.90］ % vs ［32.18 ± 15.24］ %, P < 0.05) and morphologically normal sperm (MNS, ［3.85 ± 1.93］ % vs ［3.52 ± 1.58］ %, P < 0.05), but increased sperm DFI (［10.45 ± 8.53］ % vs ［14.53 ± 12.85］ %, P < 0.05) and ROS in the seminal plasma (［12.20 ± 8.10］ vs ［24.10 ± 18.50］ nmol/mg prot, P < 0.05). Cigarette smoking was correlated positively with the ROS level in the seminal plasma (r = 0.235, P < 0.05), while the ROS level of the smokers negatively with the total sperm count (r = －136, P < 0.05), PMS (r = －0.381, P < 0.01) and MNS (r = －0.218, P < 0.01), but positively with sperm DFI in the preconception males (r = 0.387, P < 0.01).

Cigarette smoking can increase the ROS level in the seminal plasma, decrease the total sperm count and sperm progressive motility, and induce sperm malformation and sperm DNA fragmentation in preconception males.