Association of cigarette smoking with reproductive hormone levels and semen quality in healthy adult men in Taiwan

The objective of this study was to evaluate the association of cigarette smoking with semen quality and reproductive hormone levels in 192 healthy men 20-65years old, Kaohsiung, Taiwan. Exposure to cigarette smoking was classified three ways based on: 1) smoking status (yes vs. no); 2) the number of cigarettes per day (0, 1-10, > 10); and 3) pack-years (0, 1-10, 11-20, > 20). Serum levels of total testosterone (TT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and total estradiol (TE) were measured. Semen quality, including concentration, motility, vitality, and morphology, were assessed. Mean levels of smoking, semen quality, and hormones were compared using the multiple linear regression, while controlling for possible confounding factors, including age, body mass index (BMI), cadmium levels in seminal plasma, and alcohol consumption. Current smokers, who smoked 10 cigarettes per day, had a lower mean percentage of normal morphology (3.2% and 5.5% in nonsmokers, P = 0.040), and a higher mean level of TT (454.7 pmol/L and 439.8 pmol/L in nonsmokers, P = 0.048), as compared with nonsmokers. Also, current smokers at > 20 pack-year had a lower percentage of normal morphology and a lower mean level of TT as compared with nonsmokers; no significant difference was observed in LH, FSH, sperm concentration, vitality, and motility between smokers and nonsmokers based on the number of cigarette per day and the pack-year. Sperm vitality statistically correlated with FSH ( = -0.36 P = 0.015) and TE ( = 0.35, P = 0.018), while motility statistically correlated with TT ( = 0.228, P = 0.045). Normal morphology did not statistically correlated with all reproductive hormones.