BACKGROUND: The aim of this study was to investigate the effects of sleep duration and bedtime on sperm health, and the possible mechanism involved.

MATERIAL AND METHODS: We randomly divided 981 healthy Chinese men into groups according to research-set bedtimes (A=8–10 PM, B=after 10 PM, and C=after midnight) and sleep durations: group 1=<6.0 h (short), group 2=7.0–8.0 h (average), and group 3=>9.0 h (long). Sperm morphology, count, survival, and motility were examined according to sleep patterns. Antisperm antibody (ASA) production in semen was determined.

RESULTS: Sperm counts and their survival rates were lower in the short sleepers as compared to others within each group (all P<0.01). The lower counts and survival rates were observed in different bedtimes, with significant differences found between measurements of C1 vs. A1 and C2 vs. A2 or B2 (all P<0.05 or 0.01). Semen motility was lower in the short sleepers as compared to the average and long sleepers (all P<0.01). There were differences in the bedtime-related results between measurements of C1 vs. A1 or B1 (P<0.05 or 0.01). Additionally, the population proportion for the ASA-positive participates and incidence of the ASA-expressed population obviously increased in the short sleepers as compared to others within each group (all P<0.05).

CONCLUSIONS: Short and long sleep durations and late bedtime were associated with impaired sperm health in the study cohort, partly through increasing ASA production in the semen.

Keywords: semen analysis, Sperm Count, Survival Rate