Objective      To investigate the association between routine semen parameters and sperm DNA damage in Chongqing college students.       Methods      A total of 639 college students which were recruited in MARHCS (Male reproductive health in Chongqing College students) cohort study in 2014 were enrolled

in this study. Semen samples were collected by masturbation. Routine semen parameters were performed by computer-aided sperm analysis system (CASA)

and Diff-Quick kit and Single cell gel electrophoresis (Comet assay) were used to evaluate sperm morphology and DNA damage

respectively. Association analysis between main semen parameters and sperm DNA damage was performed by Spearman correlation.       Results      The median semen parameters in college students were as following

semen volume 3.6 mL

sperm concentration 52.0×10

6

/mL

sperm total motility 89.4%

sperm progressive motile 57.0%

and sperm normal morphology 21.3%. Sperm DNA damage (Comet assay parameters) study showed that DNA in the comet tail (Tail DNA%) was 19.4%

tail length (TL) was 35.7 pixels

comet length (CL) was 81.6 pixels

tail moment (TM) was 7.6

and olive tail moment (OTM) was 6.3. Spearman correlation analysis showed that sperm concentration was negatively correlated with Tail DNA% (P0.05)

sperm total motility (%) was negatively associated with Tail DNA%

CL

TM and OTM (P0.01)

and sperm progressive motile (%) was negatively associated with Tail DNA%

CL

TL

TM and OTM (P0.05).       Conclusion      Sperm concentration

total sperm motility

and progressive motility are all negatively associated with sperm DNA damage parameters in Chongqing college students.