Poor Semen Quality Predicts Increased Mortality

Abstract

ISEE-300 Objective: Over recent decades a possible decrease in semen quality and an increase in the incidence of testicular cancer have been reported. In addition, men with poor semen quality have been reported to be at increased risk of developing testicular cancer whereas the risk of other cancers is not increased. The long-term survival of men with poor semen quality is, however, unknown. We therefore studied the associations between semen characteristics and subsequent mortality. Material and Methods: The Copenhagen Sperm Analysis Laboratory is one of several public semen analysis laboratories in Denmark and examines semen samples mostly from men in the area of Copenhagen. Men are referred to the clinic by general practitioners and urologists, and the investigations are paid for through the public health system. A total of 34.442 men had a semen analysis done at the laboratory during 1963 to 1995. Through a personal identification number they were linked to the Danish Cancer Registry and the National Death Register, which hold information on all cases of cancer and deaths, respectively, in the Danish population. The men were followed up until December 31, 2004, death, or censoring, whichever occurred first. Standardized mortality ratios (SMR) compared with total population of Danish men were calculated according to sperm concentration, motility, and morphology. Results: Men with a sperm concentration between 1 and 9 and 10 and 19 million/mL had SMRs of 1.57 (95% CI 1.35–1.81) and 1.23 (1.00–1.51), respectively, compared with men with sperm concentration above 20 million/mL. Men with poor sperm motility had SMR 1.35 (1.06–1.71) compared with men with normal sperm motility, and men with more than 75% abnormal spermatozoa had SMR 1.76 (1.49–2.09). The increased SMRs were also found for men without testicular cancer. We are currently analyzing different causes of death and the effect of social factors. Conclusions: Our preliminary results suggest that men with poor semen quality have a higher mortality than men with normal semen quality.