How does sperm count predicts differential in survival for an Andrologic Clinical Cohort?

Abstract

Background: There are few studies Eisenberg et al. (2014), Jensen et al. (2009) and our own group (Gross et al. 2006) showing that men with impaired semen quality parameters have a lower survival than men with normal parameters. None of these studies uses information on biological/social children. Such information is indispensible for answering the study question. Study design: We have reviewed 2295 men born between 1892 and 1941, without significant co-morbidity, undergoing semen analysis at the University Hospital in Marburg 1949 – 1995. Of 1398 men we have reviewed the vital status until 31.12.2010 with 572 dead, 826 alive. From a survey of survivors or proxies, performed in 2010 – 2011, we have data on biological or social children of 631 men (201 dead, 430 alive by 31.12.2010). In addition, pair wise matched to fertile cases, we have 567 external controls with information on their vital status until 31.12.2010: Methods: The fertility status was categorized in normal and abnormal sperm counts followed by WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO, 2010). The survival analysis was provided with the gamma-Gompertz model, the standard parametrical model for advanced ages mortality Main results: Differences in survival between cases with normal sperm count and with abnormal sperm count were shown by the Kaplan-Meier-Survival estimates. Fitting the gamma-Gompertz model the Hazard Ratio (HR) of 0,79, (95% CI 0,67 – 0,95) indicates significant lower mortality for men with normal sperm count respect to men with abnormal fertility. No statistical significant differences in survival were shown for men with normal sperm count in comparison to the age-matched controls from the general population. Conclusion: Men with abnormal sperm count had a higher mortality than men with normal sperm count, but biological or social children per se are not the protective factor for the male longevity.