Fecundity as a biomarker of health? - Semen quality and subsequent hospitalization

Male infertility measured as semen quality has been suggested as a biomarker of health and a number of studies have documented an association between semen quality and later health and survival. Factors such as social, behavioural and biological factors may influence the association between semen quality and health or survival. In a number of studies we have attempted to examine the association between semen quality and health or survival and to disentangle the factors influencing the association. Here we present our studies on male fecundity measured as semen quality and health and survival using data from two unique Danish cohorts; The Copenhagen Sperm Analysis Laboratory and the Fertility Clinic - Frederiksberg Hospital. In total, semen samples from 51,543 and 4,712 men from the two cohorts respectively for the period 1963-2010 was used for the analysis. The data was linked to the Danish Hospital Discharge Registry for hospitalizations and the Central Person Registry to obtain information on vital status and childhood status. A clear dose - response relationship between semen quality (total sperm count, sperm concentration or sperm motility) and survival was observed in both cohorts indicating a biological explanation. Men with low semen quality had a higher risk of dying in both cohorts and this effect was robust also when the men succeeded to conceive a child. Similar men with low semen quality had worse health following their semen analysis compared to men with good semen quality. Men with a low total sperm count had a 50% higher risk of first hospitalization from all causes of disease (95%CI: 1.4-1.6). The higher risk of hospitalization was robust across disease categories and not confined to specific diseases. A man with low sperm concentration (0-10 mill/ml) had an average first hospitalisation following semen analysis 7 years before men with very high sperm concentration (above 200 mill/ml). Our results illustrate that semen quality is a robust biomarker of both health and survival and that a low capability to conceive also indicate an individual with worse health and survivability.