Semen quality and lifespan: a study of 78 284 men followed for up to 50 years.
Level 3 - non-randomized controlled study
Non-randomized registry-linked cohort study with long-term follow-up.
PubMed 40037905 · doi:10.1093/humrep/deaf023
What was done
A retrospective registry-linked cohort study of 78,284 men who had semen quality evaluated between 1965 and 2015 at a public laboratory in Copenhagen due to reported couple infertility. Semen parameters included volume, concentration, motility, morphology, total sperm count, and total motile sperm count. Participants were followed for all-cause mortality through Danish national registers for a median of 23 years (5th–95th percentile: 8–45 years; 8,600 deaths). Cox regression models estimated hazard ratios for mortality, adjusting for educational level and pre-existing diagnoses in a subpopulation of 59,657 men evaluated between 1987 and 2015.
What was found
Men with a total motile sperm count >120 million had an estimated life expectancy of 80.3 years compared to 77.6 years in men with >0–5 million (a 2.7-year difference). All semen parameters were negatively associated with all-cause mortality in a dose-response relationship (P-trend < 0.001). In the adjusted subpopulation, compared to the reference group (>120 million total motile sperm), adjusted hazard ratios for all-cause mortality were 1.39 for azoospermia, 1.61 for >0–5 million, 1.38 for >5–10 million, 1.27 for >10–40 million, 1.16 for >40–80 million, and 1.19 for >80–120 million (P-trend < 0.001).
Why it matters
This study provides large-scale evidence that semen quality serves as a marker of overall somatic health and life expectancy, extending beyond reproductive potential.
Limits
The study was restricted to men evaluated for couple infertility, which may not generalize to the broader population. Information on health behaviors like smoking, diet, and physical activity was unavailable. Baseline disease information was limited to hospital diagnoses from the National Patient Register and was only accessible for the 1987–2015 subcohort. Men with azoospermia could not be differentiated into obstructive and non-obstructive subtypes.
Cited by
- supports Lower sperm concentrations and poorer semen parameters are dose-dependently associated with higher all-cause mortality and younger age at death.