Varicocele Is Associated with Impaired Semen Quality and Reproductive Hormone Levels: A Study of 7035 Healthy Young Men from Six European Countries.
Level 4 - case-series / case-control
Cross-sectional multicentre observational study
PubMed 27423503 · doi:10.1016/j.eururo.2016.06.044
What was done
A cross-sectional multicentre study investigated 7035 young men (median age 19 years) from the general population across six European countries (Denmark, Finland, Germany, Estonia, Latvia, and Lithuania) between 1996 and 2010. Researchers evaluated physical examination results for varicocele (grades 1 to 3), conventional semen variables, and serum reproductive hormones using multivariable regression analyses.
What was found
Of the cohort, 1102 men (15.7%) had grade 1–3 varicocele. Increasing varicocele grade was associated with poorer semen quality, starting even at grade 1. In grade 3 varicocele, sperm concentration was less than half of that in men without varicocele. Varicocele presence was also associated with higher serum levels of follicle-stimulating hormone, higher luteinising hormone, and lower inhibin B. Differences in testosterone and free testosterone were not statistically significant. The abstract does not provide exact numerical values for hormone levels or semen parameters.
Why it matters
This paper demonstrates that the adverse effects of varicocele on semen quality and testicular endocrine function are present in unselected healthy young men from the general population, not only in clinical fertility cohorts.
Limits
The cross-sectional design precludes conclusions regarding varicocele progression over time or response to treatment. Clinical fertility and pregnancy outcomes were not measured, and specific numerical estimates, effect sizes, and confidence intervals were omitted from the abstract.
Cited by
- supports The prevalence of varicoceles in males is approximately 15%.