A prolonged observational study of semen quality and interstitial cells of Leydig function in infertile men has shown that men who have been found with spermatogenic failure (SgF) should be advised not to postpone fertility treatment.
Without being able to predict individual outcomes, it cannot be determined whether partly compensated Leydig cell insufficiency in men with SgF will eventually develop into overt testosterone deficiency.
However, it is estimated that infertile men with severely reduced semen quality risk further deterioration of semen quality 15 years after treatment for infertility. Also, a lower baseline sperm concentration was associated with a more pronounced increase in LH and decrease in testosterone/LH ratio at follow-up.
While male factors account for up to 50% of human infertility, yet the life course of semen quality and testosterone production in such men has not been described.
The study is a follow – up of an earlier research that was performed 15 years before and was an initial infertility assessment between January 1995 and December 2000.
Hospital records were used to identify potential participants for the study. For that purpose, a total of 137 men with primary male infertility due to SgF and 70 controls with good semen quality from couples with female factor infertility who attended a tertiary referral centre were included: the participation rate was 31% and 26%, respectively. The men provided semen samples and underwent a physical examination. Blood samples were taken to measure levels of reproductive hormones (FSH, LH, testosterone, sex hormone-binding globulin, estradiol and inhibin B). Current results were compared with results from the initial assessments.
At the time of the results, the SgF men had significantly lower Leydig cell capacity than the control group as well as much lower semen quality. For the SgF men, between baseline sampling and follow up, the median sperm concentration decreased from 1.9 to 0.6 mill/ml and total sperm count from 7.7 to 2.0 million (P = 0.019 and 0.012, respectively), and 10% developed azoospermia. Calculated free testosterone (cFT), but not total testosterone (tT) decreased in the SgF group by ~0.6% (95% CI 0.1–1.2%) per year. In the SgF group, LH increased by 1.6% (CI 0.9–2.3%) annually, and consequently tT/LH and cFT/LH ratios had decreased by 1.3% (CI 0.5–2.1) and 2.1% (CI 1.2–3.0%), respectively. The increase in LH and the decreases in tT/LH and cFT/LH ratios were more pronounced in men with lower baseline sperm concentrations.
The researchers consider the case group as representative of infertile men not in need of testosterone treatment at baseline investigation, but do not have information on those that chose not to participate in the follow-up study.