Endocrine Abstracts

Introduction: Gonadotropins from the pituitary gland are essential for testosterone production and spermatogenesis. However, little is known about semen quality in patients with adult onset gonadotropin insufficiency.

Aim: To investigate semen quality in men with adult onset hypogonadotropic hypogonadism requiring testosterone replacement therapy.

Patients and method: A single center study comprising all hypogonadal men with pituitary disease (year 2003–2016, n=28, (median(IQR) 30 (27–37) years), who accepted cryopreservation of semen before initiation of testosterone therapy. On the day semen samples were cryopreserved, reproductive hormone levels were measured. Semen parameters, hormone levels and size of testicles were compared to those of young men (n=340, 19 (18–20) years) from the general population.

Results: Patients vs controls had lower serum testosterone 5.6 (3.5–7.8) vs 19.7 (15.5–24.5) nmol/l (P<0.001), free testosterone index 33.3 (18.1–55.1) vs 73.7 (57.8–91.7) (P<0.001), luteinizing hormone 1.5 (1.1–2.1) vs 3.1 (2.3–4.0) U/l (P<0.001), and inhibin-B 142 (126–187) vs 229 (176–285) ng/l (P<0.001). Levels of follicle stimulating hormone were unchanged 2.3 (1.4–4.4) vs 2.2 (1.5–3.3) U/l (P=0.47). There were no differences on semen volume 3.0 (1.5–5.0) vs 3.2 (2.3–4.3) ml (P=0.33), sperm concentration 35 (6–62) vs 43 (22–73) mill/ml (P=0.1), or total sperm counts 102 (8–236) vs 136 (65–235) mill (P=0.09). Forty-seven percent of patients and 77% of controls had normal semen quality, WHO criteria (volume >1.5 ml, concentration>15 mill/ml and AB-motile sperm>42%) (P=0.001). Three had azoospermia. Testicular size was unchanged 18 (13–25) vs 20 (19–25) ml (P=0.46).

Conclusion: Patients with acquired pituitary insufficiency had reduced semen quality, supporting the need for early cryopreservation of semen in this group of patients. However, despite severe Leydig cell insufficiency almost half of patients had normal semen quality based on determination of three variables. This finding is in contrast to men with hypergonadotrpic hypogonadism where spermatogenesis is often severely compromised before Leydig cell insufficiency occurs.