Coordinated European investigations of semen quality: results from studies of Scandinavian young men is a matter of concern

Abstract

For many years it has been acknowledged that Danish and Norwegian men have one of the highest risks in the world for testicular cancer in sharp contrast to neighbouring Baltic men from Finland, Estonia and Lithuania. As an association between poor semen quality and testicular cancer has been established, it was suggested that men from high-risk testicular cancer areas would be more likely to have poor semen quality. However, previous studies were not able to elucidate this question due to their retrospective nature. In prospectively designed and strictly controlled studies of fertile men, the existence of regional differences in semen quality was confirmed. In addition, studies of men from the general populations were undertaken and a similar regional difference in semen quality was detected. Men from the eastern part of the Nordic-Baltic area had better semen quality than men from the western part. These findings parallel the incidence of testicular cancer in these regions. Approximately 20% of young men from Norway and Denmark had sperm concentrations below the World Health Organization reference level of 20 x 10(6) spermatozoa/mL, and approximately 40% had <40 x 10(6) spermatozoa/mL which, according to recent publications, may be the 'threshold' below which fecundity declines. In Denmark, the situation is of concern and a continued surveillance of semen quality in young men was established in 2001 by a government-supported programme.

Sperm quality before treatment in patients with early stage Hodgkin's lymphoma enrolled in EORTC-GELA Lymphoma Group trials

“…The only two completely random samples came from Denmark, but the sperm quality of men in this country is reputed to be among the lowest in Europe. 25 It appeared that the median concentration and motility of sperm from our study population were in line with those of sperm from non-selected, young Danish men, either undergoing an examination for military service 26 or being Danish trade union members without children or known fertility problems. 27 Nowadays, patients with intermediate or poor quality sperm are still eligible to enter sperm cryopreservation programs with a view to subsequent in vitro fertilization or intracytoplasmatic sperm injection.…”

Fetal programming of adult Leydig cell function by androgenic effects on stem/progenitor cells

“…It has been suggested that it may be indicative of a common underlying (fetal) cause (18), and our present animal experimental studies provide direct supporting evidence for this suggestion. This suggested connection has widespread implications, because one in six young men in northern European countries has a low sperm count (<20 million/mL) (68), and testosterone levels in men of all ages are declining (4-6). Moreover, it has implications for morbidities associated with aging and the aging-related decline in testosterone levels (3,(7)(8)(9)69), because ∼10% of aging men exhibit compensated Leydig cell failure (7).…”

Administration of testosterone inhibits initiation of seminal tubule growth and decreases Sertoli cell number in the earliest period of rat's postnatal development.

“…In several European countries 20% or more of young men may have abnormally low sperm counts relative to World Health Organization criteria [1]. As each Sertoli cell (SC) can support a finite number of germ cells, the number of SCs is a key factor in determining testis size and the number of spermatozoa in adulthood [2].…”