earticle

영어

Infertility is defined as the inability to conceive after 1 year of unprotected intercourse. Approximately 15% of all human couples are recognized as infertile, and about 50 % of these cases are associated with male fertility factors. However, the causes of male infertility are largely unknown. To date, multiple factors have been implicated in reduced sperm count and motility including genito-urinary infections, environmental exposure to hazardous chemicals, anatomic and physical obstructions, hormonal imbalances and immunologic disorders. Spermatogenesis is a complex developmental process regulated by pituitary-testis axis. Another important molecule involved in the spermatogenesis is insulin-like growth factor-1 (IGF-1). IGF-1 affects various reproductive processes and plays an essential role in the onset, progress, and regulation of spermatogenesis. IGFs are produced mainly in the liver in response to growth hormone (GH) from the anterior pituitary. In the male reproductive tract, IGF-1 is secreted by Leydig cells and Sertoli cells in the testis. IGF-1 receptor has been identified on Sertoli cells, Leydig cells, secondary spermatocytes, spermatids, and spermatozoa as well. However, only a few studies have investigated the association of the IGF-1 level and male infertility. To obtain a better understanding of the role of IGF-l in male fertility, we determined the relationship between serum IGF-1 concentration, seminal plasma IGF-1 concentration, and sperm parameter abnormalities. To this end, a total of 79 men were enrolled and were prospectively analyzed with parameters including age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal sperm (n=31), abnormal sperm motility (athenospermia, n=12), abnormal sperm morphology (teratospermia, n=20), and two or more abnormal parameters (multi, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Men with teratospermia had significantly lower levels of serum IGF-1 compared with men with normal sperm morphology (p<0.05). Men with both teratospermia and athenospermia had significantly lower levels of serum IGF-I as well (p<0.01). Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality.