REPRODUCTIVE FUNCTIONS OF THE AGEING MALE Moshe Shalev MD Department of Urology Meir Medical Center Kfar-Saba, Israel

REPRODUCTIVE FUNCTIONS OF THE AGEING MALE Do semen parameters show age-dependent alterations? Is there a male contribution to reduced fertility and fecundity of older couples? Is there a genetic risk for offspring attributable to increased paternal age?

REPRODUCTIVE FUNCTIONS OF THE AGEING MALE Do semen parameters show age-dependent alterations? Is there a male contribution to reduced fertility and fecundity of older couples? Is there a genetic risk for offspring attributable to increased paternal age?

Age dependent alterations in testes Testis volume remains constant over a long period of life Specific effects of age demonstrated a reduction of testicular volume only in the 8 th decade of life Testes volume in this age group is 31% lower than in year old men. (Handelsman 1985, Mahmoud 2003)

Morphological characteristics of aging testes Reduced number of sperm arising from one cell division of a spermatogonium. Reduced number of type-A dark spermatogonia Increased occurrence of multinucleated spermatogonia. Megalospermatocytes, giant spermatids Multilayered spermatogonia and diverticula of the seminiferous tubules. (Holstein 1988, 1989; Johnson 1990)

Morphological characteristics of aging testes Reduced number of sertoli cells and accumulation of lipid droplets in their cytoplasma. Reduced number of leydig cells which may be multinucleated. Tubule involution leading to progressive sclerosis Testicular sclerosis is associated with defective vascularization of the testicular parenchyma and with systemic arteriosclerosis of affected men. (Harbitz 1973, Johnson 1986, Paniagua 1986, 1987; Regadera 1985)

Causes for alteration of semen parameters Urogenital infections : a retrospective cross-sectional study in 3698 infertile men showed infection rate of the accessory glands in 6.1% in pts aged 40 with sig. lower total sperm count. Accumulation of toxic substances: polychlorinated biphenyls (PBC) and cadmium.

Variations in semen volume over time Decrease of semen volume(5 controlled studies) in ranges between 0.5% per year. Decrease of semen volume of 20% when comparing 50 year old with 30 year old men. One controlled study failed to detect a significant change of semen volume with age when including men up to an age of 50. Fructose decreases with age but zinc and  -glucosidase remain constant over the age range. (Rolf 1996, 2002; Andolz 1999, Fisch 1996, Eskenazi 2003)

Variations in sperm motility and concentration over time Six controlled studies found a significant decrease of sperm motility over time in a range of 0.17% and 0.7% per year. Focusing on sperm concentration studies could not provide a uniform picture. ( Fisch 1996, Eskenazi 2003, Schwartz 1983, Auger 1995, Rolf 1996,2002; Andolz 1999,)

Variations in sperm morphology over time Four well controlled studies found a significant deterioration with age in both fertile and non fertile men. The decrease per annum of normal sperm ranges between 0.2% and 0.9%. (Kidd 2001, Andolz 1999, Auger 1985)

Age dependent changes in testes and semen Develop gradually without a sudden age threshold Alterations in semen parameters fall within normal ranges. Age-dependent alterations of testicular histology and semen parameters are accompanied by a significant increase in FSH and a slight but significant decrease in Inhibin B, which are also found in men with apparently normal semen parameters.