Seminal plasma fructose and zinc levels as indicators of androgenic activity in male infertility

ABSTRACT

In this study, we aimed to investigate the possibility of using seminal plasma fructose and zinc levels as indicators of androgenic activity. A cross sectional study was conducted on three groups of infertile patients [n = 68] of clearly different sperm densities [20 azoospermic, 24 oligozoospermic and 24 normozoospermic patients]. The patients were randomly selected for this study. The study also included 20 normal subjects as a control group that is a totally different group of men of proven fertility who have recently fathered one or more children and who do not suffer any endocrine or systemic disease. Blood and semen samples were collected from each. Semen analysis was done; serum testosterone, Follicle stimulating hormone [FSH] and luteinizing hormone [LH] were measured using radioimmunoassay technique. Zinc level in seminal plasma was determined using atomic absorption spectroscopy and seminal plasma fructose was measured using colorimetry. Results of analysis showed that seminal plasma zinc levels whether per ml or per total ejaculate were found to increase gradually from azoospermic [6.56 mg/ml, 17mg/ejaculate], through oligozoospermic [11.49 mg/ml, 30.3 mg/ ejaculate] to normozoospermic [12.42 mg/ml, 33.3 mg/ejaculate] infertile patients, indicating increased androgenic activity with increased sperm density. The difference between the azo- and oligozoospermic groups is statistically significant [p < 0.05] and between azo- and normozoospermic is even higher [p < 0.005]. The azoospermic group is not really one homogeneous group but a mixture of two distinct subgroups. A subgroup with severe Leydig cell damage, and consequently low testosterone level and elevated FSH level [Normal range of serum FSH is 1.0 - 8.0 mIU/ml] having a seminal plasma fructose mean level [205.3 mg/ml, 295.7 mg/ejaculate] which is higher than that of the oligozoospermic group [188.3 mg/ml, 537 mg/ejaculate] and much higher than that of normozoospermic group [151.3 mg/ml, 457 mg/ejaculate] whereas, the other subgroup with no interstitial cells involvement [obstructive azoospermic] have normal FSH and testosterone levels and a fructose mean level significantly [p < 0.5] higher than all other groups [217.2 mg/ml, 547 mg/ejaculate] due to normal hormonal stimuli and non-utilization. It seems in case of fructose that the situation is reversed compared to zinc as fructose level is the highest in the subgroup of azoospermic patients and decreases as sperm density increases due to utilization by spermatozoa. Zinc level may act as a good indicator of androgenic activity whereas, fructose level can not be used reliably, except in the azoospermic group. This is mainly due to consumption of fructose by spermatozoa and many other interfering factors which the present study tends to clarify