Correlation of zinc level in spermoplasm with fertility characteristics of human ejaculate

Background: Zinc is essential for the normal functioning of the male reproductive system. The data on the diagnostic value of the determination of zinc in human spermoplasm and the relationship of its level with the main parameters of sperm fertility are contradictory. 
Aims: Study of correlations of zinc level in spermoplasm with spermogram characteristics. 
Methods: Sperm of men of reproductive age (n=486, average age 33.073.03 years) was studied. In addition to the standard spermogram, MAR tests (IgA, IgG and IgM) were performed in the sperm samples, the degree of fragmentation of sperm DNA was assessed, the interaction of sperm with hyaluronic acid was assessed, acrosine activity, neutral alpha-glucosidase activity was determined, citric acid, fructose and glycodelin levels were determined, the level of reactive oxygen species was studied. Determination of the zinc level in the spermoplasm was carried out by a standard spectrophotometric method with 5-Br-PAPS chromogen. Pearson's formula was used for correlation analysis. The study was conducted from 2018 to May 2022, once. 
Results: A significant negative correlation of the zinc level in the spermoplasm with the age of men was revealed (r=-0.1625, p0.001). The level of zinc in the spermoplasm was weakly negatively correlated with the dilution time and with the viscosity of the sperm. The positive correlation was with the number of spermatozoa (r=0.1345, p0.01) and their mobility (r=0.3825, p0.00001). The level of zinc in the spermoplasm negatively correlates with the degree of fragmentation of sperm DNA and with the amount of reactive oxygen species, and with the test for binding of sperm with hyaluronic acid positively. 
Conclusions: The level of zinc in the spermoplasm significantly correlates with a number of physiological and biochemical characteristics of sperm. The data obtained allow us to recommend the determination of zinc in the sperm plasma not only to assess the functional activity of the prostate gland, but also to diagnose the fertility of the ejaculate, as well as to optimize therapy with zinc-containing drugs and improve control over the effectiveness of the treatment.