Seminal glucose levels: a prognostic factor of sperm survival to cryopreservation?

Objective: Considering that glucose is an important component of seminal plasma and is a cryoprotectant at high concentrations, the aim of this study was to investigate the possible association of glucose levels in fresh semen with the sperm survival and motility rates following cryopreservation.Methods: This was a prospective study including 149 men undergoing semen analysis due to male and/ or female infertility. The seminal samples were analyzed according to the World Health Organization standards and glucose concentrations were measured using a dipstick glucometer. Samples were cryopreserved with Test Yolk Buffer-Gentamicine freezing medium under liquid nitrogen for an average of 120 days. The frozen aliquots were thawed at 37 degrees C for 10 minutes and analyzed using the same methods and protocols used pre-freezing.Results: Glucose levels ranged from 14 to 99 mg/ dL and were similar in individuals with normal (n=100) vs. abnormal (n=49) semen analysis. The rates of sperm recovery (total, alive or motile sperm) in the cryopreserved samples did not change among samples with different glucose levels (p>0.05, Kruskal-Wallis ANOVA and Spearman's correlation coefficient).Conclusions: There appears to be no association between glucose levels in human semen samples and their resistance to cryopreservation.