Relationship between Testicular Volume and Conventional or Nonconventional Sperm Parameters

Background. Reduced testicular volume (TV) (<12 cm(3)) is associated with lower testicular function. Several studies explored the conventional sperm parameters (concentration, motility, and morphology) and the endocrine function (gonadotropins and testosterone serum concentrations) in the patients with reduction of TV. No other parameters have been examined. Aim. This study aims at evaluating some biofunctional sperm parameters by flow cytometry in the semen of men with reduced TV compared with that of subjects with normal TV. Methods. 78 patients without primary scrotal disease were submitted to ultrasound evaluation of the testis. They were divided into two groups according to testicular volume: A Group, including 40 patients with normal testicular volume (TV > 15 cm(3)) and B Group, including 38 patients with reduced testicular volume (TV ≤ 12 cm(3)). All patients underwent serum hormone concentration, conventional and biofunctional (flow cytometry) sperm parameters evaluation. Results. With regard to biofunctional sperm parameters, all values (mitochondrial membrane potential, phosphatidylserine externalization, chromatin compactness, and DNA fragmentation) were strongly negatively correlated with testicular volume (P < 0.0001). Conclusions. This study for the first time in the literature states that the biofunctional sperm parameters worsen and with near linear correlation, with decreasing testicular volume.