Efficacy of Aromatase Inhibitors for Azoospermia Caused by AZFc Microdeletion: A Cross-Sectional Descriptive Research Study in Chinese Population

Background. Aromatase inhibitors (AIs) can significantly improve semen parameters in infertile men. In this study, we investigated the efficacy of AIs for azoospermia in a Chinese population with AZFc microdeletion. Aims. Patients with AZFc microdeletion who were treated with AIs were analyzed retrospectively by collecting clinical data, including their hormone profile and treatment outcome. Patients were divided into those with sperm in their semen after AI treatment (group A) and those without sperm in their semen after AI treatment (group B). Results. The rate of Y chromosome AZF microdeletions was 9.30% (313/3364) from March 2015 to March 2021, among which patients with complete AZFc microdeletion accounted for 63.2% (198/313), and of the 198 patients with AZFc microdeletion, 69.7% (138/198) showed azoospermia. Forty-six (33.3%) of the azoospermic patients had sperm in their semen after AI administration. Testosterone (T) and testosterone-to-estradiol ratio (T/E-2) levels were higher in group A than those in group B after treatment, and the differences were significant (T, P=0.038; T/E-2, P=0.004). Paired t-test demonstrated that the change of T levels before and after treatment was statistically significant (P=0.003). The increased E-2 and T/E-2 ratio levels before and after treatment were not statistically significant (P=0.057 and 0.080), but they were close to the threshold value (P=0.05). Conclusions. Patients with AZFc microdeletion accounted for the largest proportion of male infertility caused by Y chromosome microdeletions. AIs can promote spermatogenesis in azoospermic patients with AZFc microdeletion, and sperm could be found in the semen of some patients after AI administration. T and T/E-2 levels after AI treatment could be used as biomarkers to distinguish azoospermic patients with AZFc microdeletion who responded better to AIs from those who did not respond well.