Impaired growth hormone secretion and increased growth hormone-binding protein levels in subfertile males

Objective: To evaluate GH secretion in subfertile males. Design: Comparing GH secretion to a GH stimulation test in two different patient groups and in a control group. Patients: Nine oligozoospermic patients, nine asthenozoospermic patients, and nine age- and body mass index-matched fertile males with normal spermograms. Intervention: All subjects underwent an TV arginine GH stimulation test. Main Outcome Measures: Serum levels of FSH, LH, PRL, E(2), T, insulin-like growth factor I (IGF-I), and GH-binding protein were measured. Results: Basal levels of GH were similar in all three groups and serum GH increased in all groups after arginine. However, there was a significant difference between the two patient groups and the control group characterized by an impaired GH response in the subfertile patients. Serum FSH and serum GH-binding protein were significantly higher in the patient groups compared with the controls. Serum LH, PRL, T, E(2), and IGF-I were similar in all three groups. Conclusions: This study demonstrates that subfertile men may suffer from relative GH insufficiency, which could have therapeutical implications.