12 Month Administration of a Long-Acting Formulation of Testosterone Undecanoate (Nebido) Improves Measures of Sexual Dysfunction and the Metabolic Syndrome

Saad, F^{(1, 2)}; Gooren, L⁽³⁾; Haider, A⁽⁴⁾; Yassin, A^{(2, 5)}

⁽¹⁾Bayer-Schering, Department of Men’s Healthcare, Berlin, Germany ⁽²⁾Gulf Medical College School of Medicine, Ajman, UAE ⁽³⁾VUmc, Amsterdam, Netherlands ⁽⁴⁾Bremerhaven, Germany ⁽⁵⁾Department of Urology, Segeberger Kliniken, Norderstedt, Germany

Introduction: Sexual dysfunction and the metabolic syndrome are inter-related conditions which co-exist in many male patients. Both are associated with reduced levels of testosterone. The aim of this study was to determine the effects of 12 months of treatment with a long-acting formulation of testosterone undecanoate (Nebido) on sexual dysfunction and the metabolic syndrome. Methods: Testosterone undecanoate was administered by intra-muscular injection at week 0, 6 and then every 12 weeks to elderly men (median age = 64 years, range 54-76 years) with sexual dysfunction and clinical signs of the metabolic syndrome. Patient sexual function questionnaires and waist circumference were assessed, and plasma levels of testosterone, total cholesterol, low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) were measured, at baseline and 12 months. Results: Treatment with testosterone undecanoate over 12 months restored plasma testosterone levels to the mid-reference range. This was associated with an improvement in International Index of Erectile Function and Aging Male Symptoms questionnaire scores. A marked improvement in markers associated with the metabolic syndrome was also observed; waist circumference fell significantly, an effect which was positively correlated with plasma levels of total and LDL-C and negatively correlated with plasma levels of HDL-C. Blood pressure was also significantly reduced. There were no safety concerns over the over the 12-month study period; liver function and levels of prostate specific antigen remained stable, and International Prostate Symptoms Score improved slightly. Hematocrit and plasma levels of hemoglobin increased significantly, but remained within reference values. Conclusion: 12 months treatment with a long-acting formulation of testosterone undecanoate restored testosterone levels to the mid-normal range had beneficial effects on sexual dysfunction and features of the metabolic syndrome.