Effects of chronic administration of the phosphodiesterase inhibitor vardenafil on serum levels of adrenal and testicular steroids in men with type 2 diabetes mellitus

Background. Steroidogenesis is a complex enzymatic pro- cess in which cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) play an important role. Phosphodiesterase-5 inhibitors(PDE5i) increase cGMP, improving NO availability. Objective. To investigate whether long-term, chronic treat- ment with the PDE5i Vardenafil affects adrenal and testicular steroidogenesis in diabetic men, using liquid chromatography- mass spectrometry (LC-MS/MS). Design. A longitudinal, prospective, investigator-started, randomized, placebo-controlled, double-blind, clinical-trial was carried out. Setting and participants. 54 male patients affected by T2DM diagnosed within the last 5 years were enrolled. 26 and 28 patients were assigned to the verum and placebo-group, re- spectively. Interventions. The study consisted of an enrolment phase, a treatment phase (24 weeks) (Vardenafil/placebo 10 mg twice- daily), and a follow-up phase (24 weeks). Outcome measurements. Progesterone (P), 17-hydroxy- progesterone (17OHP), androstenedione (A), testosterone (T), dehydroepiandrosterone (DHEA), DHEA sulphate (DHEAS), corticosterone, 11-deoxycortisol and cortisol (C), were evalu- ated using LC-MS/MS. Results. No differences were seen in sex testicular steroids between study and control group. For the adrenal gland, steroids were considered according to the zona in which they are pro- duced. Considering steroids produced in the zona fasciculata, no significant differences were seen in 11-deoxycortisol and C among visits, both in the study and in the control group. For the zona reticularis, DHEA significantly decreased during treatment only in the study group (p=0.007). At post-hoc test DHEA showed higher levels at visit 2 and 8 than in other visits. The DHEAS/DHEAS ratio significantly increased during treatment only in the verum group. Considering the adrenal zona glomeru- losa, corticosterone significantly changed among visits both in the study and in the control group (p<0.001). At post-hoc test, in ПРОБЛЕМЫ ЭНДОКРИНОЛОГИИ, 5, 2016 both groups, corticosterone was significantly higher at visit 2 (p=0.028), 8 (p=0.003) and 10 (p=0.044), i.e. in coincidence with the complete clinical and instrumental examination per- formed only at these visits according to the study protocol. Conclusions. This is the first double-blind, placebo-con- trolled clinical-trial in which steroidogenesis is extensively in- vestigated by LC-MS/MS in T2DM men chronically treated with Vardenafil for 6 months, and followed-up for 6 months after therapy-withdrawal. Chronically administered Vardenafil reduces DHEA levels and increases DHEAS/DHEA ratio as possible consequences of modulation of steroidogenic enzymes by tissue changes in cGMP and/or cAMP availability. A possi- bly stress-related increase in corticosterone is suggested for the first time.