Effect of Testosterone on Endothelial Function and Microcirculation in Type 2 Diabetic Patients With Hypogonadism
Status:
Terminated
Trial end date:
2014-09-14
Target enrollment:
Participant gender:
Summary
Diabetes mellitus is associated with long-term complications affecting mainly the eyes,
nerves and kidneys. One of the main underlying causes for this is damage to the lining of the
small blood vessels supplying these organs with dysfunction of the endothelium (lining of the
small blood vessels). Testosterone has been shown to have an effect macro (large) blood
vessels with limited data available on the micro (small) blood vessels. Testosterone is
recognised to have important effects on metabolism and vascular behaviour beyond the accepted
effects on secondary sexual characteristics. Physiological testosterone therapy is associated
with some beneficial effects on the cardiovascular system and has been used with some success
to treat patients with stable angina and chronic heart failure. The investigators therefore
propose to study the effects of testosterone replacement therapy in patients with
hypogonadism (low testosterone levels) on the endothelium in males with type 2 diabetes. 40
diabetic patients with type 2 diabetes and low testosterone levels and erectile dysfunction
(impotence) will be recruited into the study. All patients will receive testosterone
replacement therapy and 10 patients will also receive Vardenafil (a drug used to treat
impotence). The investigators hope to demonstrate an improvement in endothelial dysfunction
by assessing biochemical markers such as nitric oxide (a chemical that causes relaxation for
the blood vessels) and C-reactive protein (a chemical that can increase in patients with
diabetes) as well as the effect on weight, blood pressure, diabetes control and cholesterol.