Thiol/Disulfide Homeostasis in Patients With Erectile Dysfunction

Although there are no sufficient data on association between oxidative stress and erectile dysfunction (ED), numerous studies have reported that imbalance between the formation of reactive oxygen species and body's antioxidant defenses may play a role in the pathogenesis of ED.

The aim of this study was to determine and compare the oxidant and antioxidant status in patients with ED and healthy controls with a novel automated assay for thiol/disulphide homeostasis test.

Our study included 123 patients with ED and 90 healthy individuals. ED was evaluated by asking questions 1-5 and 15 of the International Index of Erectile Function form. In this study, we used Erel and Neselioglu's thiol/disulfide homeostasis test, which is one of the novel methods that can measure both variables of the oxidative/antioxidative balance individually and collectively.

This method measured serum antioxidant (total thiol [toSH], native thiol [SH]) and oxidant (disulfide [SS]) levels. The statistical comparisons were performed between patients with ED (ED+ group) and without ED (ED- group) first and then within the ED+ group. After toSH, SH, and SS levels were determined; SS/toSH%, SS/SH%, and SH/toSH% levels were analyzed separately and compared statistically.

We found a significant difference between ED- and ED+ groups in terms of toSH, SH, SS/toSH%, and SS/SH% ratios. SS parameters were increased in patients with ED, but there was no significant difference in terms of SS and SH/toSH% values.

Clarification of the factors involved in the etiology of ED such as oxidative/antioxidative balance may open new grounds in the early diagnosis and treatment of the disease.

It is a prospective, randomized clinical study with the use of a novel, reliable, and fully automated technique. The limitations of the study are use of a subjective tool such as the International Index of Erectile Function, obtaining blood samples from the peripheral vein instead of penile cavernosal tissue, and relatively small sample size.

The results of this study showed that thiol/disulfide homeostasis is altered in ED, and this imbalance may be a factor in its pathophysiology. We determined that as ED gets more severe, toSH and SH parameters decrease, whereas SS parameter increases. Micoogullari U, Karatas OF, Kisa E, et al. Thiol/Disulfide Homeostasis in Patients With Erectile Dysfunction. J Sex Med 2020;17:1934-1941.