Trimethyl amine oxide (TMAO) and lipopolysaccharide levels in vascular and idiopathic erectile dysfunction

ED is the persistent inability to achieve or maintain adequate penile erection necessary for sexual intercourse. ED has been found to be associated with endothelial dysfunction, as well as being an important indicator of cardiovascular diseases (CVD). It has been demonstrated that changes in the intestinal microbiota are associated with many chronic diseases such as cardiovascular diseases (CVD), type 2 diabetes mellitus (DM), and hypertension (HT). It has been determined that the intestinal microbiota affects cardiovascular health through its metabolites such as lipopolysaccharides (LPS) and trimethylamine-N-oxide (TMAO), thus being effective in the development of endothelial dysfunction, CVD, atherosclerosis and HT. The research on the roles of TMAO and LPS in ED is still very limited. Thus, our study aimed to evaluate TMAO and LPS levels in vascular and idiopathic ED. Patients who applied to our polyclinic of Elazığ Fırat University, Department of Urology, with complaints of ED between 01.02.2022-01.02.2023 were separated according to etiology by anamnesis, physical examination, laboratory and imaging methods, and serum TMAO and LPS levels were evaluated in patients with 50 vasculogenic, 50 idiopathic ED and 51 heralthy controls. The diagnosis of ED was based on the patient's anamnesis and International Erectile Function Scale (IIEF scoring) test results. Serum TMAO and LPS levels of the individuals included in the study were determined in the laboratories of Fırat University Faculty of Medicine, Department of Medical Biochemistry; Penile color Doppler ultrasonography (USG) examinations were performed in Fırat University Radiology Department USG unit. The average age of the participants was 51,41±10,38. A statistically significant difference was found between vascular ED, idiopathic ED and healthy control groups according to age (mean 58,74±7,61 years, 45,20±10,60 years and 50,31±7,94 years, respectively) (p<0,05) and according to the IIEF variable (9,46±2,72, 14,46±3,17 and 27,01±1,34, respectively) (p<0,05). Statistically significant difference was not found between the groups for TMAO variable (2,02±1,11, 1,76±1,28 and 1,81±0,67, respectively) (p>0,05). According to the LPS variable, a statistically significant difference was found between the vascular ED group and the other two groups (497,36±87,83, 430,62±69,72 and 436,98±105,37, respectively) (p<0,05). The mean age is highest in the vascular ED group and lowest in the idiopathic ED group. The mean IIEF was lowest in the vascular ED group and highest in the healthy control group. There was no statistically significant difference between the TMAO averages of the groups. However, the highest value was found in the vascular ED group and the lowest value was found in the idiopathic ED group. Similar to TMAO, a statistically significant difference was found between the LPS averages of the groups; the highest value was found in the vascular ED group and the lowest value was found in the idiopathic ED group.