Clinical predictive factors of sildenafil response: a penile hemodynamic study.

Phosphodiestrase-5 inhibitors are an important line of treatment for erectile dysfunction (ED). To detect the clinical and hemodynamic predictors of sildenafil response, we conducted this study on 124 Egyptian men with ED. All patients were evaluated by thorough history and clinical assessment with measurement of the abridged international index of erectile function-5 (IIEF-5) score. All patients were then subjected to intracavernosal injection (ICI) of trimix and pharmaco-penile duplex ultrasonography (PPDU). Patients were then classified into sildenafil responders and non-responders after six consecutive doses of 100 mg sildenafil. On doing the binary logistic stepwise regression analysis, only ED duration, IIEF-5 score, and response to ICI were the significant independent predictors of sildenafil response. These three parameters together correctly predicted the sildenafil response by 81.5% (p value <0.001). With the receiver operator characteristic curve analysis, the cut-off value of ED duration was 2.5 years and it was 14 for the IIEF-5 score. These findings indicate that ED duration, the IIEF-5 score and response to ICI are more significant predictors of sildenafil response than the more expensive and time-consuming PPDU testing.

Diagnostic value of nitric oxide, lipoprotein(a), and malondialdehyde levels in the peripheral venous and cavernous blood of diabetics with erectile dysfunction.

Diabetes mellitus (DM) is the single most common cause of erectile dysfunction (ED) seen in clinical practice. Evaluation of penile arterial insufficiency in diabetic patients currently entails expensive and invasive testing. We assessed the diagnostic value of certain peripheral and cavernous blood markers as predictors of penile arterial insufficiency in diabetic men with ED. This study was conducted on a total of 51 subjects in three groups: 26 impotent diabetics, 15 psychogenic impotent men and 10 normal age matched control males. All subjects underwent standard ED evaluation including estimation of postprandial blood sugar and serum lipid profile. Peripheral venous levels of nitric oxide (NO), lipoprotein(a) (LP(a)), malondialdehyde (MDA) and glycosylated hemoglobin (HbA1c) were obtained in all subjects. Patients in the two impotent groups underwent additional measurement of NO, LP(a) and MDA levels in cavernous blood. They also underwent intracavernosal injection (ICI) of a trimix (papaverine, prostaglandin E1 and phentolamine mixture) and pharmaco-penile duplex ultrasonography (PPDU). Compared to patients in the psychogenic group, diabetic men had significantly lower erectile response to ICI (P<0.001), lower peak systolic velocity (PSV) (P<0.001), and smaller increase in cavernosal artery diameter (CAD) (P<0.001). Peripheral and cavernous levels of both LP(a) and MDA were higher in the diabetic group as compared to the psychogenic ED group (P<0.001), while the values of peripheral venous and cavernous NO were lower (P<0.001) in the diabetic men. Comparison of biochemical marker assays with the PPDU results showed a significant negative correlation between both venous and cavernous LP(a) and MDA levels on the one hand, and PSV, and the percentage of CAD increase on the other. At the same time, peripheral and cavernous NO levels had a significant positive correlation with the same parameters. Lipoprotein(a), MDA and NO levels were better predictors of low PSV than HbA1c, cholesterol or triglyceride levels. The finding of high levels of LP(a) and MDA with low levels of NO in the peripheral and cavernous venous blood of diabetic men with ED correlates strongly with severity of ED as measured by PPDU. This provides a rationale for further studies of biochemical markers as a surrogate for traditional invasive testing in the diagnosis of penile arterial insufficiency.

The pathophysiology of varicocele-associated male infertility.

Varicocele is the most commonly identifiable, surgically correctable lesion associated with male-factor infertility. Surgical correction of a varicocele, whether unilateral or bilateral, results in improvement not only in semen parameters but also in spontaneous and assisted pregnancy rates. Varicoceles seem to induce a number of changes in the testicular microenvironment. These alterations in temperature, hemodynamics, and reactive oxidative species and antioxidant concentrations have been demonstrated to produce deleterious effects on spermatogenesis. However, despite current knowledge in the pathophysiology of varicocele-associated male infertility, the exact mechanism--or mechanisms--by which varicoceles impair fertility remains elusive. This review examines scientific evidence regarding the pathophysiology of varicocele-associated male infertility.