The results of foreign researchers are comparable with those obtained in the survey 276 patients with diabetes type 1 and 335 patients with type 2 diabetes in Russia. So, according to PG Enz RAMS prevalence of ED among patients with diabetes types 1 and 2 was 38.7 and 66.2% respectively, exceeding the per se in men without diabetes for more than 3 times. Thus the prevalence of erectile dysfunction increases not only with age, but with increasing duration of SD. The study also obtained results showing the relationship of erectile dysfunction and the nature of their diabetes. Thus, indicators of HbA1c in patients with ED and SD were significantly higher than those of patients without erectile dysfunction, ie, indicators of the diabet patients with ED have been worse. In addition, patients with ED and DM of complications of DM was also significantly higher than in patients with diabetes and the lack of erectile dysfunction.
As in the general population of ED in diabetic patients is caused by organic and / or psychogenic causes. The etiology of erectile dysfunction in DM is multifactorial – disorders of the endocrine system, cardiovascular disorders, decompensated diabetes, neuropathy, and psychogenic factors. Moreover, it leads to erectile dysfunction, or exacerbate its course may be drugs used by patients with diabetes.
Numerous researchers have shown that even in the initial stages of the DM primary cause of erectile dysfunction is diabetic neuropathy, and microangiopathy, based on one of the first places is a violation of carbohydrate metabolism. Thus, in men with signs of peripheral neuropathy erectile dysfunction detected more frequently than in patients with diabetes without neuropathy. Furthermore, in patients with diabetes for men, there is increased adrenergic tone and level of autonomic dysfunction of the parasympathetic nervous system. Many patients with diabetes and erectile dysfunction revealed abnormal results of tests on a local tactile and vibration sensitivity. Often in patients with diabetes, along with neurogenic there and vaskulogenny factor in the development of ED, ie there is a multifactorial nature of pathogenesis.
A number of studies of foreign authors arterial insufficiency of the corpora cavernosa was detected in 50% of diabetic patients: in 15% of cases in an isolated form, and in 30% of cases with venous insufficiency. This frequency forms of erectile dysfunction in patients with diabetes increases with age. A number of patients with diabetes have signs of veno-occlusive insufficiency. However, in contrast to the study, El-Sakka et al. (2003) did not reveal a significant statistical association between the presence of type 2 diabetes and end-diastolic velocity of blood flow in penile arteries, and resistance index – an indicator characterizing the disturbances in the venous system of the penis.
A number of erectile dysfunction patients with diabetes may be due to the local pathological changes in the cavernous bodies, which in many respects similar to the manifestations of diabetic microangiopathy.
In neurogenic and vaskulogennoy forms of ED in diabetic patients, it is common endocrine form. In recent years uncovered the role of androgens in causing an erection: found that the NO-synthase – the enzyme responsible for the synthesis of nitric oxide, is androgen. An additional indication of the androgen-dependent NO-synthase is the detection of androgen receptors in neurons of pelvic parasympathetic ganglia, which is a synthesis of NO and VIP, as well as stimulation of NO synthesis in the ganglia under the influence of androgens. It hypogonadism is a frequent symptom in patients with diabetes. Reasons for a decrease in testosterone levels in men with diabetes are different. Those are the reasons may be overweight or obese, as well as age-related decrease in testosterone secretion.
The majority of diabetic patients is accompanied by organic psychogenic factors in the development of sexual disorders. According to research psychogenic component is the sole cause of erectile dysfunction in 11% of surveyed men with diabetes and related causes – 17% of patients. All psychological problems contribute to the weighting of erectile dysfunction caused by organic disorders, but also lead to a decrease in the motivation of psychogenic erectile function.
However, ED is often a long time not identified due to the fact that patients often do not make doctors related complaints. Despite regular monitoring in Diabetes clinics, only 30-35% of patients discussed the problem of erectile dysfunction with their physician. Also, there is not enough active questioning of patients by physicians, despite the fact that these disorders are common among diabetic patients.
In the arsenal of medical practice today have everything necessary for the erectile dysfunction treatment. Because patients with diabetes represent a special group (due to the presence of specific complications), preference is given to medication therapy treatments, among which is the most effective inhibitors of phosphodiesterase (PDE5), such as sildenafil, Cialis (tadalafil), vardenafil. Preparations of this group are modulators of erection. It is crucial that in the absence of sexual stimulation, PDE5 inhibitors have no effect. Due to the fact that the SD is characterized by the development of complications, leading to the emergence of erectile dysfunction (diabetic neuropathy, diabetic micro-and macroangiopathy), the patient requires constant use of PDE5 inhibitors.

The experience with sildenafil in patients with diabetes demonstrated its effectiveness, which does not decrease with prolonged use, and it does not require increasing the selected individual dose. The average effect of the drug develops within 40-50 min after administration and persists for 4-6 h. According to the results of a comparative study of sildenafil with placebo, sildenafil therapy did not influence sexual desire partners, as well as sexual arousal, orgasm and the feeling of satisfaction men.
The effectiveness of vardenafil in the treatment of erectile dysfunction in diabetic patients was evaluated in a multicenter, placebo-controlled, double-On th ¬ pom study, including 452 patients. In assessing the results of treatment after 12 weeks of a dose-dependent improvement in Erec ¬ tion was observed in 52 and 72% of men treated with 10 and 20 mg vardenafil matched ¬ tively, whereas in the placebo group improving ¬ tion of erection was observed in only 13% of patients.
Efficacy and safety of Cialis (tadalafil) in patients with diabetes has been demonstrated in the study of Fonseca V. et al. (2004), which was conducted a retrospective analysis of combined data 12 placebo-controlled studies in patients with ED, CD, and without it. The study included 637 men with diabetes and 1681 men without SD, who received tadalafil in doses of 10 and 20 mg or placebo for 12 weeks. Patients with diabetes have more severe erectile dysfunction compared with patients without SD, with the score on the IIEF erectile dysfunction inversely correlated with levels of HbA1c. Compared with placebo, tadalafil doses of 10 mg and 20 mg significantly improved erectile function in both groups, which is accompanied by improved quality of life of patients (statistically significant increase in the GAQ compared with placebo). In the group of patients with diabetes treated with tadalafil 20 mg, it was noted that 53% of their attempts to hold intercourse were successful, compared with 22% for placebo. These indicators in patients without CD were 71 and 33% respectively. The effectiveness of tadalafil did not depend on the degree of compensation of carbohydrate metabolism and received on the SD treatment. Thus, despite the more severe erectile dysfunction in patients with diabetes, tadalafil was effective and well tolerated [59]. Since tadalafil is the longest half-life (17.5 hours), this provides a significantly longer duration of its action and returns the natural sexual relations [60]. The patient was withdrawn direct psychological dependence on medication and it is possible to maintain the natural sexual life, which is certainly true in the presence of additional psychogenic factors, aggravating erectile dysfunction in diabetic patients [61]. It should be noted that, according to a study Stroberg P. et al. (2003), patients taking sildenafil and replace it with tadalafil, tadalafil preferred in the ratio 9:1. The data confirm the results of the study Eardly I. et al. (2005), under which men accept as sildenafil and tadalafil, in 29% of cases preferred sildenafil and 71% – tadalafil, as well as research Lee J. et al. (2006), which demonstrated preference for tadalafil sildenafil patients and their sexual partners.
However, according to researchers at 20-40% of patients with erectile dysfunction PDE5 inhibitor therapy is ineffective, that in some cases due to the presence of patients hypogonadism (androgen deficiency). Thus, according to Yassin A. et al. (2003), the study of 69 patients did not respond to PDE5 inhibitor therapy, the use of tadalafil resulted in normalization of erections in 40% of cases after 4-week course of testosterone replacement therapy and in 65% cases – after a 10-week course. Consequently, if the patient has erectile dysfunction in combination with hypogonadism before his appointment to the holding of PDE5 inhibitor therapy, aimed at eliminating hypogonadism.
Thus, the basic principles of selection of modern therapy of ED in diabetic patients can be defined as follows. The initial treatment is removal of pathogenetic factors of ED (removal of stressful factors, hypogonadism, compensation of carbohydrate metabolism, correction of dyslipidemia, etc.). In the case of failure of pathogenetic therapy encourages the use of oral medications, including drugs of choice are PDE5 inhibitors. When ineffectiveness PDE5 inhibitors may conduct intrakavernoznoy therapy or surgical treatment.
The above review of the literature on the prevalence, etiology, pathogenesis and treatment of erectile dysfunction in diabetic patients, reflecting both the significant achievements, as well as the presence of unresolved problems in this area. Further improvement in methods of treating these patients should be closely connected with the study of pathogenetic mechanisms of the formation of erectile dysfunction on the background of the SD, which opens for specialists to study this problem, new frontiers for scientific activity.