A similar situation develops in the fragile penile circulation. Any disturbance in nitric oxide production lowers the capacity to dilate penile arteries, impairing penile engorgement for erection. Release of nitric oxide is readily sabotaged by many conditions, including elevated levels of cholesterol, high blood pressure, increased triglycerides, smoking, metabolic syndrome and diabetes, and excessive consumption of dietary saturated fat.9 If an artery’s inner wall can’t produce nitric oxide, an abnormal constriction of the arteries to the penis follows, effectively choking off blood flow.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (66) | Google ScholarSee all References However, some researchers have questioned whether the strain of sexual activity can be compared accurately with standard types of physical activity and whether sexual activity is more closely related to episodes of anger or fear.85x85DeBusk, RF. Evaluating the cardiovascular tolerance for sex. Am J Cardiol. 2000; 86: 51F–56F
Other effective Diabetic Erectile Dysfunction Treatment therapies available include (a) an intraurethral suppository of the vasodilator drug alprostadil (prostaglandin E1), (b) intracavernosal self injection (penile self injection) of the non-specific PDE drug papaverine, the non-selective alpha-adrenergic antagonist phentolamine, and the vasodilator prostaglandin E1, used alone or in combination, or (c) penile prostheses (penile implants).

Diuretics: Also called water pills, this medication is a common treatment for reducing blood pressure. They work by getting rid of unnecessary water and salt in the urine. This essentially helps lower blood pressure and can make it easier for the heart to pump blood. Unfortunately, diuretics can reduce the blood flow to the penis, making erections difficult to achieve. Zinc levels have been known to diminish due to diuretic use, which may lead to a decreased production of overall testosterone.
Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.
Diabetes mellitus (DM) is strongly associated with an increased risk of erectile dysfunction (ED), the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance, but this condition can be successfully treated in the majority of diabetes patients. ED is present in 32% of type 1 and 46% of type 2 DM patients. Several population- based studies of ED prevalence calculated the odds ratios for the association between ED and various chronic diseases. An odds ratio must be sufficiently greater than 1.0 to identify an increased risk. Diabetes has an odds ratio, ED risk multiplier of 4.1, compared with 1.7 for hyperlipidemia and 1.6 for hypertension. Erectile dysfunction in diabetes mellitus (EDDM) patients has been considered to have an organic etiology. Healthcare providers have long realized that ED can be the first symptom of DM.
The second way relates to the risk associated with the sexual activity in a patient with either overt or occult CVD. In this case, the diagnosis of ED should prompt an initial cardiovascular assessment based on the history and clinical examination in order to define the baseline risk according to (i) the likelihood of silent CAD18,31 (especially since ED patients have a high probability to have silent CAD) or to the stage of clinically evident CAD, (ii) other cardiovascular conditions either unrelated, or related to ED (e.g. heart failure, peripheral arterial disease).
The mechanisms of action by which antihypertensive medications cause ED are currently unknown. Some investigators have theorized that antihypertensive medications affect erectile function by decreasing blood pressure, which reduces the perfusion pressure needed to maintain sufficient blood flow for erections through atherosclerotic penile arteries.37x37Benet, AE and Melman, A. The epidemiology of erectile dysfunction. Urol Clin North Am. 1995; 22: 699–709
Most cases of sexual dysfunction are related to a physical cause. The most common causes are diabetes, heart disease, neurological trauma or disease, and side effects of medications. Stress and anxiety can also contribute to impotence. While most of the focus has been on men with erectile dysfunction, a number of women also suffer from this disorder.
Relaxation of erectile tissue requires nitric oxide from nonadrenergic-noncholinergic neurons and the endothelium.21 Penile tissue from diabetic men with ED demonstrates impaired neurogenic and endothelium-mediated relaxation of smooth muscle,22 increased accumulation of advanced glycation end products (AGEs),23 and upregulation arginase, a competitor with nitric oxide synthase for its substrate L-arginine.24 Normal responses to direct smooth muscle relaxants in most of these studies implies that the impairments are due to decreased synthesis, release, or activity of nitric oxide. The fundamental mechanisms mediating these changes are thought to be the same as for other diabetic complications: increased polyol pathway flux, intracellular accumulation of AGEs, activation of protein kinase C, and increased flux through the hexosamine pathway.25
The mechanisms of action by which antihypertensive medications cause ED are currently unknown. Some investigators have theorized that antihypertensive medications affect erectile function by decreasing blood pressure, which reduces the perfusion pressure needed to maintain sufficient blood flow for erections through atherosclerotic penile arteries.37x37Benet, AE and Melman, A. The epidemiology of erectile dysfunction. Urol Clin North Am. 1995; 22: 699–709
Normal penile erection is controlled by two mechanisms: reflex erection and psychogenic erection. Reflex erection occurs by directly touching the shaft of the penis, while psychogenic erection occurs by erotic or emotional stimuli. ED is a condition where erection does not take place by either mechanism. ED can occur because of hormonal imbalance, neural disorders or lack of adequate blood supply to the penis.54 Lack of blood supply can be a result of impaired endothelial function associated with CAD.54
For oral erectile dysfunction medicines to work as desired, they must be used properly in the first place. This means taking the medicine 30–45 minutes before engaging in sexual intimacy; taking the drug on an empty stomach or at least avoiding a heavy or high-fat meal before taking the drug (this is especially important when using sildenafil); and engaging in adequate genital stimulation before attempting intercourse. Drinking small amounts of alcohol (one to two drinks) should not compromise the effectiveness of erectile dysfunction medicines, but larger amounts of alcohol can diminish a man’s ability to have an erection.
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