Diabetes care providers, while becoming more aware of the high prevalence of ED in men with diabetes, may not appreciate the importance of maintaining erectile function to their patients. A recent study by Rance et al.40 underscores the fact that diabetic men, regardless of whether they actually have ED, believe that ED has a major impact on quality of life and that it is as important to treat as many other conditions associated with diabetes. In an effort to determine the relative importance of treatment for ED compared to other diabetic complications, they gave 192 consecutive diabetic men and 51 control patients seen at two hospitals a standardized questionnaire that assessed the relative importance of a number of diabetic complications and the patients' willingness to pay per month to avoid a particular complication.
Towards this direction, several sufficiently powered studies have demonstrated a higher incidence of erectile dysfunction in patients with coronary artery disease, either asymptomatic or overt. At the same time, patients with erectile dysfunction are more prone to have established coronary artery stenosis of more than 50% and consequently evident CV disease. This is in conformity with the “artery size hypothesis” according to which smaller arteries (e.g., penile arteries) are the first to undergo a vascular lesion prior to the larger ones (e.g., coronary arteries). Moreover, in such patients erectile dysfunction is connected to the number of occluded vessels and more interestingly occurs over three years before coronary artery disease becomes apparent[76-80].
The common associations between cardiovascular disease and ED have led some researchers to explore whether onset of ED can be an effective predictor of the presence of cardiovascular disease. A study of 40 patients with cardiac disease found an association between sexual dysfunction and the presence of cardiovascular disease, as well as a correlation between the severity of ED and the number of coronary arteries with extensive atherosclerosis.16x16Greenstein, A, Chen, J, Miller, H, Matzkin, H, Villa, Y, and Braf, Z. Does severity of ischemic coronary disease correlate with erectile function?. Int J Impot Res. 1997; 9: 123–126
A considerable number of patients with ED can have psychogenic factors as the only cause, or in combination with organic causes of ED. Depression, low self-esteem and social stresses are among the psychogenic factors that can lead to ED. Depression is an independent risk factor for both ED and IHD; these three disease conditions are interlinked.51 Psychogenic ED can be managed by multiple psychological interventions such as cognitive behavioural therapy, couples counselling and guided sexual stimulation techniques.52
While a widely held perception is that CVD drugs cause ED, data attest towards the contrary and some agents may be even beneficial.41 Only thiazide diuretics lead clearly to ED, while some older beta-blockers also do so, but the side-effect of ED was very low (∼3%) when the patient was blinded for the drug administration.42 In fact, the vasodilating nebivolol may even improve erectile function.35,43 ACE-inhibitors, angiotensin-receptor blockers, and calcium-channel blockers are reported to have neutral or even a positive effect on erectile function35,41,43 but more evidence is needed. Regarding statins, the largest body of evidence point towards a beneficial effect.44 A negative effect has been reported in high statin doses, possibly related to a potential reduction in serum testosterone levels, but this dose dependency warrants further investigation. In terms of patient management, when ED onset and therapy initiation are linked and a cause-and-effect association is presumed, a short period of drug withdrawal with monitoring for ED resolution for verification may be an option. In patients who developed ED long after the initiation of CV drug treatment, sexual dysfunction is less likely to be drug associated and PDE5 inhibition therapy may be initiated.
The safety of PDE5 inhibitors in patients with IHD has been shown in multiple trials. Arruda-Olson et al. investigated the safety of sildenafil during exercise stress tests in patients with IHD to ascertain whether the drug induces or exacerbates myocardial ischaemia. This was a prospective, randomised crossover study that demonstrated safety of sildenafil when given 1 hour before an exercise stress test.69 Another study that investigated 120 trials of sildenafil revealed that the rates of MI and cardiovascular death with sildenafil are as low as with placebo.70
Besides mammalian organs, insects and arthropods are also consumed as aphrodisiacs in Eastern medicine. These include scorpions, spiders, beetles, flies and other bugs (32). Penile erections can be observed following administration of neurotoxins as it causes repetitive firing of the somatic, sympathetic and parasympathetic neurons, resulting in autonomic and neuromuscular over-excitation. Scorpions are often used as an ingredient found in herbal wines. However, there is a general lack of literature regarding the consumption of scorpion neurotoxins for potency.
Although the results provide evidence that PDE5 inhibitors may benefit heart health, the retrospective study design makes it impossible to ascertain direct cause and effect, Andersson noted. It is possible that using erectile dysfunction drugs simply indicates a more active sex life, which could itself contribute to, or be a marker of, a heart-healthy lifestyle overall.
Crossref | PubMed | Scopus (697) | Google ScholarSee all References Subsequent in vitro electrical stimulation of these tissue samples showed decreased neurogenic and endothelium-dependent smooth muscle relaxation in the tissue from the patients with diabetes. These effects persisted even after controlling for smoking and hypertension. Other studies have shown a heightened smooth muscle tone in patients with diabetes mellitus.24x24Christ, GJ, Stone, B, and Melman, A. Age-dependent alterations in the efficacy of phenylephrine-induced contractions in vascular smooth muscle isolated from the corpus cavernosum of impotent men. Can J Physiol Pharmacol. 1991; 69: 909–913
When antihypertensive medication comes to the fore, certain issues need to be carefully addressed. This is due to the fact that medically induced erectile dysfunction is one of the major reasons for non-adherence and treatment discontinuation, a reality that could have deleterious consequences on patient’s cardiovascular profile and health quality in the long term[38,39].
In fact, one common reason many younger men visit their doctor is to get erectile dysfunction medication. Often, men with erectile dysfunction suffer with diabetes or heart disease, or may be sedentary or obese, but they don’t realize the impact of these health conditions on sexual function. Along with erectile dysfunction treatment, the doctor may recommend managing the illness, being more physically active, or losing weight.
It is recommended that testosterone be measured in patients with ED because low levels are a reliable measure of hypogonadism. Hypogonadism is not only a treatable cause of ED, but can also lead to reduced or lack of response to PDE5 inhibitors.73 Testosterone deficiency is also associated with increased cardiovascular and all-cause mortality.74 Levels >350 ng/dl do not usually require replacement, but in patients with testosterone <230 ng/dl, replacement can usually be beneficial.57 In patients with congestive heart failure, testosterone replacement can lead to fluid retention, so caution is advised. In these patients, the aim should be to keep testosterone levels in the middle range, i.e. 350–600 ng/dl.57
Crossref | Google ScholarSee all References Other investigators have suggested these medications may exert a hormonal effect. β-Blockers have been associated with decreased free and total testosterone levels in placebo-controlled trials.39x39Rosen, RC and Weiner, DN. Cardiovascular disease and sleep-related erections. J Psychosom Res. 1997; 42: 517–530
Erectile dysfunction (ED), or impotence, is when a man has difficulty getting or maintaining a strong enough erection for sexual intercourse or other sexual activity. It can be caused by stress, anxiety or excessive alcohol consumption. But it can also be a symptom of an underlying condition such as atherosclerosis (narrowing of the arteries), diabetes or high blood pressure. Some medications can cause erectile dysfunction, for example beta-blockers and diuretics (commonly used to treat a variety of heart-related conditions such as high blood pressure and heart failure).
Crossref | PubMed | Scopus (53) | Google ScholarSee all References A study of 24 patients with ED and untreated essential hypertension showed decreased levels of free and total serum testosterone compared with normal controls.31x31Hughes, GS, Mathur, RS, and Margolius, HS. Sex steroid hormones are altered in essential hypertension. J Hypertens. 1989; 7: 181–187
Abstract | Full Text | Full Text PDF | PubMed | Scopus (46) | Google ScholarSee all References The significant sympathetic discharge associated with sexual intercourse may contribute to the development of arrythmias in susceptible patients.81x81Drory, Y, Fisman, EZ, Shapira, Y, and Pines, A. Ventricular arrhythmias during sexual activity in patients with coronary artery disease. Chest. 1996; 109: 922–924
A follow-up study from the ExCEED database compared men with ED and prostate cancer to men with ED without prostate cancer and found that the prostate cancer survivors had worse erectile function but reported better quality of life than those without prostate cancer.37 The authors hypothesized that the prostate cancer survivors were able to “rationalize” away their sexual dysfunction with the knowledge that they may have been “cured” of their prostate cancer. Clearly, diabetic men could not use the same rationale.
Crossref | PubMed | Scopus (539) | Google ScholarSee all References Possible etiologies for ED secondary to hypertension include vascular damage due to hypertensive changes as well as hormonal abnormalities such as elevated prolactin levels.30x30Jaffe, A, Chen, Y, Kisch, ES, Fischel, B, Alon, M, and Stern, N. Erectile dysfunction in hypertensive subjects: assessment of potential determinants. Hypertension. 1996; 28: 859–862
Crossref | PubMed | Google ScholarSee all References After controlling for age, trauma, hypertension, and diabetes mellitus, a study of 97 young patients with ED who underwent selective pudendal angiography showed a significant relationship between lifetime cigarette smoking and the degree of internal pudendal and common penile arterial atherosclerosis.28x28Rosen, MP, Greenfield, AJ, Walker, TG et al. Cigarette smoking: an independent risk factor for atherosclerosis in the hypogastric-cavernous arterial bed of men with arteriogenic impotence. J Urol. 1991; 145: 759–763
Until recently, erectile dysfunction (ED) was one of the most neglected complications of diabetes. In the past, physicians and patients were led to believe that declining sexual function was an inevitable consequence of advancing age or was brought on by emotional problems. This misconception, combined with men’s natural reluctance to discuss their sexual problems and physicians’ inexperience and unease with sexual issues, resulted in failure to directly address this problem with the majority of patients experiencing it.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (395) | Google ScholarSee all References Phosphodiesterase type 5 is primarily responsible for the breakdown of cGMP in cavernosal tissues. The inhibition of PDE-5 by sildenafil therefore causes continued activation of the NO-cGMP pathway in the cavernosal tissue, thereby improving erectile function.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
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.
The use of shock wave therapy has revolutionized the treatment of many aspects of medicine. High intensity extracorporeal shockwave therapy has been used for the treatment of nephro-urolithiasis while medium intensity shockwave therapy is used by orthopaedic surgeons to treat joint pain as well as tendinitis. Low intensity shockwaves therapy was first noted to improve ischaemia-induced myocardial dysfunction in animal studies when low intensity shockwaves were applied to porcine myocardium (13). Shockwaves induces a localized stress on cell membranes in the same way that shear stress affects endothelial cell membranes (14) and this triggers the release of angiogenic factors, such as increased NO production through increased activity of endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) (15). These shockwaves also cause membrane hyperpolarization (16), activation of the Ras signaling pathway, non-enzymatic synthesis of NO and induction of stress fibers and intercellular gaps (17).
Erectile dysfunction is very common as men age. Erectile dysfunction is frequently a sign of atherosclerosis, a clogging or narrowing of the blood vessels that causes heart attacks. Erectile dysfunction usually comes 3 to 5 years before a heart attack, so after ED is diagnosed, there is time to treat atherosclerosis and prevent a heart attack. Treating atherosclerosis involves diet, exercise, and medications, if necessary. Talk with your doctor about a broken sex life, and you might be able to prevent a broken heart.
The third Princeton Consensus (Expert Panel) Conference recommends assessing cardiovascular risk in all patients with ED and CVD. This refers to estimating the risk of mortality and morbidity associated with sexual activity. The current recommendations classify patients into low-, intermediate- and high-risk, based on their New York Heart Association class.57 The consensus also recommended that all patients with ED and CVD should undergo lifestyle changes, such as exercise, smoking cessation, healthy diet and weight reduction. These measures are likely to reduce cardiovascular risk and improve erectile function.58
Second-generation cardioselective beta-blockers (atenolol, metoprolol, bisoprolol, etc.) can also lead to ED. Atenolol was shown to cause significant reduction of sexual activity compared with placebo in a double-blind, parallel-arm study.22 The same study also showed a significant reduction in testosterone levels with atenolol versus valsartan. An open, prospective study of hypertensive men treated with atenolol, metoprolol and bisoprolol for at least 6 months showed high prevalence of ED – approaching 66 % – in these patients.23
It's an all too common problem: Roughly half of men with diabetes—and up to 25 percent of men overall—experience erectile dysfunction (ED) at some point in their lives. And it's a complicated problem, too, with diverse physical origins and complex emotional ramifications. Yet diabetes-related ED needn't be a no-sex sentence for men. There are ways to avoid this disorder and to treat it at any age. While much of the research on ED is still in its infancy, here is what science has to say so far.
Ginkgo is an herb that’s been used medicinally for thousands of years to treat a variety of ailments. This supplement may improve penile blood flow. Additionally, some reports suggest that ginkgo can increase bleeding risk. This makes it particularly dangerous for people using blood thinners. Other studies, including one from 2011, found no evidence of increased bleeding while using ginkgo.
Logically, ED secondary to testosterone deficiency should be treated by testosterone replacement. Testosterone levels in men decrease with age.4 Both epidemiological and observational studies have demonstrated that reduced testosterone is associated with increased cardiovascular risk. One meta-analysis showed lower testosterone and higher 17β oestradiol as significant risk predictors despite adjustment for age and body mass index.4 Patients with coronary artery disease (CAD) have been found to have lower testosterone levels than controls, and there is inverse correlation between testosterone and the incidence of major cardiovascular disease (CVD).4 A significant negative correlation has been reported between total testosterone levels and Framingham risk score.4 However, it has been pointed out that ‘It is unclear if this is a causal association or due to low testosterone being a biomarker of poor health’.4 Testosterone replacement as a treatment for …
Abstract | Full Text | Full Text PDF | PubMed | Scopus (30) | Google ScholarSee all References Erections result from relaxation of the corpora cavernosa, which is mediated either by increasing intracellular cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate or by inhibition of their degradation. Increased parasympathetic tone results in a decrease in norepinephrine release and an increase in the release of acetylcholine; subsequently, NO synthase activity increases, which releases NO from both endothelial cells and nonadrenergic, noncholinergic neurons.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
If you have several atherosclerotic risk factors or symptoms of heart disease, your doctor might do additional tests to look for atherosclerosis in the coronary arteries. A stress test involves monitoring the heart with an electrocardiogram or images before and after exercise. An angiogram, or cardiac catheterization, involves entering a blood vessel in the leg or wrist to pass instruments into the heart to directly visualize the coronary arteries. During this procedure, atherosclerosis can be treated by inflating a balloon or placing a metal stent in the coronary blood vessel to keep it open. If you and your doctor begin a treatment plan to prevent atherosclerosis at the first sign of ED, then you may significantly delay or prevent the need for these more invasive procedures.
Patients who use this therapy should be trained under the guidance of a urologist, and sterile technique must be used. The drugs must be injected into the shaft of the penis and into one of the penile erectile bodies (corpus cavernosum) 10–15 min before intercourse. Most patients do not complain of pain upon injection. Sexual stimulation is not required, and resulting erections may last for hours. Side effects include penile pain and priapism. The cost is about $12–20 per injection.
Due to their vasorelaxing effect, administration of PDE-5 inhibitors in hypertensive individuals was initially confronted with great suspicion. A wealth of clinical data however has proven that PDE-5 inhibitors are associated with few side effects and provoke a small and insignificant reduction in blood pressure with minimal heart rate alterations in both normotensive and hypertensive patients as well. As a matter of fact, they can be safely and effectively administered to hypertensive individuals even when they are already taking multiple antihypertensive agents[51-56]. The sole exception to the rule is co-administration with organic nitrates, which is an absolute contraindication due to profound and possibly hazardous hypotension effect[57,58]. Moreover, precaution should be taken when PDE-5 inhibitors are combined with a-blockers where, due to possible orthostatic hypotension effect, lower starting doses should be implemented in the therapeutic regime[59-62].
Penile vibratory stimulator is a battery operated device with oscillating discs that can provide excitation of afferent penile nerves at various regulated frequency and amplitudes. PVS has been utilised to activate the ejaculatory reflex for patients with spinal cord injury above T10 seeking to collect retrogradely ejaculated semen in fertility treatment (10). The Viberect is a vibratory stimulation handheld device approved by FDA for treatment of ED. It is clamp-shaped with two oscillating discs facing each other near the tips, and the glans penis is placed between the two oscillating discs to receive concurrent dorsal and ventral stimulation at adjustable frequencies and amplitudes.
The causes of ED are numerous but generally fall into two categories: organic or psychogenic. The organic causes can be subdivied into five categories: vascular, traumatic/postsurgical, neurological, endocrine-induced, and drug-induced. Examples of the psychogenic causes are depression, performance anxiety, and relationship problems. In people with diabetes, the main risk factors are neuropathy, vascular insufficiency, poor glycemic control, hypertension, low testosterone levels, and possibly a history of smoking.
While all three forms of male sexual dysfunction can be found among diabetic men, this review will focus on the most common form, ED, because the literature is most mature in this area. Defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance, ED is highly prevalent in diabetic men1 and is almost always organic in its etiology. Given that many patients feel that their ED is “in their heads” and that “their provider will dismiss any sexual problems they might bring up,”2 it may be a relief for patients to learn that their ED is physical, related to their diabetes, and treatable. To this end, the goal of this article is to review the epidemiology, pathophysiology, quality of life effect, and treatment of ED in men with type 2 diabetes.
Jelqing is penile massage technique of ancient Arabic origin (52). Men who practise jelqing will stretch their penises while in a semi-erected state and repeatedly milk their penises from base to glans, with their thumb and index finger touching to form an “OK” hand sign around their penile shaft. This massage can be done daily with the aim to achieve greater penile length and harder erections. Unwanted side effects of bruising, pain and fibrosis had been reported. No studies have been done to evaluate the efficacy of jelqing objectively.
In subsequent clinical studies, a surprisingly high percentage of EDDM patients–10% to 20%–claimed that the placebo "improved my erections," thus indicating a psychological basis for their ED. In the latter half of the 1980s, objective means were developed that could help determine if a EDDM patient had organic or psychogenic ED. The absence of rigid sleep erections confirmed by penile monitors was one criterion for organic ED. The failure of vasoactive agents (papaverine, Trimix, or prostaglandin E-1 [PGE-1]) injected into the corpora cavernosa to induce penile rigidity was another criterion for organic disease. Intracavernosal maintenance flow rates during pharmacocavernosometry and maximum cavernosal arterial flow during penile Doppler ultrasonography were additional determinants.
Other treatment options such as penile self-injection therapy, external vacuum pumps and the medicated urethral system for erection are on rare occasions an effective long-term treatment. A very small percentage of men will continue with these treatments as evidenced by a very high drop out rate and a very low refill rate for these treatments. These procedures require extensive planning which interfere with sexual spontaneity and are really not a realistic long-term treatment for young patients with permanent ED.
Eastern medicine should be fully exploited, and integrated with modern medicine to combine the advantages of both TCM and Western medicine. More research should be conducted into the efficacy and safety of TCM, and integration of TCM and Western medicine may provide promising breakthroughs in future clinical treatment. This strategy may allow for the development of new therapeutic strategies based on concepts of TCM and integrated medicine. There is a need for multimodal therapy and holistic approach to treat men (and their partners) with ED through complementary use of herbal supplements and modern drug to optimize underlying medical comorbidities; acupuncture, exercise or massage to reduce stress and strengthen the body; introduction and escalation of various medical therapy with use of mechanical therapy to further enhance penile erection; and lastly surgical intervention in suboptimal or refractory ED cases.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Sildenafil has a 4000-fold increased selectivity for PDE-5 over PDE-3, has negligible effects on heart rate, and has only a modest effect on blood pressure level in healthy persons, with an average systolic pressure decrease of 10 mm Hg with a single dose of 100 mg.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of hims, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.
Table 3Metabolic Equivalent (MET) Values for Various Physical Activities56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C
Vascular disease: Vascular diseases are those that affect the blood vessels. These diseases include atherosclerosis (hardening of the arteries), hypertension (high blood pressure), and high cholesterol. These diseases, which account for 70% of physical-related causes of ED, restrict blood flow to the heart, the brain, and--in the case of ED--to the penis. Atherosclerosis alone accounts for 50%-60% of ED cases in men over age 60.
Nonsustained erection with detumescence after penetration is most commonly caused by anxiety or the vascular steel syndrome. In the vascular steel syndrome, blood is diverted from the engorged corpora cavernosae to accommodate the oxygen requirements of the thrusting pelvis. Questions should be asked regarding the presence or absence of nocturnal or morning erections and the ability to masturbate. Complete loss of nocturnal erections and the ability to masturbate are signs of neurological or vascular disease. It is important to remember that sexual desire is not lost with ED—only the ability to act on those emotions.
Usually patients will try less invasive alternatives to treat impotence before opting for surgery. These alternatives may include supplements, herbs, lifestyle changes and even medications. In cases where other treatments do not work to resolve ED, surgery might be a last-resort option. Surgery involves implanting a penile prosthesis. This is a saline-filled silicone device or a malleable device. Although the likelihood of serious side effects is considered to be low, certain risks are associated with surgery to correct erectile dysfunction. These side effects may include: anesthetic risk, device infection, and device malfunction or mechanical failure. Some studies have found that five years following surgery around 10–20 percent of men experience device malfunction and failure. Infection rates are low. Around one percent of men who opt for this type of surgery get an infection.
Yohimbe. Before Viagra and the other prescription erectile dysfunction drugs became available, doctors sometimes prescribed a derivative of the herb yohimbe (yohimbine hydrochloride) to their patients suffering from ED. But experts say the medication is not particularly effective, and it can cause jitteriness and other problems. "It's not a great drug," says McCullough. "And I suspect the herb is not as potent as the pharmaceutical version." What's more, evidence shows that yohimbe is associated with high blood pressure, anxiety, headache, and other health problems. Experts discourage its use.
Men can judge themselves pretty harshly when it comes to their performance in between the sheets. The unsettling fear of not being able to rise to the occasion becomes a reccurring nightmare for men that is often equated with failure, loss of dignity, and masculinity. If you suffer from erectile dysfunction (ED), don’t be so hard on yourself, since impotence can almost always be improved with treatment, without having to rely on Viagra or other medications. Whether you suffer from ED, or hope to prevent the condition, here are six tips to overcome impotence without the side effects of the little blue pill.
Erectile dysfunction (ED) is common in cardiac patients and shares the same risk factors--smoking, hypertension, hyperlipidaemia and diabetes mellitus. Sexual activity is not unduly stressful to the heart and, providing patients are properly assessed using established guidelines, sexual intercourse can be enjoyed without increased risk. The treatment of ED in patients with cardiovascular disease has been transformed by the introduction of the oral phosphodiesterase type 5 inhibitors, the first of which was sildenafil. Success in restoring erectile function is possible in up to 80% of patients (depending on the aetiology) with minimal adverse effects. A synergistic hypotensive effect with nitrates, and almost certainly nicorandil, is the only major contraindication. ED in asymptomatic patients may be a marker of silent vascular disease or increased vascular risk factors and should alert the physician to the need for cardiac risk screening. ED is common in patients with cardiovascular disease and should be routinely enquired about. ED is a distressing condition for the man and his partner, and severely impairs quality of life. Patients with cardiovascular disease and patients with diabetes represent the largest group of patients with ED, the majority of whom benefit from the drug therapies currently available. Addressing ED in patients with cardiovascular disease can lead to a substantial improvement in quality of life and success is not difficult to achieve.
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