A deficiency of L-arginine, however, does not generally disrupt nitric oxide synthesis because L-arginine availability is not the rate-limiting step in this process. In fact, research over the past five years has identified an endogenous (occurs in the body naturally) inhibitor called “asymmetric dimethylarginine” or ADMA, an amino acid which blocks the production of nitric oxide. By acting as an L-arginine mimic, this damaging look-alike effectively elbows out L-arginine and pushes it off to the side in the biochemical pathway leading to the synthesis of nitric oxide. ADMA is relatively elevated in patients with hypertension, high levels of cholesterol, triglycerides, homocysteine and low-density lipoprotein (LDL), and low levels of high-density lipoprotein (HDL), as well as with aging itself. This inhibitor of nitric oxide synthesis may very well be the common factor shared by all of these abnormal conditions. Increased levels of this detrimental inhibitor (ADMA) block nitric oxide production, leading to endothelial dysfunction.
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.
Medicines known as PDE5 inhibitors can help two-thirds of men with ED. These include Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil). You may need to take several doses over time before they work properly, and you may need to adjust the dose. National guidelines say you can be prescribed these drugs from six months after a heart attack, providing your condition is stable.
Crossref | PubMed | Scopus (539) | Google ScholarSee all References Aside from the economic costs, ED can have severe psychological effects, resulting in poor self-image, decreased self-esteem, depression, and mental stress, and negative effects on personal relationships.2x2NIH Consensus Development Panel on Impotence. NIH Consensus Conference: impotence. JAMA. 1993; 270: 83–90
Cigarette smoking is an established risk factor in the development of atherosclerotic vascular changes and thus would be expected to play a role in the development of vasculogenic ED. The MMAS 9-year follow-up study found that the risk of developing moderate or complete ED in smokers was nearly doubled (odds ratio, 1.97) compared with that in matched nonsmokers.5x5Feldman, HA, Johannes, CB, Derby, CA et al. Erectile dysfunction and coronary risk factors: prospective results from the Massachusetts Male Aging Study. Prev Med. 2000; 30: 328–338
Conversely, and of significant clinical importance, is how often patients with ED as their first and sole clinical manifestation suffer from subclinical CAD.17 Previous studies reported a rate of inducible ischaemia by exercise stress testing (EST) in 22% (with a wide range of 5–56%) of ED patients reflecting differences in patient population, risk factors and criteria used for ED and CAD diagnosis. Interestingly, those patients further assessed with coronary angiography had obstructive atherosclerosis in >90% of cases.4,18 In a prospective angiographic study, we documented that 19% of ED patients suffer from clinically silent obstructive CAD.18
PubMed | Google ScholarSee all References However, other studies have noted that, when blood pressure levels are monitored after initiation of antihypertensive therapy, changes in blood pressure level are not correlated with sexual function.38x38Rosen, RC, Kostis, JB, Jekelis, A, and Taska, LS. Sexual sequelae of antihypertensive drugs: treatment effects on self-report and physiological measures in middle-aged male hypertensives. Arch Sex Behav. 1994; 23: 135–152
The research is based on a Swedish national database of health records that includes all hospitals in Sweden. Researchers analyzed the records of men age 80 years or younger who were hospitalized for a first heart attack between 2007 and 2013. Tracking the men for an average of 3.3 years following this first heart attack, they compared outcomes among those who subsequently filled a prescription for a PDE5 inhibitor or alprostadil to those who did not. Overall just over 7 percent of men were prescribed an erectile dysfunction drug, 92 percent of whom were prescribed a PDE5 inhibitor and 8 percent of whom were prescribed alprostadil.

But recently Brandon had some troubles keeping it up. At first, Kayla just thought it was her and that he needed some kind of a change to what they usually did, but later Brandon admitted that as of late, he just couldn’t seem to maintain an erection, and that it took way too much effort to go long. It wasn’t that he wasn’t aroused; his body just wasn’t keeping up.
Table 1 offers elements for distinction between organic and psychogenic disease.7 Of note is that in cases of organic origin, a psychogenic component may co-exist. The most common organic aetiology of ED is vasculogenic (see below ‘ED and CAD: common pathophysiology’).2,3 Co-existence of vascular disease, advancing age, and the presence of CVD risk factors and metabolic disorders increase the likelihood that ED is of vasculogenic aetiology.

Experimental hyperglycemia may also affect cavernosal smooth muscle cell contractile responses. In experimental diabetes, penile smooth muscle has augmented force responses to vaconstrictors, possibly mediated by changes in expression of protein kinase C and the RhoA-Rho kinase Ca2+-sensitization pathway.32 These changes may promote flaccidity and alter the relaxation responses to nitric oxide. End-stage penile dysfunction may occur as a result of diabetes, with progressive loss of normal cavernosal endothelium and smooth muscle cells from the corpus cavernosum.33 Replacement by fibrotic tissue may lead to complete erectile failure.34
Neelima V. Chu, MD, is an endocrinology fellow in the Division of Endocrinology and Metabolism at the University of California, San Diego. Steven V. Edelman, MD, is an associate professor of medicine in the Division of Endocrinology and Metabolism at the University of California, San Diego, and the Division of Endocrinology and Metabolism at the San Diego VA Health Care Systems in San Diego. He is founder and director of Taking Control of Your Diabetes, a nonprofit organization, and an associate editor of Clinical Diabetes.
Actually the first simple step to managing your blood pressure is to start tracking it! Get an inexpensive blood pressure cuff at CVS or on Amazon. Download the free Hello Heart app (iOS, Android) from the iTunes Store and Google Play.  Start recording your daily blood pressure. Just the simple act of daily recording can have a very beneficial effect.
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
Physical and emotional stress — whether over-exercising, under-sleeping or just dealing with everyday stressors like work and a busy schedule — causes an increase in “stress hormones,” including cortisol and adrenaline. Stress can lower desire for sex. This is because stress can contribute to fatigue or preoccupation with other tasks. It can also significantly affect blood flow by increasing inflammation.
The wide range of prevalence rates noted among the studies can be attributed to a number of factors. First, prevalence rates are affected by the sensitivity and specificity of methods used to assess ED.1 In addition, a number of these studies used medical record review to identify patients with ED, as opposed to anonymous patient reports. It has been shown in other disease states that patients tend to underreport ED when questioned directly by their providers.3 Therefore, the use of validated questionnaires that are either self-administered in an anonymous, neutral setting or administered by an objective third-party interviewer are preferred.
Dey J. “Evaluation and treatment of erectile dysfunction in men with diabetes mellitus.” Mayo Clinic Proceedings 77. 2002. 276-282. Shabsigh R. “Erectile Dysfunction in Men with Diabetes Mellitus.” Men’s Sexual Health Consult Collection. 2006 Nov. Moore C, Wang R. “Pathophysiology and treatment of diabetic erectile dysfunction.” Asian J Andrology. 2006 Nov. 8: 67-684. Penson D, Latini D, Lubeck D, Wallace K, Henning J, Lue T. “Do impotent men with diabetes have more severe erectile dysfunction and worse quality of life than general population of impotent patients?” Diabetes Care 26. 2003. 1093-1099. Sun P, Cameron A, Seftel A, Shabsigh R, Niederberger C, Guay A. “Erectile dysfunction – an observable marker of diabetes mellitus? A large national epidemiological study.” Journal of Urology 176. 2006. 1081-1085.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (164) | Google ScholarSee all References Several double-blind, placebo-controlled studies have shown vardenafil to be more effective than placebo in the treatment of ED secondary to a wide range of other etiologies as well.71x71Hellstrom, WJ, Gittelman, M, Karlin, G..., and Vardenafil Study Group. Sustained efficacy and tolerability of vardenafil, a highly potent selective phosphodiesterase type 5 inhibitor, in men with erectile dysfunction: results of a randomized, double-blind, 26-week placebo-controlled pivotal trial. Urology. 2003; 61: 8–14
Cigarette smoking is an established risk factor in the development of atherosclerotic vascular changes and thus would be expected to play a role in the development of vasculogenic ED. The MMAS 9-year follow-up study found that the risk of developing moderate or complete ED in smokers was nearly doubled (odds ratio, 1.97) compared with that in matched nonsmokers.5x5Feldman, HA, Johannes, CB, Derby, CA et al. Erectile dysfunction and coronary risk factors: prospective results from the Massachusetts Male Aging Study. Prev Med. 2000; 30: 328–338
The body’s source for nitric oxide production is the amino acid L-arginine, which is naturally found in many foods. The average American ingests about 3,000–5,000 mg of L-arginine per day, as it is an amino acid naturally contained in many foods. Meats of all varieties, nuts, and dairy products are rich in L-arginine, so the body is accustomed to intake levels of several thousand milligrams every day.
Abstract | PubMed | Scopus (136) | Google ScholarSee all References In a prospective review of 3250 men aged 26 to 83 years without ED at their first examination, total cholesterol and high-density lipoprotein (HDL) cholesterol levels were found to be strongly predictive of onset of ED after controlling for age, diabetes mellitus, stress level, cardiovascular disease, and prostate disease.25x25Wei, M, Macera, CA, Davis, DR, Hornung, CA, Nankin, HR, and Blair, SN. Total cholesterol and high density lipoprotein cholesterol as important predictors of erectile dysfunction. Am J Epidemiol. 1994; 140: 930–937
Physical and emotional stress — whether over-exercising, under-sleeping or just dealing with everyday stressors like work and a busy schedule — causes an increase in “stress hormones,” including cortisol and adrenaline. Stress can lower desire for sex. This is because stress can contribute to fatigue or preoccupation with other tasks. It can also significantly affect blood flow by increasing inflammation.
Despite its limitations in detecting CVD without significant stenosis, EST (with or without imaging) can further define the cardiovascular risk in patients with ED and no overt CAD and may be particularly helpful for identifying silent CAD in patients with diabetes. Chemical stress tests are appropriate for patients who cannot complete an EST or in whom ECG is non-interpretable. In patients with established CVD, an interpretable EST is mandatory in the indeterminate risk category and is at the discretion of the cardiologist in the low risk category (Table 3B), since it determines exercise ability and estimates cardiovascular risk associated with sexual activity.
Getting frequent exercise and maintaining a healthy weight are, of course, also important. Plus, avoiding or minimizing risky dietary factors such as salt, alcohol, caffeine, and too much animal products is crucial. Animal protein elevates insulin-like growth factor 1 (IGF-1) in the blood, a growth-promoting hormone that is associated with increased risk of several cancers and cardiovascular disease.19, 20

Crossref | PubMed | Scopus (53) | Google ScholarSee all References This study found that, although hypertensive patients had more coronary artery disease, no direct evidence supported an association between hypertension and arteriogenic impotence, as measured by the PBI, peak systolic velocity, and resistive index, in patients with mild to moderate hypertension.

A number of over-the-counter herbal supplements claim to treat ED. However, according to the Mayo Clinic, you should avoid products labeled as “herbal Viagra.” These supplements can increase blood flow and cause dangerous drops in blood pressure. Risk may be particularly high for men who are using nitrates. Herbal Viagra can also interact with other prescription drugs. Herbal Viagra products may contain potentially toxic compounds that aren’t listed on the label.
Sexual intercourse is an infrequent cause of myocardial infarction. In a study of 1774 patients after myocardial infarction, only 1.5% of these events occurred within 2 hours of sexual intercourse, and sexual activity was considered a direct contributing factor in 0.9%.8x8Muller, JE, Mittleman, A, Maclure, M, Sherwood, JB, Tofler, GH, and Determinants of Myocardial Infarction Onset Study Investigators. Triggering myocardial infarction by sexual activity: low absolute risk and prevention by regular physical exertion. JAMA. 1996; 275: 1405–1409
A significant proportion (ranging from ∼60 to 90%) of heart failure patients report ED and marked decrease in sexual interest, with ultimately one-quarter reporting cessation of sexual activity altogether.48 Erectile dysfunction contributes further to the poor quality of life and aggravates depression. Of interest, many heart failure patients place a greater importance on improving the quality of life (including sexual activity) than on improving survival. Sexual function correlates with the symptomatic status (i.e. NYHA functional class and 6-minute walk test).48 In the Evaluation of Role of Sexual Dysfunction in the Saarland (EROSS) Program, left ventricular dysfunction was a risk factor for ED independent of heart failure symptoms. While heart failure and ED share common pre-disposing risk factors, heart failure by itself can cause ED or affect engagement to sexual activity. Neurohumoral activation, medication (thiazides), limited exercise capacity, and depression are responsible.49
Crossref | Google ScholarSee all References A 1985 study found that ED accounted for 400,000 outpatient visits and 30,000 hospital admissions per year in the United States, with a direct total cost of $146 million.4x4Feldman, HA, Goldstein, I, Hatzichristou, DG, Krane, RJ, and McKinlay, JB. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol. 1994; 151: 54–61
At the same time, people with diabetes are susceptible to a type of blood vessel damage known as endothelial dysfunction. A recent study found that men with ED are at a greater risk of heart disease, which is also associated with endothelial dysfunction. If blood vessels aren't in good working order, the penis may not get enough blood for an erection.
No matter what erectile dysfunction treatment or treatments (whether herbal remedies or not) a man ultimately decides upon, experts say it's important to eat healthily and to avoid smoking and heavy drinking. Moreover, adequate exercise, stress reduction, and sleep can improve erectile dysfunction in many. In addition, says Lamm, "A loving, receptive, and responsive partner is a home run. After all, this is still a couple's issue."

Several other facts support the close relationship between sexual dysfunction and CV disease. Endothelial dysfunction mediated by decreased nitric-oxide bioavailability as well as atherosclerotic lesions constitute a common pathophysiologic substrate affecting both CV disease and erectile dysfunction, a disease considered to be primarily of vascular origin[76,80-82]. Several traditional CV risk factors (diabetes mellitus, hypertension, dyslipidemia, and smoking) are frequently found in individuals with erectile dysfunction, conferring a detrimental cardiovascular burden to them. More interestingly, the increased cardiovascular risk observed in those patients is independent of the aforementioned CV risk factors[81-88].

Hypertension can affect endothelial function in many ways. It can reduce endothelium-dependent vasodilatation by increasing the vasoconstrictor tone as a result of increased peripheral sympathetic activity.41–43 Another mechanism is hypertension-induced increase in cyclooxygenase activity that leads to an increase in reactive oxygen species; these in turn damage endothelial cells and disrupt their function.44–46 In some cases, endothelial NO synthase (eNOS) gene variations may relate to hypertension-associated endothelial dysfunction.6
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].
The use of penile support device such as penile cast worn externally during intercourse has been tried to provide length and rigidity to the penile shaft (24). Each device can be customised to the patient’s penile size and provided an option for patients who are seeking non-pharmaceutical/non-invasive treatment, or have end-organ failure who may not be candidates for, or unable to afford, penile prosthesis implant.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (272) | Google ScholarSee all References Between 1987 and 1989, the Massachusetts Male Aging Study (MMAS), a community-based random sample observational study of 1709 men, used self-administered sexual activity questionnaires to gather information about noninstitutionalized men aged 40 to 70 years in cities near Boston.4x4Feldman, HA, Goldstein, I, Hatzichristou, DG, Krane, RJ, and McKinlay, JB. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol. 1994; 151: 54–61
Abstract | Full Text | Full Text PDF | PubMed | Scopus (56) | Google ScholarSee all References Of 1774 patients with a history of myocardial infarction, only 2 who had experienced a myocardial infarction after sexual intercourse were able to exercise to at least 6 METs without symptoms.8x8Muller, JE, Mittleman, A, Maclure, M, Sherwood, JB, Tofler, GH, and Determinants of Myocardial Infarction Onset Study Investigators. Triggering myocardial infarction by sexual activity: low absolute risk and prevention by regular physical exertion. JAMA. 1996; 275: 1405–1409
Since 1998, when sildenafil (brand name Viagra) first came on the market, oral therapy has been successfully used to treat erectile dysfunction in many men with diabetes. (Sildenafil was followed in 2003 by the drugs tadalafil [Cialis], vardenafil [Levitra] and avanafil [Stendra], which work in much the same way.) Some 50% of men with Type 1 diabetes who try the drugs report improved erections, and some 60% men with Type 2 diabetes do, too. However, that leaves a large percentage of men with diabetes and erectile dysfunction who do not respond to therapy with one of these pills. This article takes a look at what can be done to treat those men who do not respond to oral therapy.
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