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.
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

Abstract | Full Text | Full Text PDF | PubMed | Scopus (328) | Google ScholarSee all References Their mean resting systolic and diastolic blood pressure levels decreased by 6% and 11%, respectively, compared with baseline. These patients also experienced a mild decrease in mean resting right atrial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, and cardiac output. However, the hemodynamic response to exercise was preserved. Phase 2 and 3 trials showed no difference in the rate of adverse events between sildenafil and placebo in patients being treated with antihypertensive medications. The effects of sildenafil on blood pressure level were similar in patients who were taking antihypertensive medications compared with those who were not. In healthy volunteers, no consistent or significant doserelated electrocardiographic (ECG) changes were noted at 1 and 2 hours after doses of sildenafil ranging from 1.25 to 200 mg.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
Crossref | PubMed | Scopus (24) | Google ScholarSee all References Almost every class of antihyper-tensive medication has been implicated in causing ED; however, most of these studies, published as case reports or patient surveys, have been relatively subjective and uncontrolled.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
Owing to its delicate nature, discussion about the sexual life of the patient is effective not on a circumstantial visit to the doctor, but on the basis of confidence between the patient and the physician, as is usually the case with the cardiologist. Thus, the cardiologist is given a unique opportunity to identify ED and thus ‘recharacterize’ the risk of the patient. In addition, since normal sexual activity is important to most men with CVD, irrespective of age, the cardiologist can clarify issues that relate to such activity after a cardiac event or to a specific cardiac condition (e.g. heart failure). Often, such issues are hampered by misconceptions from the side of the patient. Therefore, while less than half of the patients receive information about resuming sexual activity after a cardiac event, proper counselling increases their likelihood to resume their previous level of sexual activity by 50%.50 Furthermore, the cardiologist can increase adherence to the medication by clarifying that it is uncommonly the true cause of ED. Finally, proper counselling is required to ensure safety of concomitant PDE5 inhibitors medication, the use of which has the additional advantage to increase compliance to CVD mediation, especially in hypertension. It should be noted that while patients are often reluctant to bring up the issue of sexual health, they are relieved and respond positively when their cardiologist has done so. It should also be emphasized that, frequently, sexual counselling is more effective when done together with their partner.
Erectile dysfunction started to become a household term after scientists discovered a drug to treat it. Nowadays, as anyone who watches TV can attest, there are several different medications for ED. Fifty to 70 percent of men with type 1 or type 2 diabetes respond to a class of drugs—including sildenafil (Viagra), var­denafil hydrochloride (Levitra), and tadalafil (Cialis)—called phosphodiesterase-5 inhibitors.
Joel Fuhrman, M.D. is a board-certified family physician, six-time New York Times bestselling author and internationally recognized expert on nutrition and natural healing, who specializes in preventing and reversing disease through nutritional methods. Dr. Fuhrman coined the term “Nutritarian” to describe his longevity-promoting, nutrient dense, plant-rich eating style.
Crossref | PubMed | Scopus (443) | Google ScholarSee all References Nitroglycerin and other NO donors work through the same NO-cGMP pathway that sildenafil affects, thereby decreasing vascular resistance and blood pressure level.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
PubMed | Google ScholarSee all References Postulated mechanisms of effect on sexual function with these centrally acting medications have included increased prolactin levels and a direct effect on α2-adrenergic receptors in the central nervous system.36x36Wein, AJ and Van Arsdalen, KN. Drug-induced male sexual dysfunction. Urol Clin North Am. 1988; 15: 23–31
Many products contain undocumented “fillers” that can cause allergic reactions.  In recent years, the FDA has found over 300 herbal products that contain hidden, deceptively labeled, or dangerous ingredients4. And since 2015, the FDA has released public warnings on more than 160 ED supplements and “male enhancement” products found to contain dangerous ingredients and contaminants5 .   An independent study of FDA data, conducted in 2018, found almost 800 herbal supplements that contained unlisted ingredients6.
Three FDA-approved oral medications, sildenafil, tadalafil, and vardenafil are available. These drugs are phosphodiesterase type 5 (PDE-5) inhibitors that can prolong levels of cGMP in tissue allowing improved smooth muscle relaxation, thus facilitating an erection. PDE-5 inhibitor drugs are effective in 56-63% of diabetic men with ED. More stringent glycemic control can improve these results. Men with testosterone deficiency may benefit from a combination of oral ED medication and testosterone supplementation.
A recent systematic review and meta-analysis of relevant studies in this field confirmed that erectile dysfunction is associated with increased risk of CV events and all-cause mortality[89]. The pooled relative risks were 1.44 (95%CI: 1.27-1.63) for total CV events, 1.19 (95%CI: 0.97-1.46) for CV mortality, 1.62 (95%CI: 1.34-1.96) for myocardial infarction, 1.39 (95%CI: 1.23-1.57) for cerebrovascular events, and 1.25 (95%CI: 1.12-1.39) for all-cause mortality, for men with vs without erectile dysfunction. Of note, the relative risk was higher in intermediate-compared with high- or low-CV-risk populations and with younger age, with obvious clinical implications. Interestingly, the relative risks were higher when erectile dysfunction was diagnosed with the use of a questionnaire compared with a single question (RR = 1.61; 95%CI: 1.38-1.86 vs RR = 1.27; 95%CI: 1.18-1.37, respectively; P = 0.006).
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.
David F. Penson, MD, MPH, is an associate professor of urology and preventive medicine in the Keck School of Medicine at the University of Southern California, in Los Angeles. Hunter Wessells, MD, is an associate professor of urology at the University of Washington School of Medicine and chief of urology at Harborview Medical Center in Seattle, Wash.
Montorsi F,  Briganti A,  Salonia A,  Rigatti P,  Margonato A,  Macchi A,  Galli S,  Ravagnani PM,  Montorsi P. Erectile dysfunction prevalence, time of onset and association with risk factors in 300 consecutive patients with acute chest pain and angiographically documented coronary artery disease, Eur Urol , 2003, vol. 44 (pg. 360-364)https://doi.org/10.1016/S0302-2838(03)00305-1
The medications used to treat high blood pressure do not take into account the symptoms of erectile dysfunction, as their intention is to lower the blood pressure to a more manageable state, reducing the stress put on blood vessels. High blood pressure and ED are seen as separate entities, with the former taking priority for pharmaceutical treatment. This means that the medications used might do nothing to cure erectile dysfunction and may, in fact, prolong it. Medications that lower blood pressure might actually cause a low blood pressure state in the groin area and the arteries supplying the penis, making it near impossible to achieve an erection. The following are examples of such medications:
A disruption anywhere along the complex chain of events will impair the capacity to have an erection. Any man who has experienced the frustration of male impotence knows that the consequences extend beyond physical dissatisfaction to anxiety, tension, and embarrassment. A common reason for failure of the erectile apparatus is disruption of the path leading to nitric oxide production and blood flow control.

88. Böhm M, Baumhäkel M, Teo K, Sleight P, Probstfield J, Gao P, Mann JF, Diaz R, Dagenais GR, Jennings GL, et al. Erectile dysfunction predicts cardiovascular events in high-risk patients receiving telmisartan, ramipril, or both: The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial/Telmisartan Randomized AssessmeNt Study in ACE iNtolerant subjects with cardiovascular Disease (ONTARGET/TRANSCEND) Trials. Circulation. 2010;121:1439–1446. [PubMed]


Mancia G,  Laurent S,  Agabiti-Rosei E,  Ambrosioni E,  Burnier M,  Caulfield MJ,  Cifkova R,  Clément D,  Coca A,  Dominiczak A,  Erdine S,  Fagard R,  Farsang C,  Grassi G,  Haller H,  Heagerty A,  Kjeldsen SE,  Kiowski W,  Mallion JM,  Manolis A,  Narkiewicz K,  Nilsson P,  Olsen MH,  Rahn KH,  Redon J,  Rodicio J,  Ruilope L,  Schmieder RE,  Struijker-Boudier HA,  van Zwieten PA,  Viigimaa M,  Zanchetti A. European Society of HypertensionReappraisal of European guidelines on hypertension management: a European Society of Hypertension Task Force document, J Hypertens , 2009, vol. 27 (pg. 2121-2158)https://doi.org/10.1097/HJH.0b013e328333146d
More than 11 million people in the United States have cardiovascular disease, and each year, about 500,000 survive a myocardial infarction. These patients often seek counseling on their relative risk of resuming sexual activity. In the past, it was often assumed that if a patient could climb 2 flights of stairs without symptoms, it was safe for the patient to engage in sexual activity.82x82Hellerstein, HK and Friedman, EH. Sexual activity and the postcoronary patient. Arch Intern Med. 1970; 125: 987–999
Abstract | Full Text | Full Text PDF | PubMed | Scopus (53) | Google ScholarSee all References Coital position has not been shown to play a role in increased cardiovascular risk; similar peak heart rates and blood pressure levels are evident with either the man or the woman in the superior position during intercourse.90x90Nemec, ED, Mansfield, L, and Kennedy, JW. Heart rate and blood pressure responses during sexual activity in normal males. Am Heart J. 1976; 92: 274–277
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

Most studies into the effect of beta-blockers on ED point to negative effects of first- and second-generation beta-blockers, while beta-blockers with vasodilating effects can improve erectile function. Alpha-blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors seem to have a neutral effect on erectile function. Multiple previous studies have demonstrated a beneficial effect of angiotensin receptor blockers on erectile function and they should probably be the favoured antihypertensive agents in patients with ED.29


Not enough info for you? No problem. Nerd out on erectile dysfunction with these studies and research from the most trusted sources on the interwebs. If you have any questions or you think we missed something important, leave a comment or book a consultation with me or one of these trained professionals and we’ll get you on the way to a healthier manhood.

Erectile dysfunction is defined as the inability to attain or maintain a penile erection sufficient for satisfactory sexual performance. Cases of ED may be classified as predominantly organic in nature, predominantly psychogenic, or mixed. Usual organic aetiologies are vasculogenic, hormonal, and neurogenic. Owing to the relationship of vasculogenic ED with CVD, it is important to distinguish men with predominantly vasculogenic ED from those with predominantly psychogenic ED or non-vasculogenic organic ED.
Relation between erectile dysfunction prevalence and type of coronary syndrome (A). Time interval (months) between erectile dysfunction and coronary artery disease symptom onset in chronic coronary syndrome according to the number of vessels involved (B). ACS, acute coronary syndrome; CCS, chronic coronary syndrome, G1: ACS and 1-VD; G2: ACS and 2-,3-VD; G3: CCS. VD, vessel disease; C: the control group with normal coronary angiography. With permission from Montorsi et al.15
Andersson said the results came as a surprise because erectile dysfunction is associated with an increased risk of heart disease in otherwise healthy men. However, previous studies have associated the use of PDE5 inhibitors with a decreased blood pressure in the left ventricle, which reduces the amount of work required to pump blood and therefore could help explain why the drugs might benefit people with heart failure. PDE5 inhibitors were initially developed to treat angina, a type of chest pain that results from constricted arteries.
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.
Finally, prevalence rates will be affected by whether the study population is accrued from a single hospital/clinic setting or from a more general population of men with diabetes. For example, Siu et al.4 studied 500 Chinese diabetic men (of which 97% had type 2 disease) seen at a single medical clinic in Hong Kong during 1999 and found the overall prevalence of ED to be 63.6%. Contrast this to Fedele et al.,5 who studied 9,756 diabetic men accrued from 178 diabetes centers in Italy. Among the 8,373 men with type 2 diabetes, only 37% reported ED, considerably less than in the Chinese study.
Sexual dysfunction has been evaluated in ancient literature of TCM in terms of subjective sensation and the actual sexual performance (3). In TCM, methods and matters related to direct sexual activity is described in terms of “ten motions”, “seven impairments” and “eight benefits”, which asserted that the ideal intensity and frequency of sexual activity should be moderate. TCM is all about balance, to achieve better overall regulation of the yin and the yang. The aim of treatment of ED using TCM is not for the end point of a penile erection but rather for a natural and harmonious sex life. TCM aims to achieve regulation in terms of the man’s anxiety, fatigability, changing hormonal levels, insomnia and gastroparesis. Medicine to invigorate qi can enhance physical fitness, and medicine to warm the kidneys can regulate sex hormones, increase libido, invigorate the spleen, regulate the stomach and improve general well-being (3). Medications used to treat a “stagnated liver” provide tranquilization and helps to stabilize the mind, hence improving mental processes and emotional wellness. As a result, the patient’s overall condition and quality of life is improved.

Oral medicines: The best known ED medications are the Big Three: Viagra (sildenafil citrate, made by Pfizer, Inc.), Levitra (vardenafil HCl, made by Bayer and GlaxoSmithKline), and Cialis (tadalafil, made by Eli Lilly). The three are chemically very similar, and all have proven very effective. Because they are effective, convenient, and relatively inexpensive (about nine dollars per pill), these medicines have become the treatment of choice for most men experiencing ED.
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