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
Testosterone therapy in hypogonadism modulates metabolic components associated with CV risk. The majority of prospective clinical studies indicates that treatment achieving testosterone levels within physiological limits has beneficial or neutral effects on a lipid profile other than HDL-C, beneficial or neutral effects on inflammatory mediators, and generally beneficial effects on glycaemic state.25 The lean body mass is typically increased in hypogonadal subjects, and visceral adiposity is decreased in several studies and unchanged in the remainder. Such metabolic effects have raised interest on the potential impact on cardiovascular health. Regarding symptoms in patients with pre-existing cardiovascular conditions (angina or heart failure) TTh has been either neutral or beneficial.25 Regarding CVD risk, available clinical trial data indicate that the use of testosterone in middle-aged to elderly men does not increase cardiovascular risk25 with the exception of one study in very frail (substantial limitation of mobility and a high rate of comorbidities) elderly subjects that used an off-label high, and rapid escalation, dosing regimen.46 Prospective data from large, well-designed, long-term trials of TTh are warranted.

Smoking is an independent risk factor for ED. Tobacco smoking causes direct toxicity to endothelial cells, including decreased eNOS activity, increased adhesion expression and impaired regulation of thrombotic factors.6 A meta-analysis of 19 studies by Tengs and Osgood suggested that 40 % of the impotent men studied were current smokers compared with 28 % who had never smoked.49
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
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References However, if optimally treated with β-blockers, lipid-lowering agents, and aspirin, these patients have no significantly increased cardiovascular risk associated with sexual activity, although they should receive appropriate risk information.88x88Jackson, G. The use of sildenafil in heart disease [editorial]. Hosp Med. 2000; 61: 526–527
SOURCES: American Urological Association, "AUA Guideline on the Management of Erectile Dysfunction: Diagnosis and Treatment Recommendations." Barksdale, J. Pharmacotherapy, May 1999; vol 19: pp 573-581. Ferrario, C. Journal of Clinical Hypertension, November/December 2002; vol 4: pp 424-432. Fogari, R. American Journal of Hypertension, January 2001; vol. 14: pp 27-31. Grimm, R. Hypertension, January 1997; vol 29: pp 8-14. Llisteri, J. American Journal of the Medical Sciences, May 2001; vol. 321: pp 336-341. WebMD Medical Reference provided in collaboration with The Cleveland Clinic: "Hypertension: Treatment With ACE Inhibitors."
In another study from ExCEED, Penson et al.38 compared erectile function and disease-specific quality of life of men with ED and diabetes to those of men with ED without diabetes. They found that those with diabetes reported significantly worse erectile function (P = 0.004) and intercourse satisfaction (P = 0.04) than those without diabetes. Importantly, the diabetic patients also reported that ED had a significantly worse psychological impact on their overall emotional life than did their nondiabetic counterparts (P = 0.01). Interestingly, no differences were noted between the two groups in the psychological impact of ED on the sexual experience.
Most importantly, herbal supplements are not well regulated in the United States.  Studies have shown that 40-50% of herbal supplements do not even contain the supposed main ingredient, and many contain substances that are not listed which may have dangerous side effects2.  Another study found that over two thirds of the products tested had substituted other plant species for the plants listed on the label, and a third of products also contained other fillers or contaminants3.  A study by the New York State Attorney General of herbal products sold at GNC, Target, Walgreens, and Walmart found that four out of every five products didn’t contain the ingredient they claimed!  Fourteen US states and territories have petitioned Congress to regulate the herbal supplements industry.

Following the breakthrough in ED treatment using PDE5-inhibitors, Western medicine has now moved on to a new frontier of regenerative medicine, with stem cell and gene therapy leading the way (25). There is a practical need for novel therapy as a significant portion of diabetic or post-prostatectomy ED patients do not respond to oral pharmacotherapy. To date, stem cells derived from different sites including adipose tissue-derived stem cells, bone marrow mesenchymal stem cells and muscle-derived stem cells have been investigated using animal models for ED, to study their effects on neural, vascular, endothelial or smooth muscle regeneration (25,26).
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.

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
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.

Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References However, if optimally treated with β-blockers, lipid-lowering agents, and aspirin, these patients have no significantly increased cardiovascular risk associated with sexual activity, although they should receive appropriate risk information.88x88Jackson, G. The use of sildenafil in heart disease [editorial]. Hosp Med. 2000; 61: 526–527
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]
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (56) | Google ScholarSee all References Cardiologists use METs of oxygen consumption to compare the energy expenditure of different forms of activity.51x51DeBusk, R, Drory, Y, Goldstein, I et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol. 2000; 86: 62F–68F

Abstract | Full Text | Full Text PDF | PubMed | Scopus (46) | Google ScholarSee all References The Princeton Consensus Panel provided guidelines (Table 4) for physicians regarding patients who are being evaluated for their level of risk in resuming sexual activity.51x51DeBusk, R, Drory, Y, Goldstein, I et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol. 2000; 86: 62F–68F


Abstract | Full Text | Full Text PDF | PubMed | Scopus (37) | Google ScholarSee all References One MET is equal to a resting state, or 3.5 mL/kg per minute. The relative MET values of sexual activity compared with other forms of activity are shown in Table 3. In general, sexual activity is similar to mild or moderate activity for most patients either with or without coronary artery disease.51x51DeBusk, R, Drory, Y, Goldstein, I et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol. 2000; 86: 62F–68F
Luckily, awareness of ED as a significant and common complication of diabetes has increased in recent years, mainly because of increasing knowledge of male sexual function and the rapidly expanding armamentarium of novel treatments being developed for impotence. Studies of ED suggest that its prevalence in men with diabetes ranges from 35–75% versus 26% in general population. The onset of ED also occurs 10–15 years earlier in men with diabetes than it does in sex-matched counterparts without diabetes.
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
The discovery in 1992 of the second messenger of cavernosal smooth muscle relaxation was the critical step that led to the era of nonhormonal oral drug therapy for ED. In 1998, the multicenter trial of sildenafil in the treatment of ED was published in the New England Journal of Medicine, and the era of the phosphodiesterase type 5 (PDE-5) inhibitor began.1 For 5 years, sildenafil was the primary therapy for men with EDDM. Recently, 2 new PDE-5 inhibitors, vardenafil and tadalafil, were introduced.
After the initiation of TTh patients should be evaluated at 3 and 6 months, and annually thereafter to assess response to treatment and monitor adverse effects. Assessment should include physical examination with particular attention to the prostate. At these intervals testosterone levels should also be monitored, as well as PSA, haematocrit, and HDL.45
In a prospective human phase 1 open-label and single-arm study reported by Haahr et al. (27), 17 men with refractory post radical prostatectomy ED were given a single intracavernosal injection of autologous adipose-derived regenerative cells (ADRCs) freshly isolated after a liposuction. The procedures were well-tolerated and over a 6-month follow-up period, 8 of 17 men showed improvement of their erectile function.
PubMed | Google ScholarSee all References In a double-blind, placebo-controlled study, sildenafil was effective in patients with diabetes mellitus.58x58Rendell, MS, Rajfer, J, Wicker, PA, Smith, MD, and Sildenafil Diabetes Study Group. Sildenafil for treatment of erectile dysfunction in men with diabetes: a randomized controlled trial. JAMA. 1999; 281: 421–426
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.
×