Penile erection is largely a vascular process, and the penile endothelium and smooth muscle tissue are very sensitive to functional and structural changes. Vasculogenic ED results from an impairment of endothelial dependent or independent smooth muscle relaxation (functional vascular ED, initial stages), occlusion of the cavernosal arteries by atherosclerosis (structural vascular ED, late stages), or a combination of these.3 Current data support a complex interplay between endothelial dysfunction, subclinical inflammation, and androgen deficiency (Figure 1). The relationship between ED and CAD at the clinical level is supported by this common pathophysiological basis. The ‘artery size’ hypothesis explains why patients with CAD frequently report ED before CAD detection.10 According to this hypothesis, for a given atherosclerotic burden, the smaller penile arteries suffer obstruction earlier than the larger coronary arteries (Figure 2). The same concept holds also true in the case of non-obstructing atherosclerosis: since the smaller penile artery have a greater endothelial surface and erection requires a large degree of vasodilation to occur when compared with arteries in other organs, the same degree of endothelial dysfunction will be symptomatic in these smaller vessels but subclinical in the larger ones (i.e. coronaries). In the same context, accelerated arterial ageing (as indicated by increased arterial stiffening that also affects large arteries of ED patients) may be a common background.11,12 Erectile dysfunction is associated with an incremental inflammatory and endothelial-pro-thrombotic activation.13 Interestingly, this activation is equal to that found in CAD patients with no ED, while when these two conditions are combined the burden is additive. Androgen deficiency may be also implicated in the common pathogenetic pathways of ED and CVD; however, this warrants further substantiation.2
Yohimbine is an indole alkaloid derived from the bark of the African yohimbe tree (33). Yohimbine has been noted to treat fatigue, depression, diabetes, and sexual dysfunction. A meta-analysis of seven placebo-controlled trials (34) deemed yohimbine superior to placebo for the treatment of ED with rare adverse events. The proposed mechanism of action (35) is via the inhibition of central alpha-2-adrenergic receptors, decreasing central inhibition of arousal, and increasing penile nerve stimulation resulting in increased NO. Common side effects include headache, sweating, agitation, hypertension and insomnia. Contraindications include patients on tricyclic antidepressants, anti-hypertensives and central nervous system stimulants.
Previous studies reported that there is a strong chance of future cardiac events when ED occurs in younger men compared with older men.11 Another study suggested that there is consistent association across age groups.12 A study of men with diabetes found that ED acts as an indicator of cardiovascular events after adjusting for other illnesses, psychological aspects and the usual cardiovascular risk factors.13 Another large-scale study comprising 25,650 men with pre-existing ED suggested that these men had a 75 % increased risk of peripheral vascular disease.14 Moreover, some studies demonstrated a relationship between ED score and number of diseased coronary arteries and plaque burden in coronary arteries.2,15
Few simple laboratory tests can help identify obvious causes of organic ED. Initial labs should include HbA1c, free testosterone, thyroid function tests, and prolactin levels. However, patients who do not respond to pharmacological therapy or who may be candidates for surgical treatment may require more in-depth testing, including nocturnal penile tumescence testing, duplex Doppler imaging, somatosensory evoked potentials, or pudendal artery angiography.
Sexual dysfunction is a common, underappreciated complication of diabetes. Male sexual dysfunction among diabetic patients can include disorders of libido, ejaculatory problems, and erectile dysfunction (ED). All three forms of male dysfunction can cause significant bother for diabetic patients and can affect their quality of life. Despite this, health care providers often do not specifically ask their male diabetic patients about sexual function. This results in considerable underdiagnosis because patients are often reluctant or embarrassed to initiate discussion of these issues themselves. By not recognizing sexual dysfunction as a common organic sequel-lae of diabetes that should be addressed and treated, providers are missing an important opportunity to improve their patients' daily existence and quality of life.
Another risk factor is that men with type 2 diabetes may produce less than normal amounts of testosterone, a condition called hypogonadism. A 2007 study found that one-third of men with type 2 diabetes had low testosterone levels. Those men were also more likely to have ED, though the link may have to do with weight, not diabetes per se. Being overweight or obese is a risk factor for hypogonadism.
Talk with your doctor about your sexual health. Do not be shy or embarrassed. Your doctor has probably dealt with this issue before. If your doctor is an older man, he might even have ED. First, your doctor will figure out what is causing your ED, which can usually be done just by talking with you. Next, your doctor will look for risk factors for atherosclerosis (the Table) by asking you questions, checking your blood pressure, and performing a few blood tests. Identifying and successfully treating atherosclerotic risk factors can reduce the chance of developing major vascular events (heart attacks and strokes).
In men without cardiovascular disease, erectile dysfunction (ED) pills are very safe. The three rivals -- Viagra, Cialis, and Levitra -- have similar side effects, including headache, facial flushing, nasal congestion, diarrhea, backache, and, in a few Viagra or Levitra users, temporary impaired color vision (men with retinitis pigmentosa, a rare eye disease, should check with their ophthalmologists before using these medications).

Impotence, or erectile dysfunction (ED), is the inability for a man to sustain an erection long enough for normal, satisfying sexual intercourse.  To understand the underlying causes of impotence, it helps to know the basics about how an erection develops, along with potential problems that get in the way. Erections begin in the brain with a thought related to sexual desire. Then a chemical message travels from the brain to the penis. Blood flow to the penis increases as blood vessels leading to the reproductive system relax and allow for increased circulation.


Erectile dysfunction (ED) is defined as the inability to achieve or maintain an erection for satisfactory sexual performance. The prevalence of ED has been estimated as nearly 40% of men >40 years of age1 although these figures are contested.2 ED increases in frequency with age and is estimated to affect 15% of men aged 40–50 years, 45% of men in their 60s and 70% of men older than 70 years.3 Successful erection is a complex system involving reflex action (peripheral nerves and spinal cord), the limbic system (psychogenic stimuli) and the release of nitric oxide. Adequate levels of testosterone are required, and hence an intact hypothalamic/pituitary/testicular axis. Hence, ED can result from disease or treatment that produces hormonal deficiency, neurological impairment, problems with penile blood flow, disorders of tissue mechanics, psychological factors or any combination of these.
What comes after an ED diagnosis in diabetic patients? Often, Dr. Eid will instantly refer these men to a cardiologist. “If a patient has diabetes and is newly diagnosed, a significant portion of these men are going to develop coronary artery disease in the next 2-3 years,” he said. “One of the things we do is recommend is that they see a cardiologist and perhaps have a stress test or some sort of evaluation.”

Sexual dysfunction is a common, underappreciated complication of diabetes. Male sexual dysfunction among diabetic patients can include disorders of libido, ejaculatory problems, and erectile dysfunction (ED). All three forms of male dysfunction can cause significant bother for diabetic patients and can affect their quality of life. Despite this, health care providers often do not specifically ask their male diabetic patients about sexual function. This results in considerable underdiagnosis because patients are often reluctant or embarrassed to initiate discussion of these issues themselves. By not recognizing sexual dysfunction as a common organic sequel-lae of diabetes that should be addressed and treated, providers are missing an important opportunity to improve their patients' daily existence and quality of life.
Third, men with Diabetes need to control their blood sugar levels. When your blood sugar is not under control, your body does not produce enough Nitric Oxide (NO) and vascular tissues don’t respond as effectively to NO. When enough blood flows into the penis, penile veins close off and block the blood from flowing out. This process results in an erection. If your body does not produce enough NO or if your penile tissues do not respond to NO, the pressure of the blood flowing into your penis is not sufficient to trap the blood, you penis will not get hard.
Basaria S,  Coviello AD,  Travison TG,  Storer TW,  Farwell WR,  Jette AM,  Eder R,  Tennstedt S,  Ulloor J,  Zhang A,  Choong K,  Lakshman KM,  Mazer NA,  Miciek R,  Krasnoff J,  Elmi A,  Knapp PE,  Brooks B,  Appleman E,  Aggarwal S,  Bhasin G,  Hede-Brierley L,  Bhatia A,  Collins L,  LeBrasseur N,  Fiore LD,  Bhasin S. Adverse events associated with testosterone administration, N Engl J Med , 2010, vol. 36 (pg. 109-122)https://doi.org/10.1056/NEJMoa1000485
Surgery for erectile dysfunction is usually considered only after all other options have failed. The two surgical options include the insertion of a semi-rigid rod or the implantation of a three-piece inflatable prosthesis. Penile prosthesis implantation has low infection, complication, and malfunction rates. However, since placement of an implant requires permanent injury to the erectile tissue of the penis, implant treatment is considered irreversible.
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