causes of erectile dysfunction

by Janet Casperson, BS, MSN, ANP-C

For the last twenty years, our sexual health clinical practice has focused on the diagnosis and treatment of erectile dysfunction (ED) using a number of methods. Prior to the development of the PDE-5 inhibitors (phosphodiesterase type 5 inhibitors) like Viagra®, erectile dysfunction was treated with penile implants, vacuum erection devices and intracavernosal penile injections. With the approval of Viagra®, our basic understanding of erectile dysfunction changed dramatically and we began to focus more on diagnosis in Viagra® failures.

Causes of Erectile Dysfunction

Because Viagra® doesn’t work for everyone, we began to look for reasons and to focus on the cause of the problem for men with erectile dysfunction. Studies repeatedly demonstrated a correlation between cardiovascular disease (CVD) and sexual dysfunction, specifically erectile dysfunction. These findings not only significantly changed the way we as clinicians view ED, but also changed the treatment of sexual dysfunction.

Risk Factors for ED

We always had some understanding of the risk factors for ED but the research showed that smoking, aging, diabetes, increased body weight, neurological diseases, side effects of medications, excessive alcohol use, psychiatric and psychological disorders and diabetes were all risk factors for erectile dysfunction. We are only beginning to understand the association between these risk factors and erectile dysfunction. Prior to these recent discoveries, the diagnosis of ED was made primarily from the patient’s self report. With this new understanding we can diagnose and treat ED more effectively.

Identifying the Cause of Erectile Dysfunction

With what we know now, it would be unacceptable to diagnose and treat ED without identifying and treating the cause. Nothing makes this point more emphatically than personal experience.

We have been treating a couple with erectile dysfunction for over fifteen years. Bob and Carol T. presented to the office for evaluation and management of mild erectile dysfunction in early 1990. Their sexual activity was an important part of their relationship and erectile dysfunction was affecting the quality of their life and relationship so dramatically that they were in counseling. We evaluated Bob with the diagnostic modalities available at the time. Bob had been a heavy smoker for many years but had cut back dramatically with his recent retirement; he was on medications for elevated cholesterol but had not altered his diet. He had a significant family history of early onset cardiovascular disease but this had never become clinically significant or been treated. He had a sedentary lifestyle and admitted that his diet was less than healthy and included a fair amount of fast food. His diet could be described as an atherogenic diet, a diet of foods that can accelerate the process of atherogenesis (the formation of lipid deposits in the arteries). His primary care physician had told him just to “watch his diet and that should take care of it”.

Bob’s erectile dysfunction was only mild. At that time, the risk and links of erectile dysfunction to cardiovascular disease were relatively unknown and drugs like Viagra®, known as PDE-5 inhibitors, were not available. Bob chose a technique called penile extracorporeal injections and was very pleased with the results.

If we knew in the early 1990’s what we know now, we would have treated him dramatically differently. As research emerged, we realized that Bob had the beginning of metabolic syndrome, a collection of metabolic risk factors which can lead to cardiovascular disease and diabetes. His body mass index (BMI) was 28. His waist was 40 inches (considered clinically significant obesity) and his cholesterol was elevated. Bob’s additional recognized risk factors included aging, his family history of early onset cardiovascular disease, a history of smoking, a sedentary lifestyle, an elevated fasting glucose (we consider values greater than 100 on a fasting glucose and greater than 126 at two hours after eating a meal to be elevated) and alcohol abuse.

These factors and a diagnosis of metabolic syndrome meant that Bob was, by definition, insulin-resistant. This would have a significant effect on his erectile function. This will be discussed extensively in another article.

Treatment for Erectile Dysfunction: Lifestyle Modification

We now routinely advise men to change their risk factors through aggressive lifestyle modification for the treatment of erectile dysfunction. Lifestyle modifications not only prevent further degradation of the erectile function but, if used aggressively, can prevent the development of erectile dysfunction later in life in a man who has normal erections. Dr. Steve Lamm, author of The Hardness Factor states, “the harder the erection, the healthier the man”.

What is ED?

Erectile dysfunction or ED has become widely known in America because of the extensive pharmaceutical marketing to consumers. In fact, medications to treat ED are the number one most advertised product in the history of the United States. We cannot watch a sporting event and not see at least one ad for one of the PDE-5 inhibitors like Viagra®. Unfortunately, this has left consumers with the impression that erectile dysfunction is an easily treated, isolated problem.

One of our patients stated “I have ED and I want treatment.” We said to him “What is ED?” He didn’t know. He merely said “I have it.” This is actually quite common because most men believe that ED is nothing more than “I can’t get an erection.” But we now feel that erectile dysfunction is representative of many more pathologies which we will detail in other articles in this center.

The letters ED are also shorthand for many facets of our discussion about erectile dysfunction.

Table 1

In the discussion of erectile dysfunction, we also talk about Early Diagnosis of cardiovascular disease, Endothelial Dysfunction leading to coronary artery disease (CAD) and erectile dysfunction, Exercise & Diet and Effective Drugs in the treatment of erectile dysfunction. The letters ED can also stand for Early Death if the underlying cause is left undiagnosed and untreated.

Talking to your Doctor about Erectile Dysfunction Can Save your Life

When a man mentions to his physician that he has a problem of erectile dysfunction, he may be saving his own life. A workup for ED may lead to the early diagnosis of cardiovascular disease (CVD). Over 2 million people have coronary disease and have no symptoms; one out of four men with no risk factors will die suddenly of a cardiovascular event. It is estimated that over 50% of men with known CVD who underwent vascular surgery had erectile dysfunction. We now view erectile dysfunction as a risk factor and an early marker for cardiovascular disease. In a study published in Circulation in 2005, Shlomo Stern, MD demonstrated that erectile dysfunction, along with fatigue, shortness of breath, feeling of rapid heartbeat and genetics all may be potential markers for silent CVD. This is earth-shattering.

Endothelial Dysfunction Leads to Erectile Dysfunction

Endothelial dysfunction is the basis of later erectile dysfunction. The endothelium is actually its own organ system and it’s one of the most metabolically active organs in the human body. The endothelium is the layer of cells that line the entire circulatory system, including the heart, the arteries and the blood vessels that control our blood pressure which in turn controls our cardiac and brain function. When the endothelium is damaged by diet, tobacco and certain lifestyles, its performance is affected. The very first symptom that we see may be erectile dysfunction.

Endothelial dysfunction affects the vascular smooth muscle cells which produce relaxation or contraction and therefore vasodilatation or vasoconstriction. In endothelial dysfunction, the arteries, heart and other endothelial-lined organs become hard and stiff. This leads to coronary artery disease (CAD) and erectile dysfunction, specifically the inability to maintain an erection adequate for sexual intercourse. The symptom of erectile dysfunction may precede coronary artery disease by as much as 48 months.

Treatment for ED: Exercise and Diet

Exercise and diet are one way to insure endothelial health and general overall health. Exercise and diet is also the most appropriate and best treatment for erectile dysfunction although unfortunately, it’s the least used treatment. Studies have demonstrated that losing weight and exercising can not only prevent erectile dysfunction but can actually reverse it.

We have never seen as many effective drugs for the treatment of men with mild to moderate erectile dysfunction as we have today. Many of the effective therapeutic options that we have today were not around even a decade ago. It’s safe to say that in five years many of us will be taking these medications for cardiovascular health rather than specifically as an on-demand treatment for the creation and maintenance of erections. Early death is what might happen if endothelial dysfunction and coronary artery disease are ignored.

One of the most difficult challenges faced by clinicians and patients is talking about sexual dysfunction. This subject is very personal and sensitive to most men. It is very difficult for a man to admit he may have a problem, because of the stigma that has been associated with erectile dysfunction. With the knowledge and treatment options that we have today, it is imperative that erectile dysfunction or other sexual dysfunction be discussed with your clinician. It may save your sex life and it may also literally save your life.

Our discussion of erectile dysfunction shouldn’t imply that it’s primarily a man’s problem. Sexual dysfunction is not the sole property of men. Sexual health is not gender specific. It’s been estimated that 30% to 50% of women experience their version of sexual dysfunction as well. Many of the risk factors for female sexual dysfunction are the exact same risk factors that we see for men including endothelial dysfunction, age, smoking and dietary considerations.

Perhaps the best way to look at sexual dysfunction in both men and women is that it is an early symptom of cardiovascular disease and it demands attention and a thorough clinical workup. Many practitioners and patients today are too focused on symptoms rather than the root cause of sexual dysfunction. By addressing the root causes of sexual dysfunction, we not only promote cardiovascular health but we can save lives as well.

References: See Bibliography

August 2006
Posted August 2008
Last updated August 2009