ED, stroke risk confirmed; ED, NAION risk refuted

August 15, 2006

Urologists attending this year's AUA annual meeting found that erectile dysfunction raises the risk of stroke and heart disease, testosterone is safe in older men, phosphodiesterase type-5 inhibitors do not appear to induce an ocular disorder known as nonarteritic anterior ischemic optic neuropathy (NAION), and aggressive antiseptic washout reduces penile prostheses infections.

John J. Mulcahy, MD, PhD, in private practice in Phoenix and a leading specialist in sexual disorders, selected and discussed the more significant studies in this field.

Erectile dysfunction is a major risk factor for stroke.

A second epidemiologic study from the University of Texas Health Science Center at San Antonio and the University of Washington School of Public Health, Seattle, looked at the 18,882 men in the Prostate Cancer Prevention trial to report that men with ED had a hazard ratio of 1.30 (95% CI=1.07-1.58; p=.008) for developing a coronary event such as angina, myocardial infarction, cerebrovascular event, transient ischemic attack, congestive heart failure, or cardiac arrhythmia. The elevated risks revealed by these studies are comparable to those raised by smoking or having a first-degree relative with coronary problems.

"This is not surprising. The basic pathophysiology of ED and heart disease is the same. It now may be wise to look at the penis for the first signs of vascular disease," Dr. Mulcahy said. "If a man in his 50s complains of erectile dysfunction, we should pursue a more extensive workup, for there are many things, such as cholesterol and high blood pressure, that can be treated and that will reduce the risk of stroke and coronary events."

Testosterone supplementation has no notable effect on prostate tissue in men over 50 years of age with androgen decline in the aging male (ADAM) syndrome.

Despite marked increases in serum testosterone and dihydrotestosterone, gene expression remained unchanged, cell proliferation was not accelerated, and histologic cancers were not increased. This finding may help dispel concerns that testosterone replacement therapy in this population may induce prostate cancer.

"This study shows that testosterone does not appear to have significant histologic effects on prostate tissue. This is important," Dr. Mulcahy emphasized. "I support the concept of supplementation to bring older men's testosterone levels up to those of their eugonadal peers.

"This and other studies I have researched show that there is no definitive correlation between testosterone supplementation and negative outcomes," he added.

"We have seen no significant coronary artery disease. We have seen no significant increase in cancers. We have seen no serious problems, and we have helped a lot of men by restoring their testosterone levels to normal."

There is no difference in the rate of return of erectile function between post-radical prostatectomy patients who take PDE-5 inhibitors daily and those who take them on demand.

An ongoing multicenter study from Italy is comparing erectile function outcomes in 233 consecutive patients who have undergone bilateral nerve-sparing radical retropubic prostatectomy and who have been assigned to a group taking PDE-5 inhibitors daily as prescribed or to a group taking the drugs on demand.

At the time of the AUA meeting, 12-month follow-up data were available on 80 men, and the researchers reported no difference in response rates.

Dr. Mulcahy lauded the researchers for their efforts and for the size of the study. However, specific erectile function recovery rates are difficult to pin down, he noted, because many studies place substantial reliance on subjective reporting, with no real clinical measurement of the quality of erections.