For men with erectile dysfunction (ED), 65 percent are unable to have an orgasm and 58 percent have problems with ejaculation, according to new research led by physician-scientists at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

The study followed 12,130 men with mild to severe ED and is the largest-ever analysis of orgasmic and ejaculatory dysfunction. Results are published in today's edition of the British Journal of Urology International.

Approximately 30 million American men, or half of all men aged 40 to 70, have trouble achieving or sustaining an erection. "While medications like Viagra or Cialis have been successful in helping many of these men, our research suggests there are other common sexual issues that remain largely unaddressed," says Dr. Darius Paduch, the study's lead author; male sexual medicine specialist at NewYork-Presbyterian Hospital/Weill Cornell Medical Center; and assistant professor of urology and reproductive medicine at Weill Cornell Medical College.

"We must expand the definition of quality of life when it comes to sexual performance," Dr. Paduch adds. "For the last few decades, we have focused on penile rigidity, with erection as a synonym of normal sexual function. However, many patients say that problems with ejaculation -- like decreased force or volume or decreased sensation of orgasm -- are just as critical.

"Despite the frequency of these issues, non-erectile sexual dysfunction is underreported and undertreated due to social stigma and misunderstandings about the physiology of male sexual response and orgasmic dysfunction in particular. For decades it was believed that only women had problems with orgasm; our study shows that orgasmic dysfunction could be as prevalent among men as it is among women."

While severity of dysfunctional ejaculation and orgasm correlated with ED severity, says Dr. Paduch, these issues were still surprisingly common in men with very mild ED: Orgasm dysfunction was reported by 26 percent in this group, and ejaculation dysfunction by 18 percent. "This suggests that non-erectile sexual dysfunction is a regular occurrence even in men without ED."

The study reported factors associated with increased risk of ejaculatory and orgasmic dysfunction which includes commonly prescribed antidepressant medications. Ejaculatory and orgasmic dysfunction can be caused by low testosterone and minor brain injury such as that sustained by motor vehicle accident victims, football players suffering from concussion, or by soldiers with combat-related blast head injuries.

The most common ejaculatory dysfunction is premature ejaculation, but the condition also describes delayed ejaculation, inability to ejaculate, painful ejaculation, retrograde ejaculation, as well as a reduced volume of ejaculate or diminished force of ejaculation. Orgasm dysfunction is defined as absence of an orgasm.

In the current study, Dr. Paduch and Alexander Bolyakov, a research associate at Weill Cornell Medical College, in collaboration with a research team from Eli Lilly and Company, analyzed questionnaires from 28 clinical trials of men with mild to moderate erectile dysfunction from a diverse, international cohort of patients enrolled in clinical trials for tadalafil (Cialis).

The study was supported by an educational grant from Eli Lilly and Company. Dr. Paduch and Bolyakov are paid investigators and/or consultants/advisers/speakers for the study sponsor. Additional co-authors included Dr. Anthony Beardsworth and Steven D. Watts -- both from Eli Lilly.

Going forward, Dr. Paduch and Bolyakov will use uniquely specialized equipment available in their lab at Weill Cornell to measure biological and subjective changes that occur in men during orgasm and ejaculation. They will look at whether testosterone-replacement therapy can help men who suffer from non-erectile sexual dysfunction.

"Sexual satisfaction is known to be linked to the likelihood of orgasm, which in turn affects emotional intimacy and relationship satisfaction. The high prevalence of both orgasmic and ejaculatory dysfunction warrants further clinical and translational research into new treatments to improve sexual health and overall quality of life for hundreds of thousands of affected men and their loved ones," says Dr. Paduch.