The larger the prostate, the more erectile dysfunction there is in men with the lower urinary tract (LUTS) problems that an enlarged prostate causes, according to a study.

The finding may help improve treatment of both LUTS and erectile-dysfunction issues, since they are connected, researchers said.

The study, “The Correlation Between Prostate Volume In Patients With Benign Prostatic Hyperplasia In Relation To Erectile Dysfunction,” was published in the journal Medical Archives.

“Erectile dysfunction is defined as the persistent inability to attain and maintain an erection sufficient to provide a satisfactory sexual intercourse,” researchers wrote. “Although considered ‘benign’ disease, [erectile dysfunction] can dramatically affect the quality of life of many men and their partners.”

Previous studies have shown that the incidence of both enlarged prostate, or benign prostatic hyperplasia (BPH), and erectile dysfunction increases with age.

To understand how prostate volume relates to erectile dysfunction, researchers looked at 150 BPH patients 40 to 60 years old. The men were divided into three groups:

• Fifty patients with prostate volume of 30 to 40 ml (group A).
• Fifty patients with a volume of 40 to 60 ml (group B).
• Fifty patients with prostate volume above 60 ml (group C).

Researchers measured erectile dysfunction with the Five-Question International Index of Erectile Function scale, or IIEF-5. The lower the IIEF-5 score, the worse the dysfunction. The scale’s maximum score is 25.

The mean IIEF-5 score was highest in group A (20.52 points), followed by group B (17.08 points), and group C (10.78 points). The results showed that the larger a man’s prostate, the more erectile dysfunction he had.

Importantly, researchers found 99 percent reliability in the correlation between prostate volume and IIEF-5 score. In other words, the larger the prostate volume, the lower the IIEF-5 score, and the more severe the erectile dysfunction. This was particularly evident in older patients.

“Patients with LUTS symptoms caused by benign prostatic hyperplasia should be evaluated [for] the presence of [erectile dysfunction] using the IIEF questionnaire, all the more, as some studies even prove that the severity of BPH [is a] better predictor of [erectile dysfunction],” the authors wrote.

“Understanding the causal link between LUTS/BPH, and thus the volume of the prostate with [erectile dysfunction] is very important, because the treatment of one illness can significantly affect the other and vice versa,” they added.