Smoking causes
erectile dysfunction by harming the health of blood
vessels, Finnish researchers report. Among ex-smokers,
erectile dysfunction could signal silent,
pre-symptomatic blood vessel (vascular) disease,
Rahman Shiri of the University of Tampere School of Public
Health and colleagues conclude.
Cigarette smoking
has been strongly linked with erectile dysfunction,
with smokers at a 50% greater risk than nonsmokers of having
difficulty achieving an erection, the investigators
note in a report in the journal Urology.
But the mechanism
by which smoking contributes to erectile dysfunction
isn't clear; it could impair penile blood flow, interfere
with the nitric oxide activity essential for erection,
or lead to atherosclerosis (hardening of the
arteries), which is known to be involved in erectile
dysfunction.
To investigate,
the researchers looked at 1,368 men in their 50s, 60s,
and 70s who completed three questionnaires every five years
from 1994 to 2004.
Men who were
smokers in 1994 and developed vascular disease later on were
three times more likely to report erectile dysfunction
during the course of the study than men who weren't
smokers at the study's outset, the researchers found.
But smokers who didn't develop vascular disease were
not at greater risk of erectile dysfunction.
Men who reported
erectile dysfunction in 1994 and were ex-smokers were
50% more likely to develop vascular disease than those who
had never smoked and didn't have erectile dysfunction
at the beginning of the study.
"Our findings
suggest that smoking may cause ED by causing vascular
disease," the researchers write. "ED may also be regarded as
a potential predictor of silent vascular disease in
smokers without clinical signs of vascular disease."
(Reuters)