|
||| ERECTILE
DYSFUNCTION |
Since the introduction of Viagra® (sildenafil
citrate) in 1998, several other drugs for
the treatment of ED have been introduced;
it has become clear that ED is far more
prevalent than may have been suspected previously.
A study conducted in the Boston area from
1987 to 1989 found that 52 percent of men
between the ages of 40 and 70 suffered some
degree of ED (Feldman HA et al 1994). By
extrapolation, about 30 million men are
affected by ED in the United States (McKay
D 2004). And given men's ever increasing
life span, it has been further estimated
that the incidence of ED worldwide will
more than double in the next quarter century
(Goldstein I 2000).
Arginine is an amino acid the body uses
to produce nitric oxide, which relaxes smooth
muscle, thus allowing for increased blood
flow in many parts of the body. This action
may explain why ED is more common in men
with forms of vascular disease in which
disorders of nitric oxide play a role, such
as ischemic heart disease and stroke. For
example, 75 percent of men with ischemic
heart disease suffer from ED (Kloner RA
et al 2003).
Risk factors for ED include conditions such
as high blood pressure, abnormally high
blood lipids (i.e., elevated low-density
lipoprotein cholesterol and triglycerides),
obesity, diabetes, and smoking (McKay D
2004). Recently, some US scientists reported
that it may be necessary to add aging itself
to the list of risk factors that produce
vascular dysfunction of the kind associated
with ED. "The normal aging process
may induce significant global vascular dysfunction
(involving the endothelium and the vascular
smooth muscle)," wrote scientists published
in the International Journal of Cardiology.
This age-associated dysfunction was judged
to occur even in the absence of clinically
diagnosed atherosclerosis and was related
to alterations in the production of endothelial
nitric oxide (Al-Shaer MH et al 2006).
The link between ED and vascular disease
is so strong that physicians are advised
to consider men who present with ED but
no diagnosis of heart disease as undiagnosed
cardiovascular patients until proven otherwise
(Jackson G et al 2006). It is believed that
alterations in the availability of vascular
endothelial nitric oxide represent the common
thread linking these interrelated pathologies
(Sullivan ME et al 1999).
|
Más
información