inflammation and immune activation and the development
of venous dysfunction (Guzik et al., 2011), with
endothelial dysfunction being thought to be the main
aetiological factor contributing to ED. Endothelial
dysfunction, which is associated with impaired vasodilatation,
precedes the development of atherosclerotic lesions
through the impaired release of NO, which is modulated
by parasympathetic non-adrenergic, non-cholinergic
nerves and by vascular endothelial cells (Vlachopoulos
et al., 2005). In addition, oxidative stress and free radical
damage interferes with the NO pathway and is directly
toxic to the endothelium (Maas et al., 2002; Chung et al.,
2011). Taken together, haemorrhoids might substantially
impair the neuronal and vascular function necessary for
erection, and thus lead to ED.
We believe the results of the present study support the
conclusions of previous clinical and basic studies, and
provide for a conceptual relationship between ED and
haemorrhoids, but realize that future investigation will be
required to elucidate this association and its underlying
mechanisms further.
This study suffers from a few limitations that should be
addressed. The first limitation of this study is the use of
ICD coding to diagnose ED. Discussing sexuality is relatively
culturally taboo in Taiwan. This might contribute
to the seemingly low frequency of ED when compared
with studies from Western countries. In recent clinical