The
relationship between erectile dysfunction and cardiovascular disease has been a
long held (albeit unsubstantiated) suspicion amongst clinicians and researchers
for some time. However, few studies have been substantial enough to create a
serious debate. Now, a large-scale study confirms that there may be a
dose-response relationship between erectile dysfunction and cardiovascular
disease.
The study, which was published in
PlosOne Medicine, included a total of 95 038 men that were above 45 years old
and reported various degrees of erectile dysfunction (including none). The men
completed a postal questionnaire, which was then compared to their medical
records during the course of the last five years. During the analysis the data
was adjusted for many important factors such as age, smoking, alcohol
consumption, marital status, income, education, physical activity, body mass
index, diabetes, and hypertension and/or hypercholesterolaemia treatment. The
key findings indicated that in comparison with men with no erectile
dysfunction, men with severe erectile dysfunction had a significantly increased
risk of peripheral vascular disease, heart failure and ischemic heart disease.
The most valuable aspect of the study was that the severity of erectile
dysfunction was compared to various types of cardiovascular diseases. Based on
the findings, the researchers suggested that erectile dysfunction ought to be
considered as a risk marker for cardiovascular disease.
This study is the largest one of its
kind to date and is commendable on many levels including the design, the data
analysis and the interpretation of implications.
The design, which is rather clever,
circumvents the distress and embarrassment that discussing such a sensitive
topic brings with it, but still provides the researchers with large amounts of
useful data. On the other hand it can also be suggested that the design can
distort the data. Patient records may not always be complete and can rely on
clinical judgement, and in the case of an embarrassing illness it could be
argued that some individuals may not self-report erectile dysfunction either
face to face or via a questionnaire or clinicians may avoid asking embarrassing
questions. However, given the sample size, it is reasonable to assume that
these numbers would be too marginal to distort the results in any significant
manner.
The data analysis uses appropriate and
robust statistical models for the purposes of the study. It also includes a
careful consideration of severity and confounding factors, which is rare in
most studies. This last observation alone further strengthens our conviction in
the reported results.
The interpretation of implications is
the part that stands out the most. By suggesting that erectile dysfunction is a
risk marker for cardiovascular disease, the researchers also imply it is not to
be seen as a risk factor. This suggests that erectile dysfunction is unlikely
to lead to cardiovascular events. Instead, erectile dysfunction may reflect an
underlying problem that results in erectile dysfunction and cardiovascular
events. The full study can be seen here.