Dr.Joe's Data Base

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Diabetes and Impotence

by

Arturo R. Rolla, MD
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Last updated 20Feb96: Added information on blood pressure medications
Updated information on treatments

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Impotence is a common complaint among men with diabetes. In order to
understand it, first we have to see what is involved in a normal
erection. I'll try to explain what it takes to have a normal erection.
Remember here the differences between impotence and lack of libido (sex
drive). In true impotence, the libido is normal but there is no
erection and therefore no performance. In decreased libido, there is
decreased interest in sex (so there are usually no erections), but the
person is not concerned about it.

The majority of erections appear when one is sexually aroused, but
erections are also common during sleep. For that reason, it is not
uncommon for a man to wake up with an "unprovoked" erection two or
three times a week. This is a good sign that helps us to know if the
pathways of an erection are functioning well or not.

To have an erection, several ingredients are required:

- A normal brain, the most important sexual organ
- Normal hormones
- Normal circulation to the pelvic and genital areas
- Normal nerve terminals

A "normal brain" means that, emotionally, one should feel very good
about himself. The most common causes of impotence are psychogenic
("psychogenic impotence") and are due to stress, too much work, not
enough sleep, and, particularly, depression. Less common are phobias
and long-term psychological trauma. In cases of psychogenic impotence,
the onset of impotence is usually sudden, and these persons have normal
erections when they first get up in the morning two-three times a week.

Normal hormones. You need to have normal function of the pituitary
gland and the testes to maintain a good level of circulating
testosterone (the "macho" hormone). An excessive amount of female
hormones may also have an effect similar to low testosterone. Male
hormones are necessary, but they are NOT a sine qua non for erections.
There are persons with low testosterone who are able to have erections,
although at a decreased frequency, because very often low testosterone
is associated with low libido. Treatment with testosterone injections
restores this function. On the other hand, to give testosterone
injections in any other form of impotence is not justified, and it's
even contraindicated because it may increase libido without increasing
performance.

Normal circulation. Erections are a "hydraulic" phenomenon that occurs
involuntarily. Nobody can will an erection! Blood supply to the area
increases by a factor of 15 - 20 because of dilatation of the arteries.
At the same time, the veins close, and this pools the blood in the
organ, increasing the pressure and causing the hardness. If there are
blockages (atherosclerosis of pelvic arteries), blood flow does not
increase, and therefore the hydraulic pressure inside of the penis does
not raise and there is less or no hardness.

Normal nerve terminals. If there is blockage of the "electrical"
connections between the brain and the penis because the "wires"
(nerves) are not normal, the orders to cause an erection do not reach
the area, and these hydraulic changes do not occur. The messages from
the brain do not arrive to the area. It may happen at times with
lesions in the spinal cord, such as in persons with multiple sclerosis,
or more commonly with abnormalities in the peripheral nerves
(neuropathy) like it's seen in diabetes.

Blood pressure medications. All the medications that lower blood
pressure tend to cause impotence because an erection is basically a
hydraulic phenomenon. The blood supply increases to the corpora
carvenosa, which dilate, and the veins close so that there is pooling of
blood with pressure. If you lower the blood pressure, there is less
pressure to send more blood into the penis. Of all the blood pressure
medications, ACE inhibitors are amongst the ones that cause less
impotence because they do not seem to decrease blood flow as much.

Finally, it's not uncommon that impotence is due to several factors
acting together (decreased circulation and abnormal nerves).

Remember that every person is different. You have to analyze with your
doctor the reasons for this problem. Do not be afraid to bring it up.
At times, doctors are afraid to talk about it, but then they feel much
better if you tell them about it.

The treatments vary according to the cause. If it is psychogenic, the
treatment is mostly psychiatric. In cases of permanent and organic
impotence, several modalities of treatment may be considered:

a) Vacuum pumps. They consist of a tube placed outside the penis that
creates a vacuum and increases the blood flow. Once the blood is pooled,
a rubber band is applied to the base of the organ to maintain the blood
and the erection. These devices are inexpensive and work for some, but
they tend to be anticlimactic because you have to stop and get the pump,
then pump, then get the rubber band, and so on.

b) Injections in the penis. There are two different products. The
newest, by Upjohn, is a prostaglandin. Using an insulin syringe, the
medication is applied, and this causes an erection for about 2 to 4
hours. Side effects are rare (plaques of scar-fibrosis if you use them
too much; prolonged, painful erections - this is called priapism).

c) Surgery. A rigid, plastic prosthesis is inserted inside of the penis,
permanently giving the organ enough rigidity to be used at any time. I
prefer the implants because they are simple and effective, and they are
usually covered by insurance. You forget you have the problem, and you
can use it any time you want without having to make any stops.