Dr. Sadovsky: Normal erectile function is mainly a neurovascular event; there are neurologic impulses that help to cause vasodilation and there's an increase in vascular flow. However, this is occurring in a milieu of both a psychologic as well as a hormone environment—and that hormone environment involves the amount of testosterone that's circulating in the male patient.
So, if you find that you have a man whose complaint is truly erectile dysfunction and you’ve tried treating him with one of the medications that are used—most commonly PDE5 inhibitors that help to promote vasodilation and increase vascular flow—and that medication doesn’t give a satisfactory response, the first step would probably be to educate the patient about how to use the medication properly, how to have better sexual activity, and perhaps even change the PDE5 inhibitor. However, if all these don't work, then certainly looking at the hormonal environment by quantitating the testosterone may be very useful. The testing that's generally used to help to identify men with low testosterone [who] have erectile dysfunction would be doing a total testosterone; doing a free testosterone and/or a sex hormone-binding globulin level may be useful if the total testosterone is borderline.1 However, if a person falls in the ranges that have been established by The Endocrine Society, notably normal testosterone being 350 ng/dL or above, and a low testosterone being 250 ng/dL or below, then additional testing is not needed. I know many urologists do [measure] the testosterone [levels] when the patient with erectile dysfunction comes into their office for the first time; many primary care doctors are waiting and not testing testosterone [levels] unless the patient already has low libido or if they fail one of the classical treatments.
Narrator: Other typical signs and symptoms of hypogonadism, such as hot flushes, loss of body hair, sleep disturbances, or reduced muscle bulk or strength should also prompt clinicians to test patients’ testosterone levels.1
Dr. Sadovsky: Of course, various situations can cause transient elevations or declines in testosterone: Malnutrition, a viral infection, stress. So, we do recheck the total testosterone twice before we make a conclusion about the testosterone level. Other indications for testing the man with erectile dysfunction for testosterone would be some of the other classical signs or symptoms of low testosterone. Those would include fatigue, depression or mood swings, but also some of the more common medical problems—we're starting to see that [the] metabolic syndrome; increasing weight; cardiovascular risk factors, such as hypertension, dyslipidemia or increased abdominal girth, all seem to be associated with low testosterone.
If your patient with erectile dysfunction fails to improve in terms of his erections with classical treatment and has low testosterone, there are several studies that have been published in the Journal of Sexual Medicine that point out that these resistant-to-treatment ED patients may improve if you normalize their testosterone level.2-4 Some of our patients who are true treatment failures, who also have low testosterone, will clearly benefit from testosterone replacement.