Effects of androgen treatment in impotent men with normal and low levels of free testosterone

Abstract

The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimum serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens.

Effect of testosterone supplementation on sexual functioning in aging men: a 6-month randomized controlled trial

“…24,40 Owing to the relatively high age of the participants in our study, it is likely that there were more causes for erectile dysfunction than the low-normal testosterone concentrations alone, such as neurological causes, cardiovascular diseases (arterial insufficiency, venous leak) and depression. Testosterone replacement therapy alone will not correct these problems.…”

Normative hypogonadism and depression: does ‘andropause’ exist?

“…There was no demonstrable effect of testosterone on erectile function, and a clinically significant effect on desire in only 3 patients in the low-desire group. Carani et al 45 2), which measures the extent to which an individual seeks sexual stimuli. There was no effect on measures of sexual behavior, including intercourse frequency, erectile function, or masturbation and no apparent effect on mood.…”

The effect of topically applied vasoactive agents and testosterone versus testosterone in the treatment of erectile dysfunction in aged men with low sexual interest

“…The effects of androgens on libido and sexual behaviour is well established, 21 ± 23 but their effect on the erectile mechanism remains contraversal. 1,4,5,14 However, Aydin et al 20 reported that response to exogenous testosterone may be mediated by heightened libido, as well as the known antidepressant effect of androgens. These effects may contribute to the return of potency in patients with stational or psychogenic impotence and in patients with underlying endocrine abnormalities.…”

“…3 The causal relationship has not been established between hypogonadism and erectile dysfunction. 4,5 Also, the minimum level of testosterone needed to maintain the sexual function has not been established. 6 Although there is no ®rm evidence that testosterone supplementation results in enhancement of erectile function, 5 the National Institute of Health (NIH) consensus development panel on impotence proposed that for some patients with hypogonadism, androgen replacement therapy may sometimes be effective in improving erectile function.…”

“…4,5 Also, the minimum level of testosterone needed to maintain the sexual function has not been established. 6 Although there is no ®rm evidence that testosterone supplementation results in enhancement of erectile function, 5 the National Institute of Health (NIH) consensus development panel on impotence proposed that for some patients with hypogonadism, androgen replacement therapy may sometimes be effective in improving erectile function. 7 Penile erection is a complex psycho-neurovascular phenomenon and the cause of impotence can be multifactorial, a large number of impotent men after the age 40 y have been found to have a low normal or low androgen levels in addition to organic anda or psychogenic cause.…”