BERKELEY, CA (UroToday.com) - Symptomatic hypoandrogenism, or low serum testosterone, is common among aging males. However, hypoandrogenism may also affect younger males desiring fertility. The rate of hypoandrogenism among young, subfertile men is highly variable and estimated to be between 3-45%. Currently, the American Urological Association (AUA) and American Society of Reproductive Medicine (ASRM) only recommend hormone screening in men desiring fertility with low sperm concentration, impaired sexual function, or clinical findings suggestive of endocrinopathy. Routine hormone screening in all men presenting for infertility evaluation is becoming more common among urologists and andrologists, but there is limited evidence to support this practice.
In this cross-sectional study of 94 men presenting to the University of Utah for male infertility evaluation, 39 men (41%) had a total serum testosterone level < 300 ng/dL, and 41 men (43%) had a bioavailable testosterone level < 155 ng/dL. Biochemical and symptomatic hypoandrogenism was common; 17 men (18%) had a total testosterone level < 300 ng/dL and > 3 positive Androgen Deficiency in the Aging Male (ADAM) responses, and 18 men (19%) had a bioavailable testosterone level < 155 ng/dL and > 3 positive ADAM responses. Azoospermia, oligozoospermia, and normospermia were not indicative of biochemical hypoandrogenism (total testosterone level < 300 ng/dL or bioavailable testosterone level < 155 ng/dL), symptomatic hypoandrogenism (> 3 positive ADAM responses), or sexual dysfunction (Sexual Health Inventory for Men (SHIM) score < 21).
Our study shows that a normal semen analysis alone cannot be used to rule out hypoandrogenism in subfertile men. In subfertile men with normal sperm concentration, 44% had a total testosterone level < 300 ng/dL, and 32% had a bioavailable testosterone level < 155 ng/dL. These men would not meet criteria for hormone screening per the AUA or ASRM guidelines. However, identification of these hypoandrogenic men and appropriate treatment to improve testosterone levels may potentially lead to improvements in the quality of their sperm and their chances of natural conception. Given the poor relationship between sperm concentration and serum testosterone levels in our study, routine serum testosterone and FSH screening in all men presenting for infertility may be helpful. However, it is uncertain whether appropriate identification and treatment of hypoandrogenism in normospermic, subfertile men improves fertility.
There are several limitations of this study. This was a retrospective cross-sectional study with a relatively small sample size. A single total testosterone measurement and calculated bioavailable testosterone rather than direct measurement are known limitations. There is a known 18%-28% intra-individual variability in 50% of patients with multiple serum testosterone measurements, which impacts analysis of our results. Calculated bioavailable testosterone is still helpful in assessing androgenic status compared with total testosterone alone.
Clinicians should have a higher suspicion of hypoandrogenism in normospermic men presenting for infertility evaluation. Low sperm concentration (azoospermia and oligozoospermia) was not associated with hypoandrogenism and serum testosterone levels in this study. This may suggest a greater role for routine hormone screening (at least serum testosterone and FSH) in men desiring fertility. It may be safer and more cost effective to identify subfertile men with associated hypoandrogenism who may potentially benefit from hormone modulators and forego the need for assisted reproduction for a successful pregnancy.
Darshan Patel, MD and James Hotaling, MD, MS as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Division of Urology, University of Utah, Salt Lake City, UT USA