An assessment of the clinical relevance of serum testosterone level determination in the evaluation of men with low sexual drive

Purpose: We evaluated the relationship between sexual drive and serum testosterone level among men with erectile dysfunction. Materials and Methods: A retrospective medical record review of 180 men who attended a hospital based erectile dysfunction clinic between April 1997 and January 1998 was performed. Sexual drive was assessed using the Brief Sexual Function Inventory questionnaire, and serum total and free testosterone levels were measured. Results: A total of 108 complete records were included in this report. Mean patient age plus or minus standard deviation was 59.5 +/- 10.2 years (range 33 to 79). Of the men 55 (50.9%) had law, 38 (35.2%) moderate and 15 (13.9%) high sexual drive. Mean sexual drive, bothersomeness and total sexual function scores among the groups were significantly different (p <0.001). Mean serum total testosterone levels among men with low, moderate and high sexual drive were 2.8, 3.2 and 3.4 mg./ml. (normal 2.8 to 8.8), respectively, and mean free testosterone levels were 9.1, 9.5 and 11.4 pg./ml. (normal 8.7 to 54.7), respectively. Differences among means were not statistically significant. As a screening test for low sexual drive, low total testosterone had a positive predictive value, negative predictive value and yield of 59.2, 55.9 and 26.9%, respectively. Conclusions: Serum total or free testosterone level is an inadequate measure of sexual drive in men. More research is needed to define the appropriate indications and value of routine testosterone level determination among men with erectile dysfunction and/or low sexual drive.