Impact of Baseline Total Testosterone Level on Successful Treatment of Sexual Dysfunction in Men Taking Once-Daily...

Controversy exists as to whether erectile response to phosphodiesterase type 5 inhibitors is compromised in men with low total testosterone (TT) levels. This is amplified by reports of improved response to phosphodiesterase type 5 inhibitor therapy after coadministration of testosterone replacement therapy in hypogonadal men unresponsive to phosphodiesterase type 5 inhibitors.

To determine whether TT and luteinizing hormone levels influence efficacy of tadalafil for erectile dysfunction in men with concomitant lower urinary tract symptoms and benign prostatic hyperplasia.

This integrated analysis included 1,075 men randomized to once-daily tadalafil 5 mg (n = 540) or placebo (n = 535) for 12 weeks in three prospective clinical trials who had not received concomitant testosterone replacement therapy. Subjects were categorized at baseline by low vs normal TT levels (n = 1,049; <300 vs ≥300 ng/dL) and normal vs high luteinizing hormone levels (n = 1,058; ≤9.4 vs >9.4 mIU/mL). Treatment-group differences in International Index of Erectile Function (IIEF) by hormone subgroups were assessed using analysis of covariance.

Changes in IIEF erectile function domain and other domain scores.

The overall study population was comprised primarily of white men (>86%) with a mean age range of 64 to 70 years. Median baseline TT level in the integrated population was 355 ng/dL; levels were lower than 300 ng/dL (cutoff for normal) in 32.4% of men. Men with low TT levels reported diabetes (21.8%), cardiovascular disease (54.1%), and hypertension (49.1%) numerically more often than men with normal TT levels (10.6%, 43.2%, and 36.7%, respectively). Low TT and high luteinizing hormone levels were associated with numerically, but not statistically significantly, lower 12-week IIEF domain scores compared with those with normal levels. Changes in most 12-week IIEF domain scores showed that tadalafil was significantly more effective than placebo (P < .02).

Low TT levels at baseline did not negatively influence response to tadalafil in men of advancing age with concomitant lower urinary tract symptoms and benign prostatic hyperplasia and erectile dysfunction.