The relationship of serum testosterone to erectile function in normal aging men.

PURPOSE

We evaluated the variation in serum testosterone in normal aging men and its relationship with erectile function.

MATERIALS AND METHODS

In a study that was not community based and during a free screening program for prostate cancer 1,071 men were invited to complete a sexual activity questionnaire, that is the abridged 5-item version of the International Index of Erectile Function (IIEF-5), as a diagnostic tool for erectile dysfunction. Possible scores on the IIEF-5 are 1 to 25 and erectile dysfunction was classified into 5 categories based on the scores, namely severe-1 to 7, moderate-8 to 11, mild to moderate-12 to 16, mild-17 to 21 and none-22 to 25. Serum total testosterone was measured between 8:00 and 10:00 a.m. in all men.

RESULTS

Of the 1,071 men 965 (90.1%) were included in this study, of whom 88% were white and 12% were black. Mean age was 60.7 years. In this sample the prevalence of all degrees of erectile dysfunction was estimated to be 53.9%. The degree of erectile dysfunction was mild in 21.5% of cases, mild to moderate in 14.1%, moderate in 6.3% and severe in 11.9%. According to age the erectile dysfunction rate was 36.4% in the 40 to 49, 42.5% in the 50 to 59, 58.1% in the 60 to 69, 79.4% in the 70 to 79 and 100% in the 80 years and older groups (p <0.05). The variation in mean serum total testosterone in the age groups was not statistically significantly different (p >0.05). Pearson coefficients of age and total testosterone did not reveal any significant correlation (r = 0.00376, p = 0.907), similar to IIEF-5 score and total testosterone (r = 0.0163, p = 0.612). However, analysis of the variables IIEF-5 and age showed a statistically significant inverse or negative relationship (r = -0.3449, p <0.05).

CONCLUSIONS

Erectile dysfunction showed a clear association with aging but no consistent correlation of total testosterone with erectile condition was identified.