FACTORS ASSOCIATED WITH WANING SEXUAL FUNCTION AMONG ELDERLY MEN AND PROSTATE-CANCER PATIENTS

Purpose: We identified factors that affect sexual function in men 50 t o 80 years old and, therefore, may confound the comparison among group s of elderly men. In particular, we identified factors that may influe nce a comparison between prostate cancer patients and the general popu lation, or confound the relationship when comparing subgroups of patie nts in nonrandomized studies. Materials and Methods: A questionnaire, including the Radiumhemmet Scale of Sexual Function and modules assess ing potential risk factors for waning sexual function, was sent to 431 patients 50 to 80 years old with prostate cancer diagnosed 1.5 to 2 y ears previously in the Stockholm area (Sweden) and a reference group o f 435 age matched randomly selected men. Results: Factors associated w ith physiological impotence included prostate cancer (relative risk 1. 9), diabetes mellitus (relative risk 2.3), myocardial infarction (rela tive risk 1.5), medication with diuretics (relative risk 1.5), hydroge n blockers (relative risk 2.3) and warfarin type anticoagulants (relat ive risk 1.7). Patients treated for prostate cancer were more likely t o be physiologically impotent compared to those with no initial treatm ent, and this was true for all treatment protocols after adjustment fo r confounding factors. Men treated with radical prostatectomy were mor e likely to be physiologically impotent than men treated with external beam radiation therapy (relative risk 1.5). Conclusions: Waning sexua l function in the prostate cancer patients was largely due to side eff ects of the treatment and this could not be explained by confounding f actors. In particular, confounding could not explain the greater risk of impotence after radical prostatectomy compared to external beam rad iation therapy.